Malaria is 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 subsequently have been imported infections acquired abroad.
In 2015, 43 malaria cases (0.8 per 100,000 population) were reported. Thirty-three (77%) cases were identified with P. falciparum, 5 (12%) with P. vivax, 2 (5%) with P. ovale, and 1 (2%) with mixed Plasmodium species infections; infections with unidentified Plasmodium species were detected in 3 cases. The median age of cases was 33 years (range, 18 to 62 years). Of the 34 cases with known race, 29 (85%) were black, 3 (9%) were white, 1 (3%) was Asian, and 1 (3%) was American Indian. Forty cases were Minnesota residents at the time of their illness, 35 (88%) of whom resided in the metropolitan area. Three patients were residents of a country other than the United States. Of the 34 cases with known country of birth, 8 (24%) were born in the United States. Thirty-nine (91%) cases in 2015 likely acquired malaria in Africa, 2 (4%) cases were likely acquired in Asia, and 1 (2%) case was likely acquired in Central America. Exposure information was not available for 1 case. Sixteen countries were considered possible exposure locations for malaria infections, including Liberia (7), Nigeria (6), Kenya (5), and Ghana (5), 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, 2015