Insecticide susceptibility status of Anopheles gambiae (s.l.) in South-West Cameroon four years after long-lasting insecticidal net mass distribution oleh Stravensky Térence Boussougou-Sambe, Wolfgang Ekoko Eyisap, Geraud Canis Taboue Tasse, Stanislas Elysee Mandeng, Lili Ranaise Mbakop, Peter Enyong, Josiane Etang, Eric Bertrand Fokam, Parfait H. Awono-Ambene