Silent Bite: Capnocytophaga meningitis with bilateral sensorineural hearing loss in splenectomized patient

Silent Bite: Capnocytophaga meningitis with bilateral sensorineural hearing loss in splenectomized patient | 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 Short Report Silent Bite: Capnocytophaga meningitis with bilateral sensorineural hearing loss in splenectomized patient Sonia Pulido, Mehwish Kishore, Konstantinos Pappas, Kaylee M. Rosenbaum This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4114497/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Splenectomized patients are at increased risk for infection with encapsulated bacteria including Capnocytophaga canimorsus found in canine oral flora. We report the clinical course, diagnostic workup, and treatment outcome of an asplenic woman who developed meningitis with bilateral sensorineural hearing loss after a dog bite. To limit the significant morbidity and mortality associated with this bacterium, it is imperative that providers consider Capnocytophaga canimorsus as the cause of infection and for the immunocompromised and symptomatic patient to seek prompt medical attention in the context of canine exposure. Capnocytophaga meningitis sensorineural hearing loss asplenia dog bite Introduction Capnocytophaga canimorsus is a gram-negative, rod-shaped commensal bacterium found in the oral flora of dogs and cats [ 1 , 2 ]. Immunocompromised individuals including the splenectomized, functionally asplenic, cirrhotic, alcoholic, and those with neoplasms or on corticotherapy are at an increased risk of infection with C. canimorsus . Infected patients often present with a history of contact with a dog or cat and may report being bitten, scratched, or licking of pre-existing lesions. A wide range of morbidities have been reported with C. canimorsus infection including pain at the site of injury, purulent discharge, localized cellulitis, lymphangitis, osteomyelitis, eye infections, high-grade bacteremia, meningitis, endocarditis, disseminated intravascular coagulation, complicated pneumonia, renal failure, hemolytic uremic syndrome, gangrene of the digits or extremities, and fulminant sepsis [ 2 , 3 ]. There are also case reports that describe hearing loss in patients with C. canimorsus infection [ 4 – 7 ]. Mortality from C. canimorsus sepsis and bacteremia ranges from 25–60% [ 3 ]. In the United States, an estimated 2 million dog bites occur annually and approximately 25,000 splenectomies are performed each year [ 8 , 9 ]. Given its potential for significant morbidity and mortality, it is prudent to consider C. canimorsus infection as a culprit for the immunocompromised patient presenting with infectious signs and symptoms and a history of canine exposure. Case presentation A 62-year-old female presented with a 1 week-history of malaise, joint aches, diarrhea, and headaches which were managed with increasing use of ibuprofen. Additionally, she noted a 1-day history of epistaxis, bleeding gums, and bilateral hearing loss with tinnitus and vertigo. Of note, the patient suffered a dog bite a few days before the symptoms started and had returned from a 2-night stay in a cabin in the woods of the Mississippi river valley region a day before. Medical history is significant for splenectomy due to trauma, gastroesophageal reflux disease on omeprazole, and osteoporosis. Physical exam revealed bilateral lower extremity petechial rash. Initial chemistry profile significant for potassium 2.6, creatinine 4.16 (baseline 0.8-1), glomerular filtration rate (GFR) 11 (baseline > 60). Initial blood counts showed thrombocytopenia with a platelet count of 8 without leukopenia or anemia. The coagulation profile revealed elevated fibrinogen, but prothrombin (PT) and partial thromboplastin time (PTT) were within normal limits. Computed tomography (CT) of the head showed no acute intracranial abnormality and stable previously known prominent pituitary gland. Initial workup for acute kidney injury (AKI) included urinalysis which was significant for trace proteinuria and hyaline casts. Urine eosinophils negative. Renal ultrasound showed no cystic or solid lesions or hydronephrosis. On admission, blood and urine cultures were collected and the patient was started on broad-spectrum antibiotics. Blood cultures were significant for Capnocytophaga canimorsus . With concerns for meningitis given her acute neurological symptoms, the patient was started on meropenem. MRI (magnetic resonance imaging) brain revealed no intracranial abnormality or abscess but was significant for mildly prominent pituitary measuring 10 mm. Initial workup for thrombocytopenia included a blood smear which was negative for schistocytes, lactate dehydrogenase (LDH) elevated at 474, haptoglobin within normal limits. Infectious causes including respiratory pathogen array, gastrointestinal pathogen array, hepatitis-C, clostridium difficile, and HIV (Human immunodeficiency virus) were all