Research
The impact of HIV-1 on the malaria parasite biomass in adults in sub-Saharan Africa contributes to the emergence of antimalarial drug resistance
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* Corresponding author: Jean-Pierre Van geertruyden jpvangeertruyden@itg.be
1 Department of Parasitology, Unit of Epidemiology Institute of Tropical Medicine Antwerpen, Nationalestraat 155 B2000, Antwerpen, Belgium
2 Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, B-2000, Antwerp, Belgium
3 Department of Clinical sciences, Institute of Tropical Medicine and University of Antwerp, Antwerp, Belgium
4 Department of Public Health, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
5 Performance Evaluation and Policy unit, The Global Fund to Fight AIDS, Tuberculosis and Malaria, Geneva, Switzerland
Malaria Journal 2008, 7:134 doi:10.1186/1475-2875-7-134
Published: 22 July 2008Abstract
Background
HIV-related immune-suppression increases the risk of malaria (infection, disease and treatment failure) and probably the circulating parasite biomass, favoring the emergence of drug resistance parasites.
Methods
The additional malaria parasite biomass related to HIV-1 co-infection in sub-Saharan Africa was estimated by a mathematical model. Parasite biomass was computed as the incidence rate of clinical malaria episodes multiplied by the number of parasites circulating in the peripheral blood of patients at the time symptoms appear. A mathematical model estimated the influence of HIV-1 infection on parasite density in clinical malaria by country and by age group, malaria transmission intensity and urban/rural area. In a multivariate sensitivity analysis, 95% confidence intervals (CIs) were calculated using the Monte Carlo simulation.
Results
The model shows that in 2005 HIV-1 increased the overall malaria parasite biomass by 18.0% (95%CI: 11.6–26.9). The largest relative increase (134.9–243.9%) was found in southern Africa where HIV-1 prevalence is the highest and malaria transmission unstable. The largest absolute increase was found in Zambia, Malawi, the Central African Republic and Mozambique, where both malaria and HIV are highly endemic. A univariate sensitivity analysis shows that estimates are sensitive to the magnitude of the impact of HIV-1 infection on the malaria incidence rates and associated parasite densities.
Conclusion
The HIV-1 epidemic by increasing the malaria parasite biomass in sub-Saharan Africa may also increase the emergence of antimalarial drug resistance, potentially affecting the health of the whole population in countries endemic for both HIV-1 and malaria.