1
|
Cramer EY, Nguyen XQ, Hertz JC, Nguyen DV, Quang HH, Mendenhall IH, Lover AA. Measuring effects of ivermectin-treated cattle on potential malaria vectors in Vietnam: A cluster-randomized trial. PLoS Negl Trop Dis 2024; 18:e0012014. [PMID: 38683855 PMCID: PMC11098492 DOI: 10.1371/journal.pntd.0012014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/16/2024] [Accepted: 02/19/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Malaria elimination using current tools has stalled in many areas. Ivermectin (IVM) is a broad-antiparasitic drug and mosquitocide and has been proposed as a tool for accelerating progress towards malaria elimination. Under laboratory conditions, IVM has been shown to reduce the survival of adult Anopheles populations that have fed on IVM-treated mammals. Treating cattle with IVM has been proposed as an important contribution to malaria vector management, however, the impacts of IVM in this One Health use case have been untested in field trials in Southeast Asia. METHODS Through a randomized village-based trial, this study quantified the effect of IVM-treated cattle on anopheline populations in treated vs. untreated villages in Central Vietnam. Local zebu cattle in six rural villages were included in this study. In three villages, cattle were treated with IVM at established veterinary dosages, and in three additional villages cattle were left as untreated controls. For the main study outcome, the mosquito populations in all villages were sampled using cattle-baited traps for six nights before, and six nights after a 2-day IVM-administration (intervention) period. Anopheline species were characterized using taxonomic keys. The impact of the intervention was analyzed using a difference-in-differences (DID) approach with generalized estimating equations (with negative binomial distribution and robust errors). This intervention was powered to detect a 50% reduction in total nightly Anopheles spp. vector catches from cattle-baited traps. Given the unusual diversity in anopheline populations, exploratory analyses examined taxon-level differences in the ecological population diversity. RESULTS Across the treated villages, 1,112 of 1,523 censused cows (73% overall; range 67% to 83%) were treated with IVM. In both control and treated villages, there was a 30% to 40% decrease in total anophelines captured in the post-intervention period as compared to the pre-intervention period. In the control villages, there were 1,873 captured pre-intervention and 1,079 captured during the post-intervention period. In the treated villages, there were 1,594 captured pre-intervention, and 1,101 captured during the post-intervention period. The difference in differences model analysis comparing total captures between arms was not statistically significant (p = 0.61). Secondary outcomes of vector population diversity found that in three villages (one control and two treatment) Brillouin's index increased, and in three villages (two control and one treatment) Brillouin's index decreased. When examining biodiversity by trapping-night, there were no clear trends in treated or untreated vector populations. Additionally, there were no clear trends when examining the components of biodiversity: richness and evenness. CONCLUSIONS The ability of this study to quantify the impacts of IVM treatment was limited due to unexpectedly large spatiotemporal variability in trapping rates; an area-wide decrease in trapping counts across all six villages post-intervention; and potential spillover effects. However, this study provides important data to directly inform future studies in the GMS and beyond for IVM-based vector control.
Collapse
Affiliation(s)
- Estee Y. Cramer
- Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts-Amherst, Massachusetts, United States of America
| | - Xuan Quang Nguyen
- Institute of Malariology-Parasitology & Entomology Quy Nhon, Ministry of Health, Vietnam
| | | | - Do Van Nguyen
- Institute of Malariology-Parasitology & Entomology Quy Nhon, Ministry of Health, Vietnam
| | - Huynh Hong Quang
- Institute of Malariology-Parasitology & Entomology Quy Nhon, Ministry of Health, Vietnam
| | - Ian H. Mendenhall
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Andrew A. Lover
- Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts-Amherst, Massachusetts, United States of America
| |
Collapse
|
2
|
Brown JJ, Pascual M, Wimberly MC, Johnson LR, Murdock CC. Humidity - The overlooked variable in the thermal biology of mosquito-borne disease. Ecol Lett 2023; 26:1029-1049. [PMID: 37349261 DOI: 10.1111/ele.14228] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 04/05/2023] [Indexed: 06/24/2023]
Abstract
Vector-borne diseases cause significant financial and human loss, with billions of dollars spent on control. Arthropod vectors experience a complex suite of environmental factors that affect fitness, population growth and species interactions across multiple spatial and temporal scales. Temperature and water availability are two of the most important abiotic variables influencing their distributions and abundances. While extensive research on temperature exists, the influence of humidity on vector and pathogen parameters affecting disease dynamics are less understood. Humidity is often underemphasized, and when considered, is often treated as independent of temperature even though desiccation likely contributes to declines in trait performance at warmer temperatures. This Perspectives explores how humidity shapes the thermal performance of mosquito-borne pathogen transmission. We summarize what is known about its effects and propose a conceptual model for how temperature and humidity interact to shape the range of temperatures across which mosquitoes persist and achieve high transmission potential. We discuss how failing to account for these interactions hinders efforts to forecast transmission dynamics and respond to epidemics of mosquito-borne infections. We outline future research areas that will ground the effects of humidity on the thermal biology of pathogen transmission in a theoretical and empirical framework to improve spatial and temporal prediction of vector-borne pathogen transmission.
