Fate of Cryptosporidium and Giardia through conventional and compact drinking water treatment plants

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Moussa, Ameen A. Ashour, Mohammad I. Soliman, Hoda A. Taha, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2683491/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 26 Aug, 2023 Read the published version in Parasitology Research → Version 1 posted 7 You are reading this latest preprint version Abstract During the past thirty years, there has been a significant increase in the contamination of drinking water by enteric pathogenic protozoa, particularly Giardia and Cryptosporidium spp. Such microbial contamination has been responsible for disease outbreaks and increased background rates of disease in developed and developing countries worldwide. As such, controlling waterborne diseases is a critical aspect of public health policy and the primary objective of drinking water treatment plants (DWTPs). Limited studies applied real-time PCR (qPCR) and/or Immunofluorescence assay (IFA) for monitoring Giardia and Cryptosporidium spp., particularly in developing countries like Egypt. Samples of water from two conventional drinking water treatment plants and two compact units (CUs) were analyzed using both IFA and qPCR methods to detect Giardia and Cryptosporidium . The conventional DWTPs showed complete removal of Giardia and Cryptosporidium gene copies, whereas Mansheyat Alqanater and Niklah CUs achieved only partial removal. Specifically, Cryptosporidium gene copies removal rates were 33.33% and 60% for Mansheyat Alqanater and Niklah CUs, respectively. Niklah CU also removed 50% of Giardia gene copies, but no Giardia gene copies were removed by Mansheyat Alqanater CU. Conventional DWTPs were more effective than CUs in removing enteric protozoa. The contamination of drinking water by enteric pathogenic protozoa remains a significant issue globally, leading to increased disease rates. Infectious disease surveillance in drinking water is an important epidemiological tool to monitor the health of a population. Cryptosporidium Giardia drinking water treatment plants immunofluorescence assay real-time PCR Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Introduction Water-related diseases are responsible for the highest number of deaths and diseases worldwide, according to the World Health Organization (WHO), with more than 3.4 million fatalities each year. Children account for around 1.4 million of these deaths ( Abuseir 2023 ). In terms of causing fatalities, the lack of clean and safe drinking water along with inadequate sanitation surpasses war, terrorism, and weapons of mass destruction combined ( Abuseir 2023 ) . Water-related illnesses, such as gastrointestinal infections, diarrhea, and systemic diseases, lead to an annual economic loss of approximately US $ 12 billion globally (Alhamlan et al. 2015 ). Protozoan parasites like Cryptosporidium spp., and Giardia spp., are from the most frequently identified as the cause of diarrheal outbreaks in developed and developing countries ( Karanis et al. 2007 ; Al-Rifai et al. 2020 ; Gad et al. 2019 ) The right to access water, which is essential for the survival of living beings, has been acknowledged as a universal human right (Taviani et al. 2022 ). Consumption or exposure to contaminated water can lead to the transmission of various pathogens, including enteric bacteria, viruses, and parasites, causing severe diseases that pose a significant global public health concern (WHO 2019 ). So, it is crucial to monitor pathogens, especially in drinking water for protecting humans and animals. Waterborne outbreaks caused by protozoa contamination are a significant concern. Cryptosporidium and Giardia species are particularly notable as they can survive in aquatic environments despite the use of chlorine disinfectants (Elmehy et al. 2021 ). Regrettably, many people worldwide do not have access to safe water, which is free from harmful pathogens and contaminants. This issue is a significant public health concern, even for developed countries, as it is closely linked to human health ( McKee and Cruz 2021 ). Protozoan parasitic diseases transmitted through contaminated water are found globally and have caused both epidemic and endemic infections in developing countries ( Cotruvo et al. 2004 ; Baldursson and Karanis 2011 ). For the past four decades, there has been a significant global focus on Cryptosporidium and Giardia species due to their ability to cause waterborne and foodborne illnesses ( Mahmoudi et al. 2017 ; Rosado-García et al. 2017 ). These protozoa are excreted through feces and have a remarkable resistance to environmental factors, such as high temperatures, chemical water disinfectants, and dehydration ( King and Monis 2007 ). In 2012, the prevalence of giardiasis in Europe was 5.43 cases per 100,000 population. As for cryptosporidiosis, the prevalence was 10.5 for females and 13.8 for males (ECDC 2014 ). The researchers conducted a systematic review of 96 studies from 35 countries, which included 327 treatment plants. They found that the overall occurrence of Cryptosporidium and Giardia in drinking water treatment plants was 3.7% and 9.9%, respectively. The study suggests that there is a need for improved water treatment technologies to ensure the removal of these protozoa ( Al-Rifai et al. 2020 ). Unfortunately, no comprehensive data are available about cryptosporidiosis and giardiasis in Egypt, and few environmental studies concerning Cryptosporidium and Giardia were found ( Gad et al. 2019 ; Rizk et al. 2019 ). The main objectives of this study were: 1) to assess the efficacy of different drinking water treatment methods in removing Cryptosporidium and Giardia parasites, which are harmful to human health, 2) to measure the concentration of these parasites using qPCR and IFA detection methods, both of which were effective in identifying Cryptosporidium and Giardia in water samples ( Karanis et al. 2007 ), and 3) to investigate the prevalence of these parasites in both raw and treated water samples. Material And Methods Sampling and DWTPs descriptions Four DWTPs were chosen for the present study; two of them were conventional DWTPs that served a large city community and the other two were small CUs that comparatively served small communities (Fig. 1 ). The two conventional DWTPs are Shubra Alkheymah, which produces 46300 m 3 of drinking water per day and serves 2.5 million persons, and is located in the Shubra Alkheymah district. Shubra Alkheymah DWTP is composed an intake system that is supplied with raw surface water from the mainstream of the Nile River, a distribution well, 12 clarifiers (working with a pulsator), 34 rapid sand filters, and a drinking water storage tank. The second conventional plant is Imbaba DWTP, which produces 1.433.344 m 3 of drinking water per day and serves people in AL- Remayah, Al-Baragil, Al-khalayfa, Nahia, Ezbet Al-Eseely, Imbaba, Al-Waraq, and AL-Kitkat districts. The intake of Imbaba DWTP is supplied with raw surface water from the main stream of the Nile River. Imbaba DWTP is composed of an intake system, distribution well, 20 clarifiers (working with a pulsator), 80 rapid sand filters, and a drinking water storage tank (Fig. S1 ). The drinking water treatment compact units (CUs) include Niklah and Mansheyat Alqanater CUs. Niklah CU produces 2040 m 3 of drinking water per day and its freshwater supply is El-Nasery canal branched from the Nile River. Mansheyat Alqanater CU produces 2000 m 3 of drinking water per day. This compact unit is continuously supplied with fresh water from El-Behery canal branched from the Nile River. A similar design was observed in both Niklah and Mansheyat Alqanater CUs. They are composed of an intake system and a compact unit where the clarification and sand filtration are consequently involved inside it and lastly followed by a final product drinking water tank (Fig. S2). Water samples were collected from the inlet (raw freshwater) and outlet (final treated drinking water) of two conventional DWTP (i.e., Shubra Alkheymah and Imbaba) and two CUs (i.e., Niklah and Mansheyat Alqanater) within Greater Cairo, Egypt (Fig. 1 ). Duplicate water samples (10 liters volume each) were monthly collected at the same time from each sampling site for one year from February 2019 to January 2020. Immunofluorescence assay One of the collected duplicate samples was processed by IFA ( EPA method 1623, 2005 ; ISO/FDIS 15553:2006) , while the other one was processed using qPCR. For IFA, briefly; 10 liters from each sample were filtered through sterile nitrocellulose membranes (142 mm diameter and 0.8µm pore size) using a sterilized stainless steel pressure filtration system (Millipore). The nitrocellulose membrane filter was removed from the filter housing and transferred into a suitable clean glass Petri dish (142mm diameter). About 25ml of eluent (0.1% Tween 80) was gently poured on the surface of the membrane filter for facilitate the detachment of particulate material from the membrane. The last step was repeated and the obtained washing solution was subjected to centrifugation at 1500 ×g for 15min. The supernatant was aspirated and the obtained pellet was re-suspended in 10 ml phosphate buffer saline (pH = 7.4), vortexed from 10 to 15 sec, and transferred into L10 tube (Leighton tube). One mL of the 10X SL-buffer-A and 1 mL of the 10X SL-buffer-B were added to L10 tube. Then, 100 µL of the resuspended Dynabeads Cryptosporidium and 100 µL of the resuspended Dynabeads Giardia were added to the solution in L10 tube. The immunomagnetic separation and immunostaining (DAPI and FITC) steps were conducted according to EPA Method 1623 ( 2005 ). Quantitative real-time PCR assay The qPCR was performed on the concentrated second part of each sample (10 L). The concentrated samples were subjected to extraction of environmental DNA using the DNeasy PowerLyzer PowerSoil Kit (QIAGEN, USA). The qPCR assay was performed to quantify the target protozoa in the samples, a qPCR reaction was performed in a 20 µL reaction volume using a QuantiNova syber green qPCR kit (Qiagen, Germany). The reaction mixture was composed of 5 µL of the DNA template, 10 µL of the master mix, 0.5 µL from each primer (forward and reverse) for Cryptosporidium ( Haque et al. 2007 ) and Giardia intestinalis ( Guy et al. 2003 ), and 4 µL of Nuclease free water. The PCR temperature conditions were 95 ◦ C for 10 min and 45 cycles of 