Methods
A necropsy was performed on the cat by the Fort Riley veterinarian, DNA extraction and PCR analyses were conducted by FADL microbiologists, histology and immunohistology analyses were conducted by the Kansas State Veterinary Diagnostic Laboratory, and feline tissue and blood were sent to the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) for confirmatory testing and strain identification of tularemia.
Results
Tularemia was identified in the spleen of the cat by the Fort Riley veterinarian and during the histological sampling of the spleen by the Kansas State Veterinary Diagnostic Laboratory. A specific subsequent real-time polymerase chain reaction (RT-PCR) in vitro diagnostic detection of target DNA sequences of F. tularensis was conducted by the FADL microbiologists using a Joint Biological Agent Identification and Diagnostic System (JBAIDS) Tularemia Detection Kit to detect a presumptive qualitative result to detect tularemia in feline and blood samples. USAMRIID also performed RT-PCR and identified genomic DNA from F. tularensis Type A, (SPL15.013.02), thus confirming the FADL's initial presumptive result of F. tularensis. USAMRIID attempted to culture F. tularensis from three samples (swab, feline tissue, and transfer pipette tip), but no growth consistent with F. tularensis was observed on the cysteine heart agar with sheep blood and antibiotics (CHAB) and chocolate (CHOC) plates. Discussions: Our case study of a dual diagnosis of presumptive F. tularensis and possible rabies exposure transmission from a pet cat to its owner provides insight on how veterinarian staff and laboratory personnel can clinically manage esoteric, unexplained, or post-mortum examinations. Our case study also demonstrates the obligation for cooperation between animal health, human health, and public health professionals in the management of zoonotic diseases.