Collapse
Affiliation(s)
- Joel J Brown
- Department of Entomology, Cornell University, Ithaca, New York, USA
| | - Mercedes Pascual
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, USA
| | - Michael C Wimberly
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, USA
| | - Leah R Johnson
- Department of Statistics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | | |
Collapse
|
3
|
Obame-Nkoghe J, Makanga BK, Zongo SB, Koumba AA, Komba P, Longo-Pendy NM, Mounioko F, Akone-Ella R, Nkoghe-Nkoghe LC, Ngangue-Salamba MF, Yangari P, Aboughe-Angone S, Fournet F, Kengne P, Paupy C. Urban Green Spaces and Vector-Borne Disease Risk in Africa: The Case of an Unclean Forested Park in Libreville (Gabon, Central Africa). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:ijerph20105774. [PMID: 37239503 DOI: 10.3390/ijerph20105774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 05/28/2023]
Abstract
In Africa, vector-borne diseases are a major public health issue, especially in cities. Urban greening is increasingly considered to promote inhabitants' well-being. However, the impact of urban green spaces on vector risk remains poorly investigated, particularly urban forests in poor hygienic conditions. Therefore, using larval sampling and human landing catches, this study investigated the mosquito diversity and the vector risk in a forest patch and its inhabited surroundings in Libreville, Gabon, central Africa. Among the 104 water containers explored, 94 (90.4%) were artificial (gutters, used tires, plastic bottles) and 10 (9.6%) were natural (puddles, streams, tree holes). In total, 770 mosquitoes belonging to 14 species were collected from such water containers (73.1% outside the forested area). The mosquito community was dominated by Aedes albopictus (33.5%), Culex quinquefasciatus (30.4%), and Lutzia tigripes (16.5%). Although mosquito diversity was almost double outside compared to inside the forest (Shannon diversity index: 1.3 vs. 0.7, respectively), the species relative abundance (Morisita-Horn index = 0.7) was similar. Ae. albopictus (86.1%) was the most aggressive species, putting people at risk of Aedes-borne viruses. This study highlights the importance of waste pollution in urban forested ecosystems as a potential driver of mosquito-borne diseases.