negative. Plasmic score was high and the follow-up test for ADAMTS13 activity was reduced but did not meet the cutoff for TTP (thrombotic thrombocytopenic purpura). Complement-mediated microangiopathic anemia was ruled out as serum ANA, C4 and C3 complement were within normal limits and UPEP (urine protein electrophoresis) and SPEP (serum protein electrophoresis) unremarkable. Suspecting possible immune thrombocytopenia, she was started on IV (intravenous) steroids. Lumbar puncture was performed, and CSF (cerebrospinal fluid) glucose, protein, and cell diff were within normal limits. CSF bacterial and VDRL (venereal disease research laboratory) were negative. Initial audiology evaluation showed poor word recognition score with hearing sensitivity of 250–8000 Hz, confirming moderate to severe sensorineural hearing loss bilaterally. Discussion Splenectomies are performed for patients with traumatic injuries, idiopathic thrombocytopenic purpura, thalassemia, hereditary spherocytosis, sickle cell anemia, and lymphoma. Although humans can survive without a spleen, there is an increased risk of overwhelming post-splenectomy infection (OPSI), and the estimated mortality rate has been reported up to 70% [ 10 ]. This significant risk for overwhelming infection can be explained by the absence of important host defense mechanisms provided by the spleen. The spleen is an intraperitoneal lymphoid organ that filters immune complexes from circulation thus protecting the body from microbial infection [ 11 , 12 ]. It holds B-lymphocytes and mononuclear phagocytes that directly attack bacteria in addition to generating IgM that is responsible for eliminating encapsulated organisms including C. canimorsus. C. canimorsus requires specific culture media for growth and has an incubation period of 1 to 14 days, with an average of 6 days, thus prolonging the ability to make a definitive microbiological diagnosis [ 1 , 2 ]. Successful growth has been achieved with standard chocolate agar or Columbia agar with 5% sheep’s blood and aerobic 5–10% CO₂-enriched atmosphere at a temperature of 35℃ to 37℃. It does not grow on MacConkey agar [ 13 ]. In 11 patients with C. canimorsus meningitis, lumbar puncture revealed an elevated protein level in 9 patients with 8 labs below < 2.0 g/L, a decreased CSF glucose level (< 0.4 g/L) for most of the patients, and WBC count range of 0-6000 cells/µL and a neutrophilic predominance in 8 patients [ 13 ]. C. canimorsus can also be identified with a Gram stain that will test positive for Gram-negative rods. Penicillin is regarded as the drug of choice for C. canimorsus infection [ 2 ]. C. canimorsus is also susceptible to imipenem, erythromycin, clindamycin, vancomycin, chloramphenicol, third generation cephalosporins, fluoroquinolones, rifampin, metronidazole, and doxycycline [ 2 , 13 ]. Resistance has been reported with aztreonam, fosfomycin, polymyxin, and trimethoprim/sulfamethoxazole. Sensorineural hearing loss (SNHL) is a known complication of acute meningitis and appears to be described often as a complication of capnocytophaga meningitis [ 4 , 5 , 14 ]. Even though our patient did not experience all the typical symptoms of meningitis, her SNHL was bilateral, acute, and coincided strongly with the development of this bacteremia. AKI was likely secondary to excessive use of NSAIDs during the viral prodrome and improved with aggressive IV hydration. The platelet count normalized with steroids, but in retrospect was likely secondary thrombocytopenia from bacteremia. Although a lumbar puncture was done and CSF profile/cultures/bacterial PCR were negative, they were taken almost a week after initiation of antibiotics with CNS (central nervous system) penetration. After otolaryngology evaluation, repeat MRI and lumbar puncture, no clear alternate cause has been determined thus far. Overall, the most likely scenario remains that her acute SNHL was related to a capnocytophaga meningitis complicating the bacteremia. Our patient has completed antimicrobial therapy. With audiology rehabilitation, she was able to improve her word recognition abilities, though she now requires hearing aids. Conclusion A thorough clinical history combined with collaboration between the clinical team and microbiologists is essential for a correct and prompt diagnosis. High-risk patients should be counseled on the risk of keeping pets and the importance of promptly seeking medical attention in the setting of a dog bite or scratch. Early recognition and treatment can limit the morbidity and mortality associated with C. canimorsus infection. Abbreviations AKI Acute kidney injury ANA Antinuclear antibody CNS Central nervous system CO₂ carbon dioxide CT Computed tomography GFR Glomerular filtration rate HIV Human immunodeficiency virus Hz Hertz IV Intravenous MRI Magnetic resonance imaging NSAID Nonsteroidal anti-inflammatory drug OPSI Overwhelming post-splenectomy infection PCR Polymerase chain reaction PT Prothrombin time PTT