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Hernández-Vásquez A, Visconti-Lopez FJ, Vargas-Fernández R. Escherichia coli Contamination of Water for Human Consumption and Its Associated Factors in Peru: A Cross-Sectional Study. Am J Trop Med Hyg 2023; 108:187-194. [PMID: 36509044 PMCID: PMC9833058 DOI: 10.4269/ajtmh.22-0240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 09/13/2022] [Indexed: 12/15/2022] Open
Abstract
The objective of the study was to determine the factors associated with the presence of Escherichia coli contamination in water supplies for human consumption in Peru. A secondary analysis of the Food and Nutrition Surveillance by Life Stages survey (VIANEV) of 2017-2018 was performed. The presence of E. coli contamination in the water samples for human consumption of the households evaluated was defined as a dependent variable. A supply was considered contaminated when there was at least 1 colony-forming unit of E. coli in 100 mL of water for human consumption. Data from 886 participants were analyzed. It was found that 25.2% of household water supply sources for human consumption had E. coli at the time of sampling. Water reservoirs such as buckets or other containers (adjusted prevalence ratio [aPR]: 1.15; 95% confidence interval [CI]: 1.18-1.93), households belonging to a poor wealth quintile (aPR: 1.82; 95% CI: 1.01-3.25), residing in a rural area (aPR: 1.36; 95% CI: 1.01-1.83), and having a low human development index (aPR: 2.12; 95% CI: 1.15-3.91) were more likely to contain E. coli in water supplies for human consumption. However, households with chlorine concentrations of 0.5 mg/L or more in water (aPR: 0.20; 95% CI: 0.11-0.33) and with household members with a higher education (aPR: 0.67; 95% CI: 0.45-0.99) were less likely to contain E. coli in drinking-water supplies. From 2017 to 2018, one in four Peruvians had contamination by E. coli in the water supply to their homes, which was associated with sociodemographic factors, management, and water treatment.
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Affiliation(s)
- Akram Hernández-Vásquez
- Centro de Excelencia en Investigaciones Económicas y Sociales en Salud, Vicerrectorado de Investigación, Universidad San Ignacio de Loyola, Lima, Peru
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Poague KIHM, Blanford JI, Anthonj C. Water, Sanitation and Hygiene in Schools in Low- and Middle-Income Countries: A Systematic Review and Implications for the COVID-19 Pandemic. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:3124. [PMID: 35270814 PMCID: PMC8910349 DOI: 10.3390/ijerph19053124] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/21/2022] [Accepted: 03/03/2022] [Indexed: 12/26/2022]
Abstract
The global COVID-19 pandemic has revealed the extent to which schools are struggling with the provision of safe drinking water, sanitation and hygiene (WASH). To describe the WASH conditions in schools and discuss the implications for the safe reopening of schools during the ongoing COVID-19 pandemic, a systematic review of peer-reviewed literature on WASH in schools in low- and middle-income countries was performed. In April 2021, five databases, including MEDLINE (via PubMed), Web of Science, Scopus, AJOL, and LILACS, were used to identify studies. Sixty-five papers met the inclusion criteria. We extracted and analyzed data considering the Joint Monitoring Programme (JMP) definitions and the normative contents of Human Rights to safe drinking water and sanitation. Publications included in this systematic review considered 18,465 schools, across 30 different countries. Results indicate a lack of adequate WASH conditions and menstrual hygiene management requirements in all countries. The largely insufficient and inadequate school infrastructure hampers students to practice healthy hygiene habits and handwashing in particular. In the context of the COVID-19 pandemic, being hindered to implement such a key strategy to contain the spread of SARS-CoV-2 in the school environment is of major concern.
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Affiliation(s)
- Kasandra I. H. M. Poague
- Faculty of Geo-Information Science and Earth Observation–ITC, University of Twente, Hengelosestraat 99, P.O. Box 217, 7500 AE Enschede, The Netherlands; (J.I.B.); (C.A.)
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Overgaard HJ, Dada N, Lenhart A, Stenström TAB, Alexander N. Integrated disease management: arboviral infections and waterborne diarrhoea. Bull World Health Organ 2021; 99:583-592. [PMID: 34354313 PMCID: PMC8319858 DOI: 10.2471/blt.20.269985] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 02/15/2021] [Accepted: 03/08/2021] [Indexed: 11/27/2022] Open
Abstract
Water-related diseases such as diarrhoeal diseases from viral, bacterial and parasitic organisms and Aedes-borne arboviral diseases are major global health problems. We believe that these two disease groups share common risk factors, namely inadequate household water management, poor sanitation and solid waste management. Where water provision is inadequate, water storage is essential. Aedes mosquitoes commonly breed in household water storage containers, which can hold water contaminated with enteric disease-causing organisms. Microbiological contamination of water between source and point-of-use is a major cause of reduced drinking-water quality. Inadequate sanitation and solid waste management increase not only risk of water contamination, but also the availability of mosquito larval habitats. In this article we discuss integrated interventions that interrupt mosquito breeding while also providing sanitary environments and clean water. Specific interventions include improving storage container design, placement and maintenance and scaling up access to piped water. Vector control can be integrated into sanitation projects that target sewers and drains to avoid accumulation of stagnant water. Better management of garbage and solid waste can reduce the availability of mosquito habitats while improving human living conditions. Our proposed integration of disease interventions is consistent with strategies promoted in several global health frameworks, such as the sustainable development goals, the global vector control response, behavioural change, and water, sanitation and hygiene initiatives. Future research should address how interventions targeting water, sanitation, hygiene and community waste disposal also benefit Aedes-borne disease control. The projected effects of climate change mean that integrated management and control strategies will become increasingly important.
