1
|
Carrasco-Tenezaca M, Jawara M, Bradley J, D'Alessandro U, Jeffries D, Knudsen JB, Lindsay SW. The effect of physical barriers under a raised house on mosquito entry: an experimental study in rural Gambia. Malar J 2024; 23:100. [PMID: 38589884 PMCID: PMC11003187 DOI: 10.1186/s12936-024-04889-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 02/21/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND Anopheles gambiae, the major malaria mosquito in sub-Saharan Africa, feed largely indoors at night. Raising a house off the ground with no barriers underneath reduces mosquito-house entry. This experiment tested whether walling off the space under an elevated hut affects mosquito-hut entry. METHODS Four inhabited experimental huts, each of which could be moved up and down, were used in rural Gambia. Nightly collections of mosquitoes were made using light traps and temperature and carbon dioxide levels monitored indoors and outdoors using loggers. Each night, a reference hut was kept at ground level and three huts raised 2 m above the ground; with the space under the hut left open, walled with air-permeable walls or solid walls. Treatments were rotated every four nights using a randomized block design. The experiment was conducted for 32 nights. Primary measurements were mosquito numbers and indoor temperature in each hut. RESULTS A total of 1,259 female Anopheles gambiae sensu lato were collected in the hut at ground level, 655 in the hut with an open ground floor, 981 in the hut with air-permeable walls underneath and 873 in the hut with solid walls underneath. Multivariate analysis, adjusting for confounders, showed that a raised hut open underneath had 53% fewer mosquitoes (95% CI 47-58%), those with air-permeable walls underneath 24% fewer (95% CI 9-36%) and huts with solid walls underneath 31% fewer (95% CI 24-37%) compared with a hut on the ground. Similar results were found for Mansonia spp. and total number of female mosquitoes, but not for Culex mosquitoes where hut entry was unaffected by height or barriers. Indoor temperature and carbon dioxide levels were similar in all huts. CONCLUSION Raising a house 2 m from the ground reduces the entry of An. gambiae and Mansonia mosquitoes, but not Culex species. The protective effect of height is reduced if the space underneath the hut is walled off.
Collapse
Affiliation(s)
- Majo Carrasco-Tenezaca
- Department of Biosciences, Durham University, Durham, UK
- Centro de Investigación Para la Salud en América Latina, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Musa Jawara
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - John Bradley
- London School of Hygiene & Tropical Medicine, London, UK
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
- London School of Hygiene & Tropical Medicine, London, UK
| | - David Jeffries
- Medical Research Council Unit The Gambia at the London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Jakob B Knudsen
- Royal Danish Academy-Architecture, Design and Conservation, Copenhagen, Denmark
| | - Steve W Lindsay
- Department of Biosciences, Durham University, Durham, UK.
- London School of Hygiene & Tropical Medicine, London, UK.
| |
Collapse
|
2
|
Bunker A, Compoaré G, Sewe MO, Laurent JGC, Zabré P, Boudo V, Ouédraogo WA, Ouermi L, Jackson ST, Arisco N, Vijayakumar G, Yildirim FB, Barteit S, Maggioni MA, Woodward A, Buonocore JJ, Regassa MD, Brück T, Sié A, Bärnighausen T. The effects of cool roofs on health, environmental, and economic outcomes in rural Africa: study protocol for a community-based cluster randomized controlled trial. Trials 2024; 25:59. [PMID: 38229177 PMCID: PMC10792891 DOI: 10.1186/s13063-023-07804-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 11/16/2023] [Indexed: 01/18/2024] Open
Abstract
BACKGROUND High ambient air temperatures in Africa pose significant health and behavioral challenges in populations with limited access to cooling adaptations. The built environment can exacerbate heat exposure, making passive home cooling adaptations a potential method for protecting occupants against indoor heat exposure. METHODS We are conducting a 2-year community-based stratified cluster randomized controlled trial (cRCT) implementing sunlight-reflecting roof coatings, known as "cool roofs," as a climate change adaptation intervention for passive indoor home cooling. Our primary research objective is to investigate the effects of cool roofs on health, indoor climate, economic, and behavioral outcomes in rural Burkina Faso. This cRCT is nested in the Nouna Health and Demographic Surveillance System (HDSS), a population-based dynamic cohort study of all people living in a geographically contiguous area covering 59 villages, 14305 households and 28610 individuals. We recruited 1200 participants, one woman and one man, each in 600 households in 25 villages in the Nouna HDSS. We stratified our sample by (i) village and (ii) two prevalent roof types in this area of Burkina Faso: mud brick and tin. We randomized the same number of people (12) and homes (6) in each stratum 1:1 to receiving vs. not receiving the cool roof. We are collecting outcome data on one primary endpoint - heart rate, (a measure of heat stress) and 22 secondary outcomes encompassing indoor climate parameters, blood pressure, body temperature, heat-related outcomes, blood glucose, sleep, cognition, mental health, health facility utilization, economic and productivity outcomes, mosquito count, life satisfaction, gender-based violence, and food consumption. We followed all participants for 2 years, conducting monthly home visits to collect objective and subjective outcomes. Approximately 12% of participants (n = 152) used smartwatches to continuously measure endpoints including heart rate, sleep and activity. DISCUSSION Our study demonstrates the potential of large-scale cRCTs to evaluate novel climate change adaptation interventions and provide evidence supporting investments in heat resilience in sub-Saharan Africa. By conducting this research, we will contribute to better policies and interventions to help climate-vulnerable populations ward off the detrimental effects of extreme indoor heat on health. TRIAL REGISTRATION German Clinical Trials Register (DRKS) DRKS00023207. Registered on April 19, 2021.
Collapse
Affiliation(s)
- Aditi Bunker
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany.
| | | | - Maquins Odhiambo Sewe
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
- Department of Public Health and Clinical Medicine, Sustainable Health Section, Umeå University, Umeå, Sweden
| | - Jose Guillermo Cedeno Laurent
- Environmental Health and Occupational Health Sciences Institute, School of Public Health, Rutgers University, Rutgers, USA
| | - Pascal Zabré
- Centre de Recherche en Santé de Nouna (CRSN), Nouna, Burkina Faso
| | - Valentin Boudo
- Centre de Recherche en Santé de Nouna (CRSN), Nouna, Burkina Faso
| | | | - Lucienne Ouermi
- Centre de Recherche en Santé de Nouna (CRSN), Nouna, Burkina Faso
| | - Susan T Jackson
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
| | - Nicholas Arisco
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, USA
| | - Govind Vijayakumar
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
| | - Ferhat Baran Yildirim
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
| | - Sandra Barteit
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
| | - Martina Anna Maggioni
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments, Berlin, Germany
- Department of Biomedical Sciences for Health, Università Degli Studi Di Milano, Milan, Italy
| | - Alistair Woodward
- Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Jonathan J Buonocore
- Department of Environmental Health, Boston University School of Public Health, Boston, USA
| | | | - Tilman Brück
- Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Großbeeren, Germany
- Thaer-Institute, Humboldt-University of Berlin, Berlin, Germany
- International Security and Development Center (ISDC), Berlin, Germany
| | - Ali Sié
- Centre de Recherche en Santé de Nouna (CRSN), Nouna, Burkina Faso
| | - Till Bärnighausen
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, USA
- Africa Health Research Institute (AHRI), KwaZulu-Natal, South Africa
| |
Collapse
|
3
|
Meta J, Mshamu S, Halifa S, Mmbando A, Wood HS, Wood OS, Bøjstrup TC, Day NPJ, Knudsen J, Lindsay SW, Deen J, von Seidlein L, Pell C. Understanding reticence to occupy free, novel-design homes: A qualitative study in Mtwara, Southeast Tanzania. PLOS GLOBAL PUBLIC HEALTH 2023; 3:e0002307. [PMID: 37992017 PMCID: PMC10664911 DOI: 10.1371/journal.pgph.0002307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 09/23/2023] [Indexed: 11/24/2023]
Abstract
INTRODUCTION The population of Africa set to reach 2 billion by 2050. There is therefore great demand for housing across the continent. Research on modified novel designs for housing is a priority to ensure that these homes are not sites of infection for diseases transmission such as malaria. One trial to assess the protection afforded by novel design houses is underway in Mtwara Region, southeastern Tanzania. After constructing 110 of such homes across 60 villages, project staff encountered a certain reticence of the target population to occupy the homes and were faced with accusations of having nefarious intentions. This article explores these accusations, their impacts on home occupancy and lessons for future housing studies. METHODS This qualitative study drew on in-depth interviews and focus group discussions with ten occupants of the intervention homes, six community leaders and a further 24 community members. Interviews were recorded, transcribed verbatim and translated to English for qualitative content analysis. RESULTS In communities around the Star Homes, during construction and handover, project staff were widely associated with 'Freemasons', a term used to practices, secrecy, and other conspiracy theories in rural Tanzania. These connections were attributed to other community members and explained in terms of knowledge deficit or envy, with others hoping to be allocated the home. The stories were embedded in assumptions of reciprocity and suspicions about study motives, linked to limited experience of research. The relationship between the accusations of freemasonry and reticence to occupy the houses was not straightforward, with project staff or relatives playing a role in decisions. The stakes were high, because the recipients of Star Homes were the poorest families in targeted communities. CONCLUSION The results indicate the need for long-term and proactive community engagement, which focuses on building relationships and providing information through recognizable voices and formats. Given the stakes at play in housing interventions, research teams should be prepared for the social upheaval the provision of free new housing can cause.