Partial thromboplastin time SNHL Sensorineural hearing loss SPEP Serum protein electrophoresis TTP Thrombotic thrombocytopenic purpura UPEP Urine protein electrophoresis VDRL Venereal disease research laboratory Declarations Conflict of interest Statement: The authors have no personal or institutional interest in the authorship and/or publication of this manuscript. IRB compliance statement and ethical adherence: This work was performed in accordance with The Code of Ethics of the World Medical Association and Declaration in Helsinki, as well as the guidelines enforced by our local Institutional Review Board regarding patient consent. Funding Disclosures: The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. Competing interests: The authors have no relevant financial or non-financial interests to disclose. Author contributions: All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Sonia Pulido and Mehwish Kishore. The first draft of the manuscript was written by Sonia Pulido and Mehwish Kishore and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Ethics approval: This work was performed in accordance with The Code of Ethics of the World Medical Association and Declaration in Helsinki, as well as the guidelines enforced by our local Institutional Review Board at the University of Illinois College of Medicine in Peoria regarding patient consent. Consent to participate: Informed consent was obtained from the patient included in the study. References Oliveira P, Figueiredo M, Paes de Faria V, Abreu G, Resende J (2021) Septic Shock Due to Capnocytophaga canimorsus Infection in a Splenectomized Patient. Cureus 13(3):e13815 Gaastra W, Lipman LJ (2010) Capnocytophaga canimorsus. Vet Microbiol 140(3–4):339–346 Butler T (2015) Capnocytophaga canimorsus: an emerging cause of sepsis, meningitis, and post-splenectomy infection after dog bites. Eur J Clin Microbiol Infect Dis 34(7):1271–1280 Cadre B, Al Oraimi M, Grinholtz-Haddad J, Benkhatar H (2019) My Dog Deafened Me! Case Report of Capnocytophaga canimorsus Infection and Literature Review. Laryngoscope 129(1):E41–E3 Gasch O, Fernandez N, Armisen A, Verdaguer R, Fernandez P (2009) Community-acquired Capnocytophaga canimorsus meningitis in adults: report of one case with a subacute course and deafness, and literature review. Enferm Infecc Microbiol Clin 27(1):33–36 Mazur EM, Field WW, Cahow CE, Schiffman FJ, Duffy TP, Forget BG (1978) Idiopathic thrombocytopenic purpura occurring in a subject previously splenectomized for traumatic splenic rupture. Role of splenosis in the pathogenesis of thrombocytopenia. Am J Med 65(5):843–846 van Samkar A, Brouwer MC, Schultsz C, van der Ende A, van de Beek D (2016) Capnocytophaga canimorsus Meningitis: Three Cases and a Review of the Literature. Zoonoses Public Health 63(6):442–448 Griego RD, Rosen T, Orengo IF, Wolf JE (1995) Dog, cat, and human bites: a review. J Am Acad Dermatol 33(6):1019–1029 Sumaraju V, Smith LG, Smith SM (2001) Infectious complications in asplenic hosts. Infect Dis Clin North Am 15(2):551–565 x Brigden ML, Pattullo AL (1999) Prevention and management of overwhelming postsplenectomy infection–an update. Crit Care Med 27(4):836–842 Tahir F, Ahmed J, Malik F (2020) Post-splenectomy Sepsis: A Review of the Literature. Cureus 12(2):e6898 Band RA, Gaieski DF, Goyal M, Perrone J (2011) A 52-year-old man with malaise and a petechial rash. J Emerg Med 41(1):39–42 Le Moal G, Landron C, Grollier G, Robert R, Burucoa C (2003) Meningitis due to Capnocytophaga canimorsus after receipt of a dog bite: case report and review of the literature. Clin Infect Dis 36(3):e42–e46 Monrad RN, Hansen DS (2012) Three cases of Capnocytophaga canimorsus meningitis seen at a regional hospital in one year. Scand J Infect Dis 44(4):320–324 Additional Declarations No competing interests reported. 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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-4114497","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":280941348,"identity":"32495c92-486e-4860-8010-b864abc632aa","order_by":0,"name":"Sonia Pulido","email":"","orcid":"","institution":"University of Illinois College of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Sonia","middleName":"","lastName":"Pulido","suffix":""},{"id":280941355,"identity":"cb0b6a18-e3be-4df0-8d74-0f14f13e9dd4","order_by":1,"name":"Mehwish Kishore","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvklEQVRIiWNgGAWjYBACCWYGNjCDn4GxAUgxk6BFsoFoLQxQLQYHwBQRWiTb2Z89+LjHJtr4RnLjB4YK68QGQlqkmXnMDWc8S8vddiOxWYLhTDphLXLMPGzSPAcOg7S0MTC2HSZGC/szoJb/uZtngLT8I0KLNDODGVDLgdwNEiAtDURokWzmMZOccSA5d8aZh80SCcfSjQlqkTh//JnEhwN2uf3t6Q8/fKixliWoBRUkkKZ8FIyCUTAKRgEuAADyaDw9fVzoSQAAAABJRU5ErkJggg==","orcid":"","institution":"OSF Saint Francis Medical Center","correspondingAuthor":true,"prefix":"","firstName":"Mehwish","middleName":"","lastName":"Kishore","suffix":""},{"id":280941361,"identity":"b2808bda-bcdf-4ddf-b73c-39d7fc092f11","order_by":2,"name":"Konstantinos