First field evidence infection of Culex perexiguus by West Nile virus in Sahara Oasis of Algeria.

BACKGROUND & OBJECTIVES: West Nile virus (WNV) is considered one of the most widely distributed arboviruses in the world which is transmitted by several mosquito species including the Culex genus. Culex pipiens is the major vector of this virus in Europe and USA whereas in African countries, other species such as Cx. perexiguus is considered as an important vector. This paper aimed to study the mosquito species involved in WNV transmission in Aougrout, one of the highly populated Oasis of Timimoun Province in Algeria where human WNV neuroinvasive diseases are prevalent. METHODS: CDC light-traps were installed in animal and human shelters for three nights. Collected mosquitoes were pooled and real-time PCR was performed to detect and identify WNV lineages 1 and 2 in the samples. Results: CDC light-traps collected 270 mosquitoes belonging to three genera. Culex genus was predominant with Cx. perexiguus as main species followed by Aedes and Anopheles genus. A total of 33 pools were tested; one pool containing Cx. perexiguus was found positive for WNV lineage 1. INTERPRETATION & CONCLUSION: This study reports for the first time a WNV natural infection of Culex perexiguus in the study region indicating that species other than Cx. pipiens should be taken into consideration in WNV surveillance, especially in specific environments like Saharan Oasis ecosystem.

First report of Aedes (Stegomyia) albopictus (Diptera: Culicidae) in Oran, West of Algeria.

The increasing globalisation of trades, human movements and environmental changes facilitate the introduction and the establishment of the invasive Asian tiger mosquito Aedes albopictus outside its native geographical area. Alerted by the complaints about mosquito biting which occurred daytime for the inhabitants of the seaside town Ain Turk (West of Algeria), an entomological survey was conducted in December 2015 to determine the origin of this nuisance. Among the collected mosquitoes, specimens of Ae. albopictus (2 males, 3 females and 3 pupae) were collected. This is the first observation of that invasive mosquito in the west of Algeria which confirms its presence and establishment in Mediterranean Africa.

Entomological investigation following the resurgence of human visceral leishmaniasis in southern Algeria.

Visceral and cutaneous leishmaniasis are the main endemic vector born diseases in Algeria. In the Hoggar region (extreme south of the country) human visceral leishmaniasis (HVL) is known to be sporadic but during the last decade the number of cases has increased significantly. In 2010, a peak of HVL cases was registered mostly among children. Therefore an entomological survey and a retrospective study on HVL cases were carried out in order to explore the transmission of the disease. Among the sand fly caught Phlebotomus bergeroti was the most frequent species (68%) followed by Sergentomyia schwetzi (22%). In this work we describe the presence of Phlebotomus (Paraphlebotomus) kazeruni for the first time in the Hoggar region.

Phlebotomus sergenti (Parrot, 1917) identified as Leishmania killicki host in Ghardaïa, south Algeria.

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.