Collapse
Affiliation(s)
- Judith Meta
- Independent Consultant and Social Scientist, Mtwara, Tanzania
- CSK Research Solutions, Mtwara, Tanzania
| | - Salum Mshamu
- CSK Research Solutions, Mtwara, Tanzania
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Arnold Mmbando
- Ifakara Health Institute, Ifakara, Tanzania
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Hannah Sloan Wood
- Royal Danish Academy, Architecture, Design, Conservation, Copenhagen, Denmark
| | - Otis Sloan Wood
- Royal Danish Academy, Architecture, Design, Conservation, Copenhagen, Denmark
| | | | - Nicholas P. J. Day
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Jakob Knudsen
- Royal Danish Academy, Architecture, Design, Conservation, Copenhagen, Denmark
| | - Steven W. Lindsay
- Department of Biosciences, Durham University, Durham, United Kingdom
| | | | - Lorenz von Seidlein
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Christopher Pell
- Amsterdam Institute for Global Health and Development (AIGHD), Amsterdam, the Netherlands
- Department of Global Health, Amsterdam UMC, location University of Amsterdam, Amsterdam, the Netherlands
- Amsterdam Public Health Research Institute (Global Health | Health Behaviours & Chronic Diseases Research), Amsterdam, the Netherlands
| |
Collapse
|
4
|
Kathet S, Sudi W, Mwingira V, Tungu P, Aalto M, Hakala T, Honkala M, Malima R, Kisinza W, Meri S, Khattab A. Efficacy of 3D screens for sustainable mosquito control: a semi-field experimental hut evaluation in northeastern Tanzania. Parasit Vectors 2023; 16:417. [PMID: 37964334 PMCID: PMC10647037 DOI: 10.1186/s13071-023-06032-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/24/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND A three-dimensional window screen (3D-Screen) has been developed to create a window double-screen trap (3D-WDST), effectively capturing and preventing the escape of mosquitoes. A 2015 laboratory study demonstrated the 3D-Screen's efficacy, capturing 92% of mosquitoes in a double-screen setup during wind tunnel assays. To further evaluate its effectiveness, phase II experimental hut trials were conducted in Muheza, Tanzania. METHODS Three experimental hut trials were carried out between 2016 and 2017. Trial I tested two versions of the 3D-WDST in huts with open or closed eaves, with one version using a single 3D-Screen and the other using two 3D-Screens. Trial II examined the 3D-WDST with two 3D-Screens in huts with or without baffles, while Trial III compared handmade and machine-made 3D structures. Mosquito capturing efficacy of the 3D-WDST was measured by comparing the number of mosquitoes collected in the test hut to a control hut with standard exit traps. RESULTS Trial I showed that the 3D-WDST with two 3D-Screens used in huts with open eaves achieved the highest mosquito-capturing efficacy. This treatment captured 33.11% (CI 7.40-58.81) of female anophelines relative to the total collected in this hut (3D-WDST and room collections) and 27.27% (CI 4.23-50.31) of female anophelines relative to the total collected in the control hut (exit traps, room, and verandahs collections). In Trial II, the two 3D-Screens version of the 3D-WDST captured 70.32% (CI 56.87-83.77) and 51.07% (CI 21.72-80.41) of female anophelines in huts with and without baffles, respectively. Compared to the control hut, the capturing efficacy for female anophelines was 138.6% (37.23-239.9) and 42.41% (14.77-70.05) for huts with and without baffles, respectively. Trial III demonstrated similar performance between hand- and machine-made 3D structures. CONCLUSIONS The 3D-WDST proved effective in capturing malaria vectors under semi-field experimental hut conditions. Using 3D-Screens on both sides of the window openings was more effective than using a single-sided 3D-Screen. Additionally, both hand- and machine-made 3D structures exhibited equally effective performance, supporting the production of durable cones on an industrial scale for future large-scale studies evaluating the 3D-WDST at the community level.
Collapse
Affiliation(s)
- Subam Kathet
- Department of Bacteriology and Immunology, Haartman Institute, and Translational Immunology Research Program, University of Helsinki, 00014, Helsinki, Finland
| | - Wema Sudi
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | - Victor Mwingira
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | - Patrick Tungu
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | | | - Tomi Hakala
- Department of Materials Science, Tampere University of Technology, P.O. Box 589, 33101, Tampere, Finland
| | - Markku Honkala
- Department of Materials Science, Tampere University of Technology, P.O. Box 589, 33101, Tampere, Finland
| | - Robert Malima
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | - William Kisinza
- Amani Medical Research Centre, National Institute for Medical Research, Muheza, Tanzania
| | - Seppo Meri
- Department of Bacteriology and Immunology, Haartman Institute, and Translational Immunology Research Program, University of Helsinki, 00014, Helsinki, Finland
- HUSLAB Diagnostic Center, Helsinki University Central Hospital, N00029, Helsinki, Finland
| | - Ayman Khattab
- Department of Bacteriology and Immunology, Haartman Institute, and Translational Immunology Research Program, University of Helsinki, 00014, Helsinki, Finland.
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, New Borg El-Arab City, 21934, Alexandria, Egypt.
| |
Collapse
|
5
|
Mshamu S, Halifa S, Meta J, Mmbando A, Lindsay SW, Okumu F, Wood HS, Wood OS, Bøjstrup TC, Day NPJ, Knudsen J, Deen J, Pell C, von Seidlein L. Studying the health benefits of improved housing in rural Tanzania: challenges and progress. Trans R Soc Trop Med Hyg 2023; 117:678-681. [PMID: 37350735 DOI: 10.1093/trstmh/trad039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/29/2023] [Accepted: 06/07/2023] [Indexed: 06/24/2023] Open
Abstract
Millions of affordable healthy homes are needed for the rapidly expanding population of sub-Saharan Africa. This enormous challenge is an opportunity to address pervasive health issues linked to housing, where diseases that most impact children-malaria, diarrhoea and respiratory tract infections-are often acquired. A pilot project in northern Tanzania demonstrated the potential of novel house designs to reduce infectious disease transmission in homes. To conduct a randomized controlled trial of one novel-design house, the research team moved to the southeast of the country. This article describes the challenges experienced during the construction and initial evaluation of the novel house.
Collapse
Affiliation(s)
- Salum Mshamu
- CSK Research Solutions, Mtwara, Tanzania
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | | | | | - Arnold Mmbando
- Ifakara Health Institute, Ifakara, Tanzania
- Department of Biosciences, Durham University, Durham, UK
| | | | | | - Hannah Sloan Wood
- Royal Danish Academy - Architecture, Design, Conservation, Copenhagen, Denmark
| | - Otis Sloan Wood
- Royal Danish Academy - Architecture, Design, Conservation, Copenhagen, Denmark
| | | | - Nicholas P J Day
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jakob Knudsen
- Royal Danish Academy - Architecture, Design, Conservation, Copenhagen, Denmark
| | | | - Christopher Pell
- Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
- Amsterdam University Medical Centers, University of Amsterdam, Department of Global Health, Amsterdam, The Netherlands
- Amsterdam Public Health Research Institute, Amsterdam, The Netherlands
| | - Lorenz von Seidlein
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| |
Collapse
|
6
|
Kayendeke M, Nabirye C, Nayiga S, Westercamp N, Gonahasa S, Katureebe A, Kamya MR, Staedke SG, Hutchinson E. House modifications as a malaria control tool: how does local context shape participants' experience and interpretation in Uganda? Malar J 2023; 22:244. [PMID: 37626312 PMCID: PMC10463640 DOI: 10.1186/s12936-023-04669-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
BACKGROUND Evidence that house design can provide protection from malaria is growing. Housing modifications such as screening windows, doors, and ceilings, and attaching insecticide-impregnated materials to the eaves (the gap between the top of the wall and bottom of the roof), can protect against malaria. To be effective at scale, however, these modifications must be adopted by household residents. There is evidence that housing modifications can be acceptable, but in-depth knowledge on the experiences and interpretation of modifications is lacking. This qualitative study was carried out to provide a holistic account of the relationship between experiences and interpretations of four types of piloted housing modifications and the local context in Jinja, Uganda. METHODS Qualitative research was conducted between January to June 2021, before and during the installation of four types of housing modifications. The methods included nine weeks of participant observations in two study villages, nine focus group discussions with primary caregivers and heads of households (11-12 participants each), and nine key informant interviews with stakeholders and study team members. RESULTS Most residents supported the modifications. Experiences and interpretation of the housing modifications were shaped by the different types of housing in the area and the processes through which residents finished their houses, local forms of land and property ownership, and cultural and spiritual beliefs about houses. CONCLUSIONS To maximize the uptake and benefit of housing modifications against malaria, programme development needs to take local context into account. Forms of local land and house ownership, preferences, the social significance of housing types, and religious and spiritual ideas shape the responses to housing modifications in Jinja. These factors may be important in other setting. Trial registration Trial registration number is NCT04622241. The first draft was posted on November 9th 2020.
