CDC monitors malaria cases in Haiti

The U.S. Centers for Disease Control and Prevention has received reports of several cases of malaria in Haiti since a 7.0 magnitude earthquake struck the country Jan. 12, according to the Morbidity and Mortality Weekly Report released March 5.

Malaria, caused by Plasmodium falciparum infection and transmitted by the mosquito Anopheles albimanus, is endemic in Haiti.

“Thus,” the CDC noted, “displaced persons living outdoors or in temporary shelters and thousands of emergency responders in Haiti are at substantial risk for malaria.”

Each year, Haiti reports about 30,000 confirmed cases of malaria to the Pan American Health Organization, but the CDC estimates as many as 200,000 may occur each year.

There is no vaccine against the parasite that causes the illness although many researchers are searching for one. Malaria quickly evolves resistance against drugs.

The CDC said the reported cases do not require a change in policy, but said anyone traveling to Haiti should take drugs to help prevent infection.

From Jan. 12 to Feb. 25, the CDC received reports of 11 laboratory-confirmed cases of P. falciparum malaria acquired in Haiti. These patients were seven U.S. residents who were emergency responders, three Haitian residents and one U.S. traveler.

Of the seven emergency responders, six were U.S. military personnel. Among the six, four cases were uncomplicated and treated locally in Haiti. Two other patients were moderately to seriously ill and transferred to the United States for intensive care; one required intubation and mechanical ventilation for acute respiratory distress syndrome. All are expected to make a full recovery, the CDC said.

All six military personnel had been provided the preventive medication doxycycline before departure from the United States and personal protective equipment (e.g., insect repellent and insecticide-treated netting and uniforms) after arrival in Haiti.

Of the 11 patients, preventive medication was recommended for the seven emergency responders and the U.S. traveler. Six of these eight people (including the two hospitalized military personnel) reported they did not adhere to the recommended malaria medication regimen.

Three cases occurred in Haitian residents who traveled to the United States, including one Haitian adoptee. The number of U.S. malaria cases imported from Haiti likely is underestimated because typically not all cases are reported to CDC.

Of the four Plasmodium species that routinely infect humans (P. falciparum, P. vivax, P. malariae and P. ovale), P. falciparum causes the most severe disease and highest mortality and is the predominant species in Haiti.

Information regarding the incidence of malaria in Haiti is limited.

Historically, malaria transmission peaks in Haiti after the two rainy seasons, with a primary peak from November to January and a secondary peak during May and June.

Although each year Haiti reports approximately 30,000 confirmed cases of malaria to the Pan American Health Organization, as many as 200,000 cases might occur annually.

Medical providers should contact the CDC Malaria Branch clinician on call at 770-488-7100 for clinical consultations and to discuss cases of apparent chloroquine treatment or prophylaxis failures and testing of parasites at CDC for resistance markers.

Additional information on malaria is available at http://www.cdc.gov/malaria/

The CDC said it is continuing to monitor malaria in Haiti.

Morbidity and Mortality Weekly Report: https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5908a1.htm