INFECTION RATES AND OUTBREAKS OF DISEASE DUE TO BABESIA ARGENTINA IN UNVACCINATED CATTLE ON 5 BEEF PROPERTIES IN SOUTH‐EASTERN QUEENSLAND

Abstract

Serums from unvaccinated groups in 5 herds of beef-cattle in South-East Queensland were tested for antibodies to Babesia argentina at intervals while the cattle were increasing in age from about 6 months. An indirect fluorescent antibody test was used. Infection rates, indicating the proportions of the groups that had been exposed to tick-transmitted infection were 49.2, 56.9 and 69.1% for cattle aged approximately 6, 12 and 18 months, respectively. The degree to which cattle were infested with the vector, Boophilus microplus, was estimated. There appeared to be a strong correlation between infection rate and tick incidence. Four serologically negative animals died of either confirmed or suspected babesiosis during the sampling period. Sickness was observed in 5 others. The serological status of 57 changes from negative to positive without symptoms being observed, indicating relatively low mortality and morbidity rates in the enzootic situation studied.

Infection rate of Babesia spp. sporokinetes in engorged Boophilus microplus from an area of enzootic stability in the State of Minas Gerais, Brazil

“…There is a relationship between age and resistance to Babesia infections (Callow et al 1976, Mahoney 1979; however, if the population of B. microplus increases clinical cases of babesiosis may occur in calves. Under these circumstances, there is a need to adopt programs of acaricide dipping to prevent emergence of disease.…”

An impedance spectroscopy method for the detection and evaluation of Babesia bovis antibodies in cattle

“…Acute infections are usually diagnosed by microscopic examination of blood smears, whereas subclinical chronic infections can be identified serologically [2]. In addition, the indirect fluorescent antibody test (IFAT) is one of the most commonly used methods for the diagnosis of B. bovis infection [3,4] and has been applied in epidemiological studies in a number of countries [5,6], but IFAT was rendered cumbersome and subjective [4,7].…”