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Wangrawa DW, Odero JO, Baldini F, Okumu F, Badolo A. Distribution and insecticide resistance profile of the major malaria vector Anopheles funestus group across the African continent. MEDICAL AND VETERINARY ENTOMOLOGY 2024; 38:119-137. [PMID: 38303659 DOI: 10.1111/mve.12706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 01/10/2024] [Indexed: 02/03/2024]
Abstract
There has been significant progress in malaria control in the last 2 decades, with a decline in mortality and morbidity. However, these gains are jeopardised by insecticide resistance, which negatively impacts the core interventions, such as insecticide-treated nets (ITN) and indoor residual spraying (IRS). While most malaria control and research efforts are still focused on Anopheles gambiae complex mosquitoes, Anopheles funestus remains an important vector in many countries and, in some cases, contributes to most of the local transmission. As countries move towards malaria elimination, it is important to ensure that all dominant vector species, including An. funestus, an important vector in some countries, are targeted. The objective of this review is to compile and discuss information related to A. funestus populations' resistance to insecticides and the mechanisms involved across Africa, emphasising the sibling species and their resistance profiles in relation to malaria elimination goals. Data on insecticide resistance in An. funestus malaria vectors in Africa were extracted from published studies. Online bibliographic databases, including Google Scholar and PubMed, were used to search for relevant studies. Articles published between 2000 and May 2023 reporting resistance of An. funestus to insecticides and associated mechanisms were included. Those reporting only bionomics were excluded. Spatial variation in species distribution and resistance to insecticides was recorded from 174 articles that met the selection criteria. It was found that An. funestus was increasingly resistant to the four classes of insecticides recommended by the World Health Organisation for malaria vector control; however, this varied by country. Insecticide resistance appears to reduce the effectiveness of vector control methods, particularly IRS and ITN. Biochemical resistance due to detoxification enzymes (P450s and glutathione-S-transferases [GSTs]) in An. funestus was widely recorded. However, An. funestus in Africa remains susceptible to other insecticide classes, such as organophosphates and neonicotinoids. This review highlights the increasing insecticide resistance of An. funestus mosquitoes, which are important malaria vectors in Africa, posing a significant challenge to malaria control efforts. While An. funestus has shown resistance to the recommended insecticide classes, notably pyrethroids and, in some cases, organochlorides and carbamates, it remains susceptible to other classes of insecticides such as organophosphates and neonicotinoids, providing potential alternative options for vector control strategies. The study underscores the need for targeted interventions that consider the population structure and geographical distribution of An. funestus, including its sibling species and their insecticide resistance profiles, to effectively achieve malaria elimination goals.
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Affiliation(s)
- Dimitri W Wangrawa
- Laboratoire d'Entomologie Fondamentale et Appliquée, Université Joseph Ki-Zerbo, Ouagadougou, Burkina Faso
- Département des Sciences de la Vie et de la Terre, Université Norbert Zongo, Koudougou, Burkina Faso
| | - Joel O Odero
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
- School of Biodiversity, One Health, and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Francesco Baldini
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
- School of Biodiversity, One Health, and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Fredros Okumu
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania
| | - Athanase Badolo
- Laboratoire d'Entomologie Fondamentale et Appliquée, Université Joseph Ki-Zerbo, Ouagadougou, Burkina Faso
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Targeting Malaria Hotspots to Reduce Transmission Incidence in Senegal. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 18:ijerph18010076. [PMID: 33374228 PMCID: PMC7796302 DOI: 10.3390/ijerph18010076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 11/16/2022]
Abstract
In central Senegal, malaria incidence declined in response to scaling-up of control measures from 2000 to 2010 and has since remained stable, making elimination unlikely in the short term. Additional control measures are needed to reduce transmission. We simulated chemoprophylaxis interventions targeting malaria hotspots using a metapopulation mathematical model, based on a differential-equation framework and incorporating human mobility. The model was fitted to weekly malaria incidence from 45 villages. Three approaches for selecting intervention targets were compared: (a) villages with malaria cases during the low transmission season of the previous year; (b) villages with highest incidence during the high transmission season of the previous year; (c) villages with highest connectivity with adjacent populations. Our results showed that intervention strategies targeting hotspots would be effective in reducing malaria incidence in both targeted and untargeted areas. Regardless of the intervention strategy used, pre-elimination (1-5 cases per 1000 per year) would not be reached without simultaneously increasing vector control by more than 10%. A cornerstone of malaria control and elimination is the effective targeting of strategic locations. Mathematical tools help to identify those locations and estimate the impact in silico.
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Milusheva S. Managing the spread of disease with mobile phone data. JOURNAL OF DEVELOPMENT ECONOMICS 2020; 147:102559. [PMID: 33144750 PMCID: PMC7561616 DOI: 10.1016/j.jdeveco.2020.102559] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 06/04/2023]
Abstract
While human mobility has important benefits for economic growth, it can generate negative externalities. This paper studies the effect of mobility on the spread of disease in a low-incidence setting when people do not internalize their risks to others. Using malaria as a case study and 15 billion mobile phone records across nine million SIM cards, this paper quantifies the relationship between travel and the spread of disease. The estimates indicate that an infected traveler contributes to 1.66 additional cases reported in the health facility at the traveler's destination. This paper develops a simulation-based policy tool that uses mobile phone data to inform strategic targeting of travelers based on their origins and destinations. The simulations suggest that targeting informed by mobile phone data could reduce the caseload by 50 percent more than current strategies that rely only on previous incidence.
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Diallo SM, Bogreau H, Papa Mze N, Ould Ahmedou Salem MS, Ould Khairy ML, Parola P, Basco L, Ould Mohamed Salem Boukhary A. Malaria epidemiology in Kobeni department, southeastern Mauritania from 2015 to 2017. Infect Dis Poverty 2020; 9:21. [PMID: 32046780 PMCID: PMC7014702 DOI: 10.1186/s40249-020-0634-5] [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: 08/12/2019] [Accepted: 01/26/2020] [Indexed: 11/21/2022] Open
Abstract
Background Plasmodium falciparum malaria is endemic in the southern sahelian zone of Mauritania where intense internal and trans-border human and livestock movement occurs. The risk of importation and spread of drug-resistant parasites need to be regularly assessed in this region. The objective of the study was to assess the recent malaria situation near the Mauritania-Mali border. Methods Between February 2015 and December 2017, patients with fever or history of fever during the previous 48 h, presenting at the health centre of Kobeni city, were screened for malaria using a rapid diagnostic test (RDT) and microscopic examination of blood smears. The diagnosis was later confirmed by PCR. Cohen’s kappa statistics was used to estimate the degree of agreement between diagnostic methods. Fisher’s exact test was used to compare proportions. The odds ratio was calculated to measure the association between the use of bed nets and malaria infection. Results A total of 2326 febrile patients (mean age, 20.2 years) were screened for malaria. The presence of malaria parasites was detected by RDT and microscopy in 53.0% and 49.3% of febrile patients, respectively, and was confirmed by PCR in 59.7% (45 missing data). Of 1361 PCR-positive samples, 1205 (88.5%) were P. falciparum, 47 (3.5%) P. vivax, and 99 (7.3%) P. falciparum-P. vivax mixed infection. Malaria transmission occurred mostly during and shortly after the rainy season. The annual rainfall was relatively low in 2016 (267 mm) and 2017 (274 mm), compared to 2015 (448 mm), and coincided with a decline in malaria prevalence in 2016–2017. Although 71.8% of febrile patients reported to possess at least one bed net in the household in our questionnaire, its reported use was not protective against malaria infection (odds ratio: 1.1, 95% CI: 0.91–1.32). Conclusions Our study confirmed that P. falciparum is the dominant species in the sahelian zone and that malaria transmission is seasonal and associated with rainfall in this zone. The application of the current national policy based on rapid and reliable malaria diagnosis, case management with artemisinin-based combination therapy, intermittent preventive treatment for pregnant women, distribution and use of long-lasting insecticide impregnated bed nets, and the planned introduction of seasonal malaria chemoprevention for all children under 6 years old is expected to sustainably reduce malaria transmission in this zone.