Collapse
Affiliation(s)
| | - Christine Nabirye
- Infectious Diseases Research Collaboration, Kampala, Uganda
- London School of Hygiene and Tropical Medicine, London, UK
| | - Susan Nayiga
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Nelli Westercamp
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, USA
| | | | | | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
- Department of Medicine, Makerere University, Kampala, Uganda
| | | | | |
Collapse
|
7
|
Kua KP. Better health through better housing - Current impact and future prospects of randomized trials. Contemp Clin Trials 2023; 127:107114. [PMID: 36758933 DOI: 10.1016/j.cct.2023.107114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/04/2023] [Accepted: 02/05/2023] [Indexed: 02/10/2023]
Abstract
Safe and stable housing in integrated neighborhoods with access to basic amenities and social elements is indispensable for good health. Recent randomized controlled trials have demonstrated that improvements in the built environment have positive impacts on malaria, fall injuries, and gun violence outcomes. There are several challenges associated with performing studies that assess house improvement as an intervention for advancing human health and well-being, including ethical issues, lack of blinding, spillover effects, and differential behavior. Future research is warranted to evaluate the clinical benefits and cost-effectiveness of prototype houses or energyefficient prefabricated modular homes by employing more holistic strategies, such as integration of data analytics, peer support, and whole health coaching, addition of social contextual perspectives on mobile technology-supported community-based interventions, and combination of digital technology-informed community-engaged citizen science and participatory action programs with multi-sector partnerships. Gleaning stronger evidence from clinical trials and model-based economic analyses that ascertain the effects of multiple intersecting factors on individuals and communities would illuminate effective policymaking options in healthy housing and guide successful implementation of sustainable public health policies. Straightforward and cost-effective pathways should therefore be created based on highest-quality scientific data to lead the scaling up of novel housing interventions and capacity building for health-in-all-policies to support population health equity, thereby ensuring that everyone has access to housing and the chance to live a healthy and productive life.
Collapse
Affiliation(s)
- Kok Pim Kua
- Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
8
|
Tizifa TA, Gowelo S, Kabaghe AN, McCann RS, Malenga T, Nkhata RM, Kadama A, Chapeta Y, Takken W, Phiri KS, van Vugt M, van den Berg H, Manda-Taylor L. Community-based house improvement for malaria control in southern Malawi: Stakeholder perceptions, experiences, and acceptability. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000627. [PMID: 36962454 PMCID: PMC10021647 DOI: 10.1371/journal.pgph.0000627] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/23/2022] [Indexed: 11/18/2022]
Abstract
House improvement (HI) refers to the full screening or closing of openings such as windows, doors, and eaves, as well as the installation of ceilings, to reduce mosquito-human contact indoors. HI is a viable supplementary intervention that reduces malaria transmission further than the existing strategies alone. In Malawi, HI has not been widely implemented and evaluated for malaria control. Concerns about lack of local evidence, durability in different epidemiological and cultural settings, and the cost of large-scale implementation are among the reasons the strategy is not utilised in many low-income countries. This study assessed community perceptions, experiences, and acceptability of community-led HI in Chikwawa district, southern Malawi. This was a qualitative study where separate focus group discussions were conducted with members from the general community (n = 3); health animators (n = 3); and HI committee members (n = 3). In-depth interviews were conducted with community members (n = 20), and key-informant interviews were conducted with health surveillance assistants and chiefs (n = 23). All interviews were transcribed and coded before performing a thematic content analysis to identify the main themes. Coded data were analysed using Nvivo 12 Plus software. Study participants had a thorough understanding of HI. Participants expressed satisfaction with HI, and they reported enabling factors to HI acceptability, such as the reduction in malaria cases in their villages and the safety and effectiveness of HI use. Participants also reported barriers to effective HI implementation, such as the unavailability and inaccessibility of some HI materials, as well as excessive heat and darkness in HI houses compared to non-HI houses. Participants indicated that they were willing to sustain the intervention but expressed the need for strategies to address barriers to ensure the effectiveness of HI. Our results showed the high knowledge and acceptability of HI by participants in the study area. Intensive and continued health education and community engagement on the significance of HI could help overcome the barriers and improve the acceptability and sustainability of the intervention.
Collapse
Affiliation(s)
- Tinashe A. Tizifa
- Division of Internal Medicine, Department of Infectious Diseases, Center for Tropical Medicine and Travel Medicine, University of Amsterdam, Amsterdam University Medical Center, Location Academic Medical Center, Amsterdam, The Netherlands
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Steven Gowelo
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Alinune N. Kabaghe
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Robert S. McCann
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
- Centre for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Tumaini Malenga
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
- African Institute for Development Policy, Lilongwe, Malawi
| | - Richard M. Nkhata
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Asante Kadama
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Yankho Chapeta
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
- Biological Sciences Department, Mzuzu University, Mzuzu, Malawi
| | - Willem Takken
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Kamija S. Phiri
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Michele van Vugt
- Division of Internal Medicine, Department of Infectious Diseases, Center for Tropical Medicine and Travel Medicine, University of Amsterdam, Amsterdam University Medical Center, Location Academic Medical Center, Amsterdam, The Netherlands
| | - Henk van den Berg
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Lucinda Manda-Taylor
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| |
Collapse
|
9
|
Mshamu S, Mmbando A, Meta J, Bradley J, Bøjstrup TC, Day NPJ, Mukaka M, Okumu F, Olotu A, Pell C, Deen J, Knudsen J, Lindsay SW, von Seidlein L. Assessing the impact of a novel house design on the incidence of malaria in children in rural Africa: study protocol for a household-cluster randomized controlled superiority trial. Trials 2022; 23:519. [PMID: 35725486 PMCID: PMC9207857 DOI: 10.1186/s13063-022-06461-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 06/09/2022] [Indexed: 11/10/2022] Open
Abstract
Background Traditional rural housing in hot, humid regions of sub-Saharan Africa usually consists of single-level, poorly ventilated dwellings. Houses are mostly poorly screened against malaria mosquitoes and limited airflow discourages the use of bednets resulting in high indoor transmission. This study aims to determine whether living in a novel design house with elevated bedrooms and permeable screened walls reduces malaria, respiratory tract infections, and diarrhoea among children in rural Tanzania. Methods/study design This is a household-randomized, controlled study in 60 villages in Mtwara, Tanzania. A total of 550 households are randomly selected, 110 of which are allocated a novel design house and 440 households continue to reside in traditional houses. A dynamic cohort of about 1650 children under 13 years will be enrolled and followed for 3 years, approximately 330 living in novel design houses and 1320 in traditional rural houses. The primary endpoint is the incidence of malaria; secondary endpoints are incidences of acute respiratory tract infections and diarrhoea diseases detected by passive and active surveillance. Exposure to malaria vectors will be assessed using light traps in all study houses. Structural, economic, and social science studies will assess the durability, cost-effectiveness, and acceptability of the new houses compared with traditional housing. Environmental data will be collected indoors and outdoors in study homes to assess the differences between house typologies. Discussion This is the first randomized controlled trial to assess the protective efficacy of a new house design targeting malaria in sub-Saharan Africa. The findings of this study could influence the future construction of homes in hot and humid zones of Africa. Trial registration ClinicalTrials.govNCT04529434. Registered on August 27, 2020
Collapse
Affiliation(s)
- Salum Mshamu
- CSK Research Solutions, Mtwara, Tanzania.,Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Arnold Mmbando
- Ifakara Health Institute, Ifakara, Tanzania.,Department of Biosciences, Durham University, Durham, UK
| | - Judith Meta
- University of Amsterdam, Amsterdam, Netherlands
| | - John Bradley
- MRC International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Nicholas P J Day
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.,Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | - Mavuto Mukaka
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.,Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
| | | | - Ally Olotu
- Ifakara Health Institute, Ifakara, Tanzania
| | | | | | - Jakob Knudsen
- The Royal Danish Academy of Fine Arts, Copenhagen, Denmark
| | | | - Lorenz von Seidlein
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK. .,Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand.
| |
Collapse
|
10
|
Klu D, Aberese-Ako M, Manyeh AK, Immurana M, Doegah P, Dalaba M, Acquah E, Alhassan RK, Ansah EK. Mixed effect analysis of factors influencing the use of insecticides treated bed nets among pregnant women in Ghana: evidence from the 2019 Malaria Indicator Survey. BMC Pregnancy Childbirth 2022; 22:258. [PMID: 35346098 PMCID: PMC8958761 DOI: 10.1186/s12884-022-04586-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 03/10/2022] [Indexed: 11/25/2022] Open
Abstract
Background Malaria during pregnancy is a major cause of maternal morbidity globally and leads to poor birth outcomes. The World Health Organization has recommended the use of insecticide treated bed nets (ITN) as one of the effective malaria preventive strategies among pregnant women in malaria endemic areas. This study, therefore, seeks to examine the individual and household factors associated with the use of ITNs among pregnant women in Ghana. Methods Data for this study was obtained from the 2019 Ghana Malaria Indicator Survey (GMIS) conducted between September 25 and November 24, 2019. The weighted sample comprised 353 pregnant women aged 15–49 years. Data was analyzed with SPSS version 22 using both descriptive and multilevel logistics regression modelling. Statistically significant level was set at p < 0.05. Results The study found that 49.2% of pregnant women in Ghana use ITN to prevent malaria. Pregnant women aged 35–49 years (AOR = 3.403, CI: 1.191–9.725), those with no formal education (AOR = 5.585, CI = 1.315–23.716), and those who had secondary education (AOR = 3.509, CI = 1.076–11.440) had higher odds of using ITN. Similarly, higher odds of ITN usage was found among who belonged to the Akan ethnic group (AOR = 7.234, CI = 1.497–34.955), dwell in male-headed households (AOR = 2.232, CI = 1.105–4.508) and those whose household heads are aged 60–69 years (AOR = 4.303, CI = 1.160–15.966). However, pregnant women who resided in urban areas (AOR = 0.355, CI = 0.216–0.582), those whose household heads aged 40–49 years (AOR = 0.175, CI = 0.066–0.467) and those who belonged to richer (AOR =0.184, CI = 0.050–0.679) and richest (AOR = 0.107, CI = 0.021–0.552) households had lower odds of using ITN for malaria prevention. Conclusions Individual socio-demographic and household factors such as pregnant women’s age, educational level, place of residence, ethnicity, sex and age of household head, and household wealth quintile are associated with the use of ITN for malaria prevention among pregnant women. These factors ought to be considered in strengthening malaria prevention campaigns and develop new interventions to help increase ITN utilization among vulnerable population living in malaria- endemic areas.