Pappas","email":"","orcid":"","institution":"OSF Saint Francis Medical Center","correspondingAuthor":false,"prefix":"","firstName":"Konstantinos","middleName":"","lastName":"Pappas","suffix":""},{"id":280941364,"identity":"2e5b0038-9cd1-462b-aef2-426418569dd7","order_by":3,"name":"Kaylee M. Rosenbaum","email":"","orcid":"","institution":"OSF Saint Francis Medical Center","correspondingAuthor":false,"prefix":"","firstName":"Kaylee","middleName":"M.","lastName":"Rosenbaum","suffix":""}],"badges":[],"createdAt":"2024-03-16 19:44:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4114497/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4114497/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":53924584,"identity":"f5e59b03-0475-404e-bcbc-d60d8413a42b","added_by":"auto","created_at":"2024-04-02 09:35:33","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":194494,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4114497/v1/54321a49-69f8-4f46-926c-6a1c729a5952.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Silent Bite: Capnocytophaga meningitis with bilateral sensorineural hearing loss in splenectomized patient","fulltext":[{"header":"Introduction","content":"\u003cp\u003e \u003cem\u003eCapnocytophaga canimorsus\u003c/em\u003e is a gram-negative, rod-shaped commensal bacterium found in the oral flora of dogs and cats [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Immunocompromised individuals including the splenectomized, functionally asplenic, cirrhotic, alcoholic, and those with neoplasms or on corticotherapy are at an increased risk of infection with \u003cem\u003eC. canimorsus\u003c/em\u003e. Infected patients often present with a history of contact with a dog or cat and may report being bitten, scratched, or licking of pre-existing lesions. A wide range of morbidities have been reported with \u003cem\u003eC. canimorsus\u003c/em\u003e infection including pain at the site of injury, purulent discharge, localized cellulitis, lymphangitis, osteomyelitis, eye infections, high-grade bacteremia, meningitis, endocarditis, disseminated intravascular coagulation, complicated pneumonia, renal failure, hemolytic uremic syndrome, gangrene of the digits or extremities, and fulminant sepsis [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. There are also case reports that describe hearing loss in patients with \u003cem\u003eC. canimorsus\u003c/em\u003e infection [\u003cspan additionalcitationids=\"CR5 CR6\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Mortality from \u003cem\u003eC. canimorsus\u003c/em\u003e sepsis and bacteremia ranges from 25\u0026ndash;60% [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. In the United States, an estimated 2\u0026nbsp;million dog bites occur annually and approximately 25,000 splenectomies are performed each year [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Given its potential for significant morbidity and mortality, it is prudent to consider \u003cem\u003eC. canimorsus\u003c/em\u003e infection as a culprit for the immunocompromised patient presenting with infectious signs and symptoms and a history of canine exposure.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 62-year-old female presented with a 1 week-history of malaise, joint aches, diarrhea, and headaches which were managed with increasing use of ibuprofen. Additionally, she noted a 1-day history of epistaxis, bleeding gums, and bilateral hearing loss with tinnitus and vertigo. Of note, the patient suffered a dog bite a few days before the symptoms started and had returned from a 2-night stay in a cabin in the woods of the Mississippi river valley region a day before. Medical history is significant for splenectomy due to trauma, gastroesophageal reflux disease on omeprazole, and osteoporosis. Physical exam revealed bilateral lower extremity petechial rash. Initial chemistry profile significant for potassium 2.6, creatinine 4.16 (baseline 0.8-1), glomerular filtration rate (GFR) 11 (baseline\u0026thinsp;\u0026gt;\u0026thinsp;60). Initial blood counts showed thrombocytopenia with a platelet count of 8 without leukopenia or anemia. The coagulation profile revealed elevated fibrinogen, but prothrombin (PT) and partial thromboplastin time (PTT) were within normal limits.\u003c/p\u003e \u003cp\u003eComputed tomography (CT) of the head showed no acute intracranial abnormality and stable previously known prominent pituitary gland. Initial workup for acute kidney injury (AKI) included urinalysis which was significant for trace proteinuria and hyaline casts. Urine eosinophils negative. Renal ultrasound showed no cystic or solid lesions or hydronephrosis. On admission, blood and urine cultures were collected and the patient was started on broad-spectrum antibiotics. Blood cultures were significant for \u003cem\u003eCapnocytophaga canimorsus\u003c/em\u003e. With concerns for meningitis given her acute neurological symptoms, the patient was started on meropenem. MRI (magnetic resonance imaging) brain revealed no intracranial abnormality or abscess but was significant for mildly prominent pituitary measuring 10 mm.