15 s at 95 ◦ C and 1 min at 60 ◦ C. Nuclease free water was also included in each run as a negative control. Absolute quantification of gene copy (GC) was performed by comparing cycle threshold (Ct) values to the DNA standard, which was included in every qPCR run. DNA standards were prepared as previously described by Rizk and Hamza ( 2021 ). The limits of detection for the assay were determined as ≤ 10 GC/reaction. Results The positive samples containing Giardia cysts and Cryptosporidium oocysts were easily distinguishable through their apple-green color when stained with immune-fluorescent stain (FITC). The oval shape cyst wall of the Giardia cysts made them easily recognizable, and each cyst contained 2–4 nuclei that were identifiable by DAPI stain. The size of the detected Giardia cysts ranged from 8–18 × 5–15µm (as shown in Figs. 2 and 3 ). Similarly, the rounded shape oocyst wall of Cryptosporidium oocysts made them easily detectable, and each oocyst contained 4 sporozoites that were visible with DAPI stain. The detected oocysts had a diameter of 4–6µm (Figs. 2 and 3 ). The qPCR analysis detected Giardia in 12.5% of all collected water samples (both raw and treated), whereas the immunofluorescence stain detected them in 11.46%. Additionally, the qPCR analysis identified Cryptosporidium in 20.83% of all collected water samples (both inlet and outlet of raw and drinking water), while the immunofluorescence stain detected it in 18.75% (Figure S3). The number of positive samples for Giardia was higher in the inlets of Imbaba DWTP (n = 4) compared to other drinking water plants (n = 1 or 2). However, the inlets of Niklah CU and Shubra Alkheymah DWTP had more positive samples for Cryptosporidium (n = 5 for each) compared to Mansheyt Alqanater CU and Imbaba DWTP (n = 3 for each). Overall, it was observed that conventional DWTPs showed higher efficiency in removing Giardia and Cryptosporidium compared to CUs. Both Giardia and Cryptosporidium removal percentages reached 100% in Shubra Alkheymah and Imbaba DWTPs. In contrast, Mansheyat Alqanater and Niklah CUs achieved Cryptosporidium oocyst removal percentages of 33.33% and 60%, respectively (Fig. 4 ). In the inlets of conventional DWTPs (Imbaba and Shubra Alkheymah), the prevalence of Giardia genes/cysts ranged from 8.33–33.33%, while it was 16.67% in the inlets of CUs (Mansheyat Alqanater and Niklah). No Giardia cysts or genes were detected in the final treated drinking water of Imbaba and Shubra Alkheymah DWTPs. However, the final treated drinking water of Mansheyat Alqanater and Niklah CUs were contaminated by Giardia cysts or genes (range: 8.33% − 16.67%) (Fig. 5 ). Furthermore, higher prevalence rates of Cryptosporidium oocysts/genes were observed in the inlets of both conventional DWTPs (range: 25% − 41.67%) and compact units (16.67% − 41.67%). Cryptosporidium genes/cysts were detected in 16.67% of CUs outlet water samples, while none were found in conventional DWTPs outlet samples (Fig. 6 ). The maximum number of Giardia cysts recorded in inlets of Imbaba DWTP was 15 cysts/10L, followed by 13 cysts/10L, 11 cysts/10L, 2 cysts/10L in Niklah CU, Shubra Alkheymah DWTP, Mansheyat Alqanater CU, respectively. However, the maximum number of Cryptosporidium oocysts was recorded in inlets of Mansheyat Alqanater CU (21 oocysts/10L), Niklah CU (18 oocysts/10L), Shubra Alkheymah DWTP (18 oocysts/10L), and Imbaba DWTP (17 oocysts/10L). Few oocysts/ cysts (≤ 3) were detected in the outlets of the CUs and no oocysts/cysts were found in the outlets of the conventional DWTPs (Fig. 7 ). The counts of Giardia and Cryptosporidium genes in the inlet water samples of conventional DWTPs ranged 0-2.61 GC/10L and 0-2.54 GC/10L, respectively. Giardia and Cryptosporidium were not detected in the outlet water samples of Imbaba and Shubra Alkheymah DWTPs. The maximum concentration of Giardia and Cryptosporidium was 2.2 GC/10L and 2.66 GC/10L, respectively in the inlet water samples of the CUs. While the maximum concentration of the same parasites in the outlet water samples was 1.17 and 2.03 GC/10L, respectively (Fig. 8 ). Discussion DWTPs use a combination of physical, chemical, and biological processes to remove contaminants from source water. The effectiveness of these processes in removing Cryptosporidium and Giardia , two common waterborne protozoan parasites, depends on several factors, including the size of the parasites, the type of treatment process used, and the operating conditions of the plant. Research has shown that Cryptosporidium and Giardia can be effectively removed through conventional DWTPs that include filtration and disinfection steps. However, the removal efficiency varies depending on the specific treatment process and the operational conditions. The removal percentage of Giardia and Cryptosporidium in conventional DWTP was 100% for both protozoa in the current study. Similar results were recorded in another study in Egypt, where the removal percentage of Giardia and Cryptosporidium by conventional DWTP was 100% ( Ali et al. 2004 ). In Malaysia, the removal percentage of Giardia and Cryptosporidium through conventional DWTP was 92.9 and 100%, respectively ( Richard et al. 2016 ). In Southern Brazil, the removal percentages of Giardia and Cryptosporidium by DWTP (the entire water treatment cycle is catchment, coagulation, flocculation, decantation, flotation, disinfection with chlorine, fluoridation, storage, and distribution) was 100% for both parasites ( Almeida et al. 2015 ). In a Spanish investigation, the removal percentages of Cryptosporidium and Giardia by conventional DWTPs reached 100% ( Carmena et al. 2007 ). On contrary, a lower removal percentage (66.7%) of Giardia through conventional DWTPs was reported in China, while there was no removal at all for Cryptosporidium ( Kui et al. 2021 ). Overall, the removal rates of Cryptosporidium and Giardia in conventional DWTPs can fluctuate due to several factors. It's important to monitor these rates regularly to ensure that the treatment processes are effective at removing parasites from the water and that the water delivered to consumers is safe to drink. Less information is available on the removal rates of Cryptosporidium and Giardia through CUs for drinking water treatment. CUs are typically designed to treat small volumes of water and are often used in remote or rural areas where conventional water treatment may not be available ( Al-Herrawy and Gad 2017 ; Ali et al. 2004 ). In Egypt, the researchers found Cryptosporidium and Giardia in the inlet water samples of the two CUs only ( Ali et al. 2004 ). In the present study, the removal rate of Giardia and Cryptosporidium in the CUs was up to 60%. A similar removal rate (64.3%) for Giardia in Spanish CUs with a similar structure was reported, while Cryptosporidium was not removed through the system ( Carmena et al. 2007 ). The removal rates of Cryptosporidium and Giardia in conventional drinking water treatment plants (DWTPs) can fluctuate depending on several factors. These factors can include changes in the water quality of the source water, variations in the operating conditions of the plant, and the efficiency of the treatment processes themselves. Some CUs may be less effective at removing parasites than conventional DWTPs due to their smaller size or lower treatment capacity. In the current research, the average prevalence of Cryptosporidium and Giardia in the Nile River (intake water samples) was 33.33% and 20.83%, respectively. Similar results for Cryptosporidium prevalence were reported in the Nile River, Egypt (33% by direct microscopy) ( El-Khayat et al. 2022 ), in raw water samples in Iran (30% by IFA) ( Mahmoudi et al. 2013 ). The higher prevalence rate for Giardia in raw water samples collected from the Quindío River basin was reported in Colombia (43.6% by PCR) ( Pinto-Duarte et al. 2022 ), for Cryptosporidium and Giardia in Greece (> 47% by IFA) ( Ligda et al. 2020 ), Giardia Cysts and Cryptosporidium oocysts in Canadain rivers (> 63% by IFA and > 50% by PCR) ( Prystajecky et al. 2014 ). However, a lower prevalence of Giardia in Ethiopian rivers (16% by IFA) was recorded ( Kifleyohannes and Robertson 2020 ). In the present study, the concentration of Giardia cysts in raw water ranged from 0 to 15 cysts/10L, while the Cryptosporidium concentration in raw water ranged from 0 to 21 oocysts/10L. Other studies have reported different ranges of concentration for Cryptosporidium and Giardia in raw water samples from various regions. For example, in Greece, the Cryptosporidium oocyst concentration ranged from 0 to 0.94 oocysts/10L, and the Giardia cyst concentration ranged from 0 to 4.28 cysts/10L ( Ligda et al. 2020 ). In Iran, the Giardia cyst concentration ranged from 1 to 1800 cysts/10L (Mahmoudi et al. 2013 ), and in Taiwan, the Giardia cyst and Cryptosporidium oocyst concentration in raw water samples ranged from 0.16 to 31.18 cysts/10L and from 0.23 to 80.14 oocysts/10L, respectively (Hsu et al. 1999 ). In Ethiopia, the Giardia cyst and Cryptosporidium oocyst concentration in raw water samples ranged from 3 to 22 cysts/10L and from 1 to 3 oocysts/10L, respectively ( Kifleyohannes and Robertson 2020 ). The prevalence and concentration of Cryptosporidium and Giardia in source waters can also vary widely depending on the location and season. Therefore, it is important to monitor water quality regularly and choose a treatment technology that is appropriate for specific conditions. Conclusion The conventional treatment processes such as coagulation, sedimentation, and filtration have been shown to be more effective in removing Cryptosporidium and Giardia from drinking water. In other words, neither Giardia nor Cryptosporidium were detected in conventional DWTPs. This indicates that the conventional DWTPs were effective in removing these parasites from the source water, resulting in safe drinking water for the consumers. Prevalence of Cryptosporidium oocysts was higher than Giardia cysts in Nile water, indicating a possible higher infection risk with the Cryptosporidium , as the parasite can cause gastrointestinal illness even at low doses. The choice of technology for removing Cryptosporidium and Giardia from drinking water should be based on a thorough evaluation of the specific context and conditions. The presence of Cryptosporidium and Giardia cysts in CUs outlets does not automatically make this technology less effective, but rather highlights the importance of regular