Letter to the Editor
To the Editor:
Recently, Mouala et al1 reported 190 imported malaria episodes observed in 178 HIV-1-infected travelers seen in several hospitals in France. A low CD4 count was a risk factor for severe Plasmodium falciparum malaria. This is concordant with what was found in HIV-1-infected individuals with preexisting malaria immunity.2 These patients, probably on highly active antiretroviral therapy or noneligible for antiretroviral, had a relatively low median CD4 count of 299 CD4 counts per microliter that may have been partially caused by a temporary malaria-induced reallocation of specific T cells. Indeed, in HIV-1-infected individuals with preexisting malarial immunity and even in HIV-negative children, CD4 counts in uncomplicated or severe malaria may decrease by 50% to 100%, respectively.3,4 Possibly, such a phenomenon occurs in HIV-1-infected travelers.
In the report of Mouala et al,1 there was no HIV-negative travelers to compare, and it is still unclear whether the risk for malaria infection and the protection provided by malaria chemoprophylaxis is altered in HIV-1-infected travelers. One observational study reported lower and less severe malaria incidences in HIV-1-infected travelers compared with other travelers.5 These results were confounded by a higher proportion of semi-immune migrants in the study population and a better pretravel counseling resulting in a more consistent use of malaria prophylaxis in HIV-infected individuals. Malaria treatment is less efficacious in HIV-1-infected adults with preexisting malaria immunity6 and HIV-1 pregnant women need more malaria prophylaxis.7 In the study by Mouala et al,1 malaria chemoprophylaxis did not reduce the risk of severe malaria. Consequently, the protective effect of chemoprophylaxis against uncomplicated or severe malaria was similar in all HIV-1-infected individuals, regardless of their degree of immune suppression. Two factors might have confounded these results. First, some patients might have been under cotrimoxazole prophylaxis (CTX), an antibiotic with antimalarial properties. CTX reduces the number of malaria attacks by over 75% in HIV-1-infected individuals with preexisting malaria immunity.8 Second, some participants might have slept under a bed net, known to significantly reduce the malaria risk.9 Therefore, besides malaria chemoprophylaxis, CTX prophylaxis, insecticide-treated bed nets, and other means of personal protection should be assessed.
Insecticide-treated bed nets and other personal malaria protection methods, by reducing the risk of clinical attacks, reduce also the potential interactions between antimalaria drugs and antiretroviral treatment as patients already on highly active antiretroviral therapy might receive antimalarial prophylaxis and/or short (and repeated) courses of antimalarials. Various drug interactions between mefloquine (Lariam) and atovaquone-proguanil (Malarone) have been described in vitro. Although poorly studied, the risk of clinically significant interactions involving antimalarials (such as lumefantrine or amodiaquine) and antiretrovirals is considerable and may result in excessive toxicity (protease inhibitors, efavirenz) or else reduced efficacy (nevirapine and possibly efavirenz).10 Therefore, next to malaria chemoprophylaxis recommended by Mouala et al,1 insecticide-treated bed nets and other means of personal protection should also be strongly promoted.
Jean-Pierre Van geertruyden, MD, PhD*
Robert Colebunders, MD, PhD†
Umberto D'Alessandro, MD, PhD*
*Department of parasitologie, Institute of Tropical Medicine, Antwerp, Belgium
†Department of Clinical sciences, Institute of Tropical Medicine and University of Antwerp, Antwerp, Belgium
1. Mouala C, Houze S, Guiguet M, et al. Imported malaria in HIV-infected patients enrolled in the ANRS CO4 FHDH study. J Acquir Immune Defic Syndr
2. Whitworth J, Morgan D, Quigley M, et al. Effect of HIV-1 and increasing immunosuppression on malaria parasitaemia and clinical episodes in adults in rural Uganda: a cohort study. Lancet
3. Van geertruyden JP, Mulenga M, Kasongo W, et al. CD4 T-cell count and HIV-1 infection in adults with uncomplicated malaria. J Acquir Immune Defic Syndr
4. Chalwe V, Van geertruyden J-P, Mukwamataba D, et al. Increased risk for severe malaria in HIV-1-infected adults, Zambia. Emerg Infect Dis
5. Bottieau E, Florence E, Clerinx J, et al. Fever after a stay in the tropics: clinical spectrum and outcome in HIV-infected travelers and migrants. J Acquir Immune Defic Syndr
6. Van geertruyden JP, Mulenga M, Mwananyanda L, et al. HIV-1 immune suppression and antimalarial treatment outcome in Zambian adults with uncomplicated malaria. J Infect Dis
7. van Eijk AM, Ayisi JG, ter Kuile FO, et al. Effectiveness of intermittent preventive treatment with sulphadoxine-pyrimethamine for control of malaria in pregnancy in western Kenya: a hospital-based study. Trop Med Int Health
8. Mermin J, Ekwaru JP, Liechty CA, et al. Effect of co-trimoxazole prophylaxis, antiretroviral therapy, and insecticide-treated bednets on the frequency of malaria in HIV-1-infected adults in Uganda: a prospective cohort study. Lancet
9. Lengeler C. Insecticide-treated bed nets and curtains for preventing malaria. Cochrane Database Syst Rev
10. Brentlinger P, Behrens C, Micek M. Challenges in the concurrent management of malaria and HIV in pregnancy in sub-Saharan Africa. Lancet Infect Dis