Climatic Influences on the Prevalence of Theileria orientalis: A Retrospective Study

Climatic Influences on the Prevalence of Theileria orientalis: A Retrospective Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Climatic Influences on the Prevalence of Theileria orientalis: A Retrospective Study Deepa PM, Vaisakhi Vikraman, R.L Rathish, A Janus, Anju Varghese, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4854260/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 23 Mar, 2026 Read the published version in Journal of Parasitic Diseases → Version 1 posted 5 You are reading this latest preprint version Abstract This study investigates the prevalence of Theileria orientalis and its correlation with climatic factors in Wayanad District, Kerala, India. A retrospective analysis of clinical cases from January 2021 to December 2023 was conducted using data from local veterinary hospitals. Biometeorological parameters, including temperature, relative humidity, rainfall, wind speed, and pan evaporation, were obtained from the College of Agriculture, Ambalavayal. The study found over a thousand cases of oriental theileriosis, with a moderate positive correlation between temperature and disease incidence. Disease prevalence varied throughout the year, with increased incidence during winter months. No significant correlations were observed with other climatic factors. These findings highlight the high prevalence of T. orientalis in Wayanad and emphasize the need for improved surveillance and targeted control strategies that account for climatic and ecological variables to mitigate the impact of the disease on livestock and local economies. T. orientalis Cattle Temperature Tick weather Prevalence Figures Figure 1 Figure 2 Figure 3 Introduction The livestock sector is vital to India's economy, contributing significantly to food security and rural livelihoods, with cattle playing a central role in dairy, beef production, and draft power. Diseases affecting cattle, such as oriental theileriosis caused by Theileria orientalis , pose major challenges to food security and rural economies. Unlike other Theileria species, T. orientalis proliferates within erythrocytes without transforming leukocytes, leading to severe clinical manifestations including pyrexia, weight loss, hypogalactia, anemia,, and jaundice, with potential mortality (Aparna et al., 2011 ; Kawamoto et al., 1990 ). The disease, primarily transmitted by Haemophysalis ticks (Uilenberg et al., 1985 ), complicates management due to its subclinical state. Despite extensive research on the clinical and molecular aspects of oriental theileriosis, the influence of climatic factors on its occurrence is not well understood, particularly in Wayanad, Kerala. This region, home to nearly 80,000 cattle and 4,500 buffaloes (Livestock Census, 2019), is highly vulnerable to the disease's impacts. Understanding the role of climatic conditions is crucial for developing effective disease management strategies. This study aims to analyze the influence of climatic factors (temperature, humidity, and rainfall) on the occurrence of clinical oriental theileriosis in Wayanad. By investigating the correlation between climate variables and disease prevalence, this research seeks to fill critical gaps in knowledge, providing insights necessary for mitigating the adverse effects on livestock health and productivity. These findings will contribute to more effective control measures for vector-borne diseases in tropical climates, ultimately supporting the sustainability of the livestock sector in affected regions. Materials and Methods Selection of Study Group This study was conducted in Wayanad District, Kerala, India (11.7032°N, 76.0834°E), an area with a high prevalence of oriental theileriosis. Wayanad, situated at an elevation between 700 and 2100 meters above sea level, features a diverse topography of hills, valleys, and meadows, with an annual average rainfall of 2322 mm. A retrospective analysis was performed over three years from January 2021 to December 2023. Data were collected from various veterinary facilities, including the District Veterinary Hospital, Veterinary Polyclinics, and the Teaching Veterinary Clinical Complex, Pookode. Clinical cases of oriental theileriosis were identified based on signs such as anaemia, pyrexia, anorexia, lymphadenopathy, and jaundice, and confirmed through peripheral blood smear examination. Daily case numbers were recorded, tabulated, and subsequently analysed. Biometeorological Study The biometeorological parameters assessed included maximum temperature (T_max), minimum temperature (T_min), average relative humidity (RH), wind speed, and pan evaporation. These data were obtained from the College of Agriculture, Ambalavayal, Wayanad. Daily incidence data of oriental theileriosis cases were matched with corresponding meteorological data. Correlation analyses were conducted to evaluate the relationships between weather variables and disease incidence. Statistical Analysis Data were systematically organized and analysed using Spearman's rank correlation coefficient to assess the strength and direction of the relationship between biometeorological variables and the incidence of oriental theileriosis. Results The study documented a high