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.

Introduction: The transmission of pathogens by blood-sucking insects to humans and other animals depends on vector-host interactions. As yet unexplored in Cape Verde, mosquito feeding behavior plays a crucial role in pathogen transmission. Herein, we aim to explore, through blood meal analysis, the relationship between mosquito species and common hosts in Santiago Island, Cape Verde.Methods: Engorged female mosquitoes were collected through mechanical aspiration from May 2016 to December 2017 in three municipalities of Santiago Island (Praia, Santa Cruz, and Santa Catarina). Blood-feeding behavior in each municipality was assessed through blood meal analysis using an enzyme-linked immunosorbent assay (ELISA).Results: We were able to determine that single-host blood meals were common in Aedes aegypti, Anopheles arabiensis, and Culex pipiens sensu lato (s.l.). In general, the mosquitoes preferred to feed on humans, dogs, and chickens, and on multiple hosts, mainly two hosts. The human blood index (HBI) was highest (i.e., 1.00) in Ae. aegypti, with the lowest value (0.40) observed in An. arabiensis. It was observed that, among single-host blood meals, the likelihood of Cx. pipiens s.l. feeding on humans was significantly high, whereas the likelihood of An. arabiensis feeding on humans was significantly low (log-odds ratio (LOR) = 0.85 and –2.44, respectively). In addition, a high likelihood of Ae. aegypti feeding on humans was observed, but this was not statistically significant (LOR = 0.85).Discussion: Overall, our findings demonstrate a lack of feeding preference in Culex pipiens s.l. compared with Ae. aegypti and An. arabiensis. These results provide insights into possible parasite transmission and pathogen spillover/spillback, which threaten human/animal health and the economy in Cape Verde.

Mosquitoes play a critical role as vectors of pathogens affecting both humans and animals. Therefore, understanding their biodiversity and distribution is crucial to developing evidence-based vector control strategies. The current study updated the composition and distribution of mosquito species through a comprehensive survey of all municipalities of Cabo Verde. From October 2017 to September 2018, mosquito larvae and pupae were collected from 814 aquatic habitats. Anopheles gambiae (Giles, 1902) and Culex pipiens (Linnaeus, 1758) complexes were subjected to PCR-based techniques for sibling species identification. Ten mosquito species from 5 genera were identified: Aedes aegypti (Linnaeus, 1762), Aedes caspius (Pallas, 1771), Anopheles arabiensis (Patton, 1905), Anopheles pretoriensis (Theobald, 1903), Culex bitaeniorhynchus (Giles, 1901), Cx. pipiens, Culex quinquefasciatus (Say, 1823), Culex tritaeniorhynchus (Giles, 1901), Culiseta longiareolata (Macquart, 1838), and Lutzia tigripes (de Grandpre & de Charmoy, 1901). Santiago Island reported the highest number of species (n = 8). Ae. aegypti and Cx. quinquefasciatus were the most widely distributed species across the country. An. arabiensis was the sole species identified within the An. gambiae complex. The findings from our study will help guide health policy decisions to effectively control mosquito-borne diseases.

Mosquito-borne diseases can pose significant burdens. In many countries, they pose a risk to national economies and the well-being of humans and animals. To mitigate this, mosquito surveillance is crucial to assess the real and potential transmission of mosquito-borne diseases. Between 2020 and 2023, mosquito larvae were collected from both indoor and outdoor breeding sites in urban and rural areas of 4 municipalities of Santiago and Boavista Islands in Cabo Verde. Mosquitoes were identified morphologically and by polymerase chain reaction-based techniques that targeted the mitochondrial cytochrome C oxidase subunit I sequence. During this period, 6,825 breeding sites were assessed, and of 8,094 mosquito specimens screened, 194 specimens of Culex thalassius were identified for the first time in the country in 4 municipalities of Santiago and Boavista Islands. This new finding highlights the importance of including entomological surveillance in health systems. Although this species has only been detected on a few islands, it is important to continuously monitor it to determine its distribution, spread/dispersal, density, and potential involvement in pathogen transmission.

Arboviral outbreaks are rising across Africa, a region that continues to face a substantial malaria burden. Cabo Verde remains vulnerable to the emergence and re-emergence of mosquito-borne diseases, including dengue, Zika, and malaria. In January 2024, the World Health Organization certified the country as malaria-free; however, the risk of reintroduction persists. Maintaining malaria-free status requires continuous robust epidemiological and entomological surveillance to prevent local transmission. Innovative vector monitoring and control tools that deliver accurate infestation data are essential in this context. We evaluated the performance of the MTego trap against the BGS traps routinely used in Cabo Verde applying a 4x4 Latin square design with four configurations: 1) BGS with BG Lure; 2) BGS with BG Lure plus CO ₂ ; 3) MTego traps with Clay Balls plus PM6 odour bait; and 4) MTego traps with Clay Balls, PM6 bait plus CO ₂ . Sampling was conducted in Praia, before and after the 2023 rainy season. Trap effectiveness was assessed using negative binomial regression models. Across all configurations, 2,673 mosquitoes were collected. Mean nightly catches were highest for BGS traps baited with CO ₂ : 20.4 (95% CI: 15.4-25.4), and lowest for MTego traps: 13.7 (95% CI: 10.0-17.5). Comparative analysis showed that MTego traps outperformed BGS traps in capturing Anopheles arabiensis , with CO ₂ -supplemented MTego trap being the most effective configuration. BGS traps performed best for Aedes aegypti and Culex pipiens sensu lato. Species-specific behavioural patterns were observed, with higher nigh-time catches of Cx pipiens s.l. and An. arabiensis , alongside differences in gonotrophic state. This study highlights the superior performance of MTego traps for malaria surveillance in Cabo Verde.