Methodology for the assessment of brucellosis management practices and its vaccination campaign: example in two Argentine districts

M.N. Aznar, M. Arregui, M.F. Humblet, L.E. Samartino, C. Saegerman

In Argentina, vaccination with Brucella abortus Strain 19 vaccine is mandatory. The objective of the study was to develop and test a method for evaluating, in an innovative way, some farmers' and veterinarians' management practices in relation to brucellosis and to assess the vaccination campaign and coverage. The work took place in Brandsen and Navarro districts. Four questionnaires were designed (for officials from Local Sanitary Entities, vaccinators, vet practitioners and farmers). Responses were coded as "ideal" (0) and "not ideal" (1). To assess the relative weight of each question ("item"), experts ranked the items according to their impact on management practices and vaccination. A weighted score was then calculated. A higher weighted score was assigned to the worse practices. Farmers obtaining a global weighted score above the third quartile were classified as "inappropriately managed farms", to be compared per type of production system and district. To assess the immunization coverage, female calves were sampled 30 to 50 days post vaccination; they were expected to react positively to serological diagnostic tests (DT+). There were significantly more inappropriately managed farms and higher global scores among beef farmers and in Brandsen. Eighty three percent (83%) of female calves were DT+, significantly under the ideal immunization coverage (95%). Only 48% of farms were considered well vaccinated. DT+ results were positively associated with the Brandsen district (OR = 25.94 [4.60-1146.21] and with the farms having more than 200 cow heads ((OR = 78.34 [4.09-1500.00]). On the contrary, DT+ were less associated with vaccinators being veterinary practitioners (OR = 0.07 [0.006-0.78]). Farmers are well advised by their veterinary practitioners but they should improve some management practices. The vaccination campaign is globally well implemented, but the immunization coverage and some vaccinators' practices should be improved. This study leads to a better understanding of the most common used management and control practices regarding brucellosis, which affect its epidemiology. Any vaccination campaign should be periodically assessed to highlight possible fails. The described methodology can be extrapolated to other countries and different contexts.