Abundance and Updated Distribution of Aedes aegypti (Diptera: Culicidae) in Cabo Verde Archipelago: A Neglected Threat to Public Health

Abstract

Background: Mosquito-borne viruses, such as Zika, dengue, yellow fever, and chikungunya, are important causes of human diseases nearly worldwide. The greatest health risk for arboviral disease outbreaks is the presence of the most competent and highly invasive domestic mosquito, Aedes aegypti. In Cabo Verde, two recent arbovirus outbreaks were reported, a dengue outbreak in 2009, followed by a Zika outbreak in 2015. This study is the first entomological survey for Ae. aegypti that includes all islands of Cabo Verde archipelago, in which we aim to evaluate the actual risk of vector-borne arboviruses as a continuous update of the geographical distribution of this species. Methods: In order to assess its current distribution and abundance, we undertook a mosquito larval survey in the nine inhabited islands of Cabo Verde from November 2018 to May 2019. Entomological larval survey indices were calculated, and the abundance analyzed. We collected and identified 4045 Ae. aegypti mosquitoes from 264 positive breeding sites in 22 municipalities and confirmed the presence of Ae. aegypti in every inhabited island. Results: Water drums were found to be the most prevalent containers (n = 3843; 62.9%), but puddles (n = 27; 0.4%) were the most productive habitats found. The overall average of the House, Container, and Breteau larval indices were 8.4%, 4.4%, and 10.9, respectively. However, 15 out of the 22 municipalities showed that the Breteau Index was above the epidemic risk threshold. Conclusion: These results suggest that if no vector control measures are considered to be in place, the risk of new arboviral outbreaks in Cabo Verde is high. The vector control strategy adopted must include measures of public health directed to domestic water storage and management.

Spatiotemporal distribution and insecticide resistance status of Aedes aegypti in Ghana

“…The high number of Ae . aegypti caught from a geographically wide range of sites in different ecological zones may be explained by the behaviour of this species, which is highly anthropophilic and associated with human habitations, as reported by many studies undertaken in Central Africa and West Africa [ 64 , 68 , 70 ]. The high abundance of Ae .…”

Update on the mosquito fauna (Diptera: Culicidae) distribution in Cabo Verde: occurrence of the species complexes Anopheles gambiae and Culex pipiens (pipiens, quinquefasciatus and their hybrids)

“…In this survey, Ae. aegypti was reported in all the municipalities, and at municipality of Maio for the first time [29].…”

A systematic review of published literature on mosquito control action thresholds across the world

“…Thirty studies (69.8% [30/43]) relied exclusively on external data sources [20, 22- [18,19,[21][22][23]26,28,31,43,44 (GT); 50,58 (GM)]. The majority of MTs originated before 2010 (52.3% [23/44]) [61][62][63][64][65][67][68][69]71,75,76,79,81,82,84,87,88,89,[91][92][93]95,100,104] while the time of origination was not clear in other MTs.…”

“…Eight inclusions (18.2% [8/44]) [66,78,86,90,96,[100][101][102] mentioned thresholds that originated from the same program. One inclusion (2.3% [1/44]) [75] mentioned a threshold with a different country origin while four inclusions (9% [4/44]) [69,88,92,94] mentioned thresholds from different continental regions. Only one inclusion (2.3% [1/44]) [81] mentioned different thresholds either with the same country origin or different country origin and one inclusion (2.3% [1/44]) [98] did not cite a cross-reference or mention the origin of the mentioned threshold.…”