Collapse
Affiliation(s)
- Judicaël Obame-Nkoghe
- Laboratoire de Biologie Moléculaire et Cellulaire, Département de Biologie, Université des Sciences et Techniques de Masuku (USTM), Franceville BP 941, Gabon
- Unité de Recherche en Écologie de la Santé, Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville BP 769, Gabon
| | - Boris Kevin Makanga
- Institut de Recherche en Écologie Tropicale (IRET/CENAREST), Libreville BP 13354, Gabon
| | - Sylvie Brizard Zongo
- Laboratoire de Biologie Moléculaire et Cellulaire, Département de Biologie, Université des Sciences et Techniques de Masuku (USTM), Franceville BP 941, Gabon
- Département Faune et Aires Protégées, École Nationale des Eaux et Forêts (ENEF), Libreville BP 3960, Gabon
| | - Aubin Armel Koumba
- Institut de Recherche en Écologie Tropicale (IRET/CENAREST), Libreville BP 13354, Gabon
| | - Prune Komba
- Unité de Recherche GéoHydrosystèmes Continentaux (UR GéHCo), Département Géosciences et Environnement, Université de Tours, 37000 Tours, France
| | - Neil-Michel Longo-Pendy
- Unité de Recherche en Écologie de la Santé, Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville BP 769, Gabon
| | - Franck Mounioko
- Laboratoire de Biologie Moléculaire et Cellulaire, Département de Biologie, Université des Sciences et Techniques de Masuku (USTM), Franceville BP 941, Gabon
- Unité de Recherche en Écologie de la Santé, Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville BP 769, Gabon
| | - Rodolphe Akone-Ella
- Unité de Recherche en Écologie de la Santé, Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville BP 769, Gabon
| | - Lynda Chancelya Nkoghe-Nkoghe
- Unité de Recherche en Écologie de la Santé, Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville BP 769, Gabon
| | - Marc-Flaubert Ngangue-Salamba
- Unité de Recherche en Écologie de la Santé, Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville BP 769, Gabon
| | - Patrick Yangari
- Unité de Recherche en Écologie de la Santé, Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville BP 769, Gabon
| | - Sophie Aboughe-Angone
- Institut de Pharmacopée et de Médecine Traditionnelle (IPHAMETRA), Libreville BP 1156, Gabon
| | - Florence Fournet
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs, Écologie, Génétique, Évolution et Contrôle (MIVEGEC), Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), 34193 Montpellier, France
| | - Pierre Kengne
- Unité de Recherche en Écologie de la Santé, Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville BP 769, Gabon
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs, Écologie, Génétique, Évolution et Contrôle (MIVEGEC), Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), 34193 Montpellier, France
| | - Christophe Paupy
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs, Écologie, Génétique, Évolution et Contrôle (MIVEGEC), Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), 34193 Montpellier, France
| |
Collapse
|
4
|
Yan C, Hii J, Ngoen-Klan R, Saeung M, Chareonviriyaphap T. Semi-field evaluation of human landing catches versus human double net trap for estimating human biting rate of Anopheles minimus and Anopheles harrisoni in Thailand. PeerJ 2022; 10:e13865. [PMID: 36101880 PMCID: PMC9464434 DOI: 10.7717/peerj.13865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/18/2022] [Indexed: 01/24/2023] Open
Abstract
Background Whilst the human landing catch (HLC) technique is considered the 'gold standard' for estimating human-biting rates, it is labor-intensive and fraught with potential risk of exposure to infectious mosquito bites. This study evaluated the feasibility and performance of an alternative method, the human double net trap (HDNT) relative to HLC for monitoring host-seeking malaria vectors of the Anopheles minimus complex in a semi-field system (SFS). Methods HDNT and HLC were positioned in two rooms, 30 m apart at both ends of the SFS. Two human volunteers were rotated between both traps and collected released mosquitoes (n = 100) from 6:00 pm till 6:00 am. Differences in Anopheles mosquito densities among the trapping methods were compared using a generalized linear model based on a negative binomial distribution. Results There were 82.80% (2,136/2,580) of recaptures of wild-caught and 94.50% (2,835/3,000) of laboratory-reared mosquitoes that were molecularly identified as An. harrisoni and An. minimus, respectively. Mean density of An. harrisoni was significantly lower in HNDT (15.50 per night, 95% CI [12.48-18.52]) relative to HLC (25.32 per night (95% CI [22.28-28.36]), p < 0.001). Similarly, the mean density of a laboratory strain of An. minimus recaptured in HDNT was significantly lower (37.87 per night, 95% CI [34.62-41.11]) relative to HLC (56.40 per night, 95% CI [55.37-57.43]), p < 0.001. Relative sampling efficiency analysis showed that HLC was the more efficient trap in collecting the An. minimus complex in the SFS. Conclusion HDNT caught proportionately fewer An. minimus complex than HLC. HDNT was not sensitive nor significantly correlated with HLC, suggesting that it is not an alternative method to HLC.
