Do African immigrants living in France have long-term malarial immunity?

Among populations living in areas endemic for malaria, repeated parasite exposure leads to a gradual increase in protective immunity to the disease. In contrast, this immunity is assumed to disappear after several years of non-exposure. This study was designed to investigate long-term immunity in subjects removed from the risk of exposure. Plasmodium falciparum malaria attacks occurring after short trips to sub-Saharan Africa were compared between 99 European patients and 252 African immigrants who had been resident in Europe for at least four years. Relative to the European patients, those originating from Africa had lower mean +/- SD parasite densities (0.8 +/- 1.5/100 red blood cells versus 1.4 +/- 2.8/100 red blood cells; P = 0.007), less frequent severe disease (4.4% versus 15.2%; P = 0.0005), accelerated parasite clearance and defervescence, and higher levels of antibodies to P. falciparum. These results suggest the persistence of acquired immunity to P. falciparum malaria after several years of non-exposure in African immigrants.

Efficacy of antimalarial chemoprophylaxis among French residents travelling to Africa.

Controversy exists about which antimalarial chemoprophylaxis regimen should be used among travellers to Africa: the WHO and other experts recommend the use of mefloquine throughout sub-Saharan Africa, whereas French experts still support the combination of chloroquine and proguanil in most of West Africa (the so-called zone 2 countries). In this case-control study based at a travel clinic, we examined the compliance with antimalarial chemoprophylaxis and its efficacy among travellers to tropical areas. Cases were patients with Plasmodium falciparum malaria (n = 131). Controls were patients who had a negative malaria film (n = 158). Of all controls, only 36 (22.8%) were adequately protected (i.e. compliant with an adapted regimen of chemoprophylaxis). In zone 2 countries, the efficacy of the combined chloroquine and proguanil was 58% (95% CI 22-78%) for all users, but increased to 100% (95% CI 89-100%) for compliant users. In zone 3 countries, the efficacy of mefloquine was 90% (95% CI 51-98%) and 100% (95% CI 58-100%) for all users and compliant users, respectively.

Once-a-day highly active antiretroviral therapy in treatment-naive HIV-1-infected adults in Senegal.

OBJECTIVES: To study the effectiveness, adherence and tolerance of a once-a-day highly active antiretroviral therapy regimen in adults in Senegal. DESIGN AND METHODS: In a prospective, open-label one-arm study, 40 treatment-naive HIV-1-infected patients took the following three drugs once a day at bedtime: didanosine, lamivudine and efavirenz. The primary endpoint was the percentage of patients with plasma HIV-1 RNA below 500 copies/ml at 6 months. The analysis was done on an intent-to treat basis. RESULTS: Eighty-five per cent of patients were at Centers for Disease Control and Prevention stage B or C and the plasma HIV RNA level was 5.4 +/- 0.4 log(10) copies/ml at baseline. The percentage of patients with plasma HIV-1 RNA below 500 copies/ml at 6 months was 95% [95% confidence interval (CI), 83-99]. The proportions of patients with plasma HIV-1 RNA below 50 copies/ml at months 3, 6, 9, 12 and 15 were 26% (n = 39; 95% CI, 12-39), 78% (n = 40; 95% CI, 65-90), 70% (n = 40; 95% CI, 56-84), 77% (n = 39; 95% CI, 64-90) and 69% (n = 39; 95% CI, 55-84), respectively. The CD4 cell count was 164 +/- 75 x 106/l at baseline and increased by a mean of 199 +/- 101 x 106/l at month 15. Permanent treatment discontinuation was never necessary for serious adverse effects. Adherence was excellent, as shown by plasma drug concentrations and according to the results of the questionnaire. CONCLUSIONS: The once-daily regimen of didanosine, lamivudine and efavirenz was safe, easy-to-take and demonstrated strong antiretroviral and immunologic effects in African patients with advanced HIV infection.