\u003c/p\u003e \u003cp\u003eInitial workup for thrombocytopenia included a blood smear which was negative for schistocytes, lactate dehydrogenase (LDH) elevated at 474, haptoglobin within normal limits. Infectious causes including respiratory pathogen array, gastrointestinal pathogen array, hepatitis-C, clostridium difficile, and HIV (Human immunodeficiency virus) were all negative. Plasmic score was high and the follow-up test for ADAMTS13 activity was reduced but did not meet the cutoff for TTP (thrombotic thrombocytopenic purpura). Complement-mediated microangiopathic anemia was ruled out as serum ANA, C4 and C3 complement were within normal limits and UPEP (urine protein electrophoresis) and SPEP (serum protein electrophoresis) unremarkable. Suspecting possible immune thrombocytopenia, she was started on IV (intravenous) steroids. Lumbar puncture was performed, and CSF (cerebrospinal fluid) glucose, protein, and cell diff were within normal limits. CSF bacterial and VDRL (venereal disease research laboratory) were negative. Initial audiology evaluation showed poor word recognition score with hearing sensitivity of 250\u0026ndash;8000 Hz, confirming moderate to severe sensorineural hearing loss bilaterally.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eSplenectomies are performed for patients with traumatic injuries, idiopathic thrombocytopenic purpura, thalassemia, hereditary spherocytosis, sickle cell anemia, and lymphoma. Although humans can survive without a spleen, there is an increased risk of overwhelming post-splenectomy infection (OPSI), and the estimated mortality rate has been reported up to 70% [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. This significant risk for overwhelming infection can be explained by the absence of important host defense mechanisms provided by the spleen. The spleen is an intraperitoneal lymphoid organ that filters immune complexes from circulation thus protecting the body from microbial infection [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. It holds B-lymphocytes and mononuclear phagocytes that directly attack bacteria in addition to generating IgM that is responsible for eliminating encapsulated organisms including \u003cem\u003eC. canimorsus.\u003c/em\u003e\u003c/p\u003e \u003cp\u003e \u003cem\u003eC. canimorsus\u003c/em\u003e requires specific culture media for growth and has an incubation period of 1 to 14 days, with an average of 6 days, thus prolonging the ability to make a definitive microbiological diagnosis [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Successful growth has been achieved with standard chocolate agar or Columbia agar with 5% sheep\u0026rsquo;s blood and aerobic 5\u0026ndash;10% CO₂-enriched atmosphere at a temperature of 35℃ to 37℃. It does not grow on MacConkey agar [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In 11 patients with \u003cem\u003eC. canimorsus\u003c/em\u003e meningitis, lumbar puncture revealed an elevated protein level in 9 patients with 8 labs below \u0026lt;\u0026thinsp;2.0 g/L, a decreased CSF glucose level (\u0026lt;\u0026thinsp;0.4 g/L) for most of the patients, and WBC count range of 0-6000 cells/\u0026micro;L and a neutrophilic predominance in 8 patients [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. \u003cem\u003eC. canimorsus\u003c/em\u003e can also be identified with a Gram stain that will test positive for Gram-negative rods.\u003c/p\u003e \u003cp\u003ePenicillin is regarded as the drug of choice for \u003cem\u003eC. canimorsus\u003c/em\u003e infection [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. \u003cem\u003eC. canimorsus\u003c/em\u003e is also susceptible to imipenem, erythromycin, clindamycin, vancomycin, chloramphenicol, third generation cephalosporins, fluoroquinolones, rifampin, metronidazole, and doxycycline [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Resistance has been reported with aztreonam, fosfomycin, polymyxin, and trimethoprim/sulfamethoxazole.\u003c/p\u003e \u003cp\u003eSensorineural hearing loss (SNHL) is a known complication of acute meningitis and appears to be described often as a complication of capnocytophaga meningitis [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Even though our patient did not experience all the typical symptoms of meningitis, her SNHL was bilateral, acute, and coincided strongly with the development of this bacteremia. AKI was likely secondary to excessive use of NSAIDs during the viral prodrome and improved with aggressive IV hydration. The platelet count normalized with steroids, but in retrospect was likely secondary thrombocytopenia from bacteremia. Although a lumbar puncture was done and CSF profile/cultures/bacterial PCR were negative, they were taken almost a week after initiation of antibiotics with CNS (central nervous system) penetration. After otolaryngology evaluation, repeat MRI and lumbar puncture, no clear alternate cause has been determined thus far. Overall, the most likely scenario remains that her acute SNHL was related to a capnocytophaga meningitis complicating the bacteremia. Our patient has completed antimicrobial therapy. With audiology rehabilitation, she was able to improve her word recognition abilities, though she now requires hearing aids.