Babesiosis is caused by intraerythrocytic protozoa of the genus Babesia. B. microti is the etiologic agent in the northeastern United States, and B. duncani is responsible for disease on the West Coast. B. divergens causes disease in Europe. The deer tick (Ixodes scapularis) transmits B. microti; the vectors of transmission for the other Babesia species are unknown.


In the United States, infections occur most frequently along the northeastern coast. In 2009, >700 cases were reported in the U.S.; this number is probably an underestimate, given that most pts experience a mild and self-limiting disease and may not seek medical attention.


Most pts develop a mild illness, but immunosuppressed pts may have more severe disease.

  • After an incubation period of 1–6 weeks, pts gradually develop fevers, fatigue, and weakness. Other symptoms may include chills, sweats, myalgias, arthralgias, headache, and—less often—neck stiffness, shortness of breath, and abdominal pain.

- Severe babesiosis is associated with parasitemia levels of >4%.

 – Risk factors include an age of >50 years, male gender, asplenia, HIV infection/AIDS, malignancy, and immunosuppression.

 – Complications include respiratory failure, DIC, CHF, and renal failure.

 – The fatality rate is 5% among all hospitalized pts and 20% among immunocompromised pts.


Giemsa-stained thin smears identify intraerythrocytic Babesia parasites, which appear round or pear-shaped.

  • Ring forms resembling P. falciparum but without pigment are most common.
  • Tetrads (“Maltese crosses”)—formed by four budding merozoites—are pathognomonic for B. microti and other small Babesia species.
  • PCR and serology can also be used for diagnostic purposes.


The medicines that can be thought of use are:-

Crotalus horridus