Collapse
Affiliation(s)
- Chanly Yan
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - Jeffrey Hii
- College of Public Health, Medical and Veterinary Sciences, James Cook University of North Queensland, North Queensland, Australia
| | - Ratchadawan Ngoen-Klan
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - Manop Saeung
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - Theeraphap Chareonviriyaphap
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand,Royal Society of Thailand, Bangkok, Thailand
| |
Collapse
|
5
|
Lun X, Wang Y, Zhao C, Wu H, Zhu C, Ma D, Xu M, Wang J, Liu Q, Xu L, Meng F. Epidemiological characteristics and temporal-spatial analysis of overseas imported dengue fever cases in outbreak provinces of China, 2005–2019. Infect Dis Poverty 2022; 11:12. [PMID: 35074010 PMCID: PMC8785556 DOI: 10.1186/s40249-022-00937-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 01/11/2022] [Indexed: 01/25/2023] Open
Abstract
Abstract
Background
Overseas imported dengue fever is an important factor in local outbreaks of this disease in the mainland of China. To better prevent and control such local outbreaks, the epidemiological characteristics and temporal-spatial distribution of overseas imported dengue fever cases in provincial-level administrative divisions (PLADs) where dengue fever is outbreak in the mainland of China were explored.
Methods
Using the Chinese National Notifiable Infectious Disease Reporting Information System (CNNDS), we identified overseas imported dengue fever cases in dengue fever outbreak areas in the mainland of China from 2005 to 2019 to draw the epidemic curve and population characteristic distribution of overseas imported cases in each PLAD. Based on spatial autocorrelation analysis of ArcGIS 10.5 and temporal-spatial scanning analysis of SaTScan 9.5, we analyzed the temporal-spatial distribution of overseas imported dengue fever in dengue fever outbreak areas in the mainland of China.
Results
A total of 11,407 imported cases, mainly from Southeast Asia, were recorded from 2005 to 2019 in these 13 PLADs. Of which 62.1% were imported into Yunnan and Guangdong Provinces. Among the imported cases, there were more males than females, mainly from the 21–50 age group. The hot spots were concentrated in parts of Yunnan, Guangdong and Fujian Provinces. We found the cluster of infected areas were expanding northward.
Conclusions
Based on the analysis of overseas imported dengue cases in 13 PLADs of the mainland of China from 2005 to 2019, we obtained the epidemiological characteristics and spatial distribution of imported dengue cases. Border controls need to pay attention to key population sectors, such as 21–50 years old men and education of key populations on dengue prevention. There is a need to improve the awareness of the prevention and control of imported cases in border areas. At the same time, northern regions cannot relax their vigilance.
Graphical Abstract
Collapse
|
6
|
Doumbe-Belisse P, Kopya E, Ngadjeu CS, Sonhafouo-Chiana N, Talipouo A, Djamouko-Djonkam L, Awono-Ambene HP, Wondji CS, Njiokou F, Antonio-Nkondjio C. Urban malaria in sub-Saharan Africa: dynamic of the vectorial system and the entomological inoculation rate. Malar J 2021; 20:364. [PMID: 34493280 PMCID: PMC8424958 DOI: 10.1186/s12936-021-03891-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/20/2021] [Indexed: 12/11/2022] Open
Abstract
Sub-Saharan Africa is registering one of the highest urban population growth across the world. It is estimated that over 75% of the population in this region will be living in urban settings by 2050. However, it is not known how this rapid urbanization will affect vector populations and disease transmission. The present study summarizes findings from studies conducted in urban settings between the 1970s and 2020 to assess the effects of urbanization on the entomological inoculation rate pattern and anopheline species distribution. Different online databases such as PubMed, ResearchGate, Google Scholar, Google were screened. A total of 90 publications were selected out of 1527. Besides, over 200 additional publications were consulted to collate information on anopheline breeding habitats and species distribution in urban settings. The study confirms high malaria transmission in rural compared to urban settings. The study also suggests that there had been an increase in malaria transmission in most cities after 2003, which could also be associated with an increase in sampling, resources and reporting. Species of the Anopheles gambiae complex were the predominant vectors in most urban settings. Anopheline larvae were reported to have adapted to different aquatic habitats. The study provides updated information on the distribution of the vector population and the dynamic of malaria transmission in urban settings. The study also highlights the need for implementing integrated control strategies in urban settings.