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Affiliation(s)
- Sileye Mamadou Diallo
- Unité de Recherche Génomes et milieux (Jeune Equipe Associée à l'Institut de Recherche pour le Développement [IRD]), Faculté des Sciences et Techniques, Université de Nouakchott Al-Aasriya, Nouakchott, Mauritania.,Aix Marseille Université, IRD, Assistance Publique-Hôpitaux de Marseille (AP-HM), Service de Santé des Armées (SSA), Vecteurs - Infections Tropicales et Méditerranéennes (VITROME), Marseille, France.,Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection, Marseille, France
| | - Hervé Bogreau
- Aix Marseille Université, IRD, Assistance Publique-Hôpitaux de Marseille (AP-HM), Service de Santé des Armées (SSA), Vecteurs - Infections Tropicales et Méditerranéennes (VITROME), Marseille, France.,Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection, Marseille, France.,Unité Parasitologie et Entomologie, Département des maladies infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France
| | - Nasserdine Papa Mze
- Aix Marseille Université, IRD, Assistance Publique-Hôpitaux de Marseille (AP-HM), Service de Santé des Armées (SSA), Vecteurs - Infections Tropicales et Méditerranéennes (VITROME), Marseille, France.,Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection, Marseille, France
| | - Mohamed Salem Ould Ahmedou Salem
- Unité de Recherche Génomes et milieux (Jeune Equipe Associée à l'Institut de Recherche pour le Développement [IRD]), Faculté des Sciences et Techniques, Université de Nouakchott Al-Aasriya, Nouakchott, Mauritania
| | - Mohamed Lemine Ould Khairy
- Ministère de la Santé, Programme National de Lutte contre le Paludisme (PNLP), Nouakchott, Mauritania.,Present Address: Direction régionale de l'action sanitaire, Nouakchott sud, Ministère de la santé, Nouakchott, Mauritania
| | - Philippe Parola
- Aix Marseille Université, IRD, Assistance Publique-Hôpitaux de Marseille (AP-HM), Service de Santé des Armées (SSA), Vecteurs - Infections Tropicales et Méditerranéennes (VITROME), Marseille, France.,Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection, Marseille, France
| | - Leonardo Basco
- Aix Marseille Université, IRD, Assistance Publique-Hôpitaux de Marseille (AP-HM), Service de Santé des Armées (SSA), Vecteurs - Infections Tropicales et Méditerranéennes (VITROME), Marseille, France.,Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection, Marseille, France
| | - Ali Ould Mohamed Salem Boukhary
- Unité de Recherche Génomes et milieux (Jeune Equipe Associée à l'Institut de Recherche pour le Développement [IRD]), Faculté des Sciences et Techniques, Université de Nouakchott Al-Aasriya, Nouakchott, Mauritania. .,Aix Marseille Université, IRD, Assistance Publique-Hôpitaux de Marseille (AP-HM), Service de Santé des Armées (SSA), Vecteurs - Infections Tropicales et Méditerranéennes (VITROME), Marseille, France.
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Ngowo HS, Kaindoa EW, Matthiopoulos J, Ferguson HM, Okumu FO. Variations in household microclimate affect outdoor-biting behaviour of malaria vectors. Wellcome Open Res 2017; 2:102. [PMID: 29552642 PMCID: PMC5829465 DOI: 10.12688/wellcomeopenres.12928.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2017] [Indexed: 01/09/2023] Open
Abstract
Background: Mosquito behaviours including the degree to which they bite inside houses or outside is a crucial determinant of human exposure to malaria. Whilst seasonality in mosquito vector abundance is well documented, much less is known about the impact of climate on mosquito behaviour. We investigated how variations in household microclimate affect outdoor-biting by malaria vectors, Anopheles arabiensis and Anopheles funestus. Methods: Mosquitoes were sampled indoors and outdoors weekly using human landing catches at eight households in four villages in south-eastern Tanzania, resulting in 616 trap-nights over 12 months. Daily temperature, relative humidity and rainfall were recorded. Generalized additive mixed models (GAMMs) were used to test associations between mosquito abundance and the microclimatic conditions. Generalized linear mixed models (GLMMs) were used to investigate the influence of microclimatic conditions on the tendency of vectors to bite outdoors (proportion of outdoor biting). Results: An. arabiensis abundance peaked during high rainfall months (February-May), whilst An. funestus density remained stable into the dry season (May-August) . Across the range of observed household temperatures, a rise of 1 ºC marginally increased nightly An. arabiensis abundance (~11%), but more prominently increased An. funestus abundance (~66%). The abundance of An. arabiensis and An. funestus showed strong positive associations with time-lagged rainfall (2-3 and 3-4 weeks before sampling). The degree of outdoor biting in An. arabiensis was significantly associated with the relative temperature difference between indoor and outdoor environments, with exophily increasing as temperature inside houses became relatively warmer. The exophily of An. funestus did not vary with temperature differences. Conclusions: This study demonstrates that malaria vector An. arabiensis shifts the location of its biting from indoors to outdoors in association with relative differences in microclimatic conditions. These environmental impacts could give rise to seasonal variation in mosquito biting behaviour and degree of protection provided by indoor-based vector control strategies.
