Babesiosis, 2013

Babesiosis is a malaria-like illness caused by the protozoan, Babesia microti or other Babesia organisms, that infects red blood cells. B. microti is transmitted to humans by bites from I. scapularis (the blacklegged tick or deer tick), the same vector that transmits the agents of Lyme disease, Anaplasmosis, one form of human ehrlichiosis, and a strain of Powassan virus. Babesia parasites can also be transmitted by blood transfusion. Babesia infections can range in severity, and while most people have asymptomatic infections, people with weak immune systems, underlying health conditions, and the elderly may become seriously ill.

In 2013, 64 confirmed and probable babesiosis cases (1.2 per 100,000 population) were reported, the second highest total since 2011’s record of 72 cases. Yearly case totals since 2005 (range, 10 to 72) have been consistently higher than reported totals from 1996 to 2004 (range, 0 to 9, [Figure 1]). In 2013, 37 (58%) of the babesiosis cases reported occurred in males. The median case age was 66 years (range, 4 to 89 years), up from 57 in 2012. Onsets of illness peaked in the summer months, with 43 (69%) of 62 cases with known onset occurring from June through August. Twenty-three (36%) cases were hospitalized for their infection in 2013 for a median duration of 7 days (range, 3 to 26 days). At least 3 reported cases died from complications of babesiosis in 2013.

• For up to date information see>> Babesiosis (Babesia microti)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2013