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Affiliation(s)
- Hans J Overgaard
- Faculty of Science and Technology, Drøbakveien 31, Norwegian University of Life Sciences, NO – 1432 Ås, Norway
| | - Nsa Dada
- Faculty of Science and Technology, Drøbakveien 31, Norwegian University of Life Sciences, NO – 1432 Ås, Norway
| | - Audrey Lenhart
- Center for Global Health, United States Centers for Disease Control and Prevention, Atlanta, United States of America
| | - Thor Axel B Stenström
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa
| | - Neal Alexander
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, England
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Naturally Occurring Microbiota Associated with Mosquito Breeding Habitats and Their Effects on Mosquito Larvae. BIOMED RESEARCH INTERNATIONAL 2021; 2020:4065315. [PMID: 33381553 PMCID: PMC7755482 DOI: 10.1155/2020/4065315] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 07/12/2020] [Accepted: 08/04/2020] [Indexed: 11/25/2022]
Abstract
Immature mosquitoes are aquatic, and their distribution, abundance, and individual fitness in a particular breeding habitat are known to be dependent on mainly three factors: biotic factors, abiotic factors, and their interaction between each other and with other associated taxa. Mosquito breeding habitats harbor a diversified naturally occurring microbiota assemblage, and the biota have different types of interactions with mosquito larvae in those habitats. Those interactions may include parasitism, pathogenism, predation, and competition which cause the mortality of larvae, natural reduction of larval abundance, or alterations in their growth. Many microbiota species serve as food items for mosquito larvae, and there are also some indigestible or toxic phytoplanktons to larvae. However, when there is coexistence or mutualism of different mosquito species along with associated microbiota, they form a community sharing the habitat requirements. With the available literature, it is evident that the abundance of mosquito larvae is related to the densities of associated microbiota and their composition in that particular breeding habitat. Potential antagonist microbiota which are naturally occurring in mosquito breeding habitats could be used in integrated vector control approaches, and this method rises as an ecofriendly approach in controlling larvae in natural habitats themselves. To date, this aspect has received less attention; only a limited number of species of microbiota inhabiting mosquito breeding habitats have been recorded, and detailed studies on microbiota assemblage in relation to diverse vector mosquito breeding habitats and their association with mosquito larvae are few. Therefore, future studies on this important ecological aspect are encouraged. Such studies may help to identify field characteristic agents that can serve as mosquito controlling candidates in their natural habitats themselves.
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Dengue Seroprevalence and Seroconversion in Urban and Rural Populations in Northeastern Thailand and Southern Laos. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17239134. [PMID: 33297445 PMCID: PMC7731008 DOI: 10.3390/ijerph17239134] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 12/15/2022]
Abstract
Dengue is the most rapidly spreading mosquito-borne viral disease in the world. The detection of clinical cases enables us to measure the incidence of dengue infection, whereas serological surveys give insights into the prevalence of infection. This study aimed to determine dengue seroprevalence and seroconversion rates in northeastern Thailand and southern Laos and to assess any association of mosquito control methods and socioeconomic factors with dengue virus (DENV) infection. Cross-sectional seroprevalence surveys were performed in May and November 2019 on the same individuals. Blood samples were collected from one adult and one child, when possible, in each of 720 randomly selected households from two urban and two rural sites in both northeastern Thailand and southern Laos. IgG antibodies against DENV were detected in serum using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Overall, 1071 individuals participated in the study. The seroprevalence rate was high (91.5%) across all 8 study sites. Only age and province were associated with seroprevalence rates. There were 33 seroconversions during the period from May to November, of which seven reported fever. More than half of the seroconversions occurred in the rural areas and in Laos. Dengue seroconversion was significantly associated with young age (<15 years old), female gender, province, and duration of living in the current residence. No socioeconomic factors or mosquito control methods were found to be associated with seroprevalence or seroconversion. Notably, however, the province with most seroconversions had lower diurnal temperature ranges than elsewhere. In conclusion, our study has highlighted the homogeneity of dengue exposure across a wide range of settings and most notably those from rural and urban areas. Dengue can no longer be considered to be solely an urban disease nor necessarily one linked to poverty.
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Arévalo-Cortés A, Mejia-Jaramillo AM, Granada Y, Coatsworth H, Lowenberger C, Triana-Chavez O. The Midgut Microbiota of Colombian Aedes aegypti Populations with Different Levels of Resistance to the Insecticide Lambda-cyhalothrin. INSECTS 2020; 11:insects11090584. [PMID: 32882829 PMCID: PMC7565445 DOI: 10.3390/insects11090584] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/11/2020] [Accepted: 08/24/2020] [Indexed: 12/12/2022]
Abstract
Insecticide resistance in Aedes aegypti populations is a problem that hinders vector control and dengue prevention programs. In this study, we determined the susceptibility of Ae. aegypti populations from six Colombian regions to the pyrethroid lambda-cyhalothrin and evaluated the presence of the V1016I mutation in the sodium channel gene, which has been broadly involved in the resistance to this insecticide. The diversity of the gut microbiota of these mosquito populations was also analyzed. Only mosquitoes from Bello were susceptible to lambda-cyhalothrin and presented a lower allelic frequency of the V1016I mutation. Remarkably, there was not an important change in allelic frequencies among populations with different resistance ratios, indicating that other factors or mechanisms contributed to the resistant phenotype. Treatment of mosquitoes with antibiotics led us to hypothesize that the intestinal microbiota could contribute to the resistance to lambda-cyhalothrin. Beta diversity analysis showed significant differences in the species of bacteria present between susceptible and resistant populations. We identified 14 OTUs of bacteria that were unique in resistant mosquitoes. We propose that kdr mutations are important in the development of resistance to lambda-cyhalothrin at low insecticide concentrations but insect symbionts could play an essential role in the metabolization of pyrethroid insecticides at higher concentrations, contributing to the resistant phenotype in Ae. aegypti.
