Malaria is a febrile illness caused by several protozoan species in the genus Plasmodium. The parasite is transmitted to humans by bites from infected Anopheles genus mosquitoes. The risk of malaria is highest in the tropical and sub-tropical regions of the world. Although local transmission of malaria frequently occurred in Minnesota over 100 years ago, all of the cases reported in Minnesota residents in recent years have been imported infections acquired abroad.
In 2013, 66 malaria cases (1.2 per 100,000 population) were reported in Minnesota residents, the highest number of cases reported since 2000 (range, 29 to 66). Forty-eight (73%) cases were identified with P. falciparum, 5 (8%) with P. vivax, 4 (6%) with P. ovale, 2 (3%) with P. malariae, and 4 (6%) with mixed Plasmodium species infections; infections with unidentified Plasmodium species were detected in 3 (5%) cases. The median age of cases was 34 years (range, 2 to 73 years). Of the 59 cases with known race, 52 (88%) were black, 5 (8%) were white, and 2 (3%) were Asian. Fifty-nine cases were Minnesota residents at the time of their illness, 42 (71%) of which resided in the metropolitan area. Five (7%) cases were residents of other states that were diagnosed in Minnesota, and 2 (3%) were residents of countries other than the United States. Of the 44 cases with known country of birth, 7 (16%) were born in the United States. Sixty-one (92%) cases in 2013 likely acquired malaria in Africa, 2 (3%) cases were likely acquired in Asia, and 1 (2%) case was exposed in South America. Exposure information was not available for 2 of the cases. Eighteen countries were considered possible exposure locations for malaria infections, including Liberia (15), Nigeria (14), Kenya (5), and India (2), as well as several other countries in sub-Saharan Africa.
- For up to date information see>> Reporting Malaria (Plasmodium spp.)
- Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2013