ABSTRACT
A prospective serological investigation was conducted to determine the prevalence and distribution of foot-and-mouth disease (FMD), as well as to monitor the effectiveness of the FMD control programme (FMD-CP) through vaccination in Karnataka, India. Random serum samples were collected every year between May and August before the start of vaccination in 2011, and subsequently following two phases of vaccination in 2012 and 2013. Infection status (seroprevalence) was inferred by subjecting the sera to indirect r3AB3 non-structural protein-ELISA, using kits developed by the Project Directorate on FMD, India. The seromonitoring of FMD-CP was carried out by detecting antibodies deemed to be protective in the pre- and post-vaccinal sera, using liquid-phase blocking-ELISA for structural proteins. The results revealed significant decrease in seroprevalence from 58 to 21 %, providing more definitive data supporting our earlier findings obtained through clinical observations (Hegde et al. in Virusdisease 25:504-509, 2014), and detecting active infection in some of the populations which were considered to be free based on passive surveillance. On the other hand, after four rounds of vaccination, a gradual and significant increase from 4.5 to 59 % of animals carrying antibody levels deemed to be protective was observed against all the three serotypes. The findings of this study could be useful for further strategizing to strengthen the ongoing FMD-CP in Karnataka State, India.
ABSTRACT
A retrospective study on the epidemiology of foot and- mouth disease (FMD) in Karnataka, India between the years 1977 and 2012-13 based on the data collected through passive and active surveillance was undertaken. A total of 11,159 outbreaks with 0.271 million cases of FMD were recorded from 30 different revenue districts of Karnataka. There was a significant difference between the years for the annual incidence of FMD (P = <0.001, F = 19.10) and also between the months (P = <0.001, F = 4.22). Cattle and buffaloes were the predominant species affected being involved in all of the outbreaks reported. A significant correlation was observed between livestock density and the number of outbreaks reported (r = 0.70, p < 0.02), and number of cases (r = 0.76, p < 0.01) for all the agro-climatic zones. The Central dry zone (n = 2257, 19.89 %) reported the highest number of outbreaks followed by the Northern dry zone (n = 1881, 16.58 %) and the Southern transition zone (n = 1761, 15.52 %), and attack rates were concentrated in the North/Northeastern/Central dry and transition zones. A large majority of the outbreaks were caused by serotype O (64.04 %), followed by Asia 1 (19.87 %) and A (12.27 %). Serotype C was not reported since 1993 in the state. In recent years, serotype O has dominated (82.59 %), with the rest of the outbreaks being almost equally caused by A (9.01 %) and Asia 1 (8.40 %). The study highlights the significance of the O serotype and cattle as the main indicator species in the epidemiology of FMD in Karnataka, India. The findings from this study can be used as baseline epidemiological data for further research to identify endemic and epidemic areas for the development of a sustainable programme for the progressive control of FMD in the state of Karnataka as well as other endemic settings.