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Affiliation(s)
- Halfan S. Ngowo
- Department of Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Emmanuel Wilson Kaindoa
- Department of Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- School of Public Health, University of the Witwatersrand, Parktown, South Africa
| | - Jason Matthiopoulos
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Heather M. Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Fredros O. Okumu
- Department of Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
- School of Public Health, University of the Witwatersrand, Parktown, South Africa
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Diouf I, Rodriguez-Fonseca B, Deme A, Caminade C, Morse AP, Cisse M, Sy I, Dia I, Ermert V, Ndione JA, Gaye AT. Comparison of Malaria Simulations Driven by Meteorological Observations and Reanalysis Products in Senegal. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14101119. [PMID: 28946705 PMCID: PMC5664620 DOI: 10.3390/ijerph14101119] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 09/14/2017] [Accepted: 09/18/2017] [Indexed: 12/03/2022]
Abstract
The analysis of the spatial and temporal variability of climate parameters is crucial to study the impact of climate-sensitive vector-borne diseases such as malaria. The use of malaria models is an alternative way of producing potential malaria historical data for Senegal due to the lack of reliable observations for malaria outbreaks over a long time period. Consequently, here we use the Liverpool Malaria Model (LMM), driven by different climatic datasets, in order to study and validate simulated malaria parameters over Senegal. The findings confirm that the risk of malaria transmission is mainly linked to climate variables such as rainfall and temperature as well as specific landscape characteristics. For the whole of Senegal, a lag of two months is generally observed between the peak of rainfall in August and the maximum number of reported malaria cases in October. The malaria transmission season usually takes place from September to November, corresponding to the second peak of temperature occurring in October. Observed malaria data from the Programme National de Lutte contre le Paludisme (PNLP, National Malaria control Programme in Senegal) and outputs from the meteorological data used in this study were compared. The malaria model outputs present some consistencies with observed malaria dynamics over Senegal, and further allow the exploration of simulations performed with reanalysis data sets over a longer time period. The simulated malaria risk significantly decreased during the 1970s and 1980s over Senegal. This result is consistent with the observed decrease of malaria vectors and malaria cases reported by field entomologists and clinicians in the literature. The main differences between model outputs and observations regard amplitude, but can be related not only to reanalysis deficiencies but also to other environmental and socio-economic factors that are not included in this mechanistic malaria model framework. The present study can be considered as a validation of the reliability of reanalysis to be used as inputs for the calculation of malaria parameters in the Sahel using dynamical malaria models.
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Affiliation(s)
- Ibrahima Diouf
- Laboratoire de Physique de l'Atmosphère et de l'Océan-Siméon Fongang, Ecole Supérieure Polytechnique de l'Université Cheikh Anta Diop (UCAD), BP 5085, Dakar-Fann, Dakar 10700, Senegal.
- Department of Geophysics and Meteorology, Universidad Complutense de, Plaza de las Ciencias s/n, Madrid 28040, Spain.
| | - Belen Rodriguez-Fonseca
- Department of Geophysics and Meteorology, Universidad Complutense de, Plaza de las Ciencias s/n, Madrid 28040, Spain.
- Instituto de Geociencias IGEO, CSIC-UCM, Agencia Estatal del Consejo Superior de Investigaciones Científicas, Madrid 28040, Spain.
| | - Abdoulaye Deme
- Unité de Formation et de Recherche de Sciences Appliquées et de Technologie, Université Gaston Berger de Saint-Louis, BP 234, Saint-Louis 32000, Senegal.
| | - Cyril Caminade
- Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Water House Building, Liverpool L693GL, UK.
- National Institute for Health Research [M1] (NIHR), Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool L69 3GL, UK.
| | - Andrew P Morse
- National Institute for Health Research [M1] (NIHR), Health Protection Research Unit in Emerging and Zoonotic Infections, Liverpool L69 3GL, UK.
- Department of Geography and Planning, School of Environmental Sciences, University of Liverpool, Roxby Building, Liverpool L69 7ZT, UK.
| | - Moustapha Cisse
- Programme National de Lutte contre le Paludisme (PNLP), BP 25 270 Dakar-Fann, Dakar 10700, Senegal.
| | - Ibrahima Sy
- Centre de Suivi Ecologique, BP 15532, Fann Résidense, Dakar 10700, Senegal.
| | - Ibrahima Dia
- Institut Pasteur de Dakar (IPD), Unité d'Entomologie Médicale, 36 Av. Pasteur, BP 220 Dakar, Dakar 12900, Senegal.
| | - Volker Ermert
- Institute of Geophysics and Meteorology, University of Cologne, Kerpenerstr. 13, D-50923 Cologne, Germany.
| | | | - Amadou Thierno Gaye
- Laboratoire de Physique de l'Atmosphère et de l'Océan-Siméon Fongang, Ecole Supérieure Polytechnique de l'Université Cheikh Anta Diop (UCAD), BP 5085, Dakar-Fann, Dakar 10700, Senegal.
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Kibret S, Wilson GG, Ryder D, Tekie H, Petros B. The Influence of Dams on Malaria Transmission in Sub-Saharan Africa. ECOHEALTH 2017; 14:408-419. [PMID: 25894956 DOI: 10.1007/s10393-015-1029-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 03/22/2015] [Accepted: 03/25/2015] [Indexed: 06/04/2023]
Abstract
The construction of dams in sub-Saharan Africa is pivotal for food security and alleviating poverty in the region. However, the unintended adverse public health implications of extending the spatial distribution of water infrastructure are poorly documented and may minimize the intended benefits of securing water supplies. This paper reviews existing studies on the influence of dams on the spatial distribution of malaria parasites and vectors in sub-Saharan Africa. Common themes emerging from the literature were that dams intensified malaria transmission in semi-arid and highland areas with unstable malaria transmission but had little or no impact in areas with perennial transmission. Differences in the impacts of dams resulted from the types and characteristics of malaria vectors and their breeding habitats in different settings of sub-Saharan Africa. A higher abundance of a less anthropophilic Anopheles arabiensis than a highly efficient vector A. gambiae explains why dams did not increase malaria in stable areas. In unstable areas where transmission is limited by availability of water bodies for vector breeding, dams generally increase malaria by providing breeding habitats for prominent malaria vector species. Integrated vector control measures that include reservoir management, coupled with conventional malaria control strategies, could optimize a reduction of the risk of malaria transmission around dams in the region.
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Affiliation(s)
- Solomon Kibret
- Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW2351, Australia.
| | - G Glenn Wilson
- Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW2351, Australia
| | - Darren Ryder
- Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW2351, Australia
| | - Habte Tekie
- Department of Zoological Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
| | - Beyene Petros
- Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
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Effect of blood type on anti-α-Gal immunity and the incidence of infectious diseases. Exp Mol Med 2017; 49:e301. [PMID: 28280265 PMCID: PMC5382557 DOI: 10.1038/emm.2016.164] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/03/2016] [Accepted: 11/07/2016] [Indexed: 02/08/2023] Open
Abstract
The identification of factors affecting the susceptibility to infectious diseases is essential toward reducing their burden on the human population. The ABO blood type correlates with susceptibility to malaria and other infectious diseases. Due to the structural similarity between blood antigen B and Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal), we hypothesized that self-tolerance to antigen B affects the immune response to α-Gal, which in turn affects the susceptibility to infectious diseases caused by pathogens carrying α-Gal on their surface. Here we found that the incidence of malaria and tuberculosis, caused by pathogens with α-Gal on their surface, positively correlates with the frequency of blood type B in endemic regions. However, the incidence of dengue fever, caused by a pathogen without α-Gal, was not related to the frequency of blood type B in these populations. Furthermore, the incidence of malaria and tuberculosis was negatively correlated with the anti-α-Gal antibody protective response. These results have implications for disease control and prevention.