Collapse
|
11
|
Mmbando AS, Bradley J, Kazimbaya D, Kasubiri R, Knudsen J, Siria D, von Seidlein L, Okumu FO, Lindsay SW. The effect of light and ventilation on house entry by Anopheles arabiensis sampled using light traps in Tanzania: an experimental hut study. Malar J 2022; 21:36. [PMID: 35123497 PMCID: PMC8818140 DOI: 10.1186/s12936-022-04063-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/26/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
In sub-Saharan Africa, house design and ventilation affects the number of malaria mosquito vectors entering houses. This study hypothesized that indoor light from a CDC-light trap, visible from outside a hut, would increase entry of Anopheles arabiensis, an important malaria vector, and examined whether ventilation modifies this effect.
Methods
Four inhabited experimental huts, each situated within a large chamber, were used to assess how light and ventilation affect the number of hut-entering mosquitoes in Tanzania. Each night, 300 female laboratory-reared An. arabiensis were released inside each chamber for 72 nights. Nightly mosquito collections were made using light traps placed indoors. Temperature and carbon dioxide concentrations were measured using data loggers. Treatments and sleepers were rotated between huts using a randomized block design.
Results
When indoor light was visible outside the huts, there was an 84% increase in the odds of collecting mosquitoes indoors (Odds ratio, OR = 1.84, 95% confidence intervals, 95% CI 1.74–1.95, p < 0.001) compared with when it was not. Although the odds of collecting mosquitoes in huts with closed eaves (OR = 0.54, 95% CI 0.41–0.72, p < 0.001) was less than those with open eaves, few mosquitoes entered either type of well-ventilated hut. The odds of collecting mosquitoes was 99% less in well-ventilated huts, compared with poorly-ventilated traditional huts (OR = 0.01, 95% CI 0.01–0.03, p < 0.001). In well-ventilated huts, indoor temperatures were 1.3 °C (95% CI 0.9–1.7, p < 0.001) cooler, with lower carbon dioxide (CO2) levels (mean difference = 97 ppm, 77.8–116.2, p < 0.001) than in poorly-ventilated huts.
Conclusion
Although light visible from outside a hut increased mosquito house entry, good natural ventilation reduces indoor carbon dioxide concentrations, a major mosquito attractant, thereby reducing mosquito-hut entry.
Collapse
|
12
|
Musiime AK, Krezanoski PJ, Smith DL, Kilama M, Conrad MD, Otto G, Kyagamba P, Asiimwe J, Rek J, Nankabirwa JI, Arinaitwe E, Akol AM, Kamya MR, Staedke SG, Drakeley C, Bousema T, Lindsay SW, Dorsey G, Tusting LS. House design and risk of malaria, acute respiratory infection and gastrointestinal illness in Uganda: A cohort study. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000063. [PMID: 36962263 PMCID: PMC10022195 DOI: 10.1371/journal.pgph.0000063] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/15/2021] [Indexed: 11/18/2022]
Abstract
House construction is rapidly modernizing across Africa but the potential benefits for human health are poorly understood. We hypothesised that improvements to housing would be associated with reductions in malaria, acute respiratory infection (ARI) and gastrointestinal illness in an area of low malaria endemicity in Uganda. Data were analysed from a cohort study of male and female child and adult residents (n = 531) of 80 randomly-selected households in Nagongera sub-county, followed for 24 months (October 4, 2017 to October 31, 2019). Houses were classified as modern (brick walls, metal roof and closed eaves) or traditional (all other homes). Light trap collections of mosquitoes were done every two weeks in all sleeping rooms. Every four weeks, we measured malaria infection (using microscopy and qPCR to detect malaria parasites), incidence of malaria, ARI and gastrointestinal illness. We collected 15,780 adult female Anopheles over 7,631 nights. We collected 13,277 blood samples of which 10.2% (1,347) were positive for malaria parasites. Over 958 person years we diagnosed 38 episodes of uncomplicated malaria (incidence 0.04 episodes per person-year at risk), 2,553 episodes of ARI (incidence 2.7 episodes per person-year) and 387 episodes of gastrointestinal illness (incidence 0.4 episodes per person-year). Modern houses were associated with a 53% lower human biting rate compared to traditional houses (adjusted incidence rate ratio [aIRR] 0.47, 95% confidence interval [CI] 0.32-0.67, p<0.001) and a 24% lower incidence of gastrointestinal illness (aIRR 0.76, 95% CI 0.59-0.98, p = 0.04) but no changes in malaria prevalence, malaria incidence nor ARI incidence. House improvements may reduce mosquito-biting rates and gastrointestinal illness among children and adults. For the health sector to leverage Africa's housing modernization, research is urgently needed to identify the healthiest house designs and to assess their effectiveness across a range of epidemiological settings in sub-Saharan Africa.
Collapse
Affiliation(s)
- Alex K Musiime
- Infectious Diseases Research Collaboration, Kampala, Uganda
- Department of Zoology, Entomology and Fisheries Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Paul J Krezanoski
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, United States of America
| | - David L Smith
- Department of Health Metrics Sciences, University of Washington, Seattle, United States of America
| | - Maxwell Kilama
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Melissa D Conrad
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, United States of America
| | - Geoffrey Otto
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Joaniter I Nankabirwa
- Infectious Diseases Research Collaboration, Kampala, Uganda
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | | | - Anne M Akol
- Department of Zoology, Entomology and Fisheries Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Sarah G Staedke
- Faculty of Infectious and Tropical Diseases, Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Steve W Lindsay
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Grant Dorsey
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, United States of America
| | - Lucy S Tusting
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Centre on Climate Change and Planetary Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| |
Collapse
|
13
|
Nieto-Sanchez C, Dens S, Solomon K, Haile A, Yuan Y, Hawer T, Yewhalaw D, Addissie A, Grietens KP. Beyond eves and cracks: An interdisciplinary study of socio-spatial variation in urban malaria transmission in Ethiopia. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000173. [PMID: 36962186 PMCID: PMC10021683 DOI: 10.1371/journal.pgph.0000173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 02/23/2022] [Indexed: 11/18/2022]
Abstract
During the past century, the global trend of reduced malaria transmission has been concurrent with increasing urbanization. Although urbanization has traditionally been considered beneficial for vector control, the adaptation of malaria vectors to urban environments has created concerns among scientific communities and national vector control programs. Since urbanization rates in Ethiopia are among the highest in the world, the Ethiopian government developed an initiative focused on building multi-storied units organized in condominium housing. This study aimed to develop an interdisciplinary methodological approach that integrates architecture, landscape urbanism, medical anthropology, and entomology to characterize exposure to malaria vectors in this form of housing in three condominiums in Jimma Town. Mosquitoes were collected using light trap catches (LTCs) both indoor and outdoor during 2019's rainy season. Architectural drawings and ethnographic research were superposed to entomological data to detect critical interactions between uses of the space and settlement conditions potentially affecting malaria vector abundance and distribution. A total of 34 anopheline mosquitoes comprising three species (Anopheles gambiae s.l, An. pharoensis and An. coustani complex) were collected during the three months of mosquito collection. Anopheles gambiae s.l, the principal malaria vector in Ethiopia, was the predominant species of all the anophelines collected. Distribution of mosquito breeding sites across scales (household, settlement, urban landscape) is explained by environmental conditions, socio-cultural practices involving modification of existing spaces, and systemic misfits between built environment and territory. Variations in mosquito abundance and distribution in this study were mainly related to standard building practices that ignore the original logics of the territory, deficiency of water and waste disposal management systems, and adaptations of the space to fit heterogeneous lifestyles of residents. Our results indicate that contextualizing malaria control strategies in relation to vector ecology, social dynamics determining specific uses of the space, as well as building and territorial conditions could strengthen current elimination efforts. Although individual housing remains a critical unit of research for vector control interventions, this study demonstrates the importance of studying housing settlements at communal level to capture systemic interactions impacting transmission at the household level and in outdoor areas.