prevalence of Theileria orientalis in Wayanad District, with over a thousand cases reported during the study period. Analysis revealed a consistent annual increase in the number of cases, regardless of seasonal variations (Fig. 2 ). The monthly prevalence of oriental theileriosis over the three consecutive years exhibited considerable variability (Fig. 3 ). Statistical analysis identified a moderate positive correlation between temperature and the incidence of oriental theileriosis, as detailed in Table 1. In contrast, other biometeorological factors, including average relative humidity, rainfall, wind speed, and pan evaporation, did not demonstrate significant correlations with disease incidence. Weather parameters Abundance of T. orientalis Correlation P-value Min Temp 0.460** 0.005 Max Temp 0.114 0.508 Mean daily Temp 0.400* 0.016 Average RH -0.106 0.539 Rainfall -0.191 0.265 Wind Speed 0.051 0.767 Pan Evp 0.063 0.715 ** Significant at 0.01 level *Significant at 0.05 level Table 1. Correlation of abundance of T. orientalis with weather parameters Discussion This study underscores the significant impact of Theileria orientalis on livestock in Wayanad District, a region characterised by extreme monsoon, winter, and moderate summer conditions. The high prevalence of theileriosis, with over a thousand cases documented, highlights the disease's economic importance in an area heavily reliant on agriculture and livestock for livelihoods. The observed increase in case numbers annually, irrespective of seasonal changes, indicates a persistent and escalating problem. The findings align with previous research that has identified various factors contributing to the high prevalence of oriental theileriosis. Factors such as the presence of tick vectors, climatic variables, and the region's rich biodiversity, along with the importation of high-producing exotic crossbred cattle and associated stressors, are significant contributors (Choi et al., 2016 ; Gebrekidan et al., 2016 ; Patial et al., 2021 ). These results are consistent with studies by Aparna et al. ( 2011 ) and Kariyappa et al. ( 2017 ), which also reported similar prevalence levels. A notable finding of this study is the moderate positive correlation between temperature and disease incidence, suggesting that temperature may influence the different stages of the tick life cycle, thus affecting the disease dynamics (Abdullah et al., 2019 ). However, the observation of increased disease incidence during winter months, particularly in January and February, suggests that T. orientalis can affect cattle year-round. This highlights the complexity of disease occurrence, which is influenced not only by tick prevalence but also by other predisposing factors (Shivakumar et al., 2022 ). The presence of subclinical infections in immune-competent animals further complicates disease management, as these animals are highly susceptible to clinical outbreaks during periods of compromised health. Additionally, the potential resistance to Buparvaquone or its transient efficacy could contribute to the recrudescence of the disease in previously treated animals (Bastos et al., 2024 ). Despite the valuable insights provided, the study has limitations. The reliance on retrospective data from veterinary records may introduce biases related to case reporting and diagnosis. Moreover, the study does not account for potential variations in tick populations or other environmental variables not covered by the biometeorological parameters examined. In conclusion, this study establishes the endemic nature of oriental theileriosis in Wayanad and emphasizes the need for more effective disease control strategies. Enhanced surveillance, integrated vector management, and targeted interventions considering climatic and ecological factors are crucial for mitigating the impact of this disease. Future research should focus on longitudinal studies and the development of novel therapeutic and preventative measures to address the challenges posed by this economically significant parasitic disease. Conclusion This study highlights the high prevalence of Theileria orientalis in Wayanad District, Kerala, with a moderate positive correlation between temperature and disease incidence. The disease persists throughout the year, influenced by seasonal and climatic variations. The findings emphasize the need for improved surveillance, targeted vector management, and tailored control strategies. Addressing the complex interplay of climatic and ecological factors is crucial for mitigating the impact of oriental theileriosis on livestock and local economies. Declarations Competing interests The authors declare no competing interests. Acknowledgement Acknowledged to Kerala Veterinary and Animal Sciences University, Pookode, Wayanad, Kerala. References Abdullah DA, Ali MS, Omer SG, Ola-Fadunsin SD, Ali FF, Gimba FI (2019) Prevalence and climatic influence on hemoparasites of cattle and sheep in Mosul, Iraq. J Adv Vet Anim Res 6:492 Aparna M, Ravindran R, Vimalkumar MB, Lakshmanan B, Rameshkumar P, Kumar KA, Promod K, Ajithkumar S, Ravishankar C, Devada K, Subramanian H (2011) Molecular characterization of Theileria orientalis causing fatal infection in crossbred adult bovines of South India. Parasitol Int 60:524–529 