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Affiliation(s)
- Andrea Arévalo-Cortés
- Group Biología y Control de Enfermedades Infecciosas, Universidad de Antioquia, Calle 70 No. 52-21, Medellín 050010, Colombia; (A.A.-C.); (A.M.M.-J.); (Y.G.)
| | - Ana M. Mejia-Jaramillo
- Group Biología y Control de Enfermedades Infecciosas, Universidad de Antioquia, Calle 70 No. 52-21, Medellín 050010, Colombia; (A.A.-C.); (A.M.M.-J.); (Y.G.)
| | - Yurany Granada
- Group Biología y Control de Enfermedades Infecciosas, Universidad de Antioquia, Calle 70 No. 52-21, Medellín 050010, Colombia; (A.A.-C.); (A.M.M.-J.); (Y.G.)
| | - Heather Coatsworth
- Centre for Cell Biology, Development, and Disease, Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada; (H.C.); (C.L.)
| | - Carl Lowenberger
- Centre for Cell Biology, Development, and Disease, Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada; (H.C.); (C.L.)
| | - Omar Triana-Chavez
- Group Biología y Control de Enfermedades Infecciosas, Universidad de Antioquia, Calle 70 No. 52-21, Medellín 050010, Colombia; (A.A.-C.); (A.M.M.-J.); (Y.G.)
- Correspondence: ; Tel.: +57-4-219-6520
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Nilsson LKJ, de Oliveira MR, Marinotti O, Rocha EM, Håkansson S, Tadei WP, de Souza AQL, Terenius O. Characterization of Bacterial Communities in Breeding Waters of Anopheles darlingi in Manaus in the Amazon Basin Malaria-Endemic Area. MICROBIAL ECOLOGY 2019; 78:781-791. [PMID: 30989355 PMCID: PMC6842340 DOI: 10.1007/s00248-019-01369-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 03/19/2019] [Indexed: 05/19/2023]
Abstract
The microbiota in mosquito breeding waters can affect ovipositing mosquitoes, have effects on larval development, and can modify adult mosquito-gut bacterial composition. This, in turn, can affect transmission of human pathogens such as malaria parasites. Here, we explore the microbiota of four breeding sites for Anopheles darlingi, the most important malaria vector in Latin America. The sites are located in Manaus in the Amazon basin in Brazil, an area of active malaria transmission. Using 16S rRNA gene sequencing by MiSeq, we found that all sites were dominated by Proteobacteria and Firmicutes and that 94% of the total number of reads belonged to 36 operational taxonomic units (OTUs) identified in all sites. Of these, the most common OTUs belonged to Escherichia/Shigella, Staphylococcus, and Pseudomonas. Of the remaining 6% of the reads, the OTUs found to differentiate between the four sites belonged to the orders Burkholderiales, Actinomycetales, and Clostridiales. We conclude that An. darlingi can develop in breeding waters with different surface-water bacteria, but that the common microbiota found in all breeding sites might indicate or contribute to a suitable habitat for this important malaria vector.
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Affiliation(s)
- Louise K J Nilsson
- Department of Cell and Molecular Biology, Microbiology, Uppsala University, P.O. Box 596, 751 24, Uppsala, Sweden
- Department of Ecology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7044, 750 07, Uppsala, Sweden
| | - Marta Rodrigues de Oliveira
- Programa de Pós-graduação em Biotecnologia e Recursos Naturais da Amazônia, Universidade do Estado do Amazonas, Manaus, AM, 69065-001, Brazil
| | - Osvaldo Marinotti
- Department of Molecular Biology and Biochemistry, University of California, 3205 Mc-Gaugh Hall, Irvine, CA, 92697, USA
| | - Elerson Matos Rocha
- Programa de Pós-graduação em Biotecnologia, Universidade Federal do Amazonas, Manaus, AM, Brazil
- Laboratório de Malária e Dengue, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM, 69011-970, Brazil
| | - Sebastian Håkansson
- Uppsala BioCenter. Department of Molecular Sciences, Swedish University of Agricultural Sciences (SLU), P.O. Box 7025, 750 07, Uppsala, Sweden
| | - Wanderli P Tadei
- Programa de Pós-graduação em Biotecnologia e Recursos Naturais da Amazônia, Universidade do Estado do Amazonas, Manaus, AM, 69065-001, Brazil
- Laboratório de Malária e Dengue, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM, 69011-970, Brazil
| | - Antonia Queiroz Lima de Souza
- Programa de Pós-graduação em Biotecnologia e Recursos Naturais da Amazônia, Universidade do Estado do Amazonas, Manaus, AM, 69065-001, Brazil
- Faculdade de Ciências Agrárias, Universidade Federal do Amazonas (FCA/UFAM), Manaus, AM, 69080-900, Brazil
| | - Olle Terenius
- Department of Cell and Molecular Biology, Microbiology, Uppsala University, P.O. Box 596, 751 24, Uppsala, Sweden.
- Department of Ecology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7044, 750 07, Uppsala, Sweden.