Collapse
Affiliation(s)
- Claudia Nieto-Sanchez
- Department of Public Health, Unit of Socio-Ecological Health Research, Institute of Tropical Medicine, Antwerp, Belgium
| | - Stefanie Dens
- Witteveen+Bos Belgium N.V., Antwerp, Belgium
- Research Group for Urban Development, Faculty of Design Sciences, University of Antwerp, Antwerp, Belgium
| | - Kalkidan Solomon
- Department of Preventive Medicine, School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Asgedom Haile
- Ethiopian Institute of Architecture, Building Construction, and City Development (EiABC), Addis Ababa University, Addis Ababa, Ethiopia
| | - Yue Yuan
- Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | | | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Adamu Addissie
- Department of Preventive Medicine, School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
| | - Koen Peeters Grietens
- Department of Public Health, Unit of Socio-Ecological Health Research, Institute of Tropical Medicine, Antwerp, Belgium
- Witteveen+Bos Belgium N.V., Antwerp, Belgium
- Research Group for Urban Development, Faculty of Design Sciences, University of Antwerp, Antwerp, Belgium
- Department of Preventive Medicine, School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia
- Ethiopian Institute of Architecture, Building Construction, and City Development (EiABC), Addis Ababa University, Addis Ababa, Ethiopia
- Faculty of Medicine, University of British Columbia, Vancouver, Canada
- Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| |
Collapse
|
14
|
Sutcliffe JF, Yin S. Effects of indoor air movement and ambient temperature on mosquito (Anopheles gambiae) behaviour around bed nets: implications for malaria prevention initiatives. Malar J 2021; 20:427. [PMID: 34717652 PMCID: PMC8557611 DOI: 10.1186/s12936-021-03957-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 10/18/2021] [Indexed: 11/10/2022] Open
Abstract
Background Until recently, relatively little research has been done on how mosquitoes behave around the occupied bed net in the indoor environment. This has been partly remedied in the last few years through laboratory and field studies, most of these using video methods and mosquito flight tracking. Despite these recent advances, understanding of the mosquito-bed net environment system, and the principles that underlie mosquito behaviour within it, is limited. This project aimed to further understand this system by studying the effects of gently moving air (such as might be introduced through room design to make the indoor environment more comfortable and conducive to ITN use) and warmer vs. cooler ambient conditions on mosquito activity around ITNs and other bed nets. Methods The activity of colonized female Anopheles gambiae around an occupied untreated bed net set up in a mosquito-proof tent in a large laboratory space was recorded under different ambient conditions using a laser detection-video recording system. Conditions tested were ‘cool’ (23–25 °C) and ‘warm’ (27–30 °C) air temperatures and the presence or absence of a cross-flow produced by a small central processing unit (CPU) fan pointed at the side of the net so that it produced a ‘low-’ or ‘high-’ speed cross-draught (approx. 0.1 and 0.4 m/s, respectively). Near-net activity in recordings was measured using video image analysis. Results In cool, still air conditions, more than 80% of near-net activity by An. gambiae occurred on the net roof. Introduction of the low-speed or high-speed cross-draught resulted in an almost total drop off in roof activity within 1 to 2 min and, in the case of the high-speed cross-draught, a complementary increase in activity on the net side. In warm, still conditions, near-net activity appeared to be lower overall than in cool, still air conditions and to be relatively less focussed on the roof. Introduction of the high-speed cross-draught in warm conditions resulted in a decrease in roof activity and increase in side activity though neither effect was statistically significant. Conclusions Results are interpreted in terms of the flow of the stimulatory odour plume produced by the net occupant which, consistent with established principles of fluid dynamics, appears to rise quickly and remain more intact above the net occupant in cool, still air than in warm, still air. Cross-draught effects are ascribed to the changes they cause in the flow of the host odour plume as opposed to mosquito flight directly. The implications of these results for house designs that promote indoor air movement, on bed net design, and on other vector control measures are discussed. How mosquitoes approach a net is influenced both by indoor temperature and ventilation and their interaction. This system is in need of further study. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03957-y.
Collapse
Affiliation(s)
- James F Sutcliffe
- Dept. Biology, Trent University, Peterborough, ON, Canada. .,Entomology Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | | |
Collapse
|
15
|
Kua KP, Lee DSWH. Home environmental interventions for prevention of respiratory tract infections: a systematic review and meta-analysis. REVIEWS ON ENVIRONMENTAL HEALTH 2021; 36:297-307. [PMID: 33544536 DOI: 10.1515/reveh-2020-0169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 01/10/2021] [Indexed: 06/12/2023]
Abstract
OBJECTIVES Poor housing conditions have been associated with increased risks of respiratory infections. This review aims to determine whether modifying the physical environment of the home has benefits in reducing respiratory infections. CONTENT We performed a systematic review and meta-analysis of the effectiveness of home environmental interventions for preventing respiratory tract infections. Ten electronic databases were searched to identify randomized controlled trials published from inception to July 31, 2020. Random-effects meta-analyses were used to assess the study outcomes. Our search identified 14 eligible studies across 12 countries, which comprised 87,428 households in total. The type of interventions on home environment included kitchen appliance and design, water supply and sanitation, house insulation, and home heating. Meta-analysis indicated a potential benefit of home environmental interventions in preventing overall respiratory tract infections (Absolute RR=0.89, 95% CI=0.78-1.01, p=0.07; Pooled adjusted RR=0.72, 95% CI=0.63-0.84, p<0.0001). Subgroup analyses depicted that home environmental interventions had no significant impact on lower respiratory tract infections, pneumonia, and severe pneumonia. A protective effect against respiratory infections was observed in high income country setting (RR=0.82, 95% CI=0.78-0.87, p<0.00001). SUMMARY AND OUTLOOK Home environmental interventions have the potential to reduce morbidity of respiratory tract infections. The lack of significant impact from stand-alone housing interventions suggests that multicomponent interventions should be implemented in tandem with high-quality health systems.
Collapse
Affiliation(s)
- Kok Pim Kua
- Puchong Health Clinic, Petaling District Health Office, Ministry of Health Malaysia, Petaling, Malaysia
| | - Dr Shaun Wen Huey Lee
- School of Pharmacy, Monash University, Bandar Sunway, 47500 Subang Jaya, Selangor, Malaysia
- Asian Centre for Evidence Synthesis in Population, Implementation, and Clinical Outcomes (PICO), Health and Well-being Cluster, Global Asia in the 21st Century (GA21) Platform, Monash University, Bandar Sunway, 47500 Subang Jaya, Selangor, Malaysia
- Gerontechnology Laboratory, Global Asia in the 21st Century (GA21) Platform, Monash University, Bandar Sunway, 47500 Subang Jaya, Selangor, Malaysia
- Faculty of Health and Medical Sciences, Taylor's University, Lakeside Campus, 47500 Subang Jaya, Selangor, Malaysia
| |
Collapse
|
16
|
A Critical Success Factor Framework for Implementing Sustainable Innovative and Affordable Housing: A Systematic Review and Bibliometric Analysis. BUILDINGS 2021. [DOI: 10.3390/buildings11080317] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The actualization of affordable housing remains a challenge. This challenge is exacerbated by the increasing societal demand for the incorporation of sustainability principles into such housing types to improve levels of occupant health and well-being whilst avouching the desired levels of affordability. Innovative technologies and practices have been described as beneficial to the effectuation of sustainable affordable housing. However, knowledge concerning the deployment of innovative technologies and practices in sustainable affordable housing (sustainable, innovative, affordable housing—SIAH) delivery remains nascent. Consequently, there is a lack of a common ontology among stakeholders concerning how to realize SIAH. This study aims to contribute toward the development of this body of knowledge through the establishment of the critical success factors (CSFs) for effective SIAH implementation. To achieve this objective, a systematic review and bibliometric analysis focusing on a juxtaposition of sustainable, innovative and affordable housing concepts was carried out based on the relevant literature. This led to the identification and clustering of CSFs for these housing concepts at individual levels and as a collective (SIAH). The findings of the study consisted of the establishment of four distinct yet interrelated facets through which SIAH can be achieved holistically, namely, housing design, house element, housing production method and housing technology. A total of 127 CSFs were found to be aligned to these facets, subsequently clustered, and conclusively used for the development of a SIAH CSF framework. The most frequently occurring CSFs with predominant interconnections were the utilization of energy-efficient systems/fittings, tenure security, a comfortable and healthy indoor environment, affordable housing price in relation to income and using water-efficient systems/fittings CSFs, and establishing the emergent SIAH CSF framework. The framework in this study is useful in the documentation of SIAH features for construction projects and further studies into SIAH CSFs.
Collapse
|
17
|
Pooseesod K, Parker DM, Meemon N, Lawpoolsri S, Singhasivanon P, Sattabongkot J, Cui L, Phuanukoonnon S. Ownership and utilization of bed nets and reasons for use or non-use of bed nets among community members at risk of malaria along the Thai-Myanmar border. Malar J 2021; 20:305. [PMID: 34229653 PMCID: PMC8259116 DOI: 10.1186/s12936-021-03837-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/27/2021] [Indexed: 11/22/2022] Open
Abstract
Background With the goal for malaria elimination in Thailand set for 2024, increased coverage and utilization of bed net, especially insecticide-treated net (ITN) or long-lasting insecticidal net (LLIN) is a key strategy. This study aims to provide the necessary information about bed net ownership and utilization among the population at risk of malaria living along the Thai-Myanmar border in Tak province. Methods A cross-sectional study was conducted using a mixed-method approach in 331 households from 5 hamlets in the villages of the Thai-Myanmar border. The research tools included a questionnaire, bed net inspection, and semi-structured interviews. Logistic regression was used to explore the sociodemographic factors associated with bed net utilization. The qualitative analysis employed a thematic analysis approach. Results This survey found that 98.5% of households had at least one bed net per household, and 74.3% had at least one ITN/LLIN. However, only 30.8% of households reached the standard policy set by the Minister of Public Health of one ITN/LLINs per two persons. Most residents used bed net (92.1% used in the previous night and 80.9% used every day). For those using bed nets, however, 61.9% used ITNs or LLINs the night before and 53.1% used them every day. Nonetheless, the usage rates of bed nets (any type) in the previous night among children and pregnant women were high, reaching 95.3% and 90.0%, respectively. Seven explanatory variables showed statistically significant associations with bed net use every day, including: “not staying overnight in the forest or the field”, “sleeping pattern based on gender”, “sufficient numbers of bed nets to cover all sleeping spaces”, “preference for free bed nets”, “age”, “gender”, and “SES score” showed statistically significant association with bed net use every day. The major reasons for the regular use of bed nets in both household and the forest were to prevent mosquito biting. The reasons for not using bednets in the household were discomfort feelings from heat, perception of unnecessity due to low mosquito density, whereas the reason for not using bed nets in the forest was inconvenience. Conclusion Despite that overall coverage and usage of bed nets was high, only one third reached the standard level specified by the policy. Overnight in the forest, the dissatisfaction with the quality of free bed nets, insufficient number of bed nets, sleeping alone, male gender, age more than 10 years, low socioeconomic status, discomfort from heat, perception of no benefits of bed nets due to low mosquito density, and inconvenience were factors influencing bed net use. Maintaining high coverage and utility rate of bed nets should be a priority for the malaria high-risk population. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03837-5.