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eA thorough clinical history combined with collaboration between the clinical team and microbiologists is essential for a correct and prompt diagnosis. High-risk patients should be counseled on the risk of keeping pets and the importance of promptly seeking medical attention in the setting of a dog bite or scratch. Early recognition and treatment can limit the morbidity and mortality associated with \u003cem\u003eC. canimorsus\u003c/em\u003e infection.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAKI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAcute kidney injury\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eANA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAntinuclear antibody\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCNS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCentral nervous system\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCO₂\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecarbon dioxide\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eComputed tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGFR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGlomerular filtration rate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHIV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHuman immunodeficiency virus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHz\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHertz\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eIntravenous\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMRI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMagnetic resonance imaging\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eNSAID\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eNonsteroidal anti-inflammatory drug\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOPSI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOverwhelming post-splenectomy infection\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePCR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePolymerase chain reaction\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eProthrombin time\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePTT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePartial thromboplastin time\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSNHL\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSensorineural hearing loss\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSPEP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSerum protein electrophoresis\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTTP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eThrombotic thrombocytopenic purpura\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eUPEP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eUrine protein electrophoresis\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eVDRL\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eVenereal disease research laboratory\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict of interest Statement:\u0026nbsp;\u003c/strong\u003eThe authors have no personal or institutional interest in the authorship and/or publication of this manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIRB compliance statement and ethical adherence:\u0026nbsp;\u003c/strong\u003eThis work was performed in accordance with The Code of Ethics of the World Medical Association and Declaration in Helsinki, as well as the guidelines enforced by our local Institutional Review Board regarding patient consent.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding Disclosures:\u0026nbsp;\u003c/strong\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors have no relevant financial or non-financial interests to disclose.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions:\u0026nbsp;\u003c/strong\u003e\u003cem\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Sonia Pulido and Mehwish Kishore. The first draft of the manuscript was written by Sonia Pulido and Mehwish Kishore and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval:\u0026nbsp;\u003c/strong\u003eThis work was performed in accordance with The Code of Ethics of the World Medical Association and Declaration in Helsinki, as well as the guidelines enforced by our local Institutional Review Board at the University of Illinois College of Medicine in Peoria regarding patient consent.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate:\u0026nbsp;\u003c/strong\u003eInformed consent was obtained from the patient included in the study.