monitoring and maintenance practices. Ultimately, the goal should be to provide safe and reliable drinking water to consumers. Declarations Author Contributions Ahmed S. Moussa: Methodology, Formal analysis, Data curation, Visualization, Writing-Original draft. Ameen A. Ashour : Supervision, Validation, Writing - Review & Editing . Mohammad I. Soliman : Supervision, Writing - Review & Editing . Hoda A. Taha: Supervision, Writing - Review & Editing. Ahmad Z. Al-Herrawy: Supervision, Resources, Funding acquisition, Writing - Review & Editing. Mahmoud Gad: Supervision, Conceptualization, Methodology, Software, Validation, Writing - Review & Editing, Resources. Funding This study was funded by the Holding Company for drinking water and Wastewater, Egypt and performed with technical assistance from Environmental Parasitology Laboratory, Water Pollution Research Department, National Research Centre, Egypt. Conflict of interest The authors declare there is no conflict Data availability The manuscript does not contain any material from third parties, and all the material is owned by the authors, and no permission is required for publication. Ethics approval Not applicable Consent to participate Not applicable References Abuseir S (2023) A systematic review of frequency and geographic distribution of water-borne parasites in the Middle East and North Africa. East Mediterr Heal J 29:151–161. https://doi.org/10.26719/emhj.23.016 emro.who.int Al-Herrawy AZ, Gad MA (2017) Assessment of two different drinking water treatment plants for the removal of free-living amoebae, Egypt. Iran J Parasitol 12: 413–422. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5623922/ Alhamlan FS, Al-Qahtani AA, Al-Ahdal MNA (2015) Recommended advanced techniques for waterborne pathogen detection in developing countries. J Infect Dev Ctries 9: 128–135. https://doi.org/10.3855/jidc.6101 Ali MA, Al-Herrawy AZ, El-Hawaary SE (2004) Detection of enteric viruses, Giardia and Cryptosporidium in two different types of drinking water treatment facilities. Water Res 38: 3931–3939. https://doi.org/10.1016/j.watres.2004.06.014 Almeida JC, Martins FDC, Ferreira Neto JM et al (2015) Occurrence of Cryptosporidium spp. and Giardia spp. in a public water-treatment system, Paraná, Southern Brazil. Rev Bras Parasitol Vet = Brazilian J Vet Parasitol Orgao Of do Col Bras Parasitol Vet 24: 303–308 https://doi.org/10.1590/S1984-29612015051 Al-Rifai RH, Loney T, Sheek-Hussein M et al (2020) Prevalence of, and factors associated with intestinal parasites in multinational expatriate workers in Al Ain City, United Arab Emirates: An occupational cross-sectional study. J Immigr Minor Heal 22: 359–374. https://link.springer.com/article/ 10.1007/s10903-019-00903-8 Baldursson S, Karanis P (2011) Waterborne transmission of protozoan parasites: review of worldwide outbreaks–an update 2004–2010. Water Res 45: 6603–6614 https://doi.org/10.1016/j.watres.2011.10.013 Carmena D, Aguinagalde X, Zigorraga C et al (2007) Presence of Giardia cysts and Cryptosporidium oocysts in drinking water supplies in northern Spain. J Appl Microbiol 102: 619–629. https://doi.org/10.1111/j.1365-2672.2006.03193.x Cotruvo JA, Dufour A, ReesG et al (2004) Waterborne zoonoses: identification, causes, and control. World Health Organization ISBN: 9241562730. https://apps.who.int/iris/handle/10665/42977 ECDC (2014) European Centre for Disease Prevention and Control. Annual Epidemiological Report – Giardiasis. [Internet]. Stockholm: ECDC; https://www.ecdc.europa.eu/sites/default/files/documents/Giardiasis%20AER pdf El-Khayat HMM, El-Wakil ES, Abdel-Motleb A et al (2022) Bacteriological, parasitological and chemical pollution of Nile River water at some Greater Cairo sites. Int J Environ Stud 79:731–747. https://doi.org/10.1080/00207233.2021.1954454 ELMehy DA, Ismail HIH, Alfattah AA et al (2021) Flow cytometric and molecular analysis of possible protozoal contamination of drinking water in Tanta, Egypt. J Egypt Soc Parasitol 51: 127–138. https://doi.org/10.21608/jesp.2021.165953 EPA method 1623, (2005) Environmental protection agency Method 1623 Cryptosporidium and Giardia in Water by Filtration/IMS/FA December 2005 https://www.epa.gov/sites/default/files/2015-07/documents/epa-1623.pdf Guy RA, Payment P, Krull UJ, Horgen PA (2003) Real-time PCR for quantification of Giardia and Cryptosporidium in environmental water samples and sewage. Appl Environ Microbiol 69:5178–5185. https://doi.org/10.1128/AEM.69.9.5178-5185.2003 Gad MA, Saleh FEZR, Morsy EA, Marouf MA, Al-Herrawy AZ (2019) Use of microscopic and molecular techniques to assess removal of parasitic protozoa via conventional and compact drinking water treatment processes. Egyp J Aqua Biol Fish 23: 327–339. https://dx.doi.org/10.21608/ejabf.2019.67228 Hsu BM, Huang C, Jiang GY, Hsu CLL (1999) The prevalence of Giardia and Cryptosporidium in Taiwan water supplies. J Toxicol Environ Heal Part A 57: 149–160. https://doi.org/10.1080/009841099157728 Haque R, Roy S, Siddique A et al (2007) Multiplex real-time PCR assay for detection of Entamoeba histolytica, Giardia intestinalis, and Cryptosporidium spp. Am J Trop Med Hyg 76: 713–717. https://www.researchgate.net/profile/S-M-Mazidur-Rahman/publication/51390330 : (2006) International Organization for Standardization (ISO), 2006. Water quality – isolation and identification of Cryptosporidium oocysts and Giardia cysts from water. https://www.iso.org/standard/39804.html , Accessed date: 30 July 2019 King BJ, Monis PT (2007) Critical processes affecting Cryptosporidium oocyst survival in the environment. Parasitology 134: 309–323. https://doi.org/10.1017/S0031182006001491 Kifleyohannes T, Robertson LJ (2020) Preliminary insights regarding water as a transmission vehicle for Cryptosporidium and Giardia in Tigray, Ethiopia. Food Waterborne Parasitol 19: e00073 https://doi.org/10.1016/j.fawpar.2020.e00073 Karanis P, Kourenti C, Smith H (2007) Waterborne transmission of protozoan parasites: a worldwide review of outbreaks and lessons learnt. J Water Health 5: 1–38 https://doi.org/10.2166/wh.2006.002 Kui CAOS, Yan JY, Ying YZ, et al (2021) Quantitative microbial risk assessment of Cryptosporidium and Giardia in public drinking water in China. Biomed Environ Sci 34:493–498. https://www.ipd.org.cn/uploadpic/file/20210727/20210727112323_39311.pdf Ligda P, Claerebout E, Kostopoulou D et al (2020) Cryptosporidium and Giardia in surface water and drinking water: Animal sources and towards the use of a machine-learning approach as a tool for predicting contamination. Environ Pollut 264: 114766. https://doi.org/10.1016/j.envpol.2020.114766 Mckee AM, Cruz MA (2021) Microbial and viral indicators of pathogens and human health risks from recreational exposure to waters impaired by fecal contamination. J Sustain Water Built Environ 7: 3121001. https://doi.org/10.1061/JSWBAY.0000936 Mahmoudi MR, Ongerth JE, Karanis P (2017) Cryptosporidium and cryptosporidiosis: the Asian perspective. Int J Hyg Environ Health 220: 1098–1109. https://doi.org/10.1016/j.ijheh.2017.07.005 Mahmoudi MR, Kazemi B, Mohammadiha A et al (2013) Detection of Cryptosporidium and Giardia (oo) cysts by IFA, PCR and LAMP in surface water from Rasht, Iran. Trans R Soc Trop Med Hyg 107: 511–517. https://doi.org/10.1093/trstmh/trt042 Prystajecky N, Huck PM, Schreier H, Isaac-Renton JL (2014) Assessment of Giardia and Cryptosporidium spp. as a microbial source tracking tool for surface water: application in a mixed-use watershed. Appl Environ Microbial 80: 2328–2336. doi: 10.1128/AEM.02037-13 . Epub 2014 Jan 24 Pinto-Duarte VA, Hérnandez-Arango NM, Marin-Gallego BJ et al (2022) Detection of Giardia duodenalis and Toxoplasma gondii in soil and water samples in the Quindío River basin, Colombia. Food Waterborne Parasitol 28: e00175. https://doi.org/https://doi.org/10.1016/j.fawpar.2022.e00175 Rizk NM, Hamza IA (2021) Molecular Quantification of Human Bocavirus in Environmental Water Samples in Giza, Egypt. Egypt J Aquat Biol Fish 25: 735–749. https://doi.org/10.21608/ejabf.2021.169523 Richard RL, Ithoi I, Abd Majid MA et al (2016) Monitoring of Waterborne Parasites in Two Drinking Water Treatment Plants: A Study in Sarawak, Malaysia. Int J Environ Res Public Health 13: 641. https://doi.org/10.3390/ijerph13070641 Rizk E, Swan JT, Cheon O et al (2019) Quality indicators to measure the effect of opioid stewardship interventions in hospital and emergency department settings. Am J Heal Pharm 76: 225–235. https://doi.org/10.1093/ajhp/zxy042 Rosado-García FM, Guerrero-Flórez M, Karanis G et al (2017) Water-borne protozoa parasites: The Latin American perspective. Int J Hyg Environ Health 220: 783–798. https://doi.org/https://doi.org/10.1016/j.ijheh.2017.03.008 Taviani E, van den Berg H, Nhassengo F et al (2022) Occurrence of waterborne pathogens and antibiotic resistance in water supply systems in a small town in Mozambique. BMC Microbiol 22: 243. https://doi.org/10.1186/s12866-022-02654-3 WHO (World Health Organization) (2019) WHO World Water Day Report—World Health Organization. Geneva, Switzerland. https://www.who.int/news-room/fact-sheets/detail/drinking-water . Accessed 14 Nov 2020. Additional Declarations No competing interests reported. Supplementary Files GadSupplementrymaterials.docx Cite Share Download PDF Status: Published Journal Publication published 26 Aug, 2023 Read the published version in Parasitology Research → Version 1 posted Editorial decision: Major revision 26 May, 2023 Reviews received at journal 13 Apr, 2023 Reviewers agreed at journal 05 Apr, 2023 Reviewers invited by journal 05 Apr, 2023 Editor assigned by journal 13 Mar, 2023 Submission checks completed at journal 13 Mar, 2023 First submitted to journal 12 Mar, 2023 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-2683491","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":183247007,"identity":"a86d57b1-f24f-489a-8602-29c04552ba6f","order_by":0,"name":"Ahmed S. Moussa","email":"","orcid":"","institution":"Drinking Water and Wastewater Holding Company","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ahmed","middleName":"S.","lastName":"Moussa","suffix":""},{"id":183247008,"identity":"44e67098-d50d-403e-8d22-9b07eb48a860","order_by":1,"name":"Ameen A. Ashour","email":"","orcid":"","institution":"Ain Shams University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ameen","middleName":"A.","lastName":"Ashour","suffix":""},{"id":183247009,"identity":"481caa97-971b-441c-915f-96f895917899","order_by":2,"name":"Mohammad