Culex pipiens, an experimental efficient vector of West Nile and Rift Valley fever viruses in the Maghreb region.

West Nile fever (WNF) and Rift Valley fever (RVF) are emerging diseases causing epidemics outside their natural range of distribution. West Nile virus (WNV) circulates widely and harmlessly in the old world among birds as amplifying hosts, and horses and humans as accidental dead-end hosts. Rift Valley fever virus (RVFV) re-emerges periodically in Africa causing massive outbreaks. In the Maghreb, eco-climatic and entomologic conditions are favourable for WNV and RVFV emergence. Both viruses are transmitted by mosquitoes belonging to the Culex pipiens complex. We evaluated the ability of different populations of Cx. pipiens from North Africa to transmit WNV and the avirulent RVFV Clone 13 strain. Mosquitoes collected in Algeria, Morocco, and Tunisia during the summer 2010 were experimentally infected with WNV and RVFV Clone 13 strain at titers of 10(7.8) and 10(8.5) plaque forming units/mL, respectively. Disseminated infection and transmission rates were estimated 14-21 days following the exposure to the infectious blood-meal. We show that 14 days after exposure to WNV, all mosquito st developed a high disseminated infection and were able to excrete infectious saliva. However, only 69.2% of mosquito strains developed a disseminated infection with RVFV Clone 13 strain, and among them, 77.8% were able to deliver virus through saliva. Thus, Cx. pipiens from the Maghreb are efficient experimental vectors to transmit WNV and to a lesser extent, RVFV Clone 13 strain. The epidemiologic importance of our findings should be considered in the light of other parameters related to mosquito ecology and biology.

DNA barcodes confirm the presence of a single member of the Anopheles maculipennis group in Morocco and Algeria: An. sicaulti is conspecific with An. labranchiae.

Anopheles labranchiae Falleroni is the only member of the Maculipennis Group known to occur in northern Africa; however, confusion exists as to the taxonomic status of its junior synonym, An. sicaulti Roubaud (type locality: near Rabat, Morocco). Based on morphological and behavioural distinctions, it has been suggested that Moroccan populations have been isolated from other North African populations by the Atlas Mountains, and that Moroccan populations may represent An. sicaulti, originally described as a variety of An. maculipennis Meigen. DNA barcodes (658bp of the mitochondrial COI gene) obtained from 89 An. maculipennis s.l. collected in Morocco (n=79) and Algeria (n=10) in 2007 and 2008 were used to determine if Moroccan populations are genetically isolated from those east of the Atlas Mountains (Algeria), and whether there is molecular evidence to support the presence of more than one member of the Maculipennis Group in the region. No evidence for speciation was found between Moroccan and Algerian populations, or within populations in northern Morocco. Moreover shared COI haplotypes between Algeria and Morocco indicate ongoing gene flow between populations in these countries, suggesting that the Atlas Mountains are not a boundary to gene flow in An. labranchiae. The synonymy of An. sicaulti with An. labranchiae is confirmed. That An. labranchiae comprises the same species in these North African countries is important for malaria control.

Description of a dermatropic Leishmania close to L. killicki (Rioux, Lanotte & Pratlong 1986) in Algeria.

Cutaneous leishmaniasis (CL) is endemic in Algeria where two forms have been previously described, the sporadic form caused by Leishmania infantum in the north and the cutaneous form caused by L. major in central and southern parts of the country. During 2005, a CL outbreak occurred in the province of Ghardaïa, located in the north of Sahara, where 2040 cases were recorded, of which several were from urban areas. Six strains isolated from patients with active lesions were identified by isoenzyme electrophoresis and by molecular typing using systematic sequencing of a large subunit of the RNA polymerase. Four of the strains belonged to a new zymodeme, MON-301, close to L. killicki MON-8. The two other isolates were identified as L. major zymodeme MON-25. The new dermatropic Leishmania close to L. killicki is reported for the first time in Algeria and coexists sympatrically with L. major MON-25 in the region of Ghardaïa where they occur in their usual vectors of Phlebotomus papatasi (L. major) and P. sergenti (L. tropica). This new parasite demonstrates the need for further investigations to elucidate the life cycle and transmission of the emergent disease and to evaluate its phylogenetic position in the taxonomy of Leishmania.