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eOliveira P, Figueiredo M, Paes de Faria V, Abreu G, Resende J (2021) Septic Shock Due to Capnocytophaga canimorsus Infection in a Splenectomized Patient. Cureus 13(3):e13815\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGaastra W, Lipman LJ (2010) Capnocytophaga canimorsus. Vet Microbiol 140(3\u0026ndash;4):339\u0026ndash;346\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eButler T (2015) Capnocytophaga canimorsus: an emerging cause of sepsis, meningitis, and post-splenectomy infection after dog bites. Eur J Clin Microbiol Infect Dis 34(7):1271\u0026ndash;1280\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCadre B, Al Oraimi M, Grinholtz-Haddad J, Benkhatar H (2019) My Dog Deafened Me! Case Report of Capnocytophaga canimorsus Infection and Literature Review. Laryngoscope 129(1):E41\u0026ndash;E3\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGasch O, Fernandez N, Armisen A, Verdaguer R, Fernandez P (2009) Community-acquired Capnocytophaga canimorsus meningitis in adults: report of one case with a subacute course and deafness, and literature review. Enferm Infecc Microbiol Clin 27(1):33\u0026ndash;36\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMazur EM, Field WW, Cahow CE, Schiffman FJ, Duffy TP, Forget BG (1978) Idiopathic thrombocytopenic purpura occurring in a subject previously splenectomized for traumatic splenic rupture. Role of splenosis in the pathogenesis of thrombocytopenia. Am J Med 65(5):843\u0026ndash;846\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003evan Samkar A, Brouwer MC, Schultsz C, van der Ende A, van de Beek D (2016) Capnocytophaga canimorsus Meningitis: Three Cases and a Review of the Literature. Zoonoses Public Health 63(6):442\u0026ndash;448\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGriego RD, Rosen T, Orengo IF, Wolf JE (1995) Dog, cat, and human bites: a review. J Am Acad Dermatol 33(6):1019\u0026ndash;1029\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSumaraju V, Smith LG, Smith SM (2001) Infectious complications in asplenic hosts. Infect Dis Clin North Am 15(2):551\u0026ndash;565 x\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrigden ML, Pattullo AL (1999) Prevention and management of overwhelming postsplenectomy infection\u0026ndash;an update. Crit Care Med 27(4):836\u0026ndash;842\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTahir F, Ahmed J, Malik F (2020) Post-splenectomy Sepsis: A Review of the Literature. Cureus 12(2):e6898\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBand RA, Gaieski DF, Goyal M, Perrone J (2011) A 52-year-old man with malaise and a petechial rash. J Emerg Med 41(1):39\u0026ndash;42\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLe Moal G, Landron C, Grollier G, Robert R, Burucoa C (2003) Meningitis due to Capnocytophaga canimorsus after receipt of a dog bite: case report and review of the literature. Clin Infect Dis 36(3):e42\u0026ndash;e46\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMonrad RN, Hansen DS (2012) Three cases of Capnocytophaga canimorsus meningitis seen at a regional hospital in one year. Scand J Infect Dis 44(4):320\u0026ndash;324\u003c/span\u003e\u003c/li\u003e \u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Capnocytophaga meningitis, sensorineural hearing loss, asplenia, dog bite","lastPublishedDoi":"10.21203/rs.3.rs-4114497/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4114497/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSplenectomized patients are at increased risk for infection with encapsulated bacteria including \u003cem\u003eCapnocytophaga canimorsus\u003c/em\u003e found in canine oral flora. We report the clinical course, diagnostic workup, and treatment outcome of an asplenic woman who developed meningitis with bilateral sensorineural hearing loss after a dog bite. To limit the significant morbidity and mortality associated with this bacterium, it is imperative that providers consider \u003cem\u003eCapnocytophaga canimorsus\u003c/em\u003e as the cause of infection and for the immunocompromised and symptomatic patient to seek prompt medical attention in the context of canine exposure.\u003c/p\u003e","manuscriptTitle":"Silent Bite: Capnocytophaga meningitis with bilateral sensorineural hearing loss in splenectomized patient","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-20 09:02:01","doi":"10.21203/rs.3.rs-4114497/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3a55fe67-da44-4625-bb9d-2d9faca2be42","owner":[],"postedDate":"March 20th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-04-02T09:35:25+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-20 09:02:01","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4114497","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4114497","identity":"rs-4114497","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}