Building the capacity of West African countries in Aedes surveillance: inaugural meeting of the West African Aedes Surveillance Network (WAASuN)

Abstract

Arboviral diseases such as dengue, Zika and chikungunya transmitted by Aedes mosquitoes have been reported in 34 African countries. Available data indicate that in recent years there have been dengue and chikungunya outbreaks in the West Africa subregion, in countries including Côte d’Ivoire, Burkina Faso, Gabon, Senegal, and Benin. These viral diseases are causing an increased public health burden, which impedes poverty reduction and sustainable development. Aedes surveillance and control capacity, which are key to reducing the prevalence of arboviral infections, need to be strengthened in West Africa, to provide information essential for the formulation of effective vector control strategies and the prediction of arboviral disease outbreaks. In line with these objectives, the West African Aedes Surveillance Network (WAASuN) was created in 2017 at a meeting held in Sierra Leone comprising African scientists working on Aedes mosquitoes. This manuscript describes the proceedings and discusses key highlights of the meeting. Graphical Abstract

Potential climate change effects on the distribution of urban and sylvatic dengue and yellow fever vectors

“…However, the current entomological capacity in Africa is primarily focused on malaria vectors, and most countries lack routine surveillance programmes, trained personnel and control activities focusing on Aedes and the viruses they transmit 38 . As outbreaks of Aedes -borne arboviruses continue to increase in Africa, it would be critical to establish a solid public health entomology infrastructure for Aedes mosquitoes to contain and prevent further outbreaks 39 .…”

Strengthening adult mosquito surveillance in Africa for disease control: learning from the present

“…This lack of capacity and capabilities is especially evident at subnational level [22] . These challenges are further intensified for other mosquito-borne disease surveillance [23] . It is evident that strengthening malaria vector surveillance directly contributes to other mosquito monitoring efforts and conversely weakened malaria vector surveillance results in weak or nonexistent surveillance of other vector-borne diseases.…”

“…Mosquito surveillance is well-established for malaria yet limited for other mosquito-borne diseases such as arboviral diseases, while their outbreaks are becoming more common 6 , 13•• , 36 , 37 . Yellow fever vector surveillance in Ghana is limited to cross-sectional studies due to ad hoc funding, but processing Aedes collected during malaria surveillance, as suggested by the West African Aedes Surveillance Network [23] , permits arbovirus surveillance to benefit from existing infrastructure. Only very few countries, such as Côte d’Ivoire and Cabo Verde, have arboviral vector surveillance systems in place 38 , 39 , which are both threatened by funding limitations.…”

“…They are largely unreliable outdoors, lack sensitivity to detect small changes, and do not collect information on vector behavior targeted by new tools such as the Attractive Targeted Sugar Baits and new bioactive agents (e.g. fungi or endosymbionts) 23• , 27 , 43 , 44• . We advocate for the development of novel mosquito collection tools that are sensitive, specific, and cost-effective [44] .…”

Biology and Behaviour of Aedes aegypti in the Human Environment: Opportunities for Vector Control of Arbovirus Transmission

“…Aedes aegypti formosus is not extensively discussed in this review, because its epidemiological role in sub-Saharan Africa is not well characterised, although the vector competence for several of its populations has been shown ([ 14 ] and references therein). Ecological studies on this subspecies in Africa lag behind the rest of the world [ 11 ] and are urgently needed if we want to reveal its role in the epidemiology of the frequent, potentially devastating, and often neglected epidemics of arboviral diseases in the African continent [ 15 , 16 ].…”