I. Soliman","email":"","orcid":"","institution":"Ain Shams University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Mohammad","middleName":"I.","lastName":"Soliman","suffix":""},{"id":183247010,"identity":"97321735-48b9-430c-afc2-1230bf56b53a","order_by":3,"name":"Hoda A. Taha","email":"","orcid":"","institution":"Ain Shams University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Hoda","middleName":"A.","lastName":"Taha","suffix":""},{"id":183247011,"identity":"7bb187ef-866e-4bf8-848e-8a1d546ef90a","order_by":4,"name":"Ahmad Z. Al-Herrawy","email":"","orcid":"","institution":"National Research Centre","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ahmad","middleName":"Z.","lastName":"Al-Herrawy","suffix":""},{"id":183247012,"identity":"1e308c66-16ba-43c5-b73f-428ddea219ba","order_by":5,"name":"Mahmoud Gad","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIiWNgGAWjYDACZhBRwJDAD+XzEKnFgCFBsoFoLQxQLQYHiHWXbjsD84cfBjZ5xrd7H35g+GMnw8DefgGvFrPDDGySPQZpxWZ3jhtLMLYl8zDwnCkgqIWBx+Bw4rYbaWwMjA0HeBgkchIIaWH++Mfgf+LmGUAtDH+AWuTfENTCIM1jcCBxgwRICxvIFvYDBLQwtknLGCQnzriRxiyRCPQLG08OXh0MZucPH/74psIusX9GGuOHD3/s7PnZjz/ArwfoZQQb5AlQaBDQggnYCdkyCkbBKBgFIwwAANokPi/kUHgAAAAAAElFTkSuQmCC","orcid":"","institution":"National Research Centre","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Mahmoud","middleName":"","lastName":"Gad","suffix":""}],"badges":[],"createdAt":"2023-03-12 11:59:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2683491/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2683491/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00436-023-07947-8","type":"published","date":"2023-08-26T15:02:03+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":34439438,"identity":"d63ed1ce-bfbb-4b9c-8a87-8ffd69edce8c","added_by":"auto","created_at":"2023-03-17 21:16:59","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":549177,"visible":true,"origin":"","legend":"\u003cp\u003eLocation of the four examined drinking water treatment plants.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/b2cfc3a71d6068026f15c6b1.jpeg"},{"id":34438739,"identity":"fa86e25a-7931-4dc8-9f1d-2cb296c94c8f","added_by":"auto","created_at":"2023-03-17 21:08:59","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":464270,"visible":true,"origin":"","legend":"\u003cp\u003ePhotomicrograph of \u003cem\u003eGiardia\u003c/em\u003e cyst and \u003cem\u003eCryptosporidium \u003c/em\u003eoocyst stained with FITC stain under fluorescent microscope. \u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eBar = 20µm.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/1f1ac85651760c40f67b5a2f.png"},{"id":34438743,"identity":"5fc0c031-752a-42ad-bb96-a1922142fa91","added_by":"auto","created_at":"2023-03-17 21:08:59","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":537497,"visible":true,"origin":"","legend":"\u003cp\u003ePhotomicrograph of \u003cem\u003eGiardia\u003c/em\u003e cyst and \u003cem\u003eCryptosporidium \u003c/em\u003eoocyst stained with DAPI stain under fluorescent microscope. Bar = 20µm.\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/001b862abe04863e863ff6ad.jpeg"},{"id":34440248,"identity":"63510ea3-e558-4165-94a3-3bc773355c5b","added_by":"auto","created_at":"2023-03-17 21:24:59","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":153963,"visible":true,"origin":"","legend":"\u003cp\u003eOccurrence and removal of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e through the DWTPs and CUs using qPCR.\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/6d7367d91c554c1629a0b920.jpeg"},{"id":34441541,"identity":"c7d9c5ab-c5cd-4156-89a0-fefb981e2055","added_by":"auto","created_at":"2023-03-17 21:32:59","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":440098,"visible":true,"origin":"","legend":"\u003cp\u003ePrevalence of \u003cem\u003eGiardia\u003c/em\u003e in raw and treated water of the DWTPs by qPCR and IFA.\u003c/p\u003e","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/7de116974073737d5b11e5f1.jpeg"},{"id":34439441,"identity":"80d9df22-09c2-4a59-9fa8-9416072dffdd","added_by":"auto","created_at":"2023-03-17 21:16:59","extension":"jpeg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":452745,"visible":true,"origin":"","legend":"\u003cp\u003ePrevalence of \u003cem\u003eCryptosporidium\u003c/em\u003e in raw and treated water of the DWTPs by qPCR and IFA.\u003c/p\u003e","description":"","filename":"floatimage6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/250b5197a4e528cbed357311.jpeg"},{"id":34439436,"identity":"4a764672-a28b-4742-840d-c7ce7607901e","added_by":"auto","created_at":"2023-03-17 21:16:59","extension":"jpeg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":195242,"visible":true,"origin":"","legend":"\u003cp\u003ePrevalence of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e by IFA in raw and treated water samples of DWTPs and CUs.\u003c/p\u003e","description":"","filename":"floatimage7.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/b4e532f9a709ea4957ad7475.jpeg"},{"id":34442671,"identity":"09ef73ba-9139-40c7-9924-fcea9f495e2b","added_by":"auto","created_at":"2023-03-17 21:40:59","extension":"jpeg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":201022,"visible":true,"origin":"","legend":"\u003cp\u003ePrevalence of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e by qPCR in raw and treated water samples of DWTPs and CUs.\u003c/p\u003e","description":"","filename":"floatimage8.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/1ce34ea691669d6a35a44e1b.jpeg"},{"id":42781259,"identity":"0a84b01c-186d-4d14-81bf-5c1a22803865","added_by":"auto","created_at":"2023-09-07 15:09:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1649713,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/1366e717-2f86-4585-8057-7a32e8b4f98a.pdf"},{"id":34438736,"identity":"564ef3e1-f29c-4a2f-b521-1ceddf40d969","added_by":"auto","created_at":"2023-03-17 21:08:59","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":61025,"visible":true,"origin":"","legend":"","description":"","filename":"GadSupplementrymaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-2683491/v1/6ec1bf9ca436e76a5ad0978c.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Fate of Cryptosporidium and Giardia through conventional and compact drinking water treatment plants","fulltext":[{"header":"Introduction","content":"\u003cp\u003eWater-related diseases are responsible for the highest number of deaths and diseases worldwide, according to the World Health Organization (WHO), with more than 3.4\u0026nbsp;million fatalities each year. Children account for around 1.4\u0026nbsp;million of these deaths \u003cb\u003e(\u003c/b\u003eAbuseir \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e \u003cb\u003e).\u003c/b\u003e In terms of causing fatalities, the lack of clean and safe drinking water along with inadequate sanitation surpasses war, terrorism, and weapons of mass destruction combined \u003cb\u003e(\u003c/b\u003eAbuseir \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e \u003cb\u003e)\u003c/b\u003e. Water-related illnesses, such as gastrointestinal infections, diarrhea, and systemic diseases, lead to an annual economic loss of approximately US\u003cspan\u003e$\u003c/span\u003e 12\u0026nbsp;billion globally (Alhamlan et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Protozoan parasites like \u003cem\u003eCryptosporidium\u003c/em\u003e spp., and \u003cem\u003eGiardia\u003c/em\u003e spp., are from the most frequently identified as the cause of diarrheal outbreaks in developed and developing countries \u003cb\u003e(\u003c/b\u003eKaranis et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Al-Rifai et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Gad et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) The right to access water, which is essential for the survival of living beings, has been acknowledged as a universal human right (Taviani et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Consumption or exposure to contaminated water can lead to the transmission of various pathogens, including enteric bacteria, viruses, and parasites, causing severe diseases that pose a significant global public health concern \u003cb\u003e(WHO 2019 ).\u003c/b\u003e So, it is crucial to monitor pathogens, especially in drinking water for protecting humans and animals.\u003c/p\u003e \u003cp\u003eWaterborne outbreaks caused by protozoa contamination are a significant concern. \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e species are particularly notable as they can survive in aquatic environments despite the use of chlorine disinfectants (Elmehy et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Regrettably, many people worldwide do not have access to safe water, which is free from harmful pathogens and contaminants. This issue is a significant public health concern, even for developed countries, as it is closely linked to human health \u003cb\u003e(\u003c/b\u003eMcKee and Cruz \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2021\u003c/span\u003e\u003cb\u003e).\u003c/b\u003e Protozoan parasitic diseases transmitted through contaminated water are found globally and have caused both epidemic and endemic infections in developing countries \u003cb\u003e(\u003c/b\u003eCotruvo et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Baldursson and Karanis \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2011\u003c/span\u003e\u003cb\u003e).\u003c/b\u003e For the past four decades, there has been a significant global focus on \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e species due to their ability to cause waterborne and foodborne illnesses \u003cb\u003e(\u003c/b\u003eMahmoudi et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Rosado-Garc\u0026iacute;a et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). These protozoa are excreted through feces and have a remarkable resistance to environmental factors, such as high temperatures, chemical water disinfectants, and dehydration \u003cb\u003e(\u003c/b\u003eKing and Monis \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2007\u003c/span\u003e\u003cb\u003e).\u003c/b\u003e\u003c/p\u003e \u003cp\u003eIn 2012, the prevalence of giardiasis in Europe was 5.43 cases per 100,000 population. As for cryptosporidiosis, the prevalence was 10.5 for females and 13.8 for males (ECDC \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2014\u003c/span\u003e\u003cb\u003e).