Sero-epidemiology and associated risk factors of brucellosis among sheep and goat population in the south western Nepal: A comparative study
Abstract BackgroundBrucellosis is a zoonotic disease of animals and humans caused by the Brucella spp. In Nepal, the presence of brucellosis in small ruminants, such as sheep and goats, has impacted farmers' livelihood and the food safety of the consumer. A cross-sectional study was conducted in the Rupandehi district of Nepal to investigate the seroepidemiology and associated risk factors of brucellosis in the sheep and goat population. Altogether, nineteen sheep and sixty goat farms located in the district were visited. The owners were interviewed to get information on animals, including their management and movement patterns. Three hundred fifty-seven samples (80 sheep and 277 goat samples) were collected proportionately based on the farm sizes. Each serum sample was tested with Rose Bengal Test and ELISA to estimate the seropositivity of brucellosis. Logistic regression was applied to calculate corresponding odds ratios of each variable associated with detection brucellosis. Results At the farm level, 31.6% (6/19; 95% CI: 12%, 54%) of sheep farms and 3.3% (2/60, 95% CI: 0.9%, 11.4 %) of the goat farms were seropositive to brucellosis. Out of 80 sheep serum samples, 12 (15%; 95% CI: 8.79%-24.41%) and out of 277 goat serum samples 3 (1.1%; 95% CI: 0.37%-3.14%) were seropositive to brucellosis. Age greater than 1.5 years (OR= 5.56, 95% CI: 1.39, 29.38, p = 0.02) and herd size of greater than a hundred (OR= 4.74, 95% CI: 1.23, 20.32, p = 0.03) were identified as significant risk factors for seropositivity of brucellosis in the sheep population. While in the goat population, none of the variables was identified as a significant risk factor. ConclusionThe study provides evidence that the older sheep and the sheep from the large herd sizes were at higher risk of detecting brucellosis. A control program should be applied immediately in the sheep population because they may transmit infections to other livestock as they were regularly moved for grazing and selling purposes. Also, strict biosecurity measures should be implemented among pastoralists to prevent brucellosis transmission in them. We suggest further one health-based study to reveal the transmission dynamics of brucellosis between animals and humans.