In summer 2015, a number of cases of malaria were reported in travelers returning to the United States from the Dominican Republic (Figure).
Figure. Malaria is endemic throughout the Dominican Republic, including in resort areas, and prophylaxis is recommended unless travel is limited to the cities of Santiago and Santo Domingo.
Many of the travelers who acquired malaria stayed in resort areas, such as those in Punta Cana. Malaria is known to be endemic in the Dominican Republic and Haiti, and the Centers for Disease Control and Prevention (CDC) has long recommended malaria prophylaxis for people planning to travel to most areas of the island, including many resort areas. Unfortunately, awareness of the risk is low, and for this reason, travelers to the Dominican Republic often do not seek pretravel care.
All malaria in the Dominican Republic is known to be Plasmodium falciparum, the most serious kind. Fortunately, no chloroquine resistance has been reported, so providers have an arsenal of possible agents for prophylaxis: atovaquone/proguanil, chloroquine, doxycycline, or mefloquine. (See Choosing a Drug to Prevent Malaria.)
It is incumbent on clinicians, when counseling patients who are planning international travel (including to areas that may seem less obvious) to be aware of the potential risks for malaria and other travel-related diseases. People may not realize that in addition to the Dominican Republic, malaria transmission occurs in India, parts of Thailand, most of Honduras, and Panama. For detailed information on malaria risk, see Malaria Information and Prophylaxis, by Country.
Providers should always check the CDC webpage Travelers' Health: Destinations for current information on vaccine recommendations, malaria prophylaxis, and any possible outbreaks when counseling international travelers. In addition, because it may not occur to travelers to these areas to seek pretravel care, providers should always use any primary care or well-patient encounter as an opportunity to ask about upcoming travel plans.
Paul Arguin, MD, is a physician who is board certified in both internal medicine and infectious diseases. He joined the CDC in 1997 and is now a captain in the US Public Health Service and chief of the Domestic Malaria Unit. He is also a clinical associate professor at Emory University.