Babesiosis is an emerging zoonosis caused by protozoan parasites of the genus Babesia. In many ways, the organism is similar to the parasites which cause malaria. Although most clinical cases have been reported on the USA, species of Babesia capable of causing disease occur worldwide. In humans, babesiosis causes a broad range of symptoms, broad, ranging from clinically silent infections with no outward signs of infection to intense malaria-like episodes resulting occasionally in death. When present, symptoms typically are nonspecific (fever, headache, and muscle pains).
Babesiosis has long been recognized as an economically important disease of cattle and is transmitted to humans by ticks which feed on cattle asnd then subsequently on a human host. But there are approximately 5 million people who receive blood donations in the USA each year, and the transmission of babesiosis is increasing – it’s not always possible to tell if a blood donor is infected as many have no symptoms. There are currently no good laboratory tests which are cost-effective to use for screening blood donations, so presently a questionnaire is used to try to screen out the highest risk donors.
There are drugs avavilable which treat this infection, although there are also signs that drug resistance may be emerging. You’ll be hearing more about Babesia over the next few years.