Human Babesiosis: An Emerging Human Zoonosis

Babesiosis, caused by infection with intraerythrocytic parasites of the genus Babesia, is one of the most common infections of free-living animals worldwide, and it is gaining attention as an emerging human zoonosis. It is also a vector-borne disease with major public health implications. Three Babesia species, B. divergens, B. microti, and B. venatorum, are primarily responsible for zoonotic babesiosis in many parts of the world. Babesia divergens originated from bovines. Ticks of the genus Ixodes are the primary vectors of babesiosis, and their geographical distribution determines the prevalence of the pathogens involved. Worryingly, the geographical range of Ixodes ticks is expanding as a result of climate change. Ixodes ticks are also vector of Borrelia burgdorferi. the main vector species of Ixodes are I. ricinus, I. scapularis, and I. persulcatus. Babesiosis is transmitted to humans through infected tick bites, but it can also be transmitted through blood transfusion and transplacental transfer from mothers. Human babesiosis symptoms include headache, fatigue, loss of appetite, fever, chills, nausea, and shortness of breath, with the elderly at a higher risk of severe symptoms like hepatomegaly, kidney failure, hemolytic anaemia, splenomegaly, and splenic complications, which can lead to death. Blood smear examination is commonly practiced for diagnosis.