Abstract:
Emergence of babesiosis in both public health and food security concern in global
perspectives cannot be ignored. The dairy farming plays an important role in food
industry that, fulfilling the protein requirement through producing both milk and
meat. The farming operations may get hampered due to non-infectious and infectious
diseases. Infectious diseases also cause huge production losses in all farming operations
in time to time. Babesiosis is well known as an emerging zoonotic disease causing heavy
production losses due to both the clinical diseases and carrier animals. Babesia
parasites, mainly Babesia bovis and B. bigemina, are tick-borne hemoparasites inducing
bovine babesiosis in cattle globally, and these parasites are considered to be endemic in
central Sri Lanka and the prevalence of babesiosis is high in other areas. Carrier cattle
infected with babesiosis have low number of parasites in circulation. Babesiosis is
difficult to detect and is a challenge to conventional diagnostic methods. However,
diagnosis of carrier animals in herd is important for preventing outbreaks by
transmission through vector ticks to healthy animals and for obtaining epidemiological
data of the disease. Here, we have conducted nested PCR detection of B. bovis in carrier
cattle (Jersey crosses, Friesian crosses and Australian milking zebu) of selected localities
of Sri Lanka. For this study, 30 blood samples collected from suspected carrier cattle
were analyzed using light microscopy and nested PCR. Screening by light microscope
indicated that 47% of the samples were positive. PCR analysis of samples diagnosed that
80% of the samples were positive. Hence, 33% of the animals appeared to be healthy
through routine light microscope diagnosis were in fact carriers posing a threat for the
healthy herd population. The high prevalence of babesiosis in carrier cattle in Sri Lanka
emphasized that island-wide control and prevention programs against bovine
babesiosis are needed to minimize the financial burden caused by the parasites to
reduce to production losses. This preliminary study on molecular detection of B. bovis in
selected localities offers a rapid and efficient screening method for suspected carrier
herds while providing new avenues to minimize losers incurred in milk production due
to unidentified carrier animals.
