[Sensitivity of Plasmodium falciparum to quinolines and therapeutic strategies: comparison of the situation in Africa and Madagascar between 1983 and 1986]. / Sensibilité de Plasmodium falciparum aux quinoléines et stratégies thérapeutiques: comparaison de la situation en Afrique et à Madagascar entre 1983 et 1986.

One thousand and twenty six P. falciparum strains isolated from cases imported in France and field surveys in four regions of Africa and Madagascar were studied in vitro against chloroquine, monodesethylamodiaquine, quinine and mefloquine, 917 in vivo tests were performed during field studies with chloroquine (10 and 25 mg/kg) and amodiaquine (10, 25, 35 mg/kg). In Madagascar, the chemoresistance remained low and stable during the study period, concerning mostly chloroquine (11% in vitro and in vivo) without obvious geographical variation. 25 mg/kg chloroquine or amodiaquine were satisfactory as respectively first and second line therapeutic regimen. In Central Africa, chemoresistance emerged with an epidemic profile and increased dramatically in disseminated urban focus. High level and prevalence of chloroquine resistance and multiresistance were observed few months after the index cases in these foci. In South West Cameroon, amodiaquine remained efficient as curative treatment but only at a dose of 35 mg/kg/5 days. Decrease of in vitro sensitivity and in vivo efficacy of quinine is a matter of concern. Given the heterogeneous and evolutive situation of drug resistance, the need for epidemiological surveillance and monitoring of P. falciparum drug sensitivity in Africa is obvious to adjust therapeutic regimen.

Seroepidemiology of hepatitis B in a population of children in central Tunisia.

The prevalence rate of HBV markers in the overall population was 18.0%. The prevalence rates of HBsAg and anti-HBs were 3.3% and 12.2% respectively. 2.5% of the children were negative for these markers but positive for anti-HBc alone. Of the 17 HBsAg positive children, 10 were HBeAg positive and four were anti-HBe positive. The statistical study using multifactorial correspondence analysis and the chi 2 test showed a positive relationship between the prevalence rate of anti-HBs and age, and a negative relationship between the prevalence rate of 'absence of markers' and age. The male sex and urban dwelling were related to higher prevalence rates of HBsAg and anti-HBc alone and to a lower prevalence rate of 'absence of markers'. No relationship was found between geographical zone, father's education and HBV markers. The implications of these results in terms of prevention are discussed.

[In vivo and in vitro sensitivity to 4-aminoquinolines of Plasmodium falciparum in Madagascar: results of 2 years' study]. / Sensibilité in vivo et in vitro aux amino-4-quinoléines de Plasmodium falciparum a Madagascar: résultats de deux années d'étude.

563 cases of Falciparum malaria were detected in 1984 and 1985 in 7 malarial zones covering 3 climatic regions in Madagascar. All subjects underwent a therapeutic test; 175 strains of Plasmodium falciparum were isolated for in vitro drug sensitivity studies. 28 strains which were moderately chloroquine resistant in vitro were identified in 1983 in these various zones. However, 16% strains studied in 1984 in Alatsinainy (plateaux area), were chloroquine-resistant in vitro. The in vitro sensitivity to the other amino-4-quinolines seemed to be retained. In vivo, 7% of resistance type RI or RII were noted with 25 mg/kg of chloroquine but none with 25 mg/kg of amodiaquine. The usual therapeutic schedule for partially immune subjects (10 mg/kg in one dose) was ineffective on day 7 in 34% of the cases with chloroquine and 5% of the cases with amodiaquine. In conclusion to this study, we recommend that chemoprophylaxis should be stopped in schools in Madagascar and that presumed malarial attacks should be treated with a minimum dose of 25 mg/kg of chloroquine in 3 days. We suggest that amodiaquine should be used in cases of therapeutic failure with chloroquine.