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Kibret S, Wilson GG, Ryder D, Tekie H, Petros B. Malaria impact of large dams at different eco-epidemiological settings in Ethiopia. Trop Med Health 2017; 45:4. [PMID: 28250711 PMCID: PMC5324293 DOI: 10.1186/s41182-017-0044-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/31/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Dams are important to ensure food security and promote economic development in sub-Saharan Africa. However, a poor understanding of the negative public health consequences from issues such as malaria could affect their intended advantages. This study aims to compare the malaria situation across elevation and proximity to dams. Such information may contribute to better understand how dams affect malaria in different eco-epidemiological settings. METHODS Larval and adult mosquitoes were collected from dam and non-dam villages around the Kesem (lowland), Koka (midland), and Koga (highland) dams in Ethiopia between October 2013 and July 2014. Determination of blood meal sources and detection of Plasmodium falciparum sporozoites was done using enzyme-linked immunosorbent assay (ELISA). Five years of monthly malaria case data (2010-2014) were also collected from health centers in the study villages. RESULTS Mean monthly malaria incidence was two- and ten-fold higher in the lowland dam village than in midland and highland dam villages, respectively. The total surface area of anopheline breeding habitats and the mean larval density was significantly higher in the lowland dam village compared with the midland and highland dam villages. Similarly, the mean monthly malaria incidence and anopheline larval density was generally higher in the dam villages than in the non-dam villages in all the three dam settings. Anopheles arabiensis, Anopheles pharoensis, and Anopheles funestus s.l. were the most common species, largely collected from lowland and midland dam villages. Larvae of these species were mainly found in reservoir shoreline puddles and irrigation canals. The mean adult anopheline density was significantly higher in the lowland dam village than in the midland and highland dam villages. The annual entomological inoculation rate (EIR) of An. arabiensis, An. funestus s.l., and An. pharoensis in the lowland dam village was 129.8, 47.8, and 33.3 infective bites per person per annum, respectively. The annual EIR of An. arabiensis and An. pharoensis was 6.3 and 3.2 times higher in the lowland dam village than in the midland dam village. CONCLUSIONS This study found that the presence of dams intensifies malaria transmission in lowland and midland ecological settings. Dam and irrigation management practices that could reduce vector abundance and malaria transmission need to be developed for these regions.
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Affiliation(s)
- Solomon Kibret
- Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351 Australia.,Present address: Program in Public Health, University of California, Irvine, CA 92697 USA
| | - G Glenn Wilson
- Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351 Australia
| | - Darren Ryder
- Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351 Australia
| | - Habte Tekie
- Department of Zoological Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
| | - Beyene Petros
- Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
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Xiao P, Ji H, Ye Y, Zhang B, Chen Y, Tian J, Liu P, Chen L, Du Z. Dietary silymarin supplementation promotes growth performance and improves lipid metabolism and health status in grass carp (Ctenopharyngodon idellus) fed diets with elevated lipid levels. FISH PHYSIOLOGY AND BIOCHEMISTRY 2017; 43:245-263. [PMID: 27632016 DOI: 10.1007/s10695-016-0283-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/29/2016] [Indexed: 06/06/2023]
Abstract
This study was carried out to evaluate whether silymarin supplementation influences growth, lipid metabolism, and health status in grass carp fed elevated dietary lipid levels. The juvenile fish (27.43 ± 0.17 g/tail) were fed six isonitrogenous and isocaloric diets in a factorial design containing 0, 100, or 200 mg kg-1 silymarin (SM0, SM100, SM200) associated with either 4 or 8 % lipid level (low lipid, LL, and high lipid, HL, respectively) for 82 days. The results showed that both dietary silymarin supplementation and high lipid level significantly enhanced growth performance (WG, SGR), protein efficiency ratio, and feed utilization. Silymarin supplementation significantly reduced the VSI, hepatic lipid content, and the total bilirubin concentration in the serum. The gallbladdersomatic index displayed higher in the SM100 groups than SM200 groups. Serum total cholesterol content exhibited lower in the SM100 groups than SM0 groups. Meanwhile, significant interactions were shown for hepatic gene expression of HSL and CPT1 by two factors, and SM100 group had higher hepatic gene expression of HSL and CPT1 in fish fed with the HL diets. The SM100 groups up-regulated hepatic gene expressions of HMGCR and CYP7A1 compared with the SM0 groups. Silymarin supplementation notably reduced the elevated serum MDA content induced by HL treatments. Thus, silymarin supplementation markedly promoted growth and protein efficiency, suppressed lipid accumulation, and improved health status in grass carp fed with high-lipid diets, which might be associated with its enhancement of lipolysis and β-oxidation, antioxidant capacity.
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Affiliation(s)
- Peizhen Xiao
- College of Animal Science and Technology, Northwest A & F University, Yangling, 712100, People's Republic of China
| | - Hong Ji
- College of Animal Science and Technology, Northwest A & F University, Yangling, 712100, People's Republic of China.
| | - Yuantu Ye
- Key Laboratory of Aquatic Nutrition of Jiangsu Province, School of Biology and Basic Medical Sciences, Soochow University, Soochow, 215123, People's Republic of China
| | - Baotong Zhang
- Open Lab for Aquatic Animal Nutrition, Beijing Research Institute for Nutritional Resources, Beijing, 100069, People's Republic of China
| | - Yongsheng Chen
- College of Animal Science and Technology, Northwest A & F University, Yangling, 712100, People's Republic of China
| | - Jingjing Tian
- College of Animal Science and Technology, Northwest A & F University, Yangling, 712100, People's Republic of China
| | - Pin Liu
- College of Animal Science and Technology, Northwest A & F University, Yangling, 712100, People's Republic of China
| | - Liqiao Chen
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Zhenyu Du
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
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11
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Mint Mohamed Lemine A, Ould Lemrabott MA, Hasni Ebou M, Mint Lekweiry K, Ould Ahmedou Salem MS, Ould Brahim K, Ouldabdallahi Moukah M, Ould Bouraya IN, Brengues C, Trape JF, Basco L, Bogreau H, Simard F, Faye O, Ould Mohamed Salem Boukhary A. Mosquitoes (Diptera: Culicidae) in Mauritania: a review of their biodiversity, distribution and medical importance. Parasit Vectors 2017; 10:35. [PMID: 28103955 PMCID: PMC5248481 DOI: 10.1186/s13071-017-1978-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/10/2017] [Indexed: 11/30/2022] Open
Abstract
Although mosquitoes (Diptera: Culicidae) are important disease vectors, information on their biodiversity in Mauritania is scarce and very dispersed in the literature. Data from the scientific literature gathered in the country from 1948 to 2016 were collected and analyzed. Overall 51 culicid species comprising 17 Anopheles spp., 14 Aedes spp., 18 Culex spp. and two Mansonia spp. have been described in Mauritania among which Anopheles arabiensis, Aedes vexans, Culex poicilipes and Culex antennatus are of epidemiological significance. Anopheles arabiensis is widely distributed throughout the country and its geographic distribution has increased northwards in recent years, shifting its northern limit form 17°32′N in the 1960s to 18°47′N today. Its presence in the central region of Tagant highlights the great ecological plasticity of the species. Conversely, the distribution of Anopheles gambiae (s.s.) and Anopheles melas has shrunk compared to that of the 1960s. Anopheles rhodesiensis and An. d’thali are mainly confined in the mountainous areas (alt. 200–700 m), whereas Anopheles pharoensis is widely distributed in the Senegal River basin. Culex poicilipes and Cx. antenattus were naturally found infected with Rift valley fever virus in central and northern Mauritania following the Rift valley outbreaks of 1998 and 2012. Recently, Ae. aegypti emerged in Nouakchott and is probably responsible for dengue fever episodes of 2015. This paper provides a concise and up-to-date overview of the existing literature on mosquito species known to occur in Mauritania and highlights areas where future studies should fill a gap in knowledge about vector biodiversity. It aims to help ongoing and future research on mosquitoes particularly in the field of medical entomology to inform evidence-based decision-making for vector control and management strategies.
