Capnocytophaga canimorsus meningitis and bacteraemia without a dog bite in an immunocompetent individual

Abstract

We describe the case of an immunocompetent 75-year-old man with Capnocytophaga canimorsus bacteraemia and meningitis. C. canimorsus is commonly found in the oral flora of dogs with human infection typically occurring following a bite. Unusually, while our patient was a dog owner, there was no history of bite nor scratch mark. Admission blood cultures flagged positive for Gram-negative bacilli, but prolonged molecular analysis was required before C. canimorsus was isolated in blood and cerebrospinal fluid. There is a high mortality rate in invasive infection, and in our patient’s case, antibiotic therapy was commenced prior to laboratory confirmation with our patient making a complete recovery. This case highlights the importance of including C. canimorsus in the differential diagnosis of unwell patients who keep dogs, even without a bite. This case occurred amid heightened awareness of COVID-19, which may represent predisposition for zoonoses during social isolation and increased human–pet contact.

Cellulitis and transient bacteremia by Capnocytophaga canis after a cat scratch in an immunocompetent patient

“…In relation to the risk factors in the patients from the cases described above, at least three of them presented risk factors that had already been related to C. canimorsus infections, as chronic and heavy alcohol consumption or splenectomy (one patient presented both) [13][14][15][16]. C. canimorsus infections have also been reported in immunocompetent patients [17][18][19]. However, in the case of C. canis this is to our knowledge the first reported case.…”

“… C. canimorsus infections have also been reported in immunocompetent patients [17–19]. However, in the case of C.…”

Meningitis caused by Capnocytophaga canimorsus in a COVID-19 patient: a rare complication of dog bites

“…Capnocytophaga infection may cause a life-threatening condition. The main risk factors are immunosuppressive medications, hematologic malignancies, diabetes, hematopoietic stem cell transplantation, renal disease, alcohol use disorder, solid organ transplantation and splenectomy 10 , 11 - 19 . Although the patient did not have these aforementioned risk factors, his age may have played a significant role in the severity of the infection.…”

The Great pretender: the first case of septic shock due to Capnocytophaga canimorsus in Sardinia. A Case report and review of the literature

“…We suppose that the published literature provided an underestimation of the relevance of this pathogen, due to its difficult microbiological diagnosis and fulminant course in the most severe cases, which can misleadingly suggest a more common etiologic agent, such as Neisseria meningitidis. The published literature offers some descriptions of purulent cases of meningitis caused by C. canimorsus, whose identification was possible by broad-range polymerase chain reaction (PCR) of cerebrospinal fluid (CSF) or 16S ribosomal RNA amplification from blood and CSF samples 72 , 128 , 138 …”

“…We suppose that the published literature provided an underestimation of the relevance of this pathogen, due to its difficult microbiological diagnosis and fulminant course in the most severe cases, which can misleadingly suggest a more common etiologic agent, such as Neisseria meningitidis. The published literature offers some descriptions of purulent cases of meningitis caused by C. canimorsus, whose identification was possible by broad-range polymerase chain reaction (PCR) of cerebrospinal fluid (CSF) or 16S ribosomal RNA amplification from blood and CSF samples 72,128,138 Capnocytophaga canimorsus is a rare cause of endocarditis and it is particularly rare in immunocompetent hosts. 85,92,122 These cases of endocarditis share a common factor: the difficult process of microorganism isolation that occurred after many blood cultures or after PCR analysis of valvular tissue.…”