Bastos RG, Hassan A, Onzere CK, Herndon DR, Villarino NF, Laughery JM, Fry LM (2024) Transient efficacy of buparvaquone against the US isolate of Theileria orientalis Ikeda genotype in sub-clinically infected cattle. Front Veterinary Sci 11:1421710 Choi KS, Yu DH, Chae JS, Park BK, Yoo JG, Park J (2016) Seasonal changes in hemograms and Theileria orientalis infection rates among Holstein cattle pastured in the mountains in the Republic of Korea. Prev Vet Med 127:77–83 Gebrekidan H, Nelson L, Smith G, Gasser RB, Jabbar A (2016) An outbreak of oriental theileriosis in dairy cattle imported to Vietnam from Australia. Parasitology 144:738–746 Kariyappa PR, Ravindran R, Nimisha M, Amrutha BM, Kurbet PS, Kumar KGA, Varghese A, Deepa CK, Dinesh CN (2017) Prevalence of bovine babesiosis and theileriosis in Kerala, India. Int J Curr Microbiol Appl Sci 6:2310–2314 Kawamoto S, Takahashi K, Onuma M, Kurosawa T, Sonoda M (1990) Invasion of bovine erythrocytes by Theileria sergenti piroplasms in vitro. Jpn J Vet Sci 52:1261–1263 Patial V, Gupta T, Angaria S, Bali D, Katoch A, Gautam M, Chahota R (2021) Theileria orientalis outbreak in an organized cattle breeding farm. Veterinary Parasitology: Reg Stud Rep 24:100572 Shivakumar V, Kasaralikar VR, Upendra HA, Shivakumar M, Naveenkumar GS, andRamesh CR, S (2022) Epidemiological study on bovine theileriosis in Hassan district, Karnataka. Pharma Innova J 11:2855–2861 Uilenberg G, Perie NM, Spanjer AA, Franssen FF (1985) Theileria orientalis , cosmopolitan parasites of cattle demonstration of the schizont stage. Res Vet Sci 38:352–360 Cite Share Download PDF Status: Published Journal Publication published 23 Mar, 2026 Read the published version in Journal of Parasitic Diseases → Version 1 posted Editorial decision: Major revisions needed 17 Sep, 2024 Reviewers agreed at journal 07 Aug, 2024 Reviewers invited by journal 06 Aug, 2024 Editor assigned by journal 05 Aug, 2024 First submitted to journal 03 Aug, 2024 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-4854260","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":336722886,"identity":"40c26ab4-2d5f-40ba-8902-8a2a63de6686","order_by":0,"name":"Deepa 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1","display":"","copyAsset":false,"role":"figure","size":310824,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eT. orientalis\u003c/em\u003e in peripheral blood smear\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4854260/v1/6832ef8e39dffcc4bd13b7d2.png"},{"id":64308158,"identity":"9c91bda0-872e-4b80-a83d-abfdcf3f9c1b","added_by":"auto","created_at":"2024-09-11 13:04:36","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":24503,"visible":true,"origin":"","legend":"\u003cp\u003eNumber of theileriosis cases reported in Wayanad district from 2021 to 2023.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4854260/v1/2a0c41fa2290f07e01beb1ab.png"},{"id":64308159,"identity":"0e0978a3-e8ca-4230-992e-7d87bc0f860b","added_by":"auto","created_at":"2024-09-11 13:04:36","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":46007,"visible":true,"origin":"","legend":"\u003cp\u003eOccurrence of theileriosis in different months in the years 2021, 2022 and 2023.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4854260/v1/896e55f9073f290cd5213d7c.png"},{"id":105755437,"identity":"6978daef-a2ed-4bd1-8ec4-96be5cefc525","added_by":"auto","created_at":"2026-03-30 16:27:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":727772,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4854260/v1/4602257f-165b-473e-87f3-7b03057d5d8e.pdf"}],"financialInterests":"","formattedTitle":"Climatic Influences on the Prevalence of Theileria orientalis: A Retrospective Study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe livestock sector is vital to India's economy, contributing significantly to food security and rural livelihoods, with cattle playing a central role in dairy, beef production, and draft power. Diseases affecting cattle, such as oriental theileriosis caused by \u003cem\u003eTheileria orientalis\u003c/em\u003e, pose major challenges to food security and rural economies. Unlike other \u003cem\u003eTheileria\u003c/em\u003e species, \u003cem\u003eT. orientalis\u003c/em\u003e proliferates within erythrocytes without transforming leukocytes, leading to severe clinical manifestations including pyrexia, weight loss, hypogalactia, anemia,, and jaundice, with potential mortality (Aparna et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Kawamoto et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e1990\u003c/span\u003e). The disease, primarily transmitted by \u003cem\u003eHaemophysalis\u003c/em\u003e ticks (Uilenberg et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e1985\u003c/span\u003e), complicates management due to its subclinical state.\u003c/p\u003e \u003cp\u003eDespite extensive research on the clinical and molecular aspects of oriental theileriosis, the influence of climatic factors on its occurrence is not well understood, particularly in Wayanad, Kerala. This region, home to nearly 80,000 cattle and 4,500 buffaloes (Livestock Census, 2019), is highly vulnerable to the disease's impacts. Understanding the role of climatic conditions is crucial for developing effective disease management strategies.