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Affiliation(s)
- Aichetou Mint Mohamed Lemine
- Unité de recherche Génomes et Milieux, Jeune Equipe Associée à l'IRD (RI3M), Université de Nouakchott Al-Aasriya, Faculté des Sciences et Techniques, Nouveau Campus Universitaire, Nouakchott, BP 5026, Mauritania.,Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Senegal
| | - Mohamed Aly Ould Lemrabott
- Unité de recherche Génomes et Milieux, Jeune Equipe Associée à l'IRD (RI3M), Université de Nouakchott Al-Aasriya, Faculté des Sciences et Techniques, Nouveau Campus Universitaire, Nouakchott, BP 5026, Mauritania
| | - Moina Hasni Ebou
- Unité de recherche Génomes et Milieux, Jeune Equipe Associée à l'IRD (RI3M), Université de Nouakchott Al-Aasriya, Faculté des Sciences et Techniques, Nouveau Campus Universitaire, Nouakchott, BP 5026, Mauritania
| | - Khadijetou Mint Lekweiry
- Unité de recherche Génomes et Milieux, Jeune Equipe Associée à l'IRD (RI3M), Université de Nouakchott Al-Aasriya, Faculté des Sciences et Techniques, Nouveau Campus Universitaire, Nouakchott, BP 5026, Mauritania
| | - Mohamed Salem Ould Ahmedou Salem
- Unité de recherche Génomes et Milieux, Jeune Equipe Associée à l'IRD (RI3M), Université de Nouakchott Al-Aasriya, Faculté des Sciences et Techniques, Nouveau Campus Universitaire, Nouakchott, BP 5026, Mauritania
| | - Khyarhoum Ould Brahim
- Unité de recherche Génomes et Milieux, Jeune Equipe Associée à l'IRD (RI3M), Université de Nouakchott Al-Aasriya, Faculté des Sciences et Techniques, Nouveau Campus Universitaire, Nouakchott, BP 5026, Mauritania
| | - Mohamed Ouldabdallahi Moukah
- Unité de recherche Génomes et Milieux, Jeune Equipe Associée à l'IRD (RI3M), Université de Nouakchott Al-Aasriya, Faculté des Sciences et Techniques, Nouveau Campus Universitaire, Nouakchott, BP 5026, Mauritania
| | | | - Cecile Brengues
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Unité Mixte de Recherche IRD224-CNRS5290-Université de Montpellier, Institut de Recherche pour le Développement (IRD), Montpellier, France
| | - Jean-François Trape
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Unité Mixte de Recherche IRD224-CNRS5290-Université de Montpellier, Institut de Recherche pour le Développement (IRD), Montpellier, France
| | - Leonardo Basco
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM 63, CNRS 7278, IRD 198, Inserm 1095, Faculté de Médecine La Timone, Aix-Marseille Université, Marseille, 13385, France
| | - Hervé Bogreau
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM 63, CNRS 7278, IRD 198, Inserm 1095, Faculté de Médecine La Timone, Aix-Marseille Université, Marseille, 13385, France.,Unité Parasitologie et Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Marseille, France
| | - Frédéric Simard
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Unité Mixte de Recherche IRD224-CNRS5290-Université de Montpellier, Institut de Recherche pour le Développement (IRD), Montpellier, France
| | - Ousmane Faye
- Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Senegal
| | - Ali Ould Mohamed Salem Boukhary
- Unité de recherche Génomes et Milieux, Jeune Equipe Associée à l'IRD (RI3M), Université de Nouakchott Al-Aasriya, Faculté des Sciences et Techniques, Nouveau Campus Universitaire, Nouakchott, BP 5026, Mauritania.
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12
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Ould Ahmedou Salem MS, Basco LK, Ouldabdallahi M, Mint Lekweiry K, Konaté L, Faye O, Ould Mohamed Salem Boukhary A. Malaria-associated morbidity during the rainy season in Saharan and Sahelian zones in Mauritania. Acta Trop 2015; 152:1-7. [PMID: 26276697 DOI: 10.1016/j.actatropica.2015.08.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 12/31/2022]
Abstract
Reliable epidemiological data based on laboratory-confirmed cases are scarce in Mauritania. A large majority of reported malaria cases are based on presumptive clinical diagnosis. The present study was conducted to establish a reliable database on malaria morbidity among febrile paediatric and adult patients consulting spontaneously at public health facilities in Nouakchott, situated in the Saharan zone, and in Hodh Elgharbi region in the Sahelian zone in south-east Mauritania during the peak transmission periods. Giemsa-stained thin and thick films were examined under the microscope, and the parasite density was determined according to the procedures recommended by the World Health Organization. Microscopy results were confirmed by rapid diagnostic test for malaria. A total of 1161 febrile patients (498 in Nouakchott and 663 in Hodh Elgharbi region) were enrolled during two successive peak transmission periods in 2009 and 2010. In Nouakchott, 253 (50.8%) febrile patients had positive smears (83% Plasmodium vivax monoinfections and 17% Plasmodium falciparum monoinfections). In Hodh Elgharbi, 378 of 663 patients (57.0%) were smear-positive, mostly due to P. falciparum monoinfections (96.6%). Unlike in Nouakchott, mixed P. falciparum-P. vivax infections, as well as P. vivax, P. ovale, and P. malariae monoinfections, were also observed at a very low prevalence in southern Mauritania. In Nouakchott, malaria occurred more frequently (P<0.05) with higher slide positivity rates (42-53%) among children aged >5 years old and adults than in young children aged <5 years old in both 2009 and 2010. In Hodh Elgharbi, high slide positivity rates (60.9-86.2%) were observed in all age groups in 2010, and there was no significant trend (P>0.05) in relation with age groups. The present study confirmed the predominance of P. falciparum in southern Mauritania reported in previous studies. The presence of P. vivax in Nouakchott is a new epidemiological reality that requires an urgent adoption of novel strategies for parasitological and vector control to combat urban malaria. Moreover, the present study provides evidence-based data on malaria burden in two regions in Mauritania that may serve as a springboard to establish and develop a national surveillance system of malaria epidemiology.