\u003c/b\u003e The researchers conducted a systematic review of 96 studies from 35 countries, which included 327 treatment plants. They found that the overall occurrence of \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e in drinking water treatment plants was 3.7% and 9.9%, respectively. The study suggests that there is a need for improved water treatment technologies to ensure the removal of these protozoa \u003cb\u003e(\u003c/b\u003eAl-Rifai et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Unfortunately, no comprehensive data are available about cryptosporidiosis and giardiasis in Egypt, and few environmental studies concerning \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e were found \u003cb\u003e(\u003c/b\u003eGad et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Rizk et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). The main objectives of this study were: 1) to assess the efficacy of different drinking water treatment methods in removing \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e parasites, which are harmful to human health, 2) to measure the concentration of these parasites using qPCR and IFA detection methods, both of which were effective in identifying \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e in water samples \u003cb\u003e(\u003c/b\u003eKaranis et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2007\u003c/span\u003e), and 3) to investigate the prevalence of these parasites in both raw and treated water samples.\u003c/p\u003e"},{"header":"Material And Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSampling and DWTPs descriptions\u003c/h2\u003e \u003cp\u003eFour DWTPs were chosen for the present study; two of them were conventional DWTPs that served a large city community and the other two were small CUs that comparatively served small communities (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The two conventional DWTPs are Shubra Alkheymah, which produces 46300 m\u003csup\u003e3\u003c/sup\u003e of drinking water per day and serves 2.5\u0026nbsp;million persons, and is located in the Shubra Alkheymah district. Shubra Alkheymah DWTP is composed an intake system that is supplied with raw surface water from the mainstream of the Nile River, a distribution well, 12 clarifiers (working with a pulsator), 34 rapid sand filters, and a drinking water storage tank. The second conventional plant is Imbaba DWTP, which produces 1.433.344 m\u003csup\u003e3\u003c/sup\u003e of drinking water per day and serves people in AL- Remayah, Al-Baragil, Al-khalayfa, Nahia, Ezbet Al-Eseely, Imbaba, Al-Waraq, and AL-Kitkat districts. The intake of Imbaba DWTP is supplied with raw surface water from the main stream of the Nile River. Imbaba DWTP is composed of an intake system, distribution well, 20 clarifiers (working with a pulsator), 80 rapid sand filters, and a drinking water storage tank (Fig.\u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe drinking water treatment compact units (CUs) include Niklah and Mansheyat Alqanater CUs. Niklah CU produces 2040 m\u003csup\u003e3\u003c/sup\u003e of drinking water per day and its freshwater supply is El-Nasery canal branched from the Nile River. Mansheyat Alqanater CU produces 2000 m\u003csup\u003e3\u003c/sup\u003e of drinking water per day. This compact unit is continuously supplied with fresh water from El-Behery canal branched from the Nile River. A similar design was observed in both Niklah and Mansheyat Alqanater CUs. They are composed of an intake system and a compact unit where the clarification and sand filtration are consequently involved inside it and lastly followed by a final product drinking water tank (Fig. S2).\u003c/p\u003e \u003cp\u003eWater samples were collected from the inlet (raw freshwater) and outlet (final treated drinking water) of two conventional DWTP (i.e., Shubra Alkheymah and Imbaba) and two CUs (i.e., Niklah and Mansheyat Alqanater) within Greater Cairo, Egypt (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Duplicate water samples (10 liters volume each) were monthly collected at the same time from each sampling site for one year from February 2019 to January 2020.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eImmunofluorescence assay\u003c/h2\u003e \u003cp\u003eOne of the collected duplicate samples was processed by IFA \u003cb\u003e(\u003c/b\u003eEPA method 1623, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; \u003cb\u003eISO/FDIS 15553:2006)\u003c/b\u003e, while the other one was processed using qPCR. For IFA, briefly; 10 liters from each sample were filtered through sterile nitrocellulose membranes (142 mm diameter and 0.8\u0026micro;m pore size) using a sterilized stainless steel pressure filtration system (Millipore). The nitrocellulose membrane filter was removed from the filter housing and transferred into a suitable clean glass Petri dish (142mm diameter). About 25ml of eluent (0.1% Tween 80) was gently poured on the surface of the membrane filter for facilitate the detachment of particulate material from the membrane. The last step was repeated and the obtained washing solution was subjected to centrifugation at 1500 \u0026times;g for 15min. The supernatant was aspirated and the obtained pellet was re-suspended in 10 ml phosphate buffer saline (pH\u0026thinsp;=\u0026thinsp;7.4), vortexed from 10 to 15 sec, and transferred into L10 tube (Leighton tube). One mL of the 10X SL-buffer-A and 1 mL of the 10X SL-buffer-B were added to L10 tube. Then, 100 \u0026micro;L of the resuspended Dynabeads \u003cem\u003eCryptosporidium\u003c/em\u003e and 100 \u0026micro;L of the resuspended Dynabeads \u003cem\u003eGiardia\u003c/em\u003e were added to the solution in L10 tube. The immunomagnetic separation and immunostaining (DAPI and FITC) steps were conducted according to EPA Method 1623 (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2005\u003c/span\u003e\u003cb\u003e).\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eQuantitative real-time PCR assay\u003c/h2\u003e \u003cp\u003eThe qPCR was performed on the concentrated second part of each sample (10 L). The concentrated samples were subjected to extraction of environmental DNA using the DNeasy PowerLyzer PowerSoil Kit (QIAGEN, USA). The qPCR assay was performed to quantify the target protozoa in the samples, a qPCR reaction was performed in a 20 \u0026micro;L reaction volume using a QuantiNova syber green qPCR kit (Qiagen, Germany). The reaction mixture was composed of 5 \u0026micro;L of the DNA template, 10 \u0026micro;L of the master mix, 0.5 \u0026micro;L from each primer (forward and reverse) for \u003cem\u003eCryptosporidium\u003c/em\u003e\u003cb\u003e(\u003c/b\u003eHaque et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2007\u003c/span\u003e) and \u003cem\u003eGiardia intestinalis\u003c/em\u003e\u003cb\u003e(\u003c/b\u003eGuy et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2003\u003c/span\u003e), and 4 \u0026micro;L of Nuclease free water. The PCR temperature conditions were 95 \u003cem\u003e◦\u003c/em\u003eC for 10 min and 45 cycles of 15 s at 95 \u003cem\u003e◦\u003c/em\u003eC and 1 min at 60 \u003cem\u003e◦\u003c/em\u003eC. Nuclease free water was also included in each run as a negative control. Absolute quantification of gene copy (GC) was performed by comparing cycle threshold (Ct) values to the DNA standard, which was included in every qPCR run. DNA standards were prepared as previously described by Rizk and Hamza (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2021\u003c/span\u003e\u003cb\u003e).\u003c/b\u003e The limits of detection for the assay were determined as \u003cem\u003e\u0026le;\u003c/em\u003e\u0026thinsp;10 GC/reaction.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThe positive samples containing \u003cem\u003eGiardia\u003c/em\u003e cysts and \u003cem\u003eCryptosporidium\u003c/em\u003e oocysts were easily distinguishable through their apple-green color when stained with immune-fluorescent stain (FITC). The oval shape cyst wall of the \u003cem\u003eGiardia\u003c/em\u003e cysts made them easily recognizable, and each cyst contained 2\u0026ndash;4 nuclei that were identifiable by DAPI stain. The size of the detected \u003cem\u003eGiardia\u003c/em\u003e cysts ranged from 8\u0026ndash;18 \u0026times; 5\u0026ndash;15\u0026micro;m (as shown in Figs.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Similarly, the rounded shape oocyst wall of \u003cem\u003eCryptosporidium\u003c/em\u003e oocysts made them easily detectable, and each oocyst contained 4 sporozoites that were visible with DAPI stain. The detected oocysts had a diameter of 4\u0026ndash;6\u0026micro;m (Figs.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The qPCR analysis detected \u003cem\u003eGiardia\u003c/em\u003e in 12.5% of all collected water samples (both raw and treated), whereas the immunofluorescence stain detected them in 11.46%. Additionally, the qPCR analysis identified \u003cem\u003eCryptosporidium\u003c/em\u003e in 20.83% of all collected water samples (both inlet and outlet of raw and drinking water), while the immunofluorescence stain detected it in 18.75% (Figure S3).