CDC: Rise in US Malaria Rate May Be Linked to Increase in International Travel

The results of a recent CDC study show that the incidence of malaria in the United States increased in 2016, following a dip in 2015.

The 2016 malaria rate was the highest since 1972 and represents a decades-long trend of increases in the number of confirmed cases.

The trend coincides with the rate of people traveling internationally by airplane, according to the CDC and the National Travel and Tourism Office.

In 2016, the CDC received reports of 2078 malaria cases with onset of symptoms. Among these reported cases, 306 were classified as severe illnesses, and 7 people died.

Most of these reported cases have been linked to mosquito transmission acquired through travel to areas around the world, including 1729 cases that originated in Africa. Of those Africa-linked cases, 61.4% came from West Africa.

However, the number of confirmed malaria incidences in 2016 also included 2 congenital cases, 3 cryptic cases, and 1 case acquired through blood transfusion.

The best way to prevent malaria is to take chemoprophylaxis medication when traveling to a country where the disease is endemic, according to the CDC.

Malaria infections can be fatal if not promptly treated with appropriate medications.

Last month, intravenous (IV) artesunate became the first-line medication for treatment of severe malaria in the United States. The drug is not FDA approved, but it is available from the CDC under an investigational new drug protocol.^1-2

The efficacy of artesunate has been proven, and the international community has used it for years, according to Dr. Katherine Tan, domestic malaria chief in the CDC's Division of Malaria and Parasitic Diseases.

FDA approval relies on drug companies submitting applications to the agency for artesunate.²

"Artesunate is the world standard," Tan said, in a previous interview.²

"The ideal situation would be to have our artesunate FDA approved," she said. "Until then, we have this mechanism to have it released [on a limited basis]."

Clinical studies have shown that IV artesunate is safe, well-tolerated and can be administered to infants, children, and pregnant women in their second and third trimesters, as well as during lactation, according to the CDC.²

In the first trimester of pregnancy, the benefits of IV artesunate treatment outweigh the risk of death and poor outcomes because of severe malaria.²

In 2018, 2 tafenoquine-based antimalarials were approved by the FDA for treating malaria.¹ They are:

• Arakoda (60 Degrees) is indicated for adults with chemoprophylaxis and can prevent relapses from P. ovale and P. vivax infections.
• Krintafel (GSK) was approved for radical cure of P. vivax infections in patients 16 and older.

A malaria rate decrease in 2015 may be attributed to altered travel trends during the Ebola virus outbreak in West Africa, according to the CDC.

In 2016, the number of confirmed malaria cases in the United States grew 36% from 2015.

References

• Mace KE, Arguin PM, Lucchi NW, Tan KR. Malaria Surveillance — United States, 2016. MMWR Surveill Summ. 2019;68(5):1-35. doi: 10.15585/mmwr.ss6805a1.
• Coppock K. New CDC guidance recommends artesunate as first-line treatment for severe malaria. Pharmacy Times. pharmacytimes.com/news/new-cdc-guidance-recommends-artesunate-as-firstline-treatment-for-severe-malaria. Updated March 29, 2019. Accessed May 21, 2019.