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Inocente EA, Nguyen B, Manwill PK, Benatrehina A, Kweka E, Wu S, Cheng X, Rakotondraibe LH, Piermarini PM. Insecticidal and Antifeedant Activities of Malagasy Medicinal Plant ( Cinnamosma sp.) Extracts and Drimane-Type Sesquiterpenes against Aedes aegypti Mosquitoes. INSECTS 2019; 10:E373. [PMID: 31731570 PMCID: PMC6920793 DOI: 10.3390/insects10110373] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/19/2019] [Accepted: 10/22/2019] [Indexed: 11/20/2022]
Abstract
The overuse of insecticides with limited modes of action has led to resistance in mosquito vectors. Thus, insecticides with novel modes of action are needed. Secondary metabolites in Madagascan plants of the genus Cinnamosma (Canellaceae) are commonly used in traditional remedies and known to elicit antifeedant and toxic effects in insect pests. Here we test the hypothesis that extracts of Cinnamosma sp. enriched in drimane sesquiterpenes are toxic and/or antifeedant to the yellow fever mosquito Aedes aegypti. We show that the bark and root extracts, which contain a higher abundance of drimane sesquiterpenes compared to leaves, were the most efficacious. Screening isolated compounds revealed cinnamodial to be the primary driver of adulticidal activity, whereas cinnamodial, polygodial, cinnafragrin A, and capsicodendrin contributed to the larvicidal activity. Moreover, an abundant lactone (cinnamosmolide) in the root extract synergized the larvicidal effects of cinnamodial. The antifeedant activity of the extracts was primarily contributed to cinnamodial, polygodial, and cinnamolide. Parallel experiments with warburganal isolated from Warburgia ugandensis (Canellaceae) revealed that aldehydes are critical for-and a hydroxyl modulates-insecticidal activity. Our results indicate that plant drimane sesquiterpenes provide valuable chemical platforms for developing insecticides and repellents to control mosquito vectors.
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Affiliation(s)
- Edna Alfaro Inocente
- Department of Entomology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA; (E.A.I.); (B.N.)
| | - Bao Nguyen
- Department of Entomology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA; (E.A.I.); (B.N.)
| | - Preston K. Manwill
- Departments of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, OH 43210, USA; (P.K.M.); (A.B.); (S.W.); (X.C.)
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Annecie Benatrehina
- Departments of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, OH 43210, USA; (P.K.M.); (A.B.); (S.W.); (X.C.)
| | - Eliningaya Kweka
- Department of Medical Parasitology, School of Medicine, Catholic University of Health and Allied Sciences-Bugando, Mwanza P.O. Box 1464, Tanzania;
- Division of Livestock and Human Disease Vector Control, Tropical Pesticides Research Institute, Arusha P.O. Box 3024, Tanzania
| | - Sijin Wu
- Departments of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, OH 43210, USA; (P.K.M.); (A.B.); (S.W.); (X.C.)
| | - Xiaolin Cheng
- Departments of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, OH 43210, USA; (P.K.M.); (A.B.); (S.W.); (X.C.)
| | - L. Harinantenaina Rakotondraibe
- Departments of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, OH 43210, USA; (P.K.M.); (A.B.); (S.W.); (X.C.)
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Peter M. Piermarini
- Department of Entomology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA; (E.A.I.); (B.N.)
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 43210, USA
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Nilsson LKJ, Sharma A, Bhatnagar RK, Bertilsson S, Terenius O. Presence of Aedes and Anopheles mosquito larvae is correlated to bacteria found in domestic water-storage containers. FEMS Microbiol Ecol 2019; 94:4956519. [PMID: 29617987 DOI: 10.1093/femsec/fiy058] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 03/28/2018] [Indexed: 12/26/2022] Open
Abstract
Water-storage containers are common in households where access to water is scarce and often act as breeding sites for vector mosquitoes. Bacteria in these containers may be important for attracting or repelling ovipositing mosquitoes. We hypothesized that bacterial community composition in water-storage containers would represent either inhibitory or suitable environmental conditions for mosquito larvae. To investigate this, we characterized the bacterial community composition in water-storage containers and correlated these communities to Aedes and Anopheles larval densities. Water samples were collected over two years from 13 containers in an Indian village and analyzed by high throughput 16S rRNA gene amplicon sequencing. Comparisons of bacterial community composition between water with and without mosquito larvae showed that Xanthomonadaceae, Comamonadaceae and Burkholderiaceae were more common (P < 0.05) in absence of larvae, while Lachnospiraceae, Synechococcaceae, Alcaligenaceae and Cryomorphaceae were more common (P < 0.05) in presence of larvae. Indicator analysis identified operational taxonomic units designated as CL500-29 marine group (Acidimicrobiaceae) and FukuN101 (Microbacteriaceae) for absence and presence of larvae, respectively. These results contribute to the understanding of which bacteria, directly or indirectly, can be linked to absence or presence of mosquitoes around households and set the basis for potential measures to be taken against these vector mosquitoes.
