The spread of SARS-CoV-2 cannot be well monitored and understood in areas without capacity for effective disease surveillance. Countries with a young population will have disproportionately large ...numbers of asymptomatic or pauci-symptomatic infections, further hindering detection of infection. Sero-surveillance on a country-wide scale by trained medical professionals may be limited in a resource-limited setting such as Mali. Novel ways of broadly sampling the human population in a non-invasive method would allow for large-scale surveillance at a reduced cost.
Here we evaluate the collection of naturally blood-fed mosquitoes to test for human anti-SARS-CoV-2 antibodies in the laboratory and at five field locations in Mali.
Immunoglobulin-G antibodies to multiple SARS-CoV-2 antigens were readily detected in mosquito bloodmeals by bead-based immunoassay through at least 10 h after feeding mean sensitivity of 0.92 (95% CI 0.78-1) and mean specificity of 0.98 (95% CI 0.88-1), indicating that most blood-fed mosquitoes collected indoors during early morning hours (and likely to have fed the previous night) are viable samples for analysis. We found that reactivity to four SARS-CoV-2 antigens rose during the pandemic from pre-pandemic levels. The crude seropositivity of blood sampled via mosquitoes was 6.3% in October and November 2020 across all sites, and increased to 25.1% overall by February 2021, with the most urban site reaching 46.7%, consistent with independent venous blood-based sero-surveillance estimates.
We have demonstrated that using mosquito bloodmeals, country-wide sero-surveillance of human diseases (both vector-borne and non-vector-borne) is possible in areas where human-biting mosquitoes are common, offering an informative, cost-effective, and non-invasive sampling option.
Mosquitoes are potentially harmful and vectors of pathogens. They compromise the rest and well-being of humans and animals. The main goal of this study is to determine the composition of mosquitoes ...responsible of human biting at the Faculty of Sciences and Technics of Bamako-Mali. Longitudinal monitoring with monthly cross-sectional visit was carried out from September to December 2019, in order to collect the endophilic and endophagic mosquitoes. The spray-catch was used as a collection methodin 21 rooms selected randomly at the FST. Mosquitoes were identified morphologically andthen by PCR. ELISA-CSP test was used for Plasmodium infection index and the ELISA blood-meal test was to determine mosquitoes blood origin. In total, 802 mosquitoes were collected: 794Culex and 8Anopheles. There were 200 males and 602 females. Female mosquitoes were separated by gonotrophic stages: 231 unfed, 223 fed, 80 semi-gravid and 68 gravid. Up to 34% of Culex and 67% of Anopheles had a preference for human blood, but no female tested positive for Plasmodium infection. This result would be due to the small number of Anopheles captured. An. coluzzii is the only Anopheles species collected.This study shows that mosquitoes are linked to serious problems of nuisance and risk of pathogens transmission in the university. They highly prefer to feed on human host.
Introduction: Les Arthropodes sont vecteurs de nombreuses maladies chez les hommes, les animaux et les plantes. Cest pourquoi lidentification des vecteurs devient necessaire afin de mener une lutte a ...travers des programmes nationaux de lutte. Methodes: Cette etude a ete conduite dans trois differentes zones eco-climatiques du Mali afin de voir la variation saisonniere des Arthropodes dinteret medical, veterinaire et Agricole au Mali. La collecte des arthropodes a ete faite a laide de deux types de piege (Piege demergence et piege en T) dans les villages de Bia, de Kenieroba et de Thierola. Les identifications ont ete faites a la loupe pour les Arthropodes, et par PCR pour les moustiques. Limportance des Arthropodes collectes a ete evaluee a travers leur dominance et leur frequence en fonction des zones et des saisons. Resultats: Letude des arthropodes des trois zones a permis davoir un apercu de lensemble de variations qualitatives et quantitatives des differents Arthropodes. Un total de 20 especes dArthropodes appartenant a trois classes a ete identifie (Arachnides, Insectes Myriapodes), 13 ordres (Araneides, Coleopteres, Dermapteres, Dictyopteres, Dipteres, Hemipteres, Hymenopteres, Lepidopteres, Nevropteres, Odonates, Orthopteres, Plecopteres, Trichopteres). Les Dipteres sont mieux representes a Bia et a Thierola et les Coleopteres frequents a Kenieroba. Conclusion: Il ressort de cette etude que les Arthropodes etaient plus frequents pendant la saison des pluies sur les sites. Les Arthropodes dinteret agricole constituaient le groupe dominant sur chacun des sites, suivi de ceux dinteret medical.
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