How Malaria Still Quietly Infects The United States

About 22,000 people in U.S. have been hospitalized with the disease since 2000

Illustration: Diana Quach
Apr 25, 2017 at 1:30 PM ET

Tuesday is World Malaria Day, in which the World Health Organization highlights global efforts to prevent malaria. The WHO has had plenty of success, with new cases dropping 21 percent worldwide between 2010 and 2015. But on a much smaller scale, the United States quietly continues to struggle with the disease. Over the last 15 years, it has cost America half a billion dollars.

Writing in the American Journal of Tropical Medicine and Hygiene, a team of researchers found that about 22,000 people were hospitalized with malaria complications between 2000 and 2015. Nearly 5,000 of them had severe issues like coma or kidney failure, and 182 died. Admittedly, those numbers don’t compare with Africa, where some 90 percent of all malaria cases occur. The continent dealt with nearly 200 million cases and 400,000 deaths in 2016 alone.

The health care cost for treating people with malaria adds up fast. The study estimates the average cost for a malaria patient is more than $25,000, with total costs between 2000 and 2014 reaching about $555 million.

The Centers for Disease Control and Prevention made a concerted and successful effort to eradicate malaria in the U.S. in the 1950s. The cases today are almost certainly the result of people traveling back from regions where malaria is still a major problem.

That still doesn’t tell the whole story, as prevention efforts like anti-malaria medications, special sleeping nets, and mosquito repellants — all of which have been essential to decreasing the global malaria rate — really ought to be affordable and accessible for most Americans traveling halfway round the world. The conclusion then, according to the researchers, is that these travelers simply aren’t bothering to take these precautions.

The data suggest men represent about 60 percent of malaria cases in the United States, which the researchers point to men being less likely to find out what precautions they need take or to follow through on them once traveling. That carelessness doesn’t just affect the returning traveler, as local outbreaks in which American mosquitos feed on an infected person and pass the malaria onto others are rare but far from impossible — there’s been roughly one such outbreak every year since the CDC eliminated the disease in 1957.