Impact of HIV infection on severity of imported malaria is restricted to patients with CD4 cell counts < 350 cells/microl.

OBJECTIVES: To study the relative impact of HIV-1 infection and associated immunodepression on the severity of Plasmodium falciparum malaria in adults returning from areas of endemic malaria.
METHODS: We conducted a cross-sectional study, based on data from 104 HIV-infected patients from the French Hospital Database on HIV cohort (FHDH-ANRS CO4) and 161 HIV-negative patients from Bichat hospital, with a diagnosis of imported P. falciparum malaria between 2000 and 2003. The severity of falciparum malaria episode was graded with World Health Organization (WHO) criteria 2000 or on 2007 French recommendations. RESULT: Depending on criteria used, 40% (WHO) and 28% (2007 French recommendations) of episodes of imported P. falciparum malaria in HIV-infected patients were classified as severe, compared with 21% (WHO) and 11% (2007 French recommendations) of episodes among HIV-negative patients. Among HIV-infected patients, the episodes were severe in between 22 (CD4 cell counts > or =350/microl) and 51% (CD4 cell counts <350/microl) of cases using WHO criteria, and between 12 (CD4 cell counts > or =350/microl) and 41% (CD4 cell counts <350/microl) of cases using 2007 French recommendations criteria. Relative to HIV-negative patients, after adjusting for confounding factors, HIV-infected patients with severe immunodepression (CD4 cell counts <350/microl) were at a significantly higher risk of severe malaria than HIV-negative patients (odds ratio 3.2-4.7, depending on the criteria) contrary to HIV-infected patients with CD4 cell counts more than 350/microl (odds ratio 0.7-0.9).
CONCLUSION: The association between HIV infection and severity of imported P. falciparum malaria is only observed for HIV-infected patients with severe immunodepression (CD4 cell counts <350/microl).