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En Algerie, la leishmaniose cutanee zoonotique a Leishmania major constitue un lourd fardeau pour la sante publique. On denombre en moyenne 10 000 nouveaux cas parmi les 15 millions de personnes exposees vivant en zone d’endemie. Le foyer de M’Sila, avec une incidence annuelle de 561,8 pour 100 000 habitants, est le plus important en Algerie apres le foyer historique de Biskra. Le reservoir principal de la maladie est Psamommys obesus, rongeur gerbillide, qui se nourrit exclusivement de plantes salees, les chenopodiacees, sous lesquelles ce dernier construit son terrier. Un des moyens de lutte contre la leishmaniose dans les regions sahariennes et pre-sahariennes, celui que l’etude atteste, est d’eliminer ces plantes autour des habitations sur un rayon de 300 metres. Dans le cadre d’un programme social de travaux d’utilite publique employant 396 jeunes chomeurs, cette experience pilote a ete menee en 2003 dans cinq communes les plus touchees dans la wilaya de M’Sila. 3 600 hectares ont ete traites avant la saison de transmission de la maladie qui debute au mois de mai. Une reduction de 31 % du nombre de cas de leishmaniose cutanee a ete notee, passant de 1 391 cas en 2003 contre 965 cas en 2004. Cette experience merite d’etre elargie a l’ensemble du territoire, pour mieux evaluer l’impact de cette methode de lutte dans la prevention de la maladie.

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. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1725-9) contains supplementary material, which is available to authorized users.

Major plant groups found around the breeding sites of Culex pipiens (s.l.) (DOCX 15 kb)

Relation between BOC5 (Biological oxygen consumption) and mean density of Culex pipiens (s.l.) larvae. (DOCX 22 kb)

PCR amplification of the flanking region of the CQ11 microsatellite of Culex pipiens collected in an aboveground rural site in Mâ Sila (Algeria). One leg was used as DNA source directly in the mix. PCR products were run on a 2% agarose gel and individuals were scored according to the band size. (DOCX 146 kb)

Since a long time, Leishmania major and L. infantum foci in Algeria were geographically separated by the mountains of the Tell Atlas which represent a natural barrier. Recently, a new focus of cutaneous leishmaniasis (CL) has emerged in the village of El M’hir, located on the north side of the chain of the Tell Atlas, in the basin of the Soummam. During the period 2004–2010, 152 CL cases have been registered and 12 isolates were obtained from patients who declared never having been outside the village the last years. The identification of the parasites showed that all strains belonged to L major MON-25. Investigations on the reservoir hosts showed the presence of the sand rat (Psammomys obesus), for the first time, in this locality. Five strains isolated from this rodent belonged to L. major MON-25. The sand rat, which is usually observed around the chotts in the Saharan and steppe areas, acts as the main reservoir of L. major in Algeria. Its presence in the new focus of El M’hir is reported for the first time. Entomological surveys carried out in 2009 showed the predominance of two sandfly species: Phlebotomus papatasi and P. perniciosus. The first one is known as a vector of L major in the Algerian Sahara. This study highlights the spread of L. major from the arid zones towards the semi arid areas, particularly in the Soummam valley. Climate changes and desertification observed in the steppe area northern Sahara could play a role in the extension of the disease.

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.

International audience; Since 2005, an outbreak of human cutaneous leishmaniasis (CL) in Ghardaïa, south Algeria, was studied and one output of these investigations was the identification of two Leishmania species, Leishmania major and Leishmania killicki, as the CL causative agents. In the present study, we were curious to focus on sand fly fauna present in this area and detection of Leishmania-positive sand fly females. Sand flies (3717) were collected during two seasons using sticky papers and CDC light traps in urban, rural and sylvatic sites. Twelve Phlebotomus species were identified. Phlebotomus papatasi was dominant in the urban site while Phlebotomus sergenti and Phlebotomus riouxi/chabaudi were dominant in the sylvatic site. Out of 74 P. sergenti females captured by CDC light traps in the sylvatic site populated by Ghardaïas' Gundi (Massoutiera mzabi), three ones were hosting Leishmania promastigotes. PCR-RFLP and sequencing of seven single-copy coding DNA sequences identified the promastigotes as L. killicki. Furthermore, laboratory experiments revealed that L. killicki isolate sampled from a CL patient inhabiting the studied region develop well in P. sergenti females. Our findings strongly suggest that the human cutaneous leishmaniases caused by L. killicki is a zoonotic disease with P. sergenti sand flies acting as hosts and vectors and gundi rodents as reservoirs.