\u003c/p\u003e \u003cp\u003eThis study aims to analyze the influence of climatic factors (temperature, humidity, and rainfall) on the occurrence of clinical oriental theileriosis in Wayanad. By investigating the correlation between climate variables and disease prevalence, this research seeks to fill critical gaps in knowledge, providing insights necessary for mitigating the adverse effects on livestock health and productivity. These findings will contribute to more effective control measures for vector-borne diseases in tropical climates, ultimately supporting the sustainability of the livestock sector in affected regions.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSelection of Study Group\u003c/h2\u003e \u003cp\u003eThis study was conducted in Wayanad District, Kerala, India (11.7032\u0026deg;N, 76.0834\u0026deg;E), an area with a high prevalence of oriental theileriosis. Wayanad, situated at an elevation between 700 and 2100 meters above sea level, features a diverse topography of hills, valleys, and meadows, with an annual average rainfall of 2322 mm. A retrospective analysis was performed over three years from January 2021 to December 2023. Data were collected from various veterinary facilities, including the District Veterinary Hospital, Veterinary Polyclinics, and the Teaching Veterinary Clinical Complex, Pookode. Clinical cases of oriental theileriosis were identified based on signs such as anaemia, pyrexia, anorexia, lymphadenopathy, and jaundice, and confirmed through peripheral blood smear examination. Daily case numbers were recorded, tabulated, and subsequently analysed.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eBiometeorological Study\u003c/h2\u003e \u003cp\u003eThe biometeorological parameters assessed included maximum temperature (T_max), minimum temperature (T_min), average relative humidity (RH), wind speed, and pan evaporation. These data were obtained from the College of Agriculture, Ambalavayal, Wayanad. Daily incidence data of oriental theileriosis cases were matched with corresponding meteorological data. Correlation analyses were conducted to evaluate the relationships between weather variables and disease incidence.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eData were systematically organized and analysed using Spearman's rank correlation coefficient to assess the strength and direction of the relationship between biometeorological variables and the incidence of oriental theileriosis.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThe study documented a high prevalence of \u003cem\u003eTheileria orientalis\u003c/em\u003e in Wayanad District, with over a thousand cases reported during the study period. Analysis revealed a consistent annual increase in the number of cases, regardless of seasonal variations (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The monthly prevalence of oriental theileriosis over the three consecutive years exhibited considerable variability (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eStatistical analysis identified a moderate positive correlation between temperature and the incidence of oriental theileriosis, as detailed in Table\u0026nbsp;1. In contrast, other biometeorological factors, including average relative humidity, rainfall, wind speed, and pan evaporation, did not demonstrate significant correlations with disease incidence.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eWeather parameters\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eAbundance of \u003cem\u003eT. orientalis\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCorrelation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMin Temp\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.460**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMax Temp\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.114\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.508\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean daily Temp\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.400*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.016\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAverage RH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.106\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.539\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRainfall\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.191\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.265\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWind Speed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.051\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.767\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePan Evp\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.063\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.715\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e** Significant at 0.01 level *Significant at 0.05 level\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;1. Correlation of abundance of \u003cem\u003eT. orientalis\u003c/em\u003e with weather parameters\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study underscores the significant impact of \u003cem\u003eTheileria orientalis\u003c/em\u003e on livestock in Wayanad District, a region characterised by extreme monsoon, winter, and moderate summer conditions. The high prevalence of theileriosis, with over a thousand cases documented, highlights the disease's economic importance in an area heavily reliant on agriculture and livestock for livelihoods. The observed increase in case numbers annually, irrespective of seasonal changes, indicates a persistent and escalating problem.