Acute-onset fever (AOF) is a common finding in cats and may be an indicator for infection with a vector-borne pathogen. To better understand the prevalence of feline vector-borne pathogens (FVBP), serological and molecular diagnostic assays were used to prospectively screen cats with AOF for FVBP. PCR was used to detect infection with Anaplasma, Bartonella, Babesia, Cytauxzoon, Ehrlichia, Hepatozoon, Mycoplasma, and Rickettsia spp. Anaplasma, Borrelia burgdorferi and Ehrlichia seroreactivity was tested by the SNAP®4DX®Plus Test; and Bartonella henselae, B. koehlerae, and B. vinsonii subsp. berkhofii seroreactivity was assessed by IFA testing. AOF cat blood and serum samples with corresponding physical examination findings, CBCs and biochemistry panels were submitted between June 2015 and December 2017 by private practice veterinarians. Inclusion criteria included flea and/or tick exposure, AOF illness (103-106°F) without an obvious historical (trauma) or physical examination (abscess) cause, and owners had to agree to return for follow-up blood collection for convalescent serology. Study objectives included: 1) determine the prevalence of specific FVBP in cats with AOF: 2) identify differences in clinicopathological abnormalities between FVBP-infected and uninfected cats. Eighty four cats met the inclusion criteria. Corresponding convalescent samples were submitted from 40/84 (47.6%) cats. Cats resided primarily in Florida (27/84; 32%) and North Carolina (32/84; 38%) and included 49 (57.6%) males, 35 (41.7%) females, 14 (16.5%) pure breeds and 70 (83.3%) mixed breeds; the average age was 4.4 years. The majority (64%) of cases occurred in the summer (29/84; 34.5%) and fall (25/84; 29.8%) seasons. FVBP were detected by PCR in 38/84 (45.2%) cats and included B. henselae (25/84; 29.8%), Mycoplasma haemominutum. (7/84; 8.3%), Hepatozoon spp. (2/84; 2.4%), M. haemofelis (1/84; 1.2%), A. phagocytophilum (1/84; 1.2%), C. felis (1/84; 1.2%) and R. felis (1/84; 1.2%). Cats were seroreactive to Bartonella spp. (57/84; 67.9%), B. burgdorferi (2/84; 2.4%), Ehrlichia spp. (1/84; 1.2%) and Anaplasma spp. (1/84; 1.2%). When comparing acute with convalescent samples (n = 40), 1 B. clarridgeae/B. henselae co-infection and 2 B. henselae infections were newly diagnosed by PCR. Most convalescent samples were Bartonella seroreactive (27/40; 67.5%) with 17 (42.5%) having been seroreactive with the corresponding acute sample; 7 (17.5%) cats had a ≥ 4 fold increase in Bartonella titers between acute and convalescent samples. One acute A. phagocytophilum PCR+ cat seroconverted to Anaplasma by SNAP®4DX®Plus Test. Clinicopathologic data was collected only at the time of acute sample collection. The average rectal temperature for all 84 AOF cats was 104.6°F. Other predominant clincopathological abnormalities included heart murmurs (17/84; 20.2%), ocular discharge (14/84; 16.6%), neutrophilia (38/84; 45.2%), anemia (24/84; 28.6%), thrombocytopenia (24/84; 28.6%), hyperbilirubinemia (15/84; 17.6%) and hyperglobulinemia (11/84; 13.1%). Of the 65 cats tested for FeLV/FIV, all were FeLV antigen negative and 4 were FIV seropositive. To evaluate potential FVBP-AOF clinicopathological risk factors, cats were grouped by FVBP PCR+ (n = 38), B. henselae PCR+ (n = 25) and PCR– (n = 48) results. In cats with AOF, neutrophilia was significantly associated with a FVBP (p = 0.037; Odds Ratio (OR) 2.6; 95% CI: 1.050 – 6.205) or B. henselae (p = 0.003; OR 4.7; 95% CI: 1.633 – 13.461) PCR+ result compared to PCR– cats. Based on our study, FVBPs are common in cats with AOF. Bartonella spp. were the most prevalent FVBP; however, prevalence rates were comparable to rates reported in cats without AOF. Hepatozoon spp. may be a more frequent cause of AOF in cats in the United States than previously determined. Clinicians should routinely promote the use of flea and tick-borne preventive strategies in cats and consider FVBP in the etiology of AOF, particularly if associated with neutrophilia.
Research Assistant Professor
Dr. Qurollo's research is focused on emerging vector-borne diseases and the epidemiological and clinicopathological effects of vector-borne disease in animals. She currently oversees molecular diagnostics for the Vector-Borne Disease Diagnostic Laboratory at NCSU.
Thursday, June 14
6:00 PM – 6:15 PM
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