Challenging the notion of Aedes aegypti as the primary chikungunya virus vector: insights from Kédougou, Southeastern Senegal.

Background: Chikungunya fever (CHIK) caused by the mosquito-borne chikungunya virus (CHIKV) and transmitted by mosquitoes, remains a public health burden throughout the tropics. During the CHIK outbreak in southeastern Senegal in August 2023, an entomologic investigation was conducted to identify the vector(s) and characterize the virus strains.

Methods: Adult mosquitoes were collected indoors and outdoors from houses of confirmed CHIK cases and their immediate neighborhoods using Prokopack aspirators and double-net traps and all water containers were inspected for aquatic stages.

Challenging the notion of Aedes aegypti as the primary chikungunya virus vector: insights from Kédougou, Southeastern Senegal.

Background: Chikungunya fever (CHIK) caused by the mosquito-borne chikungunya virus (CHIKV) and transmitted by mosquitoes, remains a public health burden throughout the tropics. During the CHIK outbreak in the southeastern Senegal in August 2023, an entomologic investigation was conducted to identify the vector(s) and characterize the virus strains.

Methods: Adult mosquitoes were collected indoors and outdoors from houses of confirmed CHIK cases and their immediate neighborhoods using Prokopack aspirators and double-net traps and all water containers were inspected for aquatic stages.

Crimean-Congo Hemorrhagic Fever Outbreak in Podor, Northern Senegal in 2022: Two Independent Emergences and Unprecedented Mortality.

Crimean-Congo hemorrhagic fever (CCHF) is a lethal zoonotic disease transmitted through tick bites and contact with infected animals or humans. As CCHF continues to expand worldwide, we report on the first severe outbreak in Senegal (Podor, Saint-Louis region) in 2022. We conducted a comprehensive outbreak investigation after a confirmed CCHF human case in Podor.

Mosquito-based detection of retroviruses and arboviruses in Senegal: expanding the scope of xenosurveillance.

Background: Mosquitoes are well-known vectors for arthropod-borne viruses, yet their role as passive carriers of non-arthropod-borne viruses remains underexplored. Xenosurveillance, a method that utilizes blood-feeding arthropods to sample host and pathogen genetic material, has emerged as a valuable tool in viral ecology. In this study, we investigated the viral landscape of blood-fed mosquitoes from Senegal and report the first detection of Jaagsiekte Sheep Retrovirus (JSRV)-related and Enzootic Nasal Tumor Virus 2 (ENTV-2)-related sequences, alongside endemic arboviruses.

Re-emergence of Crimean Congo hemorrhagic fever virus in Kedougou, south-eastern Senegal in 2023: Epidemiological and zoological investigations of the first symptomatic human case.

Crimean-Congo hemorrhagic fever (CCHF) is a zoonosis transmitted mainly by ticks. In Senegal, the CCHF virus has been circulating since at least 2003. However, the first symptomatic human case was detected and confirmed only in 2023 in the southeastern part of the country.

Mosquito-Based Detection of Endogenous Jaagsiekte Sheep Retrovirus in Senegal: Expanding the Scope of Xenosurveillance.

Background: Mosquitoes are well-known vectors for arthropod-borne viruses, yet their role as passive carriers of non-arthropod-borne viruses remains underexplored. Xenosurveillance, a method that utilizes blood-feeding arthropods to sample host and pathogen genetic material, has emerged as a valuable tool in viral ecology. In this study, we report the first identification of Jaagsiekte Sheep Retrovirus (JSRV)-related sequences in blood-fed mosquitoes collected in Senegal.

Tick Species Infesting Livestock in Three Bioclimatic Areas of Senegal: Bioecology, Prevalence of Tick Infestation, Associated Categorical Factors and Crimean-Congo Haemorrhagic Fever Virus Infection.

Background: Crimean-Congo haemorrhagic fever (CCHF), a disease of medical and veterinary importance in several countries including Senegal, is transmitted by ticks or exposure to infected body fluids. Severe human cases of CCHF were recently observed across Senegal suggesting modification of the endemicity area and the tick fauna.

Objective: This study aims to investigate some aspects associated with the bioecology of ticks infesting livestock and their infection with CCHF virus (CCHFV) across three bioclimatic areas of Senegal.

Insecticide Resistance and Target-Site Mutations , , and in Populations in a Low-Malaria-Transmission Zone in the Sudanian Region of Senegal.

Significant progress in malaria control has been achieved through long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS), raising hopes for malaria elimination. However, emerging insecticide resistance threatens these gains. This study assessed the susceptibility of populations to public health insecticides, examined the frequencies of , , and mutations, and explored their associations with phenotypic resistance in Dielmo and Ndiop, Senegal.

Re-Emergence of Rift Valley Fever Virus Lineage H in Senegal in 2022: In Vitro Characterization and Impact on Its Global Emergence in West Africa.

Rift Valley fever (RVF) is a re-emerging vector-borne zoonosis with a high public health and veterinary impact. In West Africa, many lineages were previously detected, but since 2020, lineage H from South Africa has been the main cause of the outbreaks. In this study, clinical samples collected through national surveillance were screened for RVF virus (RVFV) acute infection by RT-PCR and IgM ELISA tests.

An amplicon-based sequencing approach for Usutu virus characterization.

Usutu virus (USUV), an arbovirus from the Flaviviridae family, genus Flavivirus, has recently gained increasing attention because of its potential for emergence. After his discovery in South Africa, USUV spread to other African countries, then emerged in Europe where it was responsible for epizootics. The virus has recently been found in Asia.

Crimean-Congo haemorrhagic fever outbreak in Northern Senegal in 2022: Prevalence of the virus in livestock and ticks, associated risk factors and epidemiological implications.

