AIDS Drug Very Effective for Malaria

Researchers have found that the drug combination trimethoprim-sulfamethoxazole (TS) that is used to protect HIV/AIDS patients from pneumonia and opportunistic bacterial infections is highly effective against falciparum malaria without selecting for a parasite population resistant to the anti-malarial drug sulfadoxine-pyrimethamine (SP).

While TS is the drug of choice in the developed world, the fear that TS might engender the spread of SP-resistant malaria has prevented widespread usage in Africa. To determine the validity of this concern, investigators at the University of Maryland (Baltimore, USA) conducted a study in an area of Mali that is endemic for malaria but has a low incidence of HIV infection in children.

A group of 160 children were given prophylactic doses of TS while a second group of 80 children received no medication. Any children who contracted malaria were then treated with SP.

Results published in the October 13, 2005, online edition of the Journal of Infectious Diseases revealed that TS was a potent anti-malarial agent with 99.5% protective efficacy against episodes of clinical malaria and 97% efficacy against infection. All eight children from this group that contracted malaria were successfully treated with SP. In the control group, there were 72 episodes of malaria and three instances of SP failure.

The findings showed that TS was effective in preventing malaria while not selecting for an SP-resistant population. The investigators concluded that, "Based on the results of this study and the clear evidence that TS prevents death in persons living with HIV in a variety of African settings, concerns about spreading SP resistance do not justify further delays in implementing TS prophylaxis.”