A new strain of drug-resistant malaria is quickly spreading through Southeast Asia. So far, the disease has hit Cambodia, Laos, Thailand, and Vietnam, with half of patients failing to be cured by the typically reliable drugs.

Usually, malaria is treated by artemisinin and piperaquine, but now it appears the malaria parasites have developed a resistance to these medicines.

According to a study published in The Lancet Infectious Diseases, which analyzed blood samples from across the region as well as the parasites’ DNA, in some areas, up to 80 percent of malaria parasites are drug resistant.

Professor Olivo Miotto, from the Wellcome Sanger Institute and University of Oxford, said, “This highly successful resistant parasite strain is capable of invading new territories and acquiring new genetic properties, raising the terrifying prospect that it could spread to Africa, where most malaria cases occur, as resistance to chloroquine did in the 1980s, contributing to millions of deaths.”

All hope is not lost, however. Traditional medicines might be proving ineffective, but alternative drugs can still be used to overcome the resistance. Staying abreast of parasite trends and continuing genetic analysis will help doctors adapt to increasingly drug-resistant malaria, and prescribe appropriate treatment for patients.

Travelers should know that there is currently no vaccine for malaria. Note that since malaria is a disease transmitted through mosquitoes, travelers should prevent mosquito bites by using repellent; covering their skin with long sleeves, long pants, and hats; using mosquito nets; staying in screened accommodations; staying indoors when mosquitoes are most active; and using permethrin-treated clothing and gear.

According to the Centers for Disease Control and Prevention, “In 2017 an estimated 219 million cases of malaria occurred worldwide and 435,000 people died, mostly children in the African Region.”