Collapse
Affiliation(s)
- Kasama Pooseesod
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Nakhon Pathom, Thailand.,Faculty of Public Health, Thammasat University, Bangkok, Thailand
| | - Daniel M Parker
- Department of Population Health & Disease Prevention, Program in Public Health Susan and Henry Samueli College of Health Sciences, University of California, Irvine, USA
| | - Natthani Meemon
- Department of Society and Health, Faculty of Social Sciences and Humanities, Mahidol University, Nakhon Pathom, Thailand
| | - Saranath Lawpoolsri
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Nakhon Pathom, Thailand
| | - Pratap Singhasivanon
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Nakhon Pathom, Thailand.,Faculty of Tropical Medicine, SEAMEO TROPMED Regional Centre for Tropical Medicine, Mahidol University, Nakhon Pathom, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Nakhon Pathom, Thailand
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Suparat Phuanukoonnon
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Nakhon Pathom, Thailand. .,Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Nakhon Pathom, Thailand.
| |
Collapse
|
18
|
Carrasco-Tenezaca M, Jawara M, Abdi MY, Bradley J, Brittain OS, Ceesay S, D'Alessandro U, Jeffries D, Pinder M, Wood H, Knudsen JB, Lindsay SW. The relationship between house height and mosquito house entry: an experimental study in rural Gambia. J R Soc Interface 2021; 18:20210256. [PMID: 34034532 PMCID: PMC8150013 DOI: 10.1098/rsif.2021.0256] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Most malaria infections in sub-Saharan Africa are acquired indoors, thus finding effective ways of preventing mosquito house entry should reduce transmission. Since most malaria mosquitoes fly less than 1 m from the ground, we tested whether raising buildings off the ground would prevent the entry of Anopheles gambiae, the principal African malaria vector, in rural Gambia. Nightly collections of mosquitoes were made using light traps from four inhabited experimental huts, each of which could be moved up or down. Mosquito house entry declined with increasing height, with a hut at 3 m reducing An. gambiae house entry by 84% when compared with huts on the ground. A propensity for malaria vectors to fly close to the ground and reduced levels of carbon dioxide, a major mosquito attractant, in elevated huts, may explain our findings. Raised buildings may help reduce malaria transmission in Africa.
Collapse
Affiliation(s)
| | - Musa Jawara
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Mahamed Y Abdi
- Royal Danish Academy - Architecture, Design and Conservation, Copenhagen, Denmark
| | - John Bradley
- London School of Hygiene & Tropical Medicine, London, UK
| | - Otis Sloan Brittain
- Royal Danish Academy - Architecture, Design and Conservation, Copenhagen, Denmark
| | - Sainey Ceesay
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia.,London School of Hygiene & Tropical Medicine, London, UK
| | - David Jeffries
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Margaret Pinder
- Department of Biosciences, Durham University, Durham, UK.,Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Hannah Wood
- Royal Danish Academy - Architecture, Design and Conservation, Copenhagen, Denmark
| | - Jakob B Knudsen
- Royal Danish Academy - Architecture, Design and Conservation, Copenhagen, Denmark
| | - Steve W Lindsay
- Department of Biosciences, Durham University, Durham, UK.,London School of Hygiene & Tropical Medicine, London, UK
| |
Collapse
|
19
|
Hii J, Hustedt J, Bangs MJ. Residual Malaria Transmission in Select Countries of Asia-Pacific Region: Old Wine in a New Barrel. J Infect Dis 2021; 223:S111-S142. [PMID: 33906222 PMCID: PMC8079134 DOI: 10.1093/infdis/jiab004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Background Despite substantial reductions in malaria burden and improvement in case management, malaria remains a major public health challenge in the Asia-Pacific region. Residual malaria transmission (RMT) is the fraction of total transmission that persists after achievement of full operational coverage with effective insecticide-treated bed nets (ITNs)/long-lasting insecticidal nets (LLINs) and/or indoor residual spray interventions. There is a critical need to standardize and share best practices for entomological, anthropological, and product development investigative protocols to meet the challenges of RMT and elimination goals. Methods A systematic review was conducted to describe when and where RMT is occurring, while specifically targeting ownership and usage of ITN/LLINs, indoor residual spray application, insecticide susceptibility of vectors, and human and vector biting behavior, with a focus on nighttime activities. Results Sixty-six publications from 1995 to present met the inclusion criteria for closer review. Associations between local vector control coverage and use with behaviors of human and mosquito vectors varied by locality and circumstance. Consequently, the magnitude of RMT is insufficiently studied and analyzed with sparse estimates of individual exposure in communities, insufficient or incomplete observations of ITN/LLIN use, and the local human population movement into and from high-risk areas. Conclusions This review identified significant gaps or deficiencies that require urgent attention, namely, developing standardized procedures and methods to estimate risk exposure beyond the peridomestic setting, analytical approaches to measure key human-vector interactions, and seasonal location-specific agricultural or forest use calendars, and establishing the collection of longitudinal human and vector data close in time and location.
Collapse
Affiliation(s)
- Jeffrey Hii
- Malaria Consortium Asia, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
| | | | - Michael J Bangs
- Public Health and Malaria Control Department, PT Freeport Indonesia, International SOS, Jl. Kertajasa, Kuala Kencana, Papua, Indonesia.,Department of Entomology, Faculty of Agriculture, Kasertart University, Bangkok, Thailand
| |
Collapse
|
20
|
Pinder M, Bradley J, Jawara M, Affara M, Conteh L, Correa S, Jeffries D, Jones C, Kandeh B, Knudsen J, Olatunji Y, Sicuri E, D'Alessandro U, Lindsay SW. Improved housing versus usual practice for additional protection against clinical malaria in The Gambia (RooPfs): a household-randomised controlled trial. Lancet Planet Health 2021; 5:e220-e229. [PMID: 33838737 PMCID: PMC8051018 DOI: 10.1016/s2542-5196(21)00002-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 12/21/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND In malaria-endemic areas, residents of modern houses have less malaria than those living in traditional houses. We aimed to assess whether children in The Gambia received an incremental benefit from improved housing, where current best practice of insecticide-treated nets, indoor residual spraying, seasonal malaria chemoprevention in children younger than 5 years, and prompt treatment against clinical malaria was in place. METHODS In this randomised controlled study, 800 households with traditional thatched-roofed houses were randomly selected from 91 villages in the Upper River Region of The Gambia. Within each village, equal numbers of houses were randomly allocated to the control and intervention groups using a sampling frame. Houses in the intervention group were modified with metal roofs and screened doors and windows, whereas houses in the control group received no modifications. In each group, clinical malaria in children aged 6 months to 13 years was monitored by active case detection over 2 years (2016-17). We did monthly collections from indoor light traps to estimate vector densities. Primary endpoints were the incidence of clinical malaria in study children with more than 50% of observations each year and household vector density. The trial is registered at ISRCTN02622179. FINDINGS In June, 2016, 785 houses had one child each recruited into the study (398 in unmodified houses and 402 in modified houses). 26 children in unmodified houses and 28 children in modified houses did not have at least 50% of visits in a year and so were excluded from analysis. 38 children in unmodified houses were recruited after study commencement, as were 21 children in modified houses, meaning 410 children in unmodified houses and 395 in modified houses were included in the parasitological analyses. At the end of the study, 659 (94%) of 702 children were reported to have slept under an insecticide-treated net; 662 (88%) of 755 children lived in houses that received indoor residual spraying; and 151 (90%) of 168 children younger than 5 years had seasonal malaria chemoprevention. Incidence of clinical malaria was 0·12 episodes per child-year in children in the unmodified houses and 0·20 episodes per child-year in the modified houses (unadjusted incidence rate ratio [RR] 1·68 [95% CI 1·11-2·55], p=0·014). Household vector density was 3·30 Anopheles gambiae per house per night in the unmodified houses compared with 3·60 in modified houses (unadjusted RR 1·28 [0·87-1·89], p=0·21). INTERPRETATION Improved housing did not provide protection against clinical malaria in this area of low seasonal transmission with high coverage of insecticide-treated nets, indoor residual spraying, and seasonal malaria chemoprevention. FUNDING Global Health Trials funded by Medical Research Council, UK Department for International Development, and Wellcome Trust.