Collapse
Affiliation(s)
- P Doumbe-Belisse
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun.,Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - E Kopya
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun.,Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - C S Ngadjeu
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun.,Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - N Sonhafouo-Chiana
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun.,Faculty of Health Sciences, University of Buea, Cameroon, P.O. Box 63, Buea, Cameroon
| | - A Talipouo
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun.,Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - L Djamouko-Djonkam
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun.,Faculty of Sciences, University of Dschang Cameroon, P.O. Box 67, Dschang, Cameroon
| | - H P Awono-Ambene
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
| | - C S Wondji
- Vector Group Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK
| | - F Njiokou
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - C Antonio-Nkondjio
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun. .,Vector Group Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK.
| |
Collapse
|
7
|
Ngom EHM, Virgillito C, Manica M, Rosà R, Pichler V, Sarleti N, Kassé I, Diallo M, della Torre A, Dia I, Caputo B. Entomological Survey Confirms Changes in Mosquito Composition and Abundance in Senegal and Reveals Discrepancies among Results by Different Host-Seeking Female Traps. INSECTS 2021; 12:692. [PMID: 34442258 PMCID: PMC8396443 DOI: 10.3390/insects12080692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022]
Abstract
Mosquitoes-borne diseases are major public health issues particularly in Africa. Vector control interventions and human-made environmental/climatic changes significantly affect the distribution and abundance of vector species. We carried out an entomological survey targeting host-seeking mosquitos in two different ecological contexts-coastal and inland-in Senegal, by CDC-light and BG-sentinel traps. Results show high predominance of Culex quinquefasciatus (90%) and of Anopheles arabiensis within malaria vectors (46%), with mean numbers of females/trap/nights =8 and <1, respectively, reinforcing previous evidence of changes in species composition and abundance, highlighting thus increasing risk of transmission of filariasis and emerging arboviruses in the Senegambia region. From the methodological perspective, results show a higher specificity of BG traps for Cx. quinquefasciatus and of CDC traps for An. gambiae s.l. and highlight that, despite both traps target the host-seeking fraction of the population, they provide different patterns of species abundance, temporal dynamics and host-seeking activity, leading to possible misinterpretation of the species bionomics. This draws attention to the need of taking into account trapping performance, in order to provide realistic quantification of the number of mosquitoes per units of space and time, the crucial parameter for evaluating vector-human contact, and estimating risk of pathogen transmission.
Collapse
Affiliation(s)
- El Hadji Malick Ngom
- Medical Zoology Pole, Institut Pasteur de Dakar, Dakar 12500, Senegal; (E.H.M.N.); (I.K.); (M.D.)
| | - Chiara Virgillito
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185 Rome, Italy; (C.V.); (V.P.); (N.S.); (A.d.T.)
- Department of Biodiversity and Molecular Ecology, Edmund Mach Foundation, 38098 San Michele all’Adige, Italy; (M.M.); (R.R.)
| | - Mattia Manica
- Department of Biodiversity and Molecular Ecology, Edmund Mach Foundation, 38098 San Michele all’Adige, Italy; (M.M.); (R.R.)
- Center for Health Emergencies, Bruno Kessler Foundation, 380123 Trento, Italy
| | - Roberto Rosà
- Department of Biodiversity and Molecular Ecology, Edmund Mach Foundation, 38098 San Michele all’Adige, Italy; (M.M.); (R.R.)
- Center Agriculture Food Environment, University of Trento, 38098 San Michele all’Adige, Italy
| | - Verena Pichler
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185 Rome, Italy; (C.V.); (V.P.); (N.S.); (A.d.T.)
| | - Noemi Sarleti
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185 Rome, Italy; (C.V.); (V.P.); (N.S.); (A.d.T.)
| | - Isseu Kassé
- Medical Zoology Pole, Institut Pasteur de Dakar, Dakar 12500, Senegal; (E.H.M.N.); (I.K.); (M.D.)
| | - Mawlouth Diallo
- Medical Zoology Pole, Institut Pasteur de Dakar, Dakar 12500, Senegal; (E.H.M.N.); (I.K.); (M.D.)
| | - Alessandra della Torre
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185 Rome, Italy; (C.V.); (V.P.); (N.S.); (A.d.T.)
| | - Ibrahima Dia
- Medical Zoology Pole, Institut Pasteur de Dakar, Dakar 12500, Senegal; (E.H.M.N.); (I.K.); (M.D.)