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13
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Kibret S, Lautze J, McCartney M, Wilson GG, Nhamo L. Malaria impact of large dams in sub-Saharan Africa: maps, estimates and predictions. Malar J 2015; 14:339. [PMID: 26337834 PMCID: PMC4560078 DOI: 10.1186/s12936-015-0873-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 08/26/2015] [Indexed: 11/24/2022] Open
Abstract
Background While there is growing recognition of the malaria impacts of large dams in sub-Saharan Africa, the cumulative malaria impact of reservoirs associated with current and future dam developments has not been quantified. The objective of this study was to estimate the current and predict the future impact of large dams on malaria in different eco-epidemiological settings across sub-Saharan Africa. Methods The locations of 1268 existing and 78 planned large dams in sub-Saharan Africa were mapped against the malaria stability index (stable, unstable and no malaria). The Plasmodium falciparum infection rate (PfIR) was determined for populations at different distances (<1, 1–2, 2–5, 5–9 km) from the associated reservoirs using the Malaria Atlas Project (MAP) and WorldPop databases. Results derived from MAP were verified by comparison with the results of detailed epidemiological studies conducted at 11 dams. Results Of the 1268 existing dams, 723 are located in malarious areas. Currently, about 15 million people live in close proximity (<5 km) to the reservoirs associated with these dams. A total of 1.1 million malaria cases annually are associated with them: 919,000 cases due to the presence of 416 dams in areas of unstable transmission and 204,000 cases due to the presence of 307 dams in areas of stable transmission. Of the 78 planned dams, 60 will be located in malarious areas and these will create an additional 56,000 cases annually. The variation in annual PfIR in communities as a function of distance from reservoirs was statistically significant in areas of unstable transmission but not in areas of stable transmission. Conclusion In sub-Saharan Africa, dams contribute significantly to malaria risk particularly in areas of unstable transmission. Additional malaria control measures are thus required to reduce the impact of dams on malaria.
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Affiliation(s)
- Solomon Kibret
- Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia.
| | - Jonathan Lautze
- International Water Management Institute, Pretoria, South Africa.
| | | | - G Glenn Wilson
- Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia.
| | - Luxon Nhamo
- International Water Management Institute, Pretoria, South Africa.
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14
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Sanford MR, Cornel AJ, Nieman CC, Dinis J, Marsden CD, Weakley AM, Han S, Rodrigues A, Lanzaro GC, Lee Y. Plasmodium falciparum infection rates for some Anopheles spp. from Guinea-Bissau, West Africa. F1000Res 2014; 3:243. [PMID: 25383188 PMCID: PMC4215749 DOI: 10.12688/f1000research.5485.2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/04/2014] [Indexed: 11/30/2022] Open
Abstract
Presence of
Plasmodiumfalciparum circumsporozoite protein (CSP) was detected by enzyme linked immunosorbent assay (ELISA) in a sample of
Anophelesgambiae s.s.,
A. melas and
A. pharoensis collected in Guinea-Bissau during October and November 2009. The percentage of
P. falciparum infected samples (10.2% overall; confidence interval (CI): 7.45-13.6%) was comparable to earlier studies from other sites in Guinea-Bissau (9.6-12.4%). The majority of the specimens collected were identified as
A.
gambiae which had an individual infection rate of 12.6 % (CI: 8.88-17.6) across collection sites. A small number of specimens of
A. coluzzii, A. coluzzii x
A. gambiae hybrids,
A.
melas and
A.
pharoensis were collected and had infection rates of 4.3% (CI:0.98-12.4), 4.1% (CI:0.35-14.5), 11.1% (CI:1.86-34.1) and 33.3% (CI:9.25-70.4) respectively. Despite being present in low numbers in indoor collections, the exophilic feeding behaviors of
A.
melas (N=18) and
A.
pharoensis (N=6) and high infection rates observed in this survey suggest
falciparum-malaria transmission potential outside of the protection of bed nets.
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Affiliation(s)
- Michelle R Sanford
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, 95616, USA ; Current Affiliation: Harris County Institute of Forensic Sciences, 1885 Old Spanish Trail, Houston, 77054, USA
| | - Anthony J Cornel
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, 95616, USA ; Department of Entomology and Nematology, University of California, Davis, 95616, USA
| | - Catelyn C Nieman
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, 95616, USA
| | - Joao Dinis
- National Institute of Public Health (INASA), Bissau, Guinea-Bissau
| | - Clare D Marsden
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, 95616, USA
| | - Allison M Weakley
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, 95616, USA
| | - Sarah Han
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, 95616, USA
| | | | - Gregory C Lanzaro
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, 95616, USA
| | - Yoosook Lee
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, 95616, USA
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15
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Lyons CL, Coetzee M, Terblanche JS, Chown SL. Desiccation tolerance as a function of age, sex, humidity and temperature in adults of the African malaria vectors Anopheles arabiensis and Anopheles funestus. ACTA ACUST UNITED AC 2014; 217:3823-33. [PMID: 25267846 DOI: 10.1242/jeb.104638] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Adult mosquito survival is strongly temperature and moisture dependent. Few studies have investigated the interacting effects of these variables on adult survival and how this differs among the sexes and with age, despite the importance of such information for population dynamic models. For these reasons, the desiccation tolerance of Anopheles arabiensis Patton and Anopheles funestus Giles males and females of three different ages was assessed under three combinations of temperature and humidity. Females were more desiccation tolerant than males, surviving for longer periods than males under all experimental conditions. In addition, younger adults were more tolerant of desiccation than older groups. Both species showed reduced water loss rate (WLR) as the primary mechanism by which they tolerate desiccation. Although A. arabiensis is often considered to be the more arid-adapted of the two species, it showed lower survival times and higher WLR than A. funestus. The current information could improve population dynamic models of these vectors, given that adult survival information for such models is relatively sparse.
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Affiliation(s)
- Candice L Lyons
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa
| | - Maureen Coetzee
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa
| | - John S Terblanche
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, Matieland 7602, South Africa
| | - Steven L Chown
- School of Biological Sciences, Monash University, VIC 3800, Australia
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16
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Gaayeb L, Sarr JB, Cames C, Pinçon C, Hanon JB, Ndiath MO, Seck M, Herbert F, Sagna AB, Schacht AM, Remoue F, Riveau G, Hermann E. Effects of malnutrition on children's immunity to bacterial antigens in Northern Senegal. Am J Trop Med Hyg 2014; 90:566-73. [PMID: 24445198 DOI: 10.4269/ajtmh.12-0657] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
To evaluate immunity to vaccine-preventable diseases according to nutritional status, a longitudinal study was conducted in Senegalese children ages 1-9 years old. A linear regression analysis predicted that weight for age was positively associated with immunoglobulin G (IgG) response to tetanus toxoid in children born during the rainy season or at the beginning of the dry season. A relationship between village, time of visits, and levels of antibodies to tetanus showed that environmental factors played a role in modulating humoral immunity to tetanus vaccine over time. Moreover, a whole-blood stimulation assay highlighted that the production of interferon-γ (IFN-γ) in response to tetanus toxoid was compromised in stunted children. However, the absence of cytokine modulation in response to Mycobacterium tuberculosis-purified protein derivatives and phytohemagglutinin suggests that the overall ability to produce IFN-γ was preserved in stunted children. Therefore, these results show that nutritional status can specifically alter the efficacy of long-lasting immunity to tetanus.