Collapse
Affiliation(s)
- Margaret Pinder
- Department of Biosciences, Durham University, Durham, UK; Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, UK
| | - Musa Jawara
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Muna Affara
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia; Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Lesong Conteh
- London School of Economics and Political Science, London, UK
| | - Simon Correa
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - David Jeffries
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Caroline Jones
- KEMRI-Wellcome Trust Programme, Kilifi, Kenya and Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Balla Kandeh
- National Malaria Control Programme, Banjul, The Gambia
| | - Jakob Knudsen
- Royal Danish Academy - Architecture, Design, Conservation, Copenhagen, Denmark
| | - Yekini Olatunji
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Elisa Sicuri
- School of Public Health, Imperial College London, London, UK; ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia; Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Steve W Lindsay
- Department of Biosciences, Durham University, Durham, UK; Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK.
| |
Collapse
|
21
|
Abstract
BACKGROUND Despite being preventable, malaria remains an important public health problem. The World Health Organization (WHO) reports that overall progress in malaria control has plateaued for the first time since the turn of the century. Researchers and policymakers are therefore exploring alternative and supplementary malaria vector control tools. Research in 1900 indicated that modification of houses may be effective in reducing malaria: this is now being revisited, with new research now examining blocking house mosquito entry points or modifying house construction materials to reduce exposure of inhabitants to infectious bites. OBJECTIVES To assess the effects of house modifications on malaria disease and transmission. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register; Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE (PubMed); Embase (OVID); Centre for Agriculture and Bioscience International (CAB) Abstracts (Web of Science); and the Latin American and Caribbean Health Science Information database (LILACS), up to 1 November 2019. We also searched the WHO International Clinical Trials Registry Platform (www.who.int/ictrp/search/en/), ClinicalTrials.gov (www.clinicaltrials.gov), and the ISRCTN registry (www.isrctn.com/) to identify ongoing trials up to the same date. SELECTION CRITERIA Randomized controlled trials, including cluster-randomized controlled trials (cRCTs), cross-over studies, and stepped-wedge designs were eligible, as were quasi-experimental trials, including controlled before-and-after studies, controlled interrupted time series, and non-randomized cross-over studies. We only considered studies reporting epidemiological outcomes (malaria case incidence, malaria infection incidence or parasite prevalence). We also summarised qualitative studies conducted alongside included studies. DATA COLLECTION AND ANALYSIS Two review authors selected eligible studies, extracted data, and assessed the risk of bias. We used risk ratios (RR) to compare the effect of the intervention with the control for dichotomous data. For continuous data, we presented the mean difference; and for count and rate data, we used rate ratios. We presented all results with 95% confidence intervals (CIs). We assessed the certainty of evidence using the GRADE approach. MAIN RESULTS Six cRCTs met our inclusion criteria, all conducted in sub-Saharan Africa; three randomized by household, two by village, and one at the community level. All trials assessed screening of windows, doors, eaves, ceilings or any combination of these; this was either alone, or in combination with eave closure, roof modification or eave tube installation (a "lure and kill" device that reduces mosquito entry whilst maintaining some airflow). In two trials, the interventions were insecticide-based. In five trials, the researchers implemented the interventions. The community implemented the interventions in the sixth trial. At the time of writing the review, two of the six trials had published results, both of which compared screened houses (without insecticide) to unscreened houses. One trial in Ethiopia assessed screening of windows and doors. Another trial in the Gambia assessed full screening (screening of eaves, doors and windows), as well as screening of ceilings only. Screening may reduce clinical malaria incidence caused by Plasmodium falciparum (rate ratio 0.38, 95% CI 0.18 to 0.82; 1 trial, 184 participants, 219.3 person-years; low-certainty evidence; Ethiopian study). For malaria parasite prevalence, the point estimate, derived from The Gambia study, was smaller (RR 0.84, 95% CI 0.60 to 1.17; 713 participants, 1 trial; low-certainty evidence), and showed an effect on anaemia (RR 0.61, 95% CI 0.42, 0.89; 705 participants; 1 trial, moderate-certainty evidence). Screening may reduce the entomological inoculation rate (EIR): both trials showed lower estimates in the intervention arm. In the Gambian trial, there was a mean difference in EIR between the control houses and treatment houses ranging from 0.45 to 1.50 (CIs ranged from -0.46 to 2.41; low-certainty evidence), depending on the study year and treatment arm. The Ethiopian trial reported a mean difference in EIR of 4.57, favouring screening (95% CI 3.81 to 5.33; low-certainty evidence). Pooled analysis of the trials showed that individuals living in fully screened houses were slightly less likely to sleep under a bed net (RR 0.84, 95% CI 0.65 to 1.09; 2 trials, 203 participants). In one trial, bed net usage was also lower in individuals living in houses with screened ceilings (RR 0.69, 95% CI 0.50 to 0.95; 1 trial, 135 participants). AUTHORS' CONCLUSIONS Based on the two trials published to date, there is some evidence that screening may reduce malaria transmission and malaria infection in people living in the house. The four trials awaiting publication are likely to enrich the current evidence base, and we will add these to this review when they become available.
Collapse
Affiliation(s)
- Joanna Furnival-Adams
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Evelyn A Olanga
- Malaria Alert Centre of the College of Medicine, Blantyre, Malawi
| | - Mark Napier
- Council for Scientific and Industrial Research, Pretoria, South Africa
- Centre for Development Support, University of the Free State, Bloemfontein, South Africa
| | - Paul Garner
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| |
Collapse
|
22
|
Kua KP, Lee SWH. Randomized trials of housing interventions to prevent malaria and Aedes-transmitted diseases: A systematic review and meta-analysis. PLoS One 2021; 16:e0244284. [PMID: 33417600 PMCID: PMC7793286 DOI: 10.1371/journal.pone.0244284] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/08/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Mosquito-borne diseases remain a significant public health problem in tropical regions. Housing improvements such as screening of doors and windows may be effective in reducing disease transmission, but the impact remains unclear. OBJECTIVES To examine whether housing interventions were effective in reducing mosquito densities in homes and the impact on the incidence of mosquito-borne diseases. METHODS In this systematic review and meta-analysis, we searched 16 online databases, including NIH PubMed, CINAHL Complete, LILACS, Ovid MEDLINE, and Cochrane Central Register of Controlled Trials for randomized trials published from database inception to June 30, 2020. The primary outcome was the incidence of any mosquito-borne diseases. Secondary outcomes encompassed entomological indicators of the disease transmission. I2 values were used to explore heterogeneity between studies. A random-effects meta-analysis was used to assess the primary and secondary outcomes, with sub-group analyses for type of interventions on home environment, study settings (rural, urban, or mixed), and overall house type (traditional or modern housing). RESULTS The literature search yielded 4,869 articles. After screening, 18 studies were included in the qualitative review, of which nine were included in the meta-analysis. The studies enrolled 7,200 households in Africa and South America, reporting on malaria or dengue only. The type of home environmental interventions included modification to ceilings and ribbons to close eaves, screening doors and windows with nets, insecticide-treated wall linings in homes, nettings over gables and eaves openings, mosquito trapping systems, metal-roofed houses with mosquito screening, gable windows and closed eaves, and prototype houses using southeast Asian designs. Pooled analysis depicted a lower risk of mosquito-borne diseases in the housing intervention group (OR = 0.68; 95% CI = 0.48 to 0.95; P = 0.03). Subgroup analysis depicted housing intervention reduced the risk of malaria in all settings (OR = 0.63; 95% CI = 0.39 to 1.01; P = 0.05). In urban environment, housing intervention was found to decrease the risk of both malaria and dengue infections (OR = 0.52; 95% CI = 0.27 to 0.99; P = 0.05).Meta-analysis of pooled odds ratio showed a significant benefit of improved housing in reducing indoor vector densities of both Aedes and Anopheles (OR = 0.35; 95% CI = 0.23 to 0.54; P<0.001). CONCLUSIONS Housing intervention could reduce transmission of malaria and dengue among people living in the homes. Future research should evaluate the protective effect of specific house features and housing improvements associated with urban development.
Collapse
Affiliation(s)
- Kok Pim Kua
- Puchong Health Clinic, Petaling District Health Office, Ministry of Health Malaysia, Petaling, Malaysia
| | - Shaun Wen Huey Lee
- School of Pharmacy, Monash University Malaysia, Sunway City, Malaysia
- Asian Center for Evidence Synthesis in Population, Implementation, and Clinical Outcomes (PICO), Health and Well-being Cluster, Global Asia in the 21st Century (GA21) Platform, Monash University Malaysia, Sunway City, Malaysia
- Gerontechnology Laboratory, Global Asia in the 21st Century (GA21) Platform, Monash University Malaysia, Sunway City, Malaysia
- Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| |
Collapse
|
23
|
Sanou R, Maïga H, Bilgo EM, Sawadogo SP, Sow BBD, Ouema A, Bayili K, Belem AMG, Toé LP, Dabiré RK, Diabaté A. Assessment of novel Lehmann's funnel entry trap prototypes performance to control malaria mosquito populations. Malar J 2021; 20:2. [PMID: 33386073 PMCID: PMC7777431 DOI: 10.1186/s12936-020-03532-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 12/07/2020] [Indexed: 12/02/2022] Open
Abstract
Background There is a global consensus that new intervention tools are needed for the final steps toward malaria elimination/eradication. In a recent study in Burkina Faso, the Lehmann Funnel Entry Trap (LFET) has shown promising results in the reduction of mosquito densities, even in areas where insecticide resistance is as high as 80%. The LFET requires no chemicals and is self-operated. However, one of the issues with the original LFET is the size of the funnel, which often occupies too much space within users’ homes. Here, the performance of three new, smaller-sized LFET prototypes that combine a screening and killing effect on mosquitoes was assessed. Methods The study was carried out over three months during the rainy season in low and high malaria vector density sites, Soumousso and Vallée du Kou, respectively. The original LFET (or ‘Prototype 1’/‘P1’) was modified to produce three new prototypes, which were referred to as prototype 2 (‘the Medium’ or ‘P2’), prototype 3 (P3) and prototype 4 (P4). Each of the new prototypes was tested on eight days per month over the three-month period to assess their effectiveness in trapping and killing mosquitoes entering houses through the windows compared to the original LFET. Results Overall, 78,435 mosquitoes (mainly Anopheles gambiae sensu lato) were collected in the two study sites, both in the traps and in the houses. A total of 56,430 (72%) mosquitoes were collected from the traps. In Vallée du Kou, the original LFET caught a greater number of mosquitoes than the medium (prototype 2), whereas no difference was observed between the other new prototypes (3 and 4) and the medium. In Soumousso, both the original and medium LFETs collected significantly greater numbers of mosquitoes compared to prototypes 3 and 4. Conclusion This study has shown that the new LFET prototypes are effective in trapping mosquitoes in high mosquito density settings. A large-scale study with one of the prototypes will be needed to assess community acceptance of the traps and their ability to control malaria vectors.