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Affiliation(s)
- Louise K J Nilsson
- Department of Ecology, Swedish University of Agricultural Sciences (SLU), 750 07 Uppsala, Sweden.,Department of Ecology and Genetics, Limnology and Science for Life Laboratory, Uppsala University, Norbyvägen 18D, 752 36 Uppsala, Sweden
| | - Anil Sharma
- Insect resistance group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.,AAiM Edupoint, Janak Puri, New Delhi-110058, India
| | - Raj K Bhatnagar
- Insect resistance group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Stefan Bertilsson
- Department of Ecology and Genetics, Limnology and Science for Life Laboratory, Uppsala University, Norbyvägen 18D, 752 36 Uppsala, Sweden
| | - Olle Terenius
- Department of Ecology, Swedish University of Agricultural Sciences (SLU), 750 07 Uppsala, Sweden.,Department of Cell and Molecular Biology, Microbiology, Uppsala University, Box 596, 751 24 Uppsala, Sweden
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Dengue-like illness surveillance: a two-year longitudinal survey in suburban and rural communities in the Lao People's Democratic Republic and in Thailand. Western Pac Surveill Response J 2019; 10:15-24. [PMID: 31110838 PMCID: PMC6507124 DOI: 10.5365/wpsar.2017.8.4.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Objective This study aimed to determine the incidences of dengue-like illness (DLI), dengue virus (DENV) infection, and serotypes and to identify socio-demographical and entomological risk factors of DLI in selected suburban and rural communities in the Lao People's Democratic Republic and in Thailand. Methods A two-year longitudinal study was conducted in four villages during the inter-epidemic period between 2011 and 2013. Entomological surveys, semi-structured interviews of household heads and observations were conducted. Occurrences of DLI were recorded weekly using the World Health Organization’s dengue definition along with blood samples; results were compared with national surveillance dengue data. Risk factors of DLI were assessed using logistic regression. Results Among the 2007 people in the study, 83 DLI cases were reported: 69 in suburban Lao People's Democratic Republic, 11 in rural Thailand, three in rural Lao People's Democratic Republic and none in suburban Thailand. Four were confirmed DENV: two from suburban Lao People's Democratic Republic (both DENV-1) and two from rural Thailand (both DENV-2). Although the number of detected DLIs during the study period was low, DLI incidence was higher in the study compared to the dengue surveillance data in both countries. DLI in suburban Lao People's Democratic Republic was associated with age and occupation, but not with the number of pupae per person. Discussion This study highlights the importance of continuous clinical and vector surveillance for dengue to improve early detection of dengue and other mosquito-borne diseases in the region.
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Jaramillo JF, Vargas S, Sarmiento-Senior D, Giraldo P. [Sustainability of interventions to prevent dengue and diarrhea in rural schools in two municipalities in Colombia: a two-year post-project evaluation]. CAD SAUDE PUBLICA 2018; 34:e00189017. [PMID: 30365746 DOI: 10.1590/0102-311x00189017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 05/30/2018] [Indexed: 11/22/2022] Open
Abstract
This study evaluated the sustainability of a set of interventions to prevent dengue and diarrhea in 33 rural schools in the municipalities (counties) of Anapoima and La Mesa, Colombia, two years post-project. The study measured sustainability in two categories: maintenance of the benefits and the interventions, and institutionalization and community capacity-building. The sustainability of the interventions was compared across four arms: interventions to prevent diarrhea, to prevent dengue, combined interventions to prevent diarrhea and dengue, and control. The final score for each arm was classified in five levels of sustainability: regressive, not sustainable, moderately sustainable, sustainable, and highly sustainable. The arms were compared with ANOVA and Kruskal-Wallis test, with significance set at 0.05. At two years post-project, the overall sustainability for the prevention of diarrhea was moderate in the four arms, while dengue prevention was not sustainable in three of the four arms, without statistically significant differences. Sustainability levels also varied in terms of benefits, interventions, capacity-building, and institutionalization. Maintenance of benefits and interventions in both diseases was more sustainable than institutionalization and capacity-building. The analysis of these variables is important for identifying the different factors that influence projects' sustainability, related to their design and execution, organizational framework, and social context.
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Affiliation(s)
| | - Sandra Vargas
- Facultad de Medicina, Universidad El Bosque, Bogotá, Colombia
| | | | - Paola Giraldo
- Instituto de Salud y Ambiente, Universidad El Bosque, Bogotá, Colombia
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Overgaard HJ, Pientong C, Thaewnongiew K, Bangs MJ, Ekalaksananan T, Aromseree S, Phanitchat T, Phanthanawiboon S, Fustec B, Corbel V, Cerqueira D, Alexander N. Assessing dengue transmission risk and a vector control intervention using entomological and immunological indices in Thailand: study protocol for a cluster-randomized controlled trial. Trials 2018; 19:122. [PMID: 29458406 PMCID: PMC5819278 DOI: 10.1186/s13063-018-2490-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 01/19/2018] [Indexed: 02/07/2023] Open
Abstract
Background Dengue fever is the most common and widespread mosquito-borne arboviral disease in the world. There is a compelling need for cost-effective approaches and practical tools that can reliably measure real-time dengue transmission dynamics that enable more accurate and useful predictions of incidence and outbreaks. Sensitive surveillance tools do not exist today, and only a small handful of new control strategies are available. Vector control remains at the forefront for combating dengue transmission. However, the effectiveness of many current vector control interventions is fraught with inherent weaknesses. No single vector control method is effective enough to control both vector populations and disease transmission. Evaluations of novel larval and adult control interventions are needed. Methods/design A cluster-randomized controlled trial will be carried out between 2017 and 2019 in urban community clusters in Khon Kaen and Roi Et cities, northeastern Thailand. The effectiveness of a pyriproxyfen/spinosad combination treatment of permanent water storage containers will be evaluated on epidemiological and entomological outcomes, including dengue incidence, number of female adult dengue vectors infected or not infected with dengue virus (DENV), human exposure to Aedes mosquito bites, and several other indices. These