Abstract & Commentary
Synopsis: Until November 2004, urban and resort areas of the Dominican Republic had been considered free of malaria. Seventeen cases of P. falciparum malaria, including 3 US travelers described here, have led to an expansion of CDC malaria recommendations. Chloroquine prophylaxis is indicated for travel, not only to rural areas of the Dominican Republic, but also the far eastern region resort areas of La Altagracia province (ie Punta Cana) and Duarte Province.
Source: Transmission of Malaria in Resort Areas—Dominican Republic, 2004. MMWR. 2005;53:1195-1198.
The Centers for Disease Control and Prevention began receiving reports of P. falciparum malaria in US travelers to the Dominican Republic during the third week of November 2004. All 3 US cases were characterized by severe disease, with need for ICU care. None of these individuals had traveled to areas considered malarious, and none had received blood transfusions in the previous year.
Case 1: A 47-year-old female was admitted to an ICU in the United States with multi-organ system failure, acute respiratory distress syndrome, and renal failure after a 6-day period of fever, chills, abdominal pain, headache, nausea, and vomiting. Symptoms began 24 hours after returning from a 1-week stay in an all-inclusive resort in Punta Cana, La Altagracia Province. Outpatient examinations were unrevealing, until 2 days prior to admission when she had jaundice. The patient was obtunded on admission, and a 35% P. falciparum parasitemia was detected, as well as anemia, leukocytosis, and profound thrombocytopenia (5000/dl). After 2 days of intravenous quinidine gluconate, the parasitemia cleared and, on day 5, quinidine was discontinued, as she was placed on doxycycline. She underwent hemodialysis for renal failure and improved. She was discharged to a rehabilitation center and remained there as of December 30, 2004.
Case 2. A 71-year-old man presented to an emergency department in Canada, 10 days after returning from a week at a resort in Punta Cana, complaining of fever, myalgias, and malaise. He was diagnosed with viral syndrome, discharged, was also seen as an outpatient, and told he had a viral syndrome. On day 6 of symptoms, he was admitted with hypotension, hypoxia, acute renal failure, and respiratory failure requiring mechanical ventilation. Blood smears on day 2 of his admission showed a 9% P. falciparum parasitemia. He received intravenous quinidine gluconate and doxycycline and underwent hemodialysis. He reported no travel other than a day trip to Santo Domingo, and remained hospitalized as of December 30, 2004.
Case 3. A 39-year-old man was admitted to an ICU in Canada 12 days after he returned from a resort in Punta Cana, where he had stayed for 2 weeks. His course was complicated by anemia, acute respiratory distress syndrome, acute renal failure, and cerebral malaria. He underwent exchange transfusion.
P. falciparum parasitemia was 2% on day 2 of his admission, and he was treated with chloroquine and quinine. His course was complicated by anemia, acute respiratory distress syndrome, acute renal failure, and cerebral malaria. He underwent exchange transfusion.
Comment by Maria D. Mileno, MD
Plasmodium falciparum is the only malaria species present in the Dominican Republic. Although it is fortunate that it still remains sensitive to chloroquine, P. falciparum is rapidly fatal and warrants intensive education of travelers regarding prevention of insect exposures, chemoprophylaxis with chloroquine, and complete discussions on when to seek care. Given the severity of the cases reported above, it is also quite fortunate that no deaths resulted. Seventeen cases were reported in total, in 3 US, 6 Canadian, and 8 European travelers. Annually in the Dominican Republic there are an average of 1500-2500 malaria cases. This most recent outbreak in the resort areas is not the only one that has occurred there. Another outbreak occurred from July 1999 to March 2000 in the wake of hurricanes Mitch and George, at which time increased breeding patterns of Anopheles albimanus mosquitoes were noted. In September 2004, hurricane Jeanne struck the Dominican Republic with heavy rains that flooded Punta Cana and the Bavaro Zone, areas that have also utilized numerous malaria-infected migrant workers for construction projects.
This is one example of how environmental events can change the locations of known malaria transmission areas. It is possible and quite concerning that new areas of drug-resistant malaria transmission may develop in regions affected by the recent Asian tsunami, as mosquito-breeding patterns may have been altered. Effective surveillance systems and rapid communication among networks are crucial to detect and intervene in cases of malaria in areas previously deemed nonmalarious.