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe number of positive samples for \u003cem\u003eGiardia\u003c/em\u003e was higher in the inlets of Imbaba DWTP (n\u0026thinsp;=\u0026thinsp;4) compared to other drinking water plants (n\u0026thinsp;=\u0026thinsp;1 or 2). However, the inlets of Niklah CU and Shubra Alkheymah DWTP had more positive samples for \u003cem\u003eCryptosporidium\u003c/em\u003e (n\u0026thinsp;=\u0026thinsp;5 for each) compared to Mansheyt Alqanater CU and Imbaba DWTP (n\u0026thinsp;=\u0026thinsp;3 for each). Overall, it was observed that conventional DWTPs showed higher efficiency in removing \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e compared to CUs. Both \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e removal percentages reached 100% in Shubra Alkheymah and Imbaba DWTPs. In contrast, Mansheyat Alqanater and Niklah CUs achieved \u003cem\u003eCryptosporidium\u003c/em\u003e oocyst removal percentages of 33.33% and 60%, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn the inlets of conventional DWTPs (Imbaba and Shubra Alkheymah), the prevalence of \u003cem\u003eGiardia\u003c/em\u003e genes/cysts ranged from 8.33\u0026ndash;33.33%, while it was 16.67% in the inlets of CUs (Mansheyat Alqanater and Niklah). No \u003cem\u003eGiardia\u003c/em\u003e cysts or genes were detected in the final treated drinking water of Imbaba and Shubra Alkheymah DWTPs. However, the final treated drinking water of Mansheyat Alqanater and Niklah CUs were contaminated by \u003cem\u003eGiardia\u003c/em\u003e cysts or genes (range: 8.33% \u0026minus;\u0026thinsp;16.67%) (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Furthermore, higher prevalence rates of \u003cem\u003eCryptosporidium\u003c/em\u003e oocysts/genes were observed in the inlets of both conventional DWTPs (range: 25% \u0026minus;\u0026thinsp;41.67%) and compact units (16.67% \u0026minus;\u0026thinsp;41.67%). \u003cem\u003eCryptosporidium\u003c/em\u003e genes/cysts were detected in 16.67% of CUs outlet water samples, while none were found in conventional DWTPs outlet samples (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe maximum number of \u003cem\u003eGiardia\u003c/em\u003e cysts recorded in inlets of Imbaba DWTP was 15 cysts/10L, followed by 13 cysts/10L, 11 cysts/10L, 2 cysts/10L in Niklah CU, Shubra Alkheymah DWTP, Mansheyat Alqanater CU, respectively. However, the maximum number of \u003cem\u003eCryptosporidium\u003c/em\u003e oocysts was recorded in inlets of Mansheyat Alqanater CU (21 oocysts/10L), Niklah CU (18 oocysts/10L), Shubra Alkheymah DWTP (18 oocysts/10L), and Imbaba DWTP (17 oocysts/10L). Few oocysts/ cysts (\u0026le;\u0026thinsp;3) were detected in the outlets of the CUs and no oocysts/cysts were found in the outlets of the conventional DWTPs (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe counts of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e genes in the inlet water samples of conventional DWTPs ranged 0-2.61 GC/10L and 0-2.54 GC/10L, respectively. \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e were not detected in the outlet water samples of Imbaba and Shubra Alkheymah DWTPs. The maximum concentration of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e was 2.2 GC/10L and 2.66 GC/10L, respectively in the inlet water samples of the CUs. While the maximum concentration of the same parasites in the outlet water samples was 1.17 and 2.03 GC/10L, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eDWTPs use a combination of physical, chemical, and biological processes to remove contaminants from source water. The effectiveness of these processes in removing \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e, two common waterborne protozoan parasites, depends on several factors, including the size of the parasites, the type of treatment process used, and the operating conditions of the plant. Research has shown that \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e can be effectively removed through conventional DWTPs that include filtration and disinfection steps. However, the removal efficiency varies depending on the specific treatment process and the operational conditions. The removal percentage of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e in conventional DWTP was 100% for both protozoa in the current study. Similar results were recorded in another study in Egypt, where the removal percentage of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e by conventional DWTP was 100% \u003cb\u003e(\u003c/b\u003eAli et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). In Malaysia, the removal percentage of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e through conventional DWTP was 92.9 and 100%, respectively \u003cb\u003e(\u003c/b\u003eRichard et al. \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). In Southern Brazil, the removal percentages of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e by DWTP (the entire water treatment cycle is catchment, coagulation, flocculation, decantation, flotation, disinfection with chlorine, fluoridation, storage, and distribution) was 100% for both parasites \u003cb\u003e(\u003c/b\u003eAlmeida et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). In a Spanish investigation, the removal percentages of \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e by conventional DWTPs reached 100% \u003cb\u003e(\u003c/b\u003eCarmena et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). On contrary, a lower removal percentage (66.7%) of \u003cem\u003eGiardia\u003c/em\u003e through conventional DWTPs was reported in China, while there was no removal at all for \u003cem\u003eCryptosporidium\u003c/em\u003e\u003cb\u003e(\u003c/b\u003eKui et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Overall, the removal rates of \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e in conventional DWTPs can fluctuate due to several factors. It's important to monitor these rates regularly to ensure that the treatment processes are effective at removing parasites from the water and that the water delivered to consumers is safe to drink.\u003c/p\u003e \u003cp\u003eLess information is available on the removal rates of \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e through CUs for drinking water treatment. CUs are typically designed to treat small volumes of water and are often used in remote or rural areas where conventional water treatment may not be available \u003cb\u003e(\u003c/b\u003eAl-Herrawy and Gad \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Ali et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). In Egypt, the researchers found \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e in the inlet water samples of the two CUs only \u003cb\u003e(\u003c/b\u003eAli et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). In the present study, the removal rate of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e in the CUs was up to 60%. A similar removal rate (64.3%) for \u003cem\u003eGiardia\u003c/em\u003e in Spanish CUs with a similar structure was reported, while \u003cem\u003eCryptosporidium\u003c/em\u003e was not removed through the system \u003cb\u003e(\u003c/b\u003eCarmena et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). The removal rates of \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e in conventional drinking water treatment plants (DWTPs) can fluctuate depending on several factors. These factors can include changes in the water quality of the source water, variations in the operating conditions of the plant, and the efficiency of the treatment processes themselves. Some CUs may be less effective at removing parasites than conventional DWTPs due to their smaller size or lower treatment capacity.\u003c/p\u003e \u003cp\u003eIn the current research, the average prevalence of \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e in the Nile River (intake water samples) was 33.33% and 20.83%, respectively. Similar results for \u003cem\u003eCryptosporidium\u003c/em\u003e prevalence were reported in the Nile River, Egypt (33% by direct microscopy) \u003cb\u003e(\u003c/b\u003eEl-Khayat et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2022\u003c/span\u003e), in raw water samples in Iran (30% by IFA) \u003cb\u003e(\u003c/b\u003eMahmoudi et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). The higher prevalence rate for \u003cem\u003eGiardia\u003c/em\u003e in raw water samples collected from the Quind\u0026iacute;o River basin was reported in Colombia (43.6% by PCR) \u003cb\u003e(\u003c/b\u003ePinto-Duarte et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2022\u003c/span\u003e), for \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e in Greece (\u0026gt;\u0026thinsp;47% by IFA) \u003cb\u003e(\u003c/b\u003eLigda et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), \u003cem\u003eGiardia\u003c/em\u003e Cysts and \u003cem\u003eCryptosporidium\u003c/em\u003e oocysts in Canadain rivers (\u0026gt;\u0026thinsp;63% by IFA and \u0026gt;\u0026thinsp;50% by PCR) \u003cb\u003e(\u003c/b\u003ePrystajecky et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). However, a lower prevalence of \u003cem\u003eGiardia\u003c/em\u003e in Ethiopian rivers (16% by IFA) was recorded \u003cb\u003e(\u003c/b\u003eKifleyohannes and Robertson \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2020\u003c/span\u003e\u003cb\u003e).\u003c/b\u003e\u003c/p\u003e \u003cp\u003eIn the present study, the concentration of \u003cem\u003eGiardia\u003c/em\u003e cysts in raw water ranged from 0 to 15 cysts/10L, while the \u003cem\u003eCryptosporidium\u003c/em\u003e concentration in raw water ranged from 0 to 21 oocysts/10L. Other studies have reported different ranges of concentration for \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e in raw water samples from various regions. For example, in Greece, the \u003cem\u003eCryptosporidium\u003c/em\u003e oocyst concentration ranged from 0 to 0.94 oocysts/10L, and the \u003cem\u003eGiardia\u003c/em\u003e cyst concentration ranged from 0 to 4.28 cysts/10L \u003cb\u003e(\u003c/b\u003eLigda et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In Iran, the \u003cem\u003eGiardia\u003c/em\u003e cyst concentration ranged from 1 to 1800 cysts/10L (Mahmoudi et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2013\u003c/span\u003e), and in Taiwan, the \u003cem\u003eGiardia\u003c/em\u003e cyst and \u003cem\u003eCryptosporidium\u003c/em\u003e oocyst concentration in raw water samples ranged from 0.16 to 31.18 cysts/10L and from 0.23 to 80.14 oocysts/10L, respectively (Hsu et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e1999\u003c/span\u003e). In Ethiopia, the \u003cem\u003eGiardia\u003c/em\u003e cyst and \u003cem\u003eCryptosporidium\u003c/em\u003e oocyst concentration in raw water samples ranged from 3 to 22 cysts/10L and from 1 to 3 oocysts/10L, respectively \u003cb\u003e(\u003c/b\u003eKifleyohannes and Robertson \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2020\u003c/span\u003e\u003cb\u003e).\u003c/b\u003e The prevalence and concentration of \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e in source waters can also vary widely depending on the location and season. Therefore, it is important to monitor water quality regularly and choose a treatment technology that is appropriate for specific conditions.