indices will also be used to develop predictive models for dengue transmission and impending outbreaks. Epidemiological and entomological data will be collected continuously for 2 years, with the intervention implemented after 1 year. Discussion The aims of the trial are to simultaneously evaluate the efficacy of an innovative dengue vector control intervention and developing predictive dengue models. Assessment of human exposure to mosquito bites by detecting antibodies generated against Aedes saliva proteins in human blood samples has, so far, not been applied in dengue epidemiological risk assessment and disease surveillance methodologies. Likewise, DENV detection in mosquitoes (adult and immature stages) has not been used in any practical way for routine disease surveillance strategies. The integration of multiple outcome measures will assist health authorities to better predict outbreaks for planning and applying focal and timely interventions. The trial outcomes will not only be important for Thailand, but also for the entire Southeast Asian region and further afield. Trial registration ISRCTN, ISRCTN73606171. Registered on 23 June 2017. Electronic supplementary material The online version of this article (10.1186/s13063-018-2490-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Chamsai Pientong
- Khon Kaen University, Khon Kaen, Thailand.,HPV & EBV and Carcinogenesis Research Group, Khon Kaen University, Khon Kaen, Thailand
| | | | - Michael J Bangs
- PT Freeport Indonesia/International SOS Indonesia, Kuala Kencana, Indonesia.,Kasetsart University, Bangkok, Thailand
| | - Tipaya Ekalaksananan
- Khon Kaen University, Khon Kaen, Thailand.,HPV & EBV and Carcinogenesis Research Group, Khon Kaen University, Khon Kaen, Thailand
| | - Sirinart Aromseree
- Khon Kaen University, Khon Kaen, Thailand.,HPV & EBV and Carcinogenesis Research Group, Khon Kaen University, Khon Kaen, Thailand
| | | | - Supranee Phanthanawiboon
- Khon Kaen University, Khon Kaen, Thailand.,HPV & EBV and Carcinogenesis Research Group, Khon Kaen University, Khon Kaen, Thailand
| | - Benedicte Fustec
- Khon Kaen University, Khon Kaen, Thailand.,Université de Montpellier, Montpellier, France
| | - Vincent Corbel
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC, UM1-CNRS 5290-IRD 224), Montpellier, France
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Vannavong N, Seidu R, Stenström TA, Dada N, Overgaard HJ. Effects of socio-demographic characteristics and household water management on Aedes aegypti production in suburban and rural villages in Laos and Thailand. Parasit Vectors 2017; 10:170. [PMID: 28376893 PMCID: PMC5381031 DOI: 10.1186/s13071-017-2107-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 03/24/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Dengue fever is a mosquito-borne disease accounting for 50-100 million annual cases globally. Laos and Thailand are countries in south-east Asia where the disease is endemic in both urban and rural areas. Household water storage containers, which are favourable breeding sites for dengue mosquitoes, are common in these areas, due to intermittent or limited access to water supply. This study assessed the effect of household water management and socio-demographic risk factors on Aedes aegypti infestation of water storage containers. METHODS A cross-sectional survey of 239 households in Laos (124 suburban and 115 rural), and 248 households in Thailand (127 suburban and 121 rural) was conducted. Entomological surveys alongside semi-structured interviews and observations were conducted to obtain information on Ae. aegypti infestation, socio-demographic factors and water management. Zero-inflated negative binomial regression models were used to assess risk factors associated with Ae. aegypti pupal infestation. RESULTS Household water management rather than socio-demographic factors were more likely to be associated with the infestation of water containers with Ae. aegypti pupae. Factors that was significantly associated with Ae. aegypti infestation were tanks, less frequent cleaning of containers, containers without lids, and containers located outdoors or in toilets/bathrooms. CONCLUSIONS Associations between Ae. aegypti pupae infestation, household water management, and socio-demographic factors were found, with risk factors for Ae. aegypti infestation being specific to each study setting. Most of the containers did not have lids, larvicides, such as temephos was seldom used, and containers were not cleaned regularly; factors are facilitating dengue vector proliferation. It is recommended that, in Lao villages, health messages should promote proper use and maintenance of tightly fitted lids, and temephos in tanks, which were the most infested containers. Recommendations for Thailand are that small water containers should be cleaned weekly. Furthermore, in addition to health messages on dengue control provided to communities, attention should be paid to larval control for indoor containers in rural villages. Temephos or other immature control measures such as the use of pyriproxyfen, antilarval bacteria, or larvivorous fish should be used where temephos resistance is prevalent. Dengue control is not possible without additional adult mosquito control and community participation.
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Affiliation(s)
- Nanthasane Vannavong
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway. .,Champasak Provincial Health Office, Pakse, Lao People's Democratic Republic.
| | - Razak Seidu
- Water and Environmental Engineering Group, Department of Civil Engineering, Institute for Marine Operations and Civil Engineering, Norwegian University of Science and Technology, Ålesund, Norway
| | - Thor-Axel Stenström
- SARChl Chair, Institute for Water and Waste Water Technology, Durban University of Technology, Durban, South Africa
| | - Nsa Dada
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
| | - Hans J Overgaard
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway.,Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (IRD 224-CNRS 5290 UM1-UM2), Montpellier, Cedex 5, France
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Hardy MC, Barrington DJ. A Transdisciplinary Approach to Managing Emerging and Resurging Mosquito-Borne Diseases in the Western Pacific Region. Trop Med Infect Dis 2017; 2:E1. [PMID: 30270860 PMCID: PMC6082050 DOI: 10.3390/tropicalmed2010001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 12/19/2016] [Accepted: 12/26/2016] [Indexed: 11/30/2022] Open
Abstract
Mosquitoes transmit a number of harmful diseases that have an impact on local communities and visitors, and many pose a threat to neighboring countries. As federal monitoring budgets shrink across the world, the increasing importance of citizen scientists in monitoring and identifying invasive species, as well as acting to prevent these diseases, are discussed. Examples of past mosquito management programs are provided, and future directions are discussed with an emphasis on the Western Pacific Region.