| | - Beniamino Caputo
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185 Rome, Italy; (C.V.); (V.P.); (N.S.); (A.d.T.)
| |
Collapse
|
8
|
Ndiaye E, Ould Mohamed Salem Boukhary A, Diallo M, Diallo D, Labbo R, Boussès P, Le Goff G, Robert V. [Mosquitoes, Distribution and Specific Richness in Eight Countries of Africa: Cape Verde, Mauritania, Senegal, Gambia, Mali, Burkina Faso, Niger and Chad]. MEDECINE TROPICALE ET SANTE INTERNATIONALE 2021; 1:mtsibulletin.2021.109. [PMID: 35586589 PMCID: PMC9022770 DOI: 10.48327/mtsibulletin.2021.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 05/25/2021] [Indexed: 11/14/2022]
Abstract
Mosquitoes (Diptera, Culicidae) form a family of insects of considerable public health importance. Mention of their presence/absence was tackled in the literature and by specialized websites for eight African countries: Cape Verde, Mauritania, Senegal, Gambia, Mali, Burkina Faso, Niger and Chad. In total, 216 species have been recorded belonging to 13 genera: Anopheles (48 species), Aedeomyia (2), Aedes (62), Coquillettidia (6), Culex (54), Culiseta (1), Eretmapodites (7), Ficalbia (3), Lutzia (1), Mansonia (2), Mimomyia (7), Toxorhynchites (4) and Uranotaenia (19). The presence of these species in the study area is certain except for three species whose presence is doubtful. This specific richness represents 6% of the world's richness. The countries with the highest specific richness are Burkina Faso (162 species), Senegal (143) and Mali (110); the country with the lowest richness is Cape Verde (11). This richness is lower in the north in hyper-arid climate and higher in the south in sub-humid climate. Chad is the least well inventoried country. All species are considered native, with the exception of Ae. (Stegomyia ) albopictus (the Asian tiger mosquito) introduced in 2016 into Mali and possibly Ae. (Ochlerotatus ) caspius into Mauritania and Ae. (Stg. ) aegypti introduced into Nouakchott, Mauritania. This synthesis of the knowledge may be useful for vector control, public health, and future research.
Collapse
Affiliation(s)
- E.H. Ndiaye
- Pôle de zoologie médicale, Institut Pasteur de Dakar, B.P. 220, Dakar, Sénégal
| | - A. Ould Mohamed Salem Boukhary
- Université de Nouakchott Al-Aasriya, Unité de recherche génomes et milieux (jeune équipe associée à l'IRD), Laboratoire environnement, santé et société LE2S, BP 880, Nouakchott, Mauritanie; Aix Marseille Univ., IRD, AP-HM, SSA, VITROME, Marseille, France
| | - M. Diallo
- Pôle de zoologie médicale, Institut Pasteur de Dakar, B.P. 220, Dakar, Sénégal
| | - D. Diallo
- Pôle de zoologie médicale, Institut Pasteur de Dakar, B.P. 220, Dakar, Sénégal
| | - R. Labbo
- Centre de recherche médicale et sanitaire (CERMES), BP 10887, Niamey, Niger
| | - P. Boussès
- Unité MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France
| | - G. Le Goff
- Unité MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France
| | - V. Robert
- Unité MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France,*
| |
Collapse
|
9
|
Valentine MJ, Ciraola B, Jacobs GR, Arnot C, Kelly PJ, Murdock CC. Effects of seasonality and land use on the diversity, relative abundance, and distribution of mosquitoes on St. Kitts, West Indies. Parasit Vectors 2020; 13:543. [PMID: 33138849 PMCID: PMC7607626 DOI: 10.1186/s13071-020-04421-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/21/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mosquito surveys that collect local data on mosquito species' abundances provide baseline data to help understand potential host-pathogen-mosquito relationships, predict disease transmission, and target mosquito control efforts. METHODS We conducted an adult mosquito survey from November 2017 to March 2019 on St. Kitts, using Biogents Sentinel 2 traps, set monthly and run for 48-h intervals. We collected mosquitoes from a total of 30 sites distributed across agricultural, mangrove, rainforest, scrub and urban land covers. We investigated spatial variation in mosquito species richness across the island using a hierarchical Bayesian multi-species occupancy model. We developed a mixed effects negative binomial regression model to predict the effects of spatial variation in land cover, and seasonal variation in precipitation on observed counts of the most abundant mosquito species observed. RESULTS There was high variation among sites in mosquito community structure, and variation in site level richness that correlated with scrub forest, agricultural, and urban land covers. The four most abundant species were Aedes taeniorhynchus, Culex quinquefasciatus, Aedes aegpyti and Deinocerites magnus, and their relative abundance varied with season and land cover. Aedes aegypti was the most commonly occurring mosquito on the island, with a 90% probability of occurring at between 24 and 30 (median = 