Malaria and HIV infections are both of great public health importance in tropical countries. James Kublin and his colleagues have found that acute malaria episodes are associated with transient increases of HIV-1 viral load in the blood, and they speculate that malaria episodes might accelerate HIV-1 disease progression and facilitate transmission.
Evidence is now emerging of the deleterious effects of HIV-1 infection on malaria. In pregnant women HIV-1 is associated with more peripheral and placental malaria, higher parasite densities, more fever, and increased risks of adverse birth outcomes. Researchers had previously worked on seven fold higher HIV-1 viral loads in adults with acute malaria compared with those without, and that this increase resolved over a few weeks after anti-malarial treatment.
35% of the study participants showed an increase in viral load tended to be greater with more severe episodes of malaria infection. Viral load is an important determinant of HIV-1 disease progression, but the average viral load increases reported in the study. Also, most of the increases were temporary, lasting less than 10 weeks, a short time in the context of an average disease course of 8-10 years.
There is evidence that many opportunistic infections are associated with immune activation and higher viral loads. HIV-1 transmission is reported to double for each log rise in viral load. Therefore the effects reported by the researchers might equate with about a 50% increase in transmission during the short period of higher viral load in blood.
Antiretroviral therapy and Co-trimoxazole prophylaxis, both of which might affect the attack rate and severity of malaria. Analyses of existing cohort studies of HIV in malaria prevalent areas would also yield useful information. Given the number of cases of HIV and malaria, even small increases in relative risks of HIV transmission and progression are important. The researcher's findings are challenging and highlight the need for better integration of health services for HIV and malaria.