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Affiliation(s)
- Lobna Gaayeb
- Center for Infection and Immunity of Lille (CIIL)-U1019 Inserm, Unité Mixte de Recherche (UMR) 8204 Centre National de la Recherche Scientifique (CNRS), Université Lille Nord de France, Institut Pasteur de Lille, Lille, France; Centre de Recherche Biomédicale Espoir Pour la Santé (EPLS), Saint-Louis, Senegal; Institut de Recherche pour le Développement Unité Mixte Internationale (UMI) 233 TransVIHmi, Centre Régional de Recherche et de Formation à la prise en charge Clinique, Centre Hospitalier Universitaire de Fann, Dakar, Senegal; Department of Biostatistics, Faculté de Pharmacie de Lille, Université Lille Nord de France, Lille, France; UMR198 URMITE, Campus International, Institut de Recherche pour le Développement, Université Cheikh Anta Diop de Dakar (UCAD), Institut de Recherche pour le Développement Hann, Dakar, Senegal; UMR Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche pour le Développement 224, CNRS5290, Université de Montpellier 1 et 2, Institut de Recherche pour le Développement, Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
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17
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Sagna AB, Gaayeb L, Sarr JB, Senghor S, Poinsignon A, Boutouaba-Combe S, Schacht AM, Hermann E, Faye N, Remoue F, Riveau G. Plasmodium falciparum infection during dry season: IgG responses to Anopheles gambiae salivary gSG6-P1 peptide as sensitive biomarker for malaria risk in Northern Senegal. Malar J 2013; 12:301. [PMID: 23988032 PMCID: PMC3766161 DOI: 10.1186/1475-2875-12-301] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 08/27/2013] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The Northern part of Senegal is characterized by a low and seasonal transmission of malaria. However, some Plasmodium falciparum infections and malaria clinical cases are reported during the dry season. This study aims to assess the relationship between IgG antibody (Ab) responses to gSG6-P1 mosquito salivary peptide and the prevalence of P. falciparum infection in children during the dry season in the Senegal River Valley. The positive association of the Ab response to gSG6-P1, as biomarker of human exposure to Anopheles vector bite, and P. falciparum infectious status (uninfected, infected-asymptomatic or infected-symptomatic) will allow considering this biomarker as a potential indicator of P. falciparum infection risk during the dry season. METHODS Microscopic examination of thick blood smears was performed in 371 and 310 children at the start (January) and at the end (June) of the dry season, respectively, in order to assess the prevalence of P. falciparum infection. Collected sera were used to evaluate IgG response to gSG6-P1 by ELISA. Association between parasitological and clinical data (infected-asymptomatic or infected-symptomatic) and the anti-gSG6-P1 IgG levels were evaluated during this period. RESULTS The prevalence of P. falciparum infection was very low to moderate according to the studied period and was higher in January (23.5%) compared to June (3.5%). Specific IgG response was also different between uninfected children and asymptomatic carriers of the parasite. Children with P. falciparum infection in the dry season showed higher IgG Ab levels to gSG6-P1 than uninfected children. CONCLUSIONS The results strengthen the hypothesis that malaria transmission is maintained during the dry season in an area of low and seasonal transmission. The measurement of IgG responses to gSG6-P1 salivary peptide could be a pertinent indicator of human malaria reservoir or infection risk in this particular epidemiological context. This promising immunological marker could be useful for the evaluation of the risk of P. falciparum exposure observed during dry season and, by consequences, could be used for the survey of potential pre-elimination situation.
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Affiliation(s)
- André B Sagna
- Centre de Recherche Biomédicale Espoir Pour La Santé, 269 Route de la corniche, Sor, BP: 226, Saint-Louis, Sénégal
- Département de Biologie Animale, Laboratoire de parasitologie générale, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Lobna Gaayeb
- Centre de Recherche Biomédicale Espoir Pour La Santé, 269 Route de la corniche, Sor, BP: 226, Saint-Louis, Sénégal
- CIIL, Inserm U1019, CNRS UMR 8204, Université Lille Nord de France, Institut Pasteur de Lille, 1 rue du Pr. Calmette, 59019 Lille cedex, France
| | - Jean B Sarr
- Centre de Recherche Biomédicale Espoir Pour La Santé, 269 Route de la corniche, Sor, BP: 226, Saint-Louis, Sénégal
- Institut de Recherche pour le Développement, UMR 224 MIVEGEC, 911 avenue Agropolis, BP: 64501F-34394 Montpellier, France
| | - Simon Senghor
- Centre de Recherche Biomédicale Espoir Pour La Santé, 269 Route de la corniche, Sor, BP: 226, Saint-Louis, Sénégal
| | - Anne Poinsignon
- Institut de Recherche pour le Développement, UMR 224 MIVEGEC, 911 avenue Agropolis, BP: 64501F-34394 Montpellier, France
| | - Samy Boutouaba-Combe
- Centre de Recherche Biomédicale Espoir Pour La Santé, 269 Route de la corniche, Sor, BP: 226, Saint-Louis, Sénégal
| | - Anne-Marie Schacht
- Centre de Recherche Biomédicale Espoir Pour La Santé, 269 Route de la corniche, Sor, BP: 226, Saint-Louis, Sénégal
- CIIL, Inserm U1019, CNRS UMR 8204, Université Lille Nord de France, Institut Pasteur de Lille, 1 rue du Pr. Calmette, 59019 Lille cedex, France
| | - Emmanuel Hermann
- CIIL, Inserm U1019, CNRS UMR 8204, Université Lille Nord de France, Institut Pasteur de Lille, 1 rue du Pr. Calmette, 59019 Lille cedex, France
| | - Ngor Faye
- Département de Biologie Animale, Laboratoire de parasitologie générale, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Franck Remoue
- Institut de Recherche pour le Développement, UMR 224 MIVEGEC, 911 avenue Agropolis, BP: 64501F-34394 Montpellier, France
- Centre de Recherche Entomologique de Cotonou, BP: 4414, Cotonou RP 01, Bénin
| | - Gilles Riveau
- Centre de Recherche Biomédicale Espoir Pour La Santé, 269 Route de la corniche, Sor, BP: 226, Saint-Louis, Sénégal
- CIIL, Inserm U1019, CNRS UMR 8204, Université Lille Nord de France, Institut Pasteur de Lille, 1 rue du Pr. Calmette, 59019 Lille cedex, France
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Sokhna C, Ndiath MO, Rogier C. The changes in mosquito vector behaviour and the emerging resistance to insecticides will challenge the decline of malaria. Clin Microbiol Infect 2013; 19:902-7. [PMID: 23910459 DOI: 10.1111/1469-0691.12314] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The preventive measures against malaria recommended by the WHO include anti-vector procedures such as indoor residual spraying, the use of long-lasting insecticide-treated bed-nets, and the destruction of larval breeding sites. The presence of insecticide-treated materials inside the mosquito habitat has consequences for the vector's population, reducing density, survival, contact with humans, and feeding frequency. However, the effectiveness of these tools is being challenged by the emergence of insecticide resistance. The evolution of resistance to insecticides in Anopheles threatens to thwart the goal of decreasing malaria transmission, in an arms race between malaria control programmes and the vector populations. Multiple mechanisms of resistance to insecticides have been observed in Anopheles populations, including target site mutation (knockdown resistance), increased metabolic detoxification, and remarkable behavioural adaptation. These disturbing observations all show the capacity of Anopheles to adapt to and circumvent strategies aimed at reducing malaria transmission. Thus, by using nets to protect ourselves, are we providing Anopheles with the entire arsenal needed to hit much harder?
