Risk Factors for Brucella Seroprevalence in Peri-Urban Dairy Farms in Five Indian Cities

Abstract

Brucellosis is endemic among dairy animals in India, contributing to production losses and posing a health risk to people, especially farmers and others in close contact with dairy animals or their products. Growing urban populations demand increased milk supplies, resulting in intensifying dairy production at the peri-urban fringe. Peri-urban dairying is under-studied but has implications for disease transmission, both positive and negative. In this cross-sectional study, five Indian cities were selected to represent different geographies and urbanization extent. Around each, we randomly selected 34 peri-urban villages, and in each village three smallholder dairy farms (defined as having a maximum of 10 dairy animals) were randomly selected. The farmers were interviewed, and milk samples were taken from up to three animals. These were tested using a commercial ELISA for antibodies against Brucella abortus, and factors associated with herd seroprevalence were identified. In all, 164 out of 1163 cows (14.1%, 95% CI 12.2–16.2%) were seropositive for Brucella. In total, 91 out of 510 farms (17.8%, 95% CI 14.6–21.4%) had at least one positive animal, and out of these, just seven farmers stated that they had vaccinated against brucellosis. In four cities, the farm-level seroprevalence ranged between 1.4–5.2%, while the fifth city had a seroprevalence of 72.5%. This city had larger, zero-grazing herds, used artificial insemination to a much higher degree, replaced their animals by purchasing from their neighbors, were less likely to contact a veterinarian in case of sick animals, and were also judged to be less clean. Within the high-prevalence city, farms were at higher risk of being infected if they had a young owner and if they were judged less clean. In the low-prevalence cities, no risk factors could be identified. In conclusion, this study has identified that a city can have a high burden of infected animals in the peri-urban areas, but that seroprevalence is strongly influenced by the husbandry system. Increased intensification can be associated with increased risk, and thus the practices associated with this, such as artificial insemination, are also associated with increased risk. These results may be important to identify high-risk areas for prioritizing interventions and for policy decisions influencing the structure and development of the dairy industry.

Risk factors for Brucella spp. and Coxiella burnetii infection among small ruminants in Eastern India

“…For Brucella spp., our study found a seroprevalence of 14% in Odisha (95% CI 10-19%), and 6% in Assam (95% CI 4-10%), higher than observations previously made of 5% seroprevalence among sheep and goats in Odisha [15], and a 2% seroprevalence recorded in goats in Assam [38]. Previous studies have however shown particularly high prevalence (70% herd prevalence) in cows in peri-urban Guwahati, the capital of Assam [39].…”

Bacteriological quality of raw milk marketed in and around Guwahati city, Assam, India

“…It provides immunogenic protection and supplies nutrients, such as proteins, fat, carbohydrates, vitamins, and minerals, in an easily digestible form than any other single food [1]. There has been an increase in milk consumption in the developing countries, including India and the trend is likely to continue as the demand for animal-source food has shown a rising trend due to population growth, changing lifestyles, increasing wealth, and increasing dependence of large vegetarian population on dairy products for proteins and other micronutrients [2,3].…”

The Extent and Structure of Peri-urban Smallholder Dairy Farming in Five Cities in India

“…The importance of milk traders in Guwahati, along with low productivity in dairy farms and low knowledge among all dairy value chain actors, has been observed in earlier studies as well ( 12 , 14 ). The difference between Guwahati and the other cities has also been demonstrated when it comes to disease prevalence ( 15 ).…”