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe conventional treatment processes such as coagulation, sedimentation, and filtration have been shown to be more effective in removing \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e from drinking water. In other words, neither \u003cem\u003eGiardia\u003c/em\u003e nor \u003cem\u003eCryptosporidium\u003c/em\u003e were detected in conventional DWTPs. This indicates that the conventional DWTPs were effective in removing these parasites from the source water, resulting in safe drinking water for the consumers. Prevalence of \u003cem\u003eCryptosporidium\u003c/em\u003e oocysts was higher than \u003cem\u003eGiardia\u003c/em\u003e cysts in Nile water, indicating a possible higher infection risk with the \u003cem\u003eCryptosporidium\u003c/em\u003e, as the parasite can cause gastrointestinal illness even at low doses. The choice of technology for removing \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e from drinking water should be based on a thorough evaluation of the specific context and conditions. The presence of \u003cem\u003eCryptosporidium\u003c/em\u003e and \u003cem\u003eGiardia\u003c/em\u003e cysts in CUs outlets does not automatically make this technology less effective, but rather highlights the importance of regular monitoring and maintenance practices. Ultimately, the goal should be to provide safe and reliable drinking water to consumers.\u003c/p\u003e "},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eAhmed S. Moussa:\u003c/strong\u003e Methodology, Formal analysis, Data curation, Visualization, Writing-Original draft. \u003cstrong\u003eAmeen A. Ashour\u003c/strong\u003e: Supervision, Validation, Writing - Review \u0026amp; Editing\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eMohammad I. Soliman\u003c/strong\u003e: Supervision, Writing - Review \u0026amp; Editing\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eHoda\u003c/strong\u003e\u003cstrong\u003eA. Taha:\u003c/strong\u003e Supervision, Writing - Review \u0026amp; Editing. \u003cstrong\u003eAhmad Z. Al-Herrawy:\u003c/strong\u003e Supervision, Resources, Funding acquisition, Writing - Review \u0026amp; Editing. \u003cstrong\u003eMahmoud Gad:\u003c/strong\u003e Supervision, Conceptualization, Methodology, Software, Validation, Writing - Review \u0026amp; Editing, Resources.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003eThis study was funded by the Holding Company for drinking water and Wastewater, Egypt and performed with technical assistance from Environmental Parasitology Laboratory, Water Pollution Research Department, National Research Centre, Egypt.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u0026nbsp;\u003c/strong\u003eThe authors declare there is no conflict\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e The manuscript does not contain any material from third parties, and all the material is owned by the authors, and no permission is required for publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e Not applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAbuseir S (2023) A systematic review of frequency and geographic distribution of water-borne parasites in the Middle East and North Africa. East Mediterr Heal J 29:151\u0026ndash;161. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.26719/emhj.23.016 emro.who.int\u003c/span\u003e\u003cspan address=\"10.26719/emhj.23.016 emro.who.int\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAl-Herrawy AZ, Gad MA (2017) Assessment of two different drinking water treatment plants for the removal of free-living amoebae, Egypt. Iran J Parasitol 12: 413\u0026ndash;422. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5623922/\u003c/span\u003e\u003cspan address=\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5623922/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlhamlan FS, Al-Qahtani AA, Al-Ahdal MNA (2015) Recommended advanced techniques for waterborne pathogen detection in developing countries. J Infect Dev Ctries 9: 128\u0026ndash;135. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3855/jidc.6101\u003c/span\u003e\u003cspan address=\"10.3855/jidc.6101\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAli MA, Al-Herrawy AZ, El-Hawaary SE (2004) Detection of enteric viruses, Giardia and Cryptosporidium in two different types of drinking water treatment facilities. Water Res 38: 3931\u0026ndash;3939. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.watres.2004.06.014\u003c/span\u003e\u003cspan address=\"10.1016/j.watres.2004.06.014\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlmeida JC, Martins FDC, Ferreira Neto JM et al (2015) Occurrence of Cryptosporidium spp. and Giardia spp. in a public water-treatment system, Paran\u0026aacute;, Southern Brazil. Rev Bras Parasitol Vet = Brazilian J Vet Parasitol Orgao Of do Col Bras Parasitol Vet 24: 303\u0026ndash;308 \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1590/S1984-29612015051\u003c/span\u003e\u003cspan address=\"10.1590/S1984-29612015051\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAl-Rifai RH, Loney T, Sheek-Hussein M et al (2020) Prevalence of, and factors associated with intestinal parasites in multinational expatriate workers in Al Ain City, United Arab Emirates: An occupational cross-sectional study. J Immigr Minor Heal 22: 359\u0026ndash;374. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://link.springer.com/article/\u003c/span\u003e\u003cspan address=\"https://link.springer.com/article/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s10903-019-00903-8\u003c/span\u003e\u003cspan address=\"10.1007/s10903-019-00903-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaldursson S, Karanis P (2011) Waterborne transmission of protozoan parasites: review of worldwide outbreaks\u0026ndash;an update 2004\u0026ndash;2010. Water Res 45: 6603\u0026ndash;6614 \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.watres.2011.10.013\u003c/span\u003e\u003cspan address=\"10.1016/j.watres.2011.10.013\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarmena D, Aguinagalde X, Zigorraga C et al (2007) Presence of Giardia cysts and Cryptosporidium oocysts in drinking water supplies in northern Spain. J Appl Microbiol 102: 619\u0026ndash;629. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/j.1365-2672.2006.03193.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1365-2672.2006.03193.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCotruvo JA, Dufour A, ReesG et al (2004) Waterborne zoonoses: identification, causes, and control. World Health Organization ISBN: 9241562730. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://apps.who.int/iris/handle/10665/42977\u003c/span\u003e\u003cspan address=\"https://apps.who.int/iris/handle/10665/42977\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eECDC (2014) European Centre for Disease Prevention and Control. Annual Epidemiological Report \u0026ndash; Giardiasis. [Internet]. Stockholm: ECDC; \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ecdc.europa.eu/sites/default/files/documents/Giardiasis%20AER pdf\u003c/span\u003e\u003cspan address=\"https://www.ecdc.europa.eu/sites/default/files/documents/Giardiasis%20AER pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEl-Khayat HMM, El-Wakil ES, Abdel-Motleb A et al (2022) Bacteriological, parasitological and chemical pollution of Nile River water at some Greater Cairo sites. Int J Environ Stud 79:731\u0026ndash;747. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/00207233.2021.1954454\u003c/span\u003e\u003cspan address=\"10.1080/00207233.2021.1954454\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eELMehy DA, Ismail HIH, Alfattah AA et al (2021) Flow cytometric and molecular analysis of possible protozoal contamination of drinking water in Tanta, Egypt. J Egypt Soc Parasitol 51: 127\u0026ndash;138. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.21608/jesp.2021.165953\u003c/span\u003e\u003cspan address=\"10.21608/jesp.2021.165953\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEPA method 1623, (2005) Environmental protection agency Method 1623 Cryptosporidium and Giardia in Water by Filtration/IMS/FA December 2005 \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.epa.gov/sites/default/files/2015-07/documents/epa-1623.pdf\u003c/span\u003e\u003cspan address=\"https://www.epa.gov/sites/default/files/2015-07/documents/epa-1623.pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuy RA, Payment P, Krull UJ, Horgen PA (2003) Real-time PCR for quantification of Giardia and Cryptosporidium in environmental water samples and sewage. Appl Environ Microbiol 69:5178\u0026ndash;5185. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1128/AEM.69.9.5178-5185.2003\u003c/span\u003e\u003cspan address=\"10.1128/AEM.69.9.5178-5185.2003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGad MA, Saleh FEZR, Morsy EA, Marouf MA, Al-Herrawy AZ (2019) Use of microscopic and molecular techniques to assess removal of parasitic protozoa via conventional and compact drinking water treatment processes. Egyp J Aqua Biol Fish 23: 327\u0026ndash;339. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://dx.doi.org/10.21608/ejabf.2019.67228\u003c/span\u003e\u003cspan address=\"10.21608/ejabf.2019.67228\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHsu BM, Huang C, Jiang GY, Hsu CLL (1999) The prevalence of Giardia and Cryptosporidium in Taiwan water supplies. J Toxicol Environ Heal Part A 57: 149\u0026ndash;160. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/009841099157728\u003c/span\u003e\u003cspan address=\"10.1080/009841099157728\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHaque R, Roy S, Siddique A et al (2007) Multiplex real-time PCR assay for detection of Entamoeba histolytica, Giardia intestinalis, and Cryptosporidium spp. Am J Trop Med Hyg 76: 713\u0026ndash;717. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.researchgate.net/profile/S-M-Mazidur-Rahman/publication/51390330\u003c/span\u003e\u003cspan address=\"https://www.researchgate.net/profile/S-M-Mazidur-Rahman/publication/51390330\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003e: (2006) International Organization for Standardization (ISO), 2006. Water quality \u0026ndash; isolation and identification of Cryptosporidium oocysts and Giardia cysts from water. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.iso.org/standard/39804.html\u003c/span\u003e\u003cspan address=\"https://www.iso.org/standard/39804.html\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e, Accessed date: 30 July 2019\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKing BJ, Monis PT (2007) Critical processes affecting Cryptosporidium oocyst survival in the environment. Parasitology 134: 309\u0026ndash;323. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1017/S0031182006001491\u003c/span\u003e\u003cspan address=\"10.1017/S0031182006001491\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKifleyohannes T, Robertson LJ (2020) Preliminary insights regarding water as a transmission vehicle for Cryptosporidium and Giardia in Tigray, Ethiopia. Food Waterborne Parasitol 19: e00073 \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.fawpar.2020.e00073\u003c/span\u003e\u003cspan address=\"10.1016/j.fawpar.2020.e00073\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaranis P, Kourenti C, Smith H (2007) Waterborne transmission of protozoan parasites: a worldwide review of outbreaks and lessons learnt. J Water Health 5: 1\u0026ndash;38 \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2166/wh.2006.002\u003c/span\u003e\u003cspan address=\"10.2166/wh.2006.002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKui CAOS, Yan JY, Ying YZ, et al (2021) Quantitative microbial risk assessment of Cryptosporidium and Giardia in public drinking water in China. Biomed Environ Sci 34:493\u0026ndash;498. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ipd.org.cn/uploadpic/file/20210727/20210727112323_39311.pdf\u003c/span\u003e\u003cspan address=\"https://www.ipd.org.cn/uploadpic/file/20210727/20210727112323_39311.pdf\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLigda P, Claerebout E, Kostopoulou D et al (2020) Cryptosporidium and Giardia in surface water and drinking water: Animal sources and towards the use of a machine-learning approach as a tool for predicting contamination. Environ Pollut 264: 114766. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envpol.2020.114766\u003c/span\u003e\u003cspan address=\"10.1016/j.envpol.2020.114766\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMckee AM, Cruz MA (2021) Microbial and viral indicators of pathogens and human health risks from recreational exposure to waters impaired by fecal contamination. J Sustain Water Built Environ 7: 3121001. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1061/JSWBAY.0000936\u003c/span\u003e\u003cspan address=\"10.1061/JSWBAY.0000936\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMahmoudi MR, Ongerth JE, Karanis P (2017) Cryptosporidium and cryptosporidiosis: the Asian perspective. Int J Hyg Environ Health 220: 1098\u0026ndash;1109. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ijheh.2017.07.005\u003c/span\u003e\u003cspan address=\"10.1016/j.ijheh.2017.07.005\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMahmoudi MR, Kazemi B, Mohammadiha A et al (2013) Detection of Cryptosporidium and Giardia (oo) cysts by IFA, PCR and LAMP in surface water from Rasht, Iran. Trans R Soc Trop Med Hyg 107: 511\u0026ndash;517. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/trstmh/trt042\u003c/span\u003e\u003cspan address=\"10.1093/trstmh/trt042\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrystajecky N, Huck PM, Schreier H, Isaac-Renton JL (2014) Assessment of Giardia and Cryptosporidium spp. as a microbial source tracking tool for surface water: application in a mixed-use watershed. Appl Environ Microbial 80: 2328\u0026ndash;2336. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1128/AEM.02037-13\u003c/span\u003e\u003cspan address=\"10.1128/AEM.02037-13\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2014 Jan 24\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePinto-Duarte VA, H\u0026eacute;rnandez-Arango NM, Marin-Gallego BJ et al (2022) Detection of Giardia duodenalis and Toxoplasma gondii in soil and water samples in the Quind\u0026iacute;o River basin, Colombia. Food Waterborne Parasitol 28: e00175. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/https://doi.org/10.1016/j.fawpar.2022.e00175\u003c/span\u003e\u003cspan address=\"10.1016/j.fawpar.2022.e00175\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRizk NM, Hamza IA (2021) Molecular Quantification of Human Bocavirus in Environmental Water Samples in Giza, Egypt. Egypt J Aquat Biol Fish 25: 735\u0026ndash;749. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.21608/ejabf.2021.169523\u003c/span\u003e\u003cspan address=\"10.21608/ejabf.2021.169523\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRichard RL, Ithoi I, Abd Majid MA et al (2016) Monitoring of Waterborne Parasites in Two Drinking Water Treatment Plants: A Study in Sarawak, Malaysia. Int J Environ Res Public Health 13: 641. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/ijerph13070641\u003c/span\u003e\u003cspan address=\"10.3390/ijerph13070641\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRizk E, Swan JT, Cheon O et al (2019) Quality indicators to measure the effect of opioid stewardship interventions in hospital and emergency department settings. Am J Heal Pharm 76: 225\u0026ndash;235. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/ajhp/zxy042\u003c/span\u003e\u003cspan address=\"10.1093/ajhp/zxy042\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRosado-Garc\u0026iacute;a FM, Guerrero-Fl\u0026oacute;rez M, Karanis G et al (2017) Water-borne protozoa parasites: The Latin American perspective. Int J Hyg Environ Health 220: 783\u0026ndash;798. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/https://doi.org/10.1016/j.ijheh.2017.03.008\u003c/span\u003e\u003cspan address=\"10.1016/j.ijheh.2017.03.008\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTaviani E, van den Berg H, Nhassengo F et al (2022) Occurrence of waterborne pathogens and antibiotic resistance in water supply systems in a small town in Mozambique. BMC Microbiol 22: 243. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12866-022-02654-3\u003c/span\u003e\u003cspan address=\"10.1186/s12866-022-02654-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWHO (World Health Organization) (2019) WHO World Water Day Report\u0026mdash;World Health Organization. Geneva, Switzerland. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/news-room/fact-sheets/detail/drinking-water\u003c/span\u003e\u003cspan address=\"https://www.who.int/news-room/fact-sheets/detail/drinking-water\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Accessed 14 Nov 2020.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"parasitology-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pare","sideBox":"Learn more about [Parasitology Research](http://link.springer.com/journal/436)","snPcode":"436","submissionUrl":"https://submission.nature.com/new-submission/436/3","title":"Parasitology Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Cryptosporidium, Giardia, drinking water treatment plants, immunofluorescence assay, real-time PCR","lastPublishedDoi":"10.21203/rs.3.rs-2683491/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2683491/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eDuring the past thirty years, there has been a significant increase in the contamination of drinking water by enteric pathogenic protozoa, particularly \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e spp. Such microbial contamination has been responsible for disease outbreaks and increased background rates of disease in developed and developing countries worldwide. As such, controlling waterborne diseases is a critical aspect of public health policy and the primary objective of drinking water treatment plants (DWTPs). Limited studies applied real-time PCR (qPCR) and/or Immunofluorescence assay (IFA) for monitoring \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e spp., particularly in developing countries like Egypt. Samples of water from two conventional drinking water treatment plants and two compact units (CUs) were analyzed using both IFA and qPCR methods to detect \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e. The conventional DWTPs showed complete removal of \u003cem\u003eGiardia\u003c/em\u003e and \u003cem\u003eCryptosporidium\u003c/em\u003e gene copies, whereas Mansheyat Alqanater and Niklah CUs achieved only partial removal. Specifically, \u003cem\u003eCryptosporidium\u003c/em\u003e gene copies removal rates were 33.33% and 60% for Mansheyat Alqanater and Niklah CUs, respectively. Niklah CU also removed 50% of \u003cem\u003eGiardia\u003c/em\u003e gene copies, but no \u003cem\u003eGiardia\u003c/em\u003e gene copies were removed by Mansheyat Alqanater CU. Conventional DWTPs were more effective than CUs in removing enteric protozoa. The contamination of drinking water by enteric pathogenic protozoa remains a significant issue globally, leading to increased disease rates. Infectious disease surveillance in drinking water is an important epidemiological tool to monitor the health of a population.\u003c/p\u003e","manuscriptTitle":"Fate of Cryptosporidium and Giardia through conventional and compact drinking water treatment plants","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-03-17 21:08:54","doi":"10.21203/rs.3.rs-2683491/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2023-05-27T01:54:02+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2023-04-13T18:36:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"013d2bca-b6e6-4bfe-b236-cb79cc04bf6f","date":"2023-04-05T09:24:34+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2023-04-05T08:04:53+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2023-03-14T03:05:28+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2023-03-14T02:15:23+00:00","index":"","fulltext":""},{"type":"submitted","content":"Parasitology Research","date":"2023-03-12T11:50:46+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"parasitology-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pare","sideBox":"Learn more about [Parasitology Research](http://link.springer.com/journal/436)","snPcode":"436","submissionUrl":"https://submission.nature.com/new-submission/436/3","title":"Parasitology Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"d8c6e893-1f71-4c6f-9a27-fa2efa8e3cff","owner":[],"postedDate":"March 17th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2023-09-07T15:06:57+00:00","versionOfRecord":{"articleIdentity":"rs-2683491","link":"https://doi.org/10.1007/s00436-023-07947-8","journal":{"identity":"parasitology-research","isVorOnly":false,"title":"Parasitology Research"},"publishedOn":"2023-08-26 15:02:03","publishedOnDateReadable":"August 26th, 2023"},"versionCreatedAt":"2023-03-17 21:08:54","video":"","vorDoi":"10.1007/s00436-023-07947-8","vorDoiUrl":"https://doi.org/10.1007/s00436-023-07947-8","workflowStages":[]},"version":"v1","identity":"rs-2683491","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2683491","identity":"rs-2683491","version":["v1"]},"buildId":"WrCJVZZCHTDjtuVLN7oU0","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}