Impact of mass vaccination on the spatiotemporal dynamics of FMD outbreaks in India, 2008-2016

Foot-and-mouth disease (FMD) is endemic in India, where circulation of serotypes O, A and Asia1 is frequent. Here, we provide an epidemiological assessment of the ongoing mass vaccination programs in regard to post-vaccination monitoring and outbreak occurrence. The objective of this study was assessing the contribution of mass vaccination campaigns in reducing the risk of FMD in India from 2008 to 2016 by evaluating sero-monitoring data and modelling the spatiotemporal dynamics of reported outbreaks. Through analyzing antibody titre data from >1 million animals sampled as part of pre- and post-vaccination monitoring, we show that the percent of animals with inferred immunological protection (based on ELISA) was highly variable across states but generally increased through time. In addition, the number of outbreaks in a state was negatively correlated with the percent of animals with inferred protection. We then analyzed the distribution of reported FMD outbreaks across states using a Bayesian space-time model. This approach provides better acuity to disentangle the effect of mass vaccination programs on outbreak occurrence, while accounting for other factors that contribute to spatiotemporal variability in outbreak counts, notably proximity to international borders and inherent spatiotemporal correlations in incidence. This model demonstrated a ∼50% reduction in the risk of outbreaks in states that were part of the vaccination program. In addition, after controlling for spatial autocorrelation in the data, states that had international borders experienced heightened risk of FMD outbreaks. These findings help inform risk-based control strategies for India as the country progresses towards reducing reported clinical disease.

in wild mesocarnivores in an endemic setting

Human trichinellosis and Trichinella infection in pigs are both still endemic in the Balkans, including Serbia. Because of the flow between the sylvatic and the domestic cycle of Trichinella spp., monitoring wildlife has been recommended for the risk assessment of Trichinella spp. infection in swine. We have previously shown the presence of Trichinella infection in wild carnivores including the wolf and the golden jackal, and here we report on Trichinella infection in several other mesocarnivore species. From a total of 469 animals collected between 1994 and 2013, Trichinella larvae were detected in 29 (6.2%, 95% CI = 4.0-8.4) animals, including 14 red foxes (4.7%), 7 wild cats (35%), 5 beech martens (4.8%), 2 pine martens (16.7%), and 1 European badger (6.25%). No Trichinella larvae were detected in the examined specimens of European polecats, steppe polecats and European otters. Species identification of the Trichinella larvae performed for 18 positive samples revealed T. spiralis in 77.8% and T. britovi in 22.2% of the isolates. Both species were detected in red foxes and wild cats. The predominance of T. spiralis in wildlife in Serbia indicates the (past or present) spillover of this pathogen from domestic to wild animals.