Objective: Crimean-Congo haemorrhagic fever (CCHF) is a severe zoonotic arboviral disease that occurs widely in Eastern and Western Europe, Asia and Africa. The disease is becoming of growing public health importance in Senegal. However, analysis of tick infestation, CCHF virus (CCHFV) circulation extent and risk factors during ongoing outbreak are scarce.

Emergence of Crimean-Congo Hemorrhagic Fever Virus in Eastern Senegal in 2022.

Crimean-Congo hemorrhagic fever (CCHF), the most widespread tick-borne viral human infection, poses a threat to global health. In this study, clinical samples collected through national surveillance systems were screened for acute CCHF virus (CCHFV) infection using RT-PCR and for exposure using ELISA. For any CCHF-positive sample, livestock and tick samples were also collected in the neighborhood of the confirmed case and tested using ELISA and RT-PCR, respectively.

Spatial and temporal dynamics of West Nile virus between Africa and Europe.

It is unclear whether West Nile virus (WNV) circulates between Africa and Europe, despite numerous studies supporting an African origin and high transmission in Europe. We integrated genomic data with geographic observations and phylogenetic and phylogeographic inferences to uncover the spatial and temporal viral dynamics of WNV between these two continents. We focused our analysis towards WNV lineages 1 (L1) and 2 (L2), the most spatially widespread and pathogenic WNV lineages.

Dengue 1 outbreak in Rosso, northern Senegal, October 2021: entomologic investigations.

Senegal has experienced periodic epidemics of dengue in urban areas with increased incidence in recent years. However, few data are available on the local ecology of the epidemic vectors. In October 2021, a dengue outbreak was reported in northern Senegal to the Institute Pasteur de Dakar.

Novel Amplicon-Based Sequencing Approach to West Nile Virus.

West Nile virus is a re-emerging arbovirus whose impact on public health is increasingly important as more and more epidemics and epizootics occur, particularly in America and Europe, with evidence of active circulation in Africa. Because birds constitute the main reservoirs, migratory movements allow the diffusion of various lineages in the world. It is therefore crucial to properly control the dispersion of these lineages, especially because some have a greater health impact on public health than others.

Assessment of the Risk of Exotic Zika Virus Strain Transmission by and from Senegal Compared to a Native Strain.

Zika virus (ZIKV) shows an enigmatic epidemiological profile in Africa. Despite its frequent detection in mosquitoes, few human cases have been reported. This could be due to the low infectious potential or low virulence of African ZIKV lineages.

Re-Introduction of West Nile Virus Lineage 1 in Senegal from Europe and Subsequent Circulation in Human and Mosquito Populations between 2012 and 2021.

West Nile virus (WNV) is a virus of the Japanese encephalitis antigenic complex and belongs to the family Flaviviridae of the genus flavivirus. The virus can cause infection in humans which in most cases is asymptomatic, however symptomatic cases exist and the disease can be severe causing encephalitis and meningoencephalitis. The virus is maintained in an enzootic cycle involving mosquitoes and birds, humans and other mammals such as horses can be accidental hosts.

Dengue vectors in Africa: A review.

Dengue fever is a mosquito-borne-disease of growing public health importance in Africa. The continuous increase of number and frequency of outbreaks of dengue fever, especially in urban area in Africa underline the need to review the current data available on vectors involved in dengue virus transmission in Africa. Here, we summarized the available data on vectors involved in the transmission of dengue virus in the sylvatic and urban environments, vertical transmission, vector competence studies, and vector control strategies used in Africa.

Blood Feeding Patterns of Aedes aegypti Populations in Senegal.

Aedes aegypti plays an important role in the transmission of several arboviruses of medical importance. The availability of information on the blood-feeding preferences of mosquito vectors is a critical step in the understanding of the transmission of human pathogens and implementation of control strategies. In Senegal, no data currently exist on the feeding pattern of Ae.

Yellow Fever Outbreak in Eastern Senegal, 2020-2021.

Yellow fever virus remains a major threat in low resource countries in South America and Africa despite the existence of an effective vaccine. In Senegal and particularly in the eastern part of the country, periodic sylvatic circulation has been demonstrated with varying degrees of impact on populations in perpetual renewal. We report an outbreak that occurred from October 2020 to February 2021 in eastern Senegal, notified and managed through the synergistic effort yellow fever national surveillance implemented by the Senegalese Ministry of Health in collaboration with the World Health Organization, the countrywide 4S network set up by the Ministry of Health, the Institut Pasteur de Dakar, and the surveillance of arboviruses and hemorrhagic fever viruses in human and vector populations implemented since mid 2020 in eastern Senegal.

Resting Behavior of Blood-Fed Females and Host Feeding Preferences of Aedes aegypti (Diptera: Culicidae) Morphological Forms in Senegal.

Aedes aegypti (Linnaeus) is the main vector of most arboviruses in tropical and subtropical urban areas. In West Africa, particularly in Senegal, domestic and wild populations have been described. Both Ae.

Insecticide resistance status and mechanisms in Aedes aegypti populations from Senegal.

Aedes aegypti is the main epidemic vector of arboviruses in Africa. In Senegal, control activities are mainly limited to mitigation of epidemics, with limited information available for Ae. aegypti populations.

First Detection of the West Nile Virus Koutango Lineage in Sandflies in Niger.

West Nile virus (WNV), belonging to the family, causes a mosquito-borne disease and shows great genetic diversity, with at least eight different lineages. The Koutango lineage of WNV (WN-KOUTV), mostly associated with ticks and rodents in the wild, is exclusively present in Africa and shows evidence of infection in humans and high virulence in mice. In 2016, in a context of Rift Valley fever (RVF) outbreak in Niger, mosquitoes, biting midges and sandflies were collected for arbovirus isolation using cell culture, immunofluorescence and RT-PCR assays.