The assessment of infectivity rate of L3 larva of Wuchereria bancrofti in six urban areas of two states in Nigeria

• To assess the infectivity rate of L3 larva of W. bancrofti within Anopheles, Culex, Aedes and Mansonia mosquitos collected in two urban states
• To determine the bio-ecological parameters of potential LF vectors in in two urban states

Urban lymphatic filariasis (LF) has been recognised as a key challenge to the ongoing global elimination efforts and decisions whether to scale-up treatment to include urban areas has remained an on-going debate. Determining transmission is more complex in urban settings, since the usual circulating filarial antigens (CFA) detected in humans may reflect imported and/or long standing infections rather than current localised transmission. Furthermore mass drug administration (MDA) in urban environments is expensive with achieving high coverage more challenging compared to rural settings.

Two cities in Nigeria had been determined by LGA level survey to require treatment. Before beginning MDA, it was necessary to determine if transmission was occurring locally within the urban area or if they had simply been subsumed in the treatment decision of the surrounding rural and peri-urban areas.

This study set out to determine the transmission potential using mosquitos as an alternative to testing humans. Since mosquitos have a short life span and a limited flight range, detection of infective stages of larva in them is indicative of localised and current transmission.

• Read the blog: Catching the mosquitoes that spread lymphatic filariasis
• Read the journal article: Informing lymphatic filariasis treatment strategy in urban settings