A post-infection serologic assessment of cattle herd immune status after a vesicular stomatitis outbreak and the agreement of antibody assays.

Vesicular stomatitis (VS) is a vesicular disease of horses, cattle, and pigs in the Western Hemisphere caused by viruses in the genus Vesiculovirus. Disease manifests as vesicles and erosions on the oral mucosa, teats, prepuce, and coronary band, and is similar in presentation to foot-and-mouth disease. Laboratory confirmation is therefore required. Conventional assays include competitive (c)ELISA and complement fixation (CF). The cELISA provides more accurate herd-level detection of VSV-exposed cattle, but may lack the ability to capture fluctuating antibody levels in individual animals. The CF assay can confirm newly infected animals because of its ability to detect antigen-antibody complexes, thus is considered to be indicative of IgM. We evaluated the immune status of 2 herds affected by VSV in 2014 by testing sera collected in June 2015. Two conventional assays were compared to a novel IgM-IgG ELISA. When sampled in 2015, both herds had detectable VSV-specific antibodies; 18% and 36% of animals tested by cELISA and 2% and 8% of animals tested by CF were positive. The novel IgM-IgG assay exhibited fair agreement (adjusted kappa score of 48) with the conventional assays, and should be evaluated further to assess its ability to replace the 2 separate assays with a single assay system, or for its ability to replace the CF assay as a more sensitive method for defining newly exposed animals.

Serologic survey of selected viral, bacterial, and protozoal agents in captive and free-ranging ungulates from central Kenya.

Serologic evidence of exposure to various disease agents in free-ranging and captive ungulates at a private game ranch in Kenya is presented, and seroprevalence values inside a fenced-in area are compared with those found on the adjacent open savanna. Zebras outside the fence had a higher prevalence of equine rhinovirus-1 than zebras inside (Fisher's exact test, P = 0.007); for all other species and all other agents, there was no such difference (P > 0.10). Results highlight possible transmission of these agents from domestic species into wildlife or vice versa at our study site.