26) sites. Mangroves yielded the most mosquitoes, with Ae. taeniorhynchus, Cx. quinquefasciatus and De. magnus predominating. Psorophora pygmaea and Toxorhynchites guadeloupensis were only captured in scrub habitat. Capture rates in rainforests were low. Our count models also suggested the extent to which monthly average precipitation influenced counts varied according to species. CONCLUSIONS There is high seasonality in mosquito abundances, and land cover influences the diversity, distribution, and relative abundance of species on St. Kitts. Further, human-adapted mosquito species (e.g. Ae. aegypti and Cx. quinquefasciatus) that are known vectors for many human relevant pathogens (e.g. chikungunya, dengue and Zika viruses in the case of Ae. aegypti; West Nile, Spondweni, Oropouche virus, and equine encephalitic viruses in the case of Cx. quinqefasciatus) are the most wide-spread (across land covers) and the least responsive to seasonal variation in precipitation.
Collapse
Affiliation(s)
- Matthew J Valentine
- One Health Centre for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, Island Main Road, West Farm, Basseterre, Saint Kitts and Nevis
| | - Brenda Ciraola
- One Health Centre for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, Island Main Road, West Farm, Basseterre, Saint Kitts and Nevis
| | - Gregory R Jacobs
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA.,River Basin Center, Odum School of Ecology, University of Georgia, Athens, Ga, 30602, USA
| | | | - Patrick J Kelly
- Department of Clinical Sciences, Ross University School of Veterinary Medicine, Island Main Road, West Farm, Basseterre, Saint Kitts and Nevis
| | - Courtney C Murdock
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA. .,River Basin Center, Odum School of Ecology, University of Georgia, Athens, Ga, 30602, USA. .,Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA. .,Center for Ecology of Infectious Diseases, Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA. .,Center for Tropical Emerging and Global Diseases, University of Georgia, Athens, GA, 30602, USA. .,Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA. .,Department of Entomology, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA.
| |
Collapse
|
10
|
Diallo D, Fall G, Diagne CT, Gaye A, Ba Y, Dia I, Faye O, Diallo M. Concurrent amplification of Zika, chikungunya, and yellow fever virus in a sylvatic focus of arboviruses in Southeastern Senegal, 2015. BMC Microbiol 2020; 20:181. [PMID: 32590939 PMCID: PMC7318437 DOI: 10.1186/s12866-020-01866-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 06/18/2020] [Indexed: 12/27/2022] Open
Abstract
Background Chikungunya (CHIKV), yellow fever (YFV) and Zika (ZIKV) viruses circulate in sylvatic transmission cycles in southeastern Senegal, where they share common hosts and vectors. All three viruses undergo periodic amplifications, during which they are detected in mosquitoes and sometimes in hosts. However, little is known about their spatio-temporal patterns in years in which they undergo concurrent amplification. The aim of this study was to describe the co-amplification of ZIKV, CHIKV, and YFV, and the daily dynamics of these arboviruses and theirs vectors within villages in southeastern Senegal. Results Mosquitoes were collected monthly from July to December 2015. Each evening, from 6 to 9 PM, landing collections were performed by teams of 3 persons working simultaneously in 70 sites situated in forest (canopy and ground), savannah, agriculture, barren, and village (indoor and outdoor) land covers. Collections within villages were continued until 6 AM. Mosquitoes were tested for virus infection by virus isolation and RT-PCR. Seventy-five mosquito pools comprising 10 mosquito species contained at least one virus. Ae. furcifer and Ae. luteocephalus were infected by all three viruses, Ae. taylori by YFV and ZIKV, and remaining seven species by only, only YFV or only ZIKV. No single mosquito pool contained more than one virus. CHIKV was the only virus detected in all land cover classes and was found in the greatest number of sampling sites (32.9%, n = 70). The proportion of sites in which more than one virus was detected was less than 6%. Ae. aegypti formosus, Ae. furcifer, Ae. luteocephalus, Ae. minutus, Ae. vittatus, and An. gambiae were found within villages. These vectors were mainly active around dusk but Ae. furcifer was collected until dawn. All viruses save ZIKV were detected indoors and outdoors, mainly around dusk. Virus positive pools were detected over 2, 3 and 4 months for YFV, CHIKV and ZIKV, respectively. Conclusion Our data indicate that the distribution of different vector species and different arboviruses vary substantially between sites, suggesting that CHIKV, YFV, and ZIKV may have different transmission cycles in Southeastern Senegal.
