[Malaria in the central highlands of Madagascar: control strategies]. / Paludisme sur les hautes terres centrales de Madagascar: stratégies de lutte.

The purpose of this article is to present data on malaria in the central highland plateaux of Madagascar and strategies to improve the national malaria control program. Use of rapid diagnosis strips, early home-based fever management with pre-packaged chloroquine treatment kits and proposed new therapeutic combination based on artemisinine are discussed for management of patients with high suspicion of malaria attack. Preventive measures including alternated targeted and full-house indoor spraying for vector control, use of insecticide-impregnated bednets, implementation of intermittent preventive treatment in risk groups, optimization of the epidemic early detection and warning system using the Lot Quality Assurance Sampling method for epidemiological investigation if the alert threshold is exceeded, and provision of rapid diagnosis strips are presented.

Paludisme sur les Hautes Terres Centrales de Madagascar : strategies de lutte

Le present article presente le paludisme sur les Hautes Terres Centrales de Madagascar et les strategies pour ameliorer les composantes du programme national de lutte contre le paludisme. Pour la prise en charge du patient suspect d'acces palustre; l'utilisation des bandelettes de diagnostic rapide; la prise en charge precoce a domicile par la chloroquine pre-emballee et les reflexions sur les nouvelles combinaisons therapeutiques a base d'artemisinine sont discutees. Pour les mesures de prevention; l'alternance des pulverisations intra domiciliaires ciblees et generalisees dans la lutte antivectorielle; l' utilisation de moustiquaires impregnees d'insecticides; le passage au traitement preventif intermittent pour les groupes a risque; l'amelioration du systeme de surveillance et d'alerte epidemique par l'utilisation de la methode de Lot Quality Assurance Sampling pour l'investigation epidemiologique en cas de depassement du seuil d'alerte et la mise a disposition des bandelettes de diagnostic rapide sont etudies

Impact of the malaria control campaign (1993-1998) in the highlands of Madagascar: parasitological and entomological data.

Malaria transmission in the central highlands of Madagascar was interrupted in the 1960s by a national control program that used DDT indoor spraying and mass treatment with chloroquine. At the end of the 1980s in this region, epidemic malaria reappeared. Italian health authorities provided technical assistance to the National Malaria Control Program since the beginning of the resurgence of malaria in the central highlands. Yearly residual house spraying performed for 5 years (1993-1998) and the availability of antimalarial drugs reduced malaria transmission to very low levels, with improvement in parasitologic and entomologic indexes. A significant reduction of malaria prevalence was observed in the villages located at altitudes of 1,000-1,500 m, corresponding to the stratum of unstable malaria that was the main target of the antivector interventions. A significant reduction of malaria prevalence was also observed in the villages located at altitudes of 900-1,000 m, where malaria transmission is stable. The main vector Anopheles funestus was dramatically reduced in abundance and distribution in the sprayed areas.

[Epidemiologic surveillance system and control of malaria in the central highlands of Madagascar: results 1999-2000]. / Système de surveillance épidémiologique et d'alerte du paludisme sur les Hautes Terres Centrales de Madagascar: résultats 1999-2000.

The central highlands in Madagascar are characterized by an unstable occurrence of malaria with the risk of sporadic outbreaks. In major parts of the region DDT indoor spraying campaigns have been carried out from 1993 to 1998. This strategy was in 1999 replaced by another anti-vector intervention program targeting residual foci as detected by a surveillance and early warning system. This system is based on monitoring of presumptive malaria cases in the communities by which the number of presumptive cases exceeded a defined warning threshold value per month. The system was in the follow-up period shown to be very sensitive to variation of the coverage of anti-vector interventions: the number of presumptive cases decreased in the villages in which indoor spraying had been carried out and a minor increase was observed in those villages, where indoor spraying has been suspended. An increase of malaria cases was observed in 44 (20.8%) out of 212 study sites in the same period. The increase was in particular predominant in areas at lower attitude at the outer zones of the central highlands.

[Drug resistance of Plasmodium falciparum along the borders of the highlands in Madagascar: outlook for a national control program]. / Chimioresistance de Plasmodium falciparum sur les marges des hautes terres malgaches: perspectives pour le programme national de lutte.

Resistance of Plasmodium falciparum to chloroquine was first suspected in Madagascar in 1975 and later confirmed in vivo and in vitro. During the period from 1985 and 1990, the network of public health monitoring stations reported that 1% of the population living on the central Highlands of Madagascar died of malaria. Thereafter the National Malaria Control Program achieved good success by spraying homes with insecticide and reorganizing distribution of chloroquine in all villages. However data recorded between 1996 and 1998 indicates that, after four years of widespread chloroquine use, resistance to amino-4-quinolones is progressing in Madagascar. The tests described in this report were performed on patients with documented malaria included in cohorts and followed year round by a physician. The three villages studied were located along the borders of the highlands between the plateaus and coastal areas. In vivo tests showed that the incidence of chloroquine resistance was 0% in Mahakary, 32% in Ankazobe and 30% in Saharivo. Clinically, however, treatment was unsuccessful in only 16% and 8% of cases respectively. In vitro tests demonstrated chloroquine sensitivity in 79% of the 153 strains tested. No resistance to quinine or halofantrine was observed. In vitro tests indicated an onset of resistance to mefloquine. Although the success rate of chloroquine treatment is nearly 80%, spread of strongly chloroquine-resistant strains is a risk especially in subjects with mild immunity to malaria.