Local Malaria Infections Found in U.S.

By Allison Kozicharow; Edited by Elizabeth Fine

In June the Centers for Disease Control and Prevention issued a health alert identifying five cases of malaria in Florida and Texas — the first locally acquired malaria infections to occur in 20 years. In July, two more locally acquired malaria cases occurred in Sarasota County, Florida, bringing the latest total to seven.

As WiRED International’s malaria modules explain, malaria is a serious and sometimes fatal noncommunicable disease. It is caused by a parasite (an organism that lives on another creature) that commonly infects a certain type of mosquito that feeds on humans.

Indeed, the majority of WiRED’s community health workers in Kenya have not only suffered from the illness themselves, often at regular intervals, but recognize it as one of the top endemic infections they find in the more than 10,000 people a month they serve with health services.

So how did locally contracted cases of malaria emerge in the U.S. after 20 years of being eradicated? None of the seven affected individuals had travelled internationally. Increasingly, scientists suggest that climate change plays an important role in the expanded range of mosquito-borne diseases, as warmer and wetter climates provide an attractive habitat for mosquitoes. Although travelers can contract malaria anytime and bring it home to areas where malaria does not exist, people catching the disease locally suggests that an expanded mosquito habitat plays a role.

Extreme climate and weather patterns such as droughts, heat waves, floods and rainfall are increasing in severity and regularity across the globe. Due to these changes mosquitoes are breeding and thriving in higher latitudes and altitudes. In particular, ongoing heat waves plague both Florida and Texas as well as other parts of the U.S. and the world.

The latest re-emergence of malaria in the continental United States demonstrates the binding relationship between human, animal and environmental health. In the scientific literature, it’s called One Health. A number of papers and studies¹ within the past 20 years have described this relationship and forecasted the impact of warming temperatures on the expanded range of mosquitos, ticks and animals and their impact on human health. Instances of these adverse One Health interactions will increase as temperatures rise globally.

As climate change grows unchecked, mosquitoes will continue to migrate out of purely tropical areas of the world and will cause an increase in all mosquito-borne diseases.