Location: Foreign Animal Disease ResearchTitle: Time to seroconversion to vesicular stomatitis virus in sentinel cows in Southern Mexico) Author
Submitted to: American Association of Veterinary Laboratory Diagnosticians
Publication Type: Abstract only
Publication Acceptance Date: 11/6/2009
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Vesicular stomatitis (VS) is a disease of livestock and some wildlife species caused by vesicular stomatitis virus (VSV). VS epidemics are frequent in certain regions of the United States and such epidemics inflict severe economic losses to affected regions of the country. In this study, a prospective cohort study design was used to assess VSV-seroconversion in four free-ranging dairy cattle herds located in highlands (greater than or equal to 500 m) and lowlands (less than 500 m) of southern Mexico. Ninety-two sentinel cows were tested, on average, every 10 weeks using serum neutralization (SN) test. Sentinel cows in herds located in highlands were at higher risk for seroconversion than cows in lowlands, regardless whether a cut-off value of SN=1:80 (RR = 6.35, CI 95%=3.18-12.69, P is less than 0.01) or SN=1:160 (RR = 7.98, CI 95%=3.43-18.53, P is less than 0.01) was assumed. Seroconversion was most frequent during the rainy season and beginning of the dry season. Hazard for VSV-seroconversion was higher for sentinel cows in highlands compared to cows in lowlands, whether cut-off values of 1:80 (HR= 3.56, CI95% HR=2.43-5.58, P is less than 0.01) or 1:160 (HR= 3.63, CI95% HR= 2.37-6.21, P is less than 0.01) were assumed. These results support the hypothesis that environmental conditions in Mexican highlands are more favorable for occurrence of the disease than in lowlands. These findings will help to understand the dynamics of the disease in the endemic setting most closely located to the United States, and ultimately, to design control and prevention strategies that are effective in preventing the occurrence of future virus incursions into the United States.