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Affiliation(s)
- C Sokhna
- URMITE, UMR CNRS 6236 - IRD 198, Inserm 1095, Aix Marseille Université, Campus Universitaire IRD de Hann, Dakar, Sénégal
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19
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Sagna AB, Sarr JB, Gaayeb L, Drame PM, Ndiath MO, Senghor S, Sow CS, Poinsignon A, Seck M, Hermann E, Schacht AM, Faye N, Sokhna C, Remoue F, Riveau G. gSG6-P1 salivary biomarker discriminates micro-geographical heterogeneity of human exposure to Anopheles bites in low and seasonal malaria areas. Parasit Vectors 2013; 6:68. [PMID: 23497646 PMCID: PMC3631127 DOI: 10.1186/1756-3305-6-68] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 03/08/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Over the past decade, a sharp decline of malaria burden has been observed in several countries. Consequently, the conventional entomological methods have become insufficiently sensitive and probably under-estimate micro-geographical heterogeneity of exposure and subsequent risk of malaria transmission. In this study, we investigated whether the human antibody (Ab) response to Anopheles salivary gSG6-P1 peptide, known as a biomarker of Anopheles exposure, could be a sensitive and reliable tool for discriminating human exposure to Anopheles bites in area of low and seasonal malaria transmission. METHODS A multi-disciplinary survey was performed in Northern Senegal where An. gambiae s.l. is the main malaria vector. Human IgG Ab response to gSG6-P1 salivary peptide was compared according to the season and villages in children from five villages in the middle Senegal River valley, known as a low malaria transmission area. RESULTS IgG levels to gSG6-P1 varied considerably according to the villages, discriminating the heterogeneity of Anopheles exposure between villages. Significant increase of IgG levels to gSG6-P1 was observed during the peak of exposure to Anopheles bites, and decreased immediately after the end of the exposure season. In addition, differences in the season-dependent specific IgG levels between villages were observed after the implementation of Long-Lasting Insecticidal Nets by The National Malaria Control Program in this area. CONCLUSION The gSG6-P1 salivary peptide seems to be a reliable tool to discriminate the micro-geographical heterogeneity of human exposure to Anopheles bites in areas of very low and seasonal malaria transmission. A biomarker such as this could also be used to monitor and evaluate the possible heterogeneous effectiveness of operational vector control programs in low-exposure areas.
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Affiliation(s)
- André Barembaye Sagna
- Centre de Recherche Biomédicale (CRB) Espoir Pour La Santé, 269 Route de la corniche, Sor - BP: 226, Saint-Louis, Sénégal.
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20
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Reddy MR, Godoy A, Dion K, Matias A, Callender K, Kiszewski AE, Kleinschmidt I, Ridl FC, Powell JR, Caccone A, Slotman MA. Insecticide resistance allele frequencies in Anopheles gambiae before and after anti-vector interventions in continental Equatorial Guinea. Am J Trop Med Hyg 2013; 88:897-907. [PMID: 23438768 DOI: 10.4269/ajtmh.12-0467] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Anti-malaria interventions that rely on insecticides can be compromised by insecticide-resistance alleles among malaria vectors. We examined frequency changes of resistance alleles at two loci, knockdown resistance (kdr) and acetylcholinesterase-1 (ace-1), which confer resistance to pyrethroids and DDT, and carbamates, respectively. A total of 7,059 Anopheles gambiae sensu stricto mosquitoes were analyzed from multiple sites across continental Equatorial Guinea. A subset of sites included samples collected pre-intervention (2007) and post-intervention (2009-2011). Both L1014S and L1014F resistance alleles were observed in almost all pre-intervention collections. In particular, L1014F was already at substantial frequencies in M form populations (17.6-74.6%), and at high frequencies (> 50%) in all but two S form populations. Comparison before and throughout anti-vector interventions showed drastic increases in L1014F, presumably caused by intensified selection pressure imposed by pyrethroids used in vector control efforts. In light of these findings, inclusion of other insecticide classes in any anti-vector intervention can be considered prudent.
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Affiliation(s)
- Michael R Reddy
- Department of Epidemiology and Public Health, Yale University, New Haven, CT 06511, USA.
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Touray S, Bâ H, Bâ O, Koïta M, Salem CBOA, Keïta M, Traoré D, Sy I, Winkler MS, Utzinger J, Cissé G. Absence of dry season Plasmodium parasitaemia, but high rates of reported acute respiratory infection and diarrhoea in preschool-aged children in Kaédi, southern Mauritania. Parasit Vectors 2012; 5:193. [PMID: 22958321 PMCID: PMC3465244 DOI: 10.1186/1756-3305-5-193] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 08/11/2012] [Indexed: 11/23/2022] Open
Abstract
Background The epidemiology of malaria in the Senegal River Gorgol valley, southern Mauritania, requires particular attention in the face of ongoing and predicted environmental and climate changes. While “malaria cases” are reported in health facilities throughout the year, past and current climatic and ecological conditions do not favour transmission in the dry season (lack of rainfall and very high temperatures). Moreover, entomological investigations in neighbouring regions point to an absence of malaria transmission in mosquito vectors in the dry season. Because the clinical signs of malaria are non-specific and overlap with those of other diseases (e.g. acute respiratory infections and diarrhoea), new research is needed to better understand malaria transmission patterns in this region to improve adaptive, preventive and curative measures. Methods We conducted a multipurpose cross-sectional survey in the city of Kaédi in April 2011 (dry season), assessing three major disease patterns, including malaria. Plasmodium spp. parasite rates were tested among children aged 6–59 months who were recruited from a random selection of households using a rapid diagnostic test and microscopic examination of Giemsa-stained thick and thin blood films. Acute respiratory infection and diarrhoea were the two other diseases investigated, administering a parental questionnaire to determine the reported prevalence among participating children. Findings No Plasmodium infection was found in any of the 371 surveyed preschool-aged children using two different diagnostic methods. Acute respiratory infections and diarrhoea were reported in 43.4% and 35.0% of the participants, respectively. About two thirds of the children with acute respiratory infections and diarrhoea required medical follow-up by a health worker. Conclusions Malaria was absent in the present dry season survey in the capital of the Gorgol valley of Mauritania, while acute respiratory infections and diarrhea were highly prevalent. Surveys should be repeated towards the end of rainy season, which will enhance our understanding of the potential changes in malaria transmission in a region known as ‘hot spot’ of predicted climate change.
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Affiliation(s)
- Sunkaru Touray
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P,O, Box,, CH-4002, Basel, Switzerland
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