\u003c/p\u003e \u003cp\u003eThe findings align with previous research that has identified various factors contributing to the high prevalence of oriental theileriosis. Factors such as the presence of tick vectors, climatic variables, and the region's rich biodiversity, along with the importation of high-producing exotic crossbred cattle and associated stressors, are significant contributors (Choi et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Gebrekidan et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Patial et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). These results are consistent with studies by Aparna et al. (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2011\u003c/span\u003e) and Kariyappa et al. (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2017\u003c/span\u003e), which also reported similar prevalence levels.\u003c/p\u003e \u003cp\u003eA notable finding of this study is the moderate positive correlation between temperature and disease incidence, suggesting that temperature may influence the different stages of the tick life cycle, thus affecting the disease dynamics (Abdullah et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). However, the observation of increased disease incidence during winter months, particularly in January and February, suggests that \u003cem\u003eT. orientalis\u003c/em\u003e can affect cattle year-round. This highlights the complexity of disease occurrence, which is influenced not only by tick prevalence but also by other predisposing factors (Shivakumar et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe presence of subclinical infections in immune-competent animals further complicates disease management, as these animals are highly susceptible to clinical outbreaks during periods of compromised health. Additionally, the potential resistance to Buparvaquone or its transient efficacy could contribute to the recrudescence of the disease in previously treated animals (Bastos et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2024\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDespite the valuable insights provided, the study has limitations. The reliance on retrospective data from veterinary records may introduce biases related to case reporting and diagnosis. Moreover, the study does not account for potential variations in tick populations or other environmental variables not covered by the biometeorological parameters examined.\u003c/p\u003e \u003cp\u003eIn conclusion, this study establishes the endemic nature of oriental theileriosis in Wayanad and emphasizes the need for more effective disease control strategies. Enhanced surveillance, integrated vector management, and targeted interventions considering climatic and ecological factors are crucial for mitigating the impact of this disease. Future research should focus on longitudinal studies and the development of novel therapeutic and preventative measures to address the challenges posed by this economically significant parasitic disease.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study highlights the high prevalence of \u003cem\u003eTheileria orientalis\u003c/em\u003e in Wayanad District, Kerala, with a moderate positive correlation between temperature and disease incidence. The disease persists throughout the year, influenced by seasonal and climatic variations. The findings emphasize the need for improved surveillance, targeted vector management, and tailored control strategies. Addressing the complex interplay of climatic and ecological factors is crucial for mitigating the impact of oriental theileriosis on livestock and local economies.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e \u003ch2\u003eAcknowledgement\u003c/h2\u003e \u003cp\u003eAcknowledged to Kerala Veterinary and Animal Sciences University, Pookode, Wayanad, Kerala.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAbdullah DA, Ali MS, Omer SG, Ola-Fadunsin SD, Ali FF, Gimba FI (2019) Prevalence and climatic influence on hemoparasites of cattle and sheep in Mosul, Iraq. J Adv Vet Anim Res 6:492\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAparna M, Ravindran R, Vimalkumar MB, Lakshmanan B, Rameshkumar P, Kumar KA, Promod K, Ajithkumar S, Ravishankar C, Devada K, Subramanian H (2011) Molecular characterization of \u003cem\u003eTheileria orientalis\u003c/em\u003e causing fatal infection in crossbred adult bovines of South India. Parasitol Int 60:524\u0026ndash;529\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBastos RG, Hassan A, Onzere CK, Herndon DR, Villarino NF, Laughery JM, Fry LM (2024) Transient efficacy of buparvaquone against the US isolate of \u003cem\u003eTheileria orientalis\u003c/em\u003e Ikeda genotype in sub-clinically infected cattle. Front Veterinary Sci 11:1421710\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChoi KS, Yu DH, Chae JS, Park BK, Yoo JG, Park J (2016) Seasonal changes in hemograms and Theileria orientalis infection rates among Holstein cattle pastured in the mountains in the Republic of Korea. Prev Vet Med 127:77\u0026ndash;83\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGebrekidan H, Nelson L, Smith G, Gasser RB, Jabbar A (2016) An outbreak of oriental theileriosis in dairy cattle imported to Vietnam from Australia. Parasitology 144:738\u0026ndash;746\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKariyappa PR, Ravindran R, Nimisha M, Amrutha BM, Kurbet PS, Kumar KGA, Varghese A, Deepa CK, Dinesh CN (2017) Prevalence of bovine babesiosis and theileriosis in Kerala, India. Int J Curr Microbiol Appl Sci 6:2310\u0026ndash;2314\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKawamoto S, Takahashi K, Onuma M, Kurosawa T, Sonoda M (1990) Invasion of bovine erythrocytes by Theileria sergenti piroplasms in vitro. Jpn J Vet Sci 52:1261\u0026ndash;1263\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePatial V, Gupta T, Angaria S, Bali D, Katoch A, Gautam M, Chahota R (2021) \u003cem\u003eTheileria orientalis\u003c/em\u003e outbreak in an organized cattle breeding farm. Veterinary Parasitology: Reg Stud Rep 24:100572\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShivakumar V, Kasaralikar VR, Upendra HA, Shivakumar M, Naveenkumar GS, andRamesh CR, S (2022) Epidemiological study on bovine theileriosis in Hassan district, Karnataka. Pharma Innova J 11:2855\u0026ndash;2861\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUilenberg G, Perie NM, Spanjer AA, Franssen FF (1985) \u003cem\u003eTheileria orientalis\u003c/em\u003e, cosmopolitan parasites of cattle demonstration of the schizont stage. Res Vet Sci 38:352\u0026ndash;360\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":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-parasitic-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jopd","sideBox":"Learn more about [Journal of Parasitic Diseases](https://www.springer.com/journal/12639)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/jopd/default.aspx","title":"Journal of Parasitic Diseases","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"T. orientalis, Cattle, Temperature, Tick, weather, Prevalence","lastPublishedDoi":"10.21203/rs.3.rs-4854260/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4854260/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study investigates the prevalence of \u003cem\u003eTheileria orientalis\u003c/em\u003e and its correlation with climatic factors in Wayanad District, Kerala, India. A retrospective analysis of clinical cases from January 2021 to December 2023 was conducted using data from local veterinary hospitals. Biometeorological parameters, including temperature, relative humidity, rainfall, wind speed, and pan evaporation, were obtained from the College of Agriculture, Ambalavayal. The study found over a thousand cases of oriental theileriosis, with a moderate positive correlation between temperature and disease incidence. Disease prevalence varied throughout the year, with increased incidence during winter months. No significant correlations were observed with other climatic factors. These findings highlight the high prevalence of \u003cem\u003eT. orientalis\u003c/em\u003e in Wayanad and emphasize the need for improved surveillance and targeted control strategies that account for climatic and ecological variables to mitigate the impact of the disease on livestock and local economies.\u003c/p\u003e","manuscriptTitle":"Climatic Influences on the Prevalence of Theileria orientalis: A Retrospective Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-09-11 13:04:31","doi":"10.21203/rs.3.rs-4854260/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revisions needed","date":"2024-09-17T05:34:13+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2024-08-07T05:52:06+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-08-06T13:27:01+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-08-05T07:28:56+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Parasitic Diseases","date":"2024-08-03T12:54:46+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-parasitic-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jopd","sideBox":"Learn more about [Journal of Parasitic Diseases](https://www.springer.com/journal/12639)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/jopd/default.aspx","title":"Journal of Parasitic Diseases","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"cfa87829-8f0c-4b7f-8269-0ae4d0bfe99e","owner":[],"postedDate":"September 11th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-03-30T16:23:28+00:00","versionOfRecord":{"articleIdentity":"rs-4854260","link":"https://doi.org/10.1007/s12639-026-01940-5","journal":{"identity":"journal-of-parasitic-diseases","isVorOnly":false,"title":"Journal of Parasitic Diseases"},"publishedOn":"2026-03-23 16:11:56","publishedOnDateReadable":"March 23rd, 2026"},"versionCreatedAt":"2024-09-11 13:04:31","video":"","vorDoi":"10.1007/s12639-026-01940-5","vorDoiUrl":"https://doi.org/10.1007/s12639-026-01940-5","workflowStages":[]},"version":"v1","identity":"rs-4854260","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4854260","identity":"rs-4854260","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}