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Affiliation(s)
- Margaret C Hardy
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia.
| | - Dani J Barrington
- Department of Marketing, Monash University, Clayton, VIC 3800, Australia.
- International Water Centre, Brisbane, QLD 4000, Australia.
- School of Public Health and Global Change Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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Ma M, Huang M, Leng P. Abundance and distribution of immature mosquitoes in urban rivers proximate to their larval habitats. Acta Trop 2016; 163:121-9. [PMID: 27515809 DOI: 10.1016/j.actatropica.2016.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 07/31/2016] [Accepted: 08/06/2016] [Indexed: 10/21/2022]
Abstract
Whether ecological restoration of polluted urban rivers would provide suitable breeding habitats for some mosquitoes was not clear yet. It was therefore important to determine how altered river conditions influence mosquito ecology. Monthly data on water quality and larval density were obtained to determine the effects of river systems on the distribution and abundance of immature mosquitoes in two coastal cities in Eastern China. In total, 5 species within two genera of mosquitoes were collected and identified in habitat with vegetation from three positive rivers. Culex pipiens pallens was the most abundant and widely distributed species. A new species (Culex fuscanus) was reported in certain districts. Physico-chemical parameters of river water were important, but not the only, set of influences on immature mosquito breeding. Aquatic vegetation could increase the likelihood of mosquito breeding while artificial aeration might prevent the approach of mosquitoes. Slow-moving water might be a new potential marginal habitat type for some Culex and Aedes albopictus. Variation of river system with ecological restoration might influence the abundance and distribution of immature mosquitoes.
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Overgaard HJ, Alexander N, Matiz MI, Jaramillo JF, Olano VA, Vargas S, Sarmiento D, Lenhart A, Stenström TA. A Cluster-Randomized Controlled Trial to Reduce Diarrheal Disease and Dengue Entomological Risk Factors in Rural Primary Schools in Colombia. PLoS Negl Trop Dis 2016; 10:e0005106. [PMID: 27820821 PMCID: PMC5098800 DOI: 10.1371/journal.pntd.0005106] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 10/12/2016] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND As many neglected tropical diseases are co-endemic and have common risk factors, integrated control can efficiently reduce disease burden and relieve resource-strained public health budgets. Diarrheal diseases and dengue fever are major global health problems sharing common risk factors in water storage containers. Where provision of clean water is inadequate, water storage is crucial. Fecal contamination of stored water is a common source of diarrheal illness, but stored water also provides breeding sites for dengue vector mosquitoes. Integrating improved water management and educational strategies for both diseases in the school environment can potentially improve the health situation for students and the larger community. The objective of this trial was to investigate whether interventions targeting diarrhea and dengue risk factors would significantly reduce absence due to diarrheal disease and dengue entomological risk factors in schools. METHODOLOGY/PRINCIPAL FINDINGS A factorial cluster randomized controlled trial was carried out in 34 rural primary schools (1,301 pupils) in La Mesa and Anapoima municipalities, Cundinamarca, Colombia. Schools were randomized to one of four study arms: diarrhea interventions (DIA), dengue interventions (DEN), combined diarrhea and dengue interventions (DIADEN), and control (CON). Interventions had no apparent effect on pupil school absence due to diarrheal disease (p = 0.45) or on adult female Aedes aegypti density (p = 0.32) (primary outcomes). However, the dengue interventions reduced the Breteau Index on average by 78% (p = 0.029), with Breteau indices of 10.8 and 6.2 in the DEN and DIADEN arms, respectively compared to 37.5 and 46.9 in the DIA and CON arms, respectively. The diarrhea interventions improved water quality as assessed by the amount of Escherichia coli colony forming units (CFU); the ratio of Williams mean E. coli CFU being 0.22, or 78% reduction (p = 0.008). CONCLUSIONS/SIGNIFICANCE Integrated control of dengue and diarrhea has never been conducted before. This trial presents an example for application of control strategies that may affect both diseases and the first study to apply such an approach in school settings. The interventions were well received and highly appreciated by students and teachers. An apparent absence of effect in primary outcome indicators could be the result of pupils being exposed to risk factors outside the school area and mosquitoes flying in from nearby uncontrolled breeding sites. Integrated interventions targeting these diseases in a school context remain promising because of the reduced mosquito breeding and improved water quality, as well as educational benefits. However, to improve outcomes in future integrated approaches, simultaneous interventions in communities, in addition to schools, should be considered; using appropriate combinations of site-specific, effective, acceptable, and affordable interventions. TRIAL REGISTRATION ClinicalTrials.gov no. ISRCTN40195031.
