Risks of cattle babesiosis (Babesia bovis) outbreaks in a semi-arid region of Argentina

The epidemiology of Babesia bovis was studied in terms of enzootic stability/instability and husbandry and abiotic factors influencing B. bovis transmission rate in northeastern Santiago del Estero province, Argentina. The area is of limited suitability for its only vector in Argentina, the tick Rhipicephalus microplus. The proportion of calf herds in a state of enzootic stability/instability to B. bovis was determined and husbandry practices and abiotic factors associated with variations in B. bovis transmission rates were explored using a cross-sectional observational study design. Daily probability of infection (inoculation rate, h) with B. bovis was calculated from age-specific seroprevalence via ELISAi in 58 herds of 4.5–8.5-month-old calves. Herds were considered to be in enzootic instability (EI) when h