[A social program for the control of zoonotic cutaneous leishmaniasis in M'Sila, Algeria]. / Un programme social pour la lutte physique contre la leishmaniose cutanée zoonotique dans la wilaya de M'Sila en Algérie.

Zoonotic cutaneous leishmaniasis due to Leishmania major is a serious public health problem in Algeria. On average, 10,000 new cases are reported every year among the 15 million people at risk of infection. With an annual incidence of 561.8 per 100,000 inhabitants, M'Sila has seen the worst outbreak of the disease in Algeria since the historic outbreak in Biskra. The main reservoir of the disease is Psammomys obesus, a gerbil that feeds exclusively on Chenopodiaceae, a salt-tolerant plant under which it makes its burrow. Removing these plants around houses within a radius of 300 meters is one of the most effective control measures. As part of a social program of public works, a pilot project aimed at controlling the disease was undertaken in 2003 in the five worst affected cities in M'Sila. 396 unemployed young people were recruited to remove the plants before the transmission season. Over 3,600 hectares were treated. The number of cases decreased from 1,391 in 2003 to 965 in 2004 (31% reduction). These measures need to be implemented in all endemic areas of the country to better assess their effectiveness in preventing the disease.

Ecological differentiation of members of the Culex pipiens complex, potential vectors of West Nile virus and Rift Valley fever virus in Algeria.

BACKGROUND: We investigated the ecological differentiation of two members of the Culex pipiens complex, Cx. p. pipiens form pipiens and Cx. p. pipiens form molestus in three sites, El-Kala, M'Sila and Tinerkouk in Algeria. These two forms are the most widespread mosquito vectors in temperate regions exhibiting important behavioural and physiological differences. Nevertheless, this group of potential vectors has been poorly studied, particularly in North Africa. METHODS: Ten larval populations of Cx. p. pipiens were sampled from various above- and underground habitats in three zones representing the three bioclimatic regions in Algeria. The reproduction characteristics were also investigated in the laboratory to define the rates of autogeny and stenogamy. Identification of Cx. p. pipiens members present in Algeria was achieved using a molecular analysis with the microsatellite CQ11 locus. RESULTS: We detected larvae of Cx. p. pipiens in all areas suggesting that the species is a ubiquitous mosquito well adapted to various environments. To our knowledge, this study provides the first molecular evidence of the presence of the Cx. p. pipiens form molestus and hybrids (molestus/pipiens) in Algeria with a high proportion of molestus form (48.3 %) in comparison with hybrids (36.8 %) and pipiens form (14.9 %). CONCLUSIONS: Some unexpected correlations between the proportion of forms pipiens, molestus and hybrids, and mosquito biological characteristics were observed suggesting some epigenetic effects controlling Cx. p. pipiens mating and reproduction. Consequences for pathogen transmission are discussed.