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Affiliation(s)
- Hans J. Overgaard
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Norway
- Institut de Recherche pour le Développement, Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Montpellier, France
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - Neal Alexander
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London
| | - Maria Ines Matiz
- Instituto de Salud y Ambiente, Universidad El Bosque, Bogota, Colombia
| | | | | | - Sandra Vargas
- Instituto de Salud y Ambiente, Universidad El Bosque, Bogota, Colombia
| | - Diana Sarmiento
- Instituto de Salud y Ambiente, Universidad El Bosque, Bogota, Colombia
| | - Audrey Lenhart
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- U.S. Centers for Disease Control and Prevention, Atlanta, United States of America
| | - Thor Axel Stenström
- SARChI Chair, Institute for Water and Waste Water Technology, Durban University of Technology, Durban, South Africa
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Bacterial Exposure at the Larval Stage Induced Sexual Immune Dimorphism and Priming in Adult Aedes aegypti Mosquitoes. PLoS One 2015; 10:e0133240. [PMID: 26181517 PMCID: PMC4504673 DOI: 10.1371/journal.pone.0133240] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 06/25/2015] [Indexed: 11/23/2022] Open
Abstract
Gender differences in the immune response of insects are driven by natural selection for females and sexual selection for males. These natural forces entail a multitude of extrinsic and intrinsic factors involved in a genotype-environment interaction that results in sex-biased expression of the genes shared by males and females. However, little is known about how an infection at a particular ontogenetic stage may influence later stages, or how it may impact sexual immune dimorphism. Using Aedes aegypti mosquitoes, the aim of the present study was to analyze the effect of a bacterial exposure at the larval stage on adult immunity in males and females. The parameters measured were phenoloxidase activity, nitric oxide production, antimicrobial activity, and the antimicrobial peptide transcript response. As a measure of the immune response success, the persistence of injected bacteria was also evaluated. The results show that males, as well as females, were able to enhance survival in the adult stage as a result of being exposed at the larval stage, which indicates a priming effect. Moreover, there was a differential gender immune response, evidenced by higher PO activity in males as well as higher NO production and greater antimicrobial activity in females. The greater bacterial persistence in females suggests a gender-specific strategy for protection after a previous experience with an elicitor. Hence, this study provides a primary characterization of the complex and gender-specific immune response of male and female adults against a bacterial challenge in mosquitoes primed at an early ontogenetic stage.
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Comparative assessment of the bacterial communities associated with Aedes aegypti larvae and water from domestic water storage containers. Parasit Vectors 2014; 7:391. [PMID: 25151134 PMCID: PMC4156648 DOI: 10.1186/1756-3305-7-391] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 08/19/2014] [Indexed: 02/01/2023] Open
Abstract
Background Domestic water storage containers constitute major Aedes aegypti breeding sites. We present for the first time a comparative analysis of the bacterial communities associated with Ae. aegypti larvae and water from domestic water containers. Methods The 16S rRNA-temporal temperature gradient gel electrophoresis (TTGE) was used to identify and compare bacterial communities in fourth-instar Ae. aegypti larvae and water from larvae positive and negative domestic containers in a rural village in northeastern Thailand. Water samples were cultured for enteric bacteria in addition to TTGE. Sequences obtained from TTGE and bacterial cultures were clustered into operational taxonomic units (OTUs) for analyses. Results Significantly lower OTU abundance was found in fourth-instar Ae. aegypti larvae compared to mosquito positive water samples. There was no significant difference in OTU abundance between larvae and mosquito negative water samples or between mosquito positive and negative water samples. Larval samples had significantly different OTU diversity compared to mosquito positive and negative water samples, with no significant difference between mosquito positive and negative water samples. The TTGE identified 24 bacterial taxa, belonging to the phyla Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and TM7 (candidate phylum). Seven of these taxa were identified in larval samples, 16 in mosquito positive and 13 in mosquito negative water samples. Only two taxa, belonging to the phyla Firmicutes and Actinobacteria, were common to both larvae and water samples. Bacilli was the most abundant bacterial class identified from Ae. aegypti larvae, Gammaproteobacteria from mosquito positive water samples, and Flavobacteria from mosquito negative water samples. Enteric bacteria belonging to the class Gammaproteobacteria were sparsely represented in TTGE, but were isolated from both mosquito positive and negative water samples by selective culture. Conclusions Few bacteria from water samples were identified in fourth-instar Ae. aegypti larvae, suggesting that established larval bacteria, most likely acquired at earlier stages of development, control the larval microbiota. Further studies at all larval stages are needed to fully understand the dynamics involved. Isolation of enteric bacteria from water samples supports earlier outcomes of E. coli contamination in Ae. aegypti infested domestic containers, suggesting the need to further explore the role of enteric bacteria in Ae. aegypti infestation.
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Shaheed A, Orgill J, Montgomery MA, Jeuland MA, Brown J. Why "improved" water sources are not always safe. Bull World Health Organ 2014; 92:283-9. [PMID: 24700996 DOI: 10.2471/blt.13.119594] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 11/26/2013] [Accepted: 11/28/2013] [Indexed: 11/27/2022] Open
Abstract
Existing and proposed metrics for household drinking-water services are intended to measure the availability, safety and accessibility of water sources. However, these attributes can be highly variable over time and space and this variation complicates the task of creating and implementing simple and scalable metrics. In this paper, we highlight those factors - especially those that relate to so-called improved water sources - that contribute to variability in water safety but may not be generally recognized as important by non-experts. Problems in the provision of water in adequate quantities and of adequate quality - interrelated problems that are often influenced by human behaviour - may contribute to an increased risk of poor health. Such risk may be masked by global water metrics that indicate that we are on the way to meeting the world's drinking-water needs. Given the complexity of the topic and current knowledge gaps, international metrics for access to drinking water should be interpreted with great caution. We need further targeted research on the health impacts associated with improvements in drinking-water supplies.
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Affiliation(s)
- Ameer Shaheed
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, England
| | - Jennifer Orgill
- Sanford School of Public Policy, Duke University, Durham, United States of America (USA)
| | - Maggie A Montgomery
- Water, Sanitation and Health Unit, World Health Organization, Geneva, Switzerland
| | - Marc A Jeuland
- Sanford School of Public Policy, Duke University, Durham, United States of America (USA)
| | - Joe Brown
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Mason Building, 790 Atlantic Drive, Atlanta, GA 30332-0355, USA
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