Collapse
Affiliation(s)
- Diawo Diallo
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal.
| | - Gamou Fall
- Pôle de Virologie, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal
| | - Cheikh Tidiane Diagne
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal
| | - Alioune Gaye
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal
| | - Yamar Ba
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal
| | - Ibrahima Dia
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal
| | - Ousmane Faye
- Pôle de Virologie, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal
| | - Mawlouth Diallo
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal
| |
Collapse
|
11
|
Eastwood G, Sang RC, Lutomiah J, Tunge P, Weaver SC. Sylvatic Mosquito Diversity in Kenya-Considering Enzootic Ecology of Arboviruses in an Era of Deforestation. INSECTS 2020; 11:insects11060342. [PMID: 32503123 PMCID: PMC7349089 DOI: 10.3390/insects11060342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/25/2020] [Accepted: 05/27/2020] [Indexed: 12/16/2022]
Abstract
As new and re-emerging vector-borne diseases are occurring across the world, East Africa represents an interesting location, being the origin of several arboviruses with a history of urbanization and global spread. Rapid expansion of urban populations and alteration of natural habitats creates the opportunity for arboviruses to host-switch from wild, sylvatic hosts or vectors into urban transmission affecting human populations. Although mosquito surveillance regularly takes place in urban areas of Kenya, for example identifying vectors of dengue virus or malaria viruses, little work has been carried out to determine the distribution and abundance of sylvatic vectors. Here, we describe the mosquito vector species and diversity collected at twelve forest habitats of rural Kenya. We conducted arbovirus screening of over 14,082 mosquitoes (47 species, 11 genera) as 1520 pools, and detected seven viruses (six bunyaviruses, and one flavivirus-bunyavirus co-infection) isolated from pools of Aedes dentatus,Anopheles funestus, Culex annulioris, and Cx. vansomereni. Awareness of sylvatic vector species and their location is a critical part of understanding the ecological foci and enzootic cycling of pathogens that may be of concern to public, animal or wildlife health. As natural ecosystems come under anthropogenic pressures, such knowledge can inform us of the One Health potential for spillover or spillback leading to outbreaks, and assist in vector control strategies.
Collapse
Affiliation(s)
- Gillian Eastwood
- Institute for Human Infections and Immunity, Center for Tropical Diseases, Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
- College of Agriculture & Life Sciences, Virginia Tech, Blacksburg, VA 24060, USA
- Correspondence: ; Tel.: +1-516-655-7462
| | - Rosemary C. Sang
- Centre for Viral Research, Kenya Medical Research Institute, Mbagathi Way, Nairobi, Kenya; (R.C.S.); (J.L.); (P.T.)
| | - Joel Lutomiah
- Centre for Viral Research, Kenya Medical Research Institute, Mbagathi Way, Nairobi, Kenya; (R.C.S.); (J.L.); (P.T.)
| | - Philip Tunge
- Centre for Viral Research, Kenya Medical Research Institute, Mbagathi Way, Nairobi, Kenya; (R.C.S.); (J.L.); (P.T.)
| | - Scott C. Weaver
- World Reference Center for Emerging Viruses and Arboviruses, Institute for Human Infections and Immunity, Center for Tropical Diseases, Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA;
| |
Collapse
|