Collapse
Affiliation(s)
- Roger Sanou
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso. .,Université Nazi BONI de Bobo-Dioulasso, PO 1091, Bobo-Dioulasso, Burkina Faso.
| | - Hamidou Maïga
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Etienne M Bilgo
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Simon P Sawadogo
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Bazoumana B D Sow
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso.,Université Nazi BONI de Bobo-Dioulasso, PO 1091, Bobo-Dioulasso, Burkina Faso
| | - Adama Ouema
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso.,Université Nazi BONI de Bobo-Dioulasso, PO 1091, Bobo-Dioulasso, Burkina Faso
| | - Koama Bayili
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | | | - Léa Paré Toé
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Roch K Dabiré
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de La Santé (IRSS)/Centre Muraz, Bobo-Dioulasso, Burkina Faso.
| |
Collapse
|
24
|
Lindsay SW, Davies M, Alabaster G, Altamirano H, Jatta E, Jawara M, Carrasco-Tenezaca M, von Seidlein L, Shenton FC, Tusting LS, Wilson AL, Knudsen J. Recommendations for building out mosquito-transmitted diseases in sub-Saharan Africa: the DELIVER mnemonic. Philos Trans R Soc Lond B Biol Sci 2020; 376:20190814. [PMID: 33357059 DOI: 10.1098/rstb.2019.0814] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In sub-Saharan Africa, most transmission of mosquito-transmitted diseases, such as malaria or dengue, occurs within or around houses. Preventing mosquito house entry and reducing mosquito production around the home would help reduce the transmission of these diseases. Based on recent research, we make key recommendations for reducing the threat of mosquito-transmitted diseases through changes to the built environment. The mnemonic, DELIVER, recommends the following best practices: (i) Doors should be screened, self-closing and without surrounding gaps; (ii) Eaves, the space between the wall and roof, should be closed or screened; (iii) houses should be Lifted above the ground; (iv) Insecticide-treated nets should be used when sleeping in houses at night; (v) houses should be Ventilated, with at least two large-screened windows to facilitate airflow; (vi) Environmental management should be conducted regularly inside and around the home; and (vii) Roofs should be solid, rather than thatch. DELIVER is a package of interventions to be used in combination for maximum impact. Simple changes to the built environment will reduce exposure to mosquito-transmitted diseases and help keep regions free from these diseases after elimination. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.
Collapse
Affiliation(s)
- Steven W Lindsay
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - Michael Davies
- Bartlett School Environment, Energy & Resources, Faculty of the Built Environment, University College London, London WC1H 0NN, UK
| | | | - Hector Altamirano
- Bartlett School Environment, Energy & Resources, Faculty of the Built Environment, University College London, London WC1H 0NN, UK
| | - Ebrima Jatta
- National Malaria Control Programme, Banjul, The Gambia
| | - Musa Jawara
- Medical Research Council Unit Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | | | - Lorenz von Seidlein
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Fiona C Shenton
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - Lucy S Tusting
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Anne L Wilson
- Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Jakob Knudsen
- The Royal Danish Academy of Fine Arts, School of Architecture, Design and Conservation, The School of Architecture, Copenhagen, Denmark
| |
Collapse
|
25
|
Abstract
BACKGROUND Despite being preventable, malaria remains an important public health problem. The World Health Organization (WHO) reports that overall progress in malaria control has plateaued for the first time since the turn of the century. Researchers and policymakers are therefore exploring alternative and supplementary malaria vector control tools. Research in 1900 indicated that modification of houses may be effective in reducing malaria: this is now being revisited, with new research now examining blocking house mosquito entry points or modifying house construction materials to reduce exposure of inhabitants to infectious bites. OBJECTIVES To assess the effects of house modifications on malaria disease and transmission. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register; Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE (PubMed); Embase (OVID); Centre for Agriculture and Bioscience International (CAB) Abstracts (Web of Science); and the Latin American and Caribbean Health Science Information database (LILACS), up to 1 November 2019. We also searched the WHO International Clinical Trials Registry Platform (www.who.int/ictrp/search/en/), ClinicalTrials.gov (www.clinicaltrials.gov), and the ISRCTN registry (www.isrctn.com/) to identify ongoing trials up to the same date. SELECTION CRITERIA Randomized controlled trials, including cluster-randomized controlled trials (cRCTs), cross-over studies, and stepped-wedge designs were eligible, as were quasi-experimental trials, including controlled before-and-after studies, controlled interrupted time series, and non-randomized cross-over studies. We only considered studies reporting epidemiological outcomes (malaria case incidence, malaria infection incidence or parasite prevalence). We also summarised qualitative studies conducted alongside included studies. DATA COLLECTION AND ANALYSIS Two review authors selected eligible studies, extracted data, and assessed the risk of bias. We used risk ratios (RR) to compare the effect of the intervention with the control for dichotomous data. For continuous data, we presented the mean difference; and for count and rate data, we used rate ratios. We presented all results with 95% confidence intervals (CIs). We assessed the certainty of evidence using the GRADE approach. MAIN RESULTS Six cRCTs met our inclusion criteria, all conducted in sub-Saharan Africa; three randomized by household, two by village, and one at the community level. All trials assessed screening of windows, doors, eaves, ceilings or any combination of these; this was either alone, or in combination with eave closure, roof modification or eave tube installation (a "lure and kill" device that reduces mosquito entry whilst maintaining some airflow). In two trials, the interventions were insecticide-based. In five trials, the researchers implemented the interventions. The community implemented the interventions in the sixth trial. At the time of writing the review, two of the six trials had published results, both of which compared screened houses (without insecticide) to unscreened houses. One trial in Ethiopia assessed screening of windows and doors. Another trial in the Gambia assessed full screening (screening of eaves, doors and windows), as well as screening of ceilings only. Screening may reduce clinical malaria incidence caused by Plasmodium falciparum (rate ratio 0.38, 95% CI 0.18 to 0.82; 1 trial, 184 participants, 219.3 person-years; low-certainty evidence; Ethiopian study). For malaria parasite prevalence, the point estimate, derived from The Gambia study, was smaller (RR 0.84, 95% CI 0.60 to 1.17; 713 participants, 1 trial; moderate-certainty evidence), and showed an effect on anaemia (RR 0.61, 95% CI 0.42, 0.89; 705 participants; 1 trial, moderate-certainty evidence). Screening may reduce the entomological inoculation rate (EIR): both trials showed lower estimates in the intervention arm. In the Gambian trial, there was a mean difference in EIR between the control houses and treatment houses ranging from 0.45 to 1.50 (CIs ranged from -0.46 to 2.41; low-certainty evidence), depending on the study year and treatment arm. The Ethiopian trial reported a mean difference in EIR of 4.57, favouring screening (95% CI 3.81 to 5.33; low-certainty evidence). Pooled analysis of the trials showed that individuals living in fully screened houses were slightly less likely to sleep under a bed net (RR 0.84, 95% CI 0.65 to 1.09; 2 trials, 203 participants). In one trial, bed net usage was also lower in individuals living in houses with screened ceilings (RR 0.69, 95% CI 0.50 to 0.95; 1 trial, 135 participants). AUTHORS' CONCLUSIONS Based on the two trials published to date, there is some evidence that screening may reduce malaria transmission and malaria infection in people living in the house. The four trials awaiting publication are likely to enrich the current evidence base, and we will add these to this review when they become available.
Collapse
Affiliation(s)
- Joanna Furnival-Adams
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Evelyn A Olanga
- Malaria Alert Centre of the College of Medicine, Blantyre, Malawi
| | - Mark Napier
- Council for Scientific and Industrial Research, Pretoria, South Africa
- Centre for Development Support, University of the Free State, Bloemfontein, South Africa
| | - Paul Garner
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| |
Collapse
|
26
|
Knudsen JB, Pinder M, Jatta E, Jawara M, Yousuf MA, Søndergaard AT, Lindsay SW. Measuring ventilation in different typologies of rural Gambian houses: a pilot experimental study. Malar J 2020; 19:273. [PMID: 32736629 PMCID: PMC7393878 DOI: 10.1186/s12936-020-03327-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 07/07/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND African houses are frequently too hot and uncomfortable to use a bed net at night. Indoor thermal comfort is often evaluated by measuring temperature and humidity, ignoring ventilation. This study explored ways to measure ventilation in single-roomed rural Gambian houses during the malaria transmission season and evaluated building designs that could increase airflow at night and help keep the occupants comfortable. METHODS Two identical mud-walled houses were constructed with a metal roof, three doors and closed eaves. Experiment 1 compared five methods for measuring ventilation in a building: (1) using a blower door, (2) increasing carbon dioxide (CO2) levels indoors using an artificial source of CO2 and then measuring the rate of gas decay, (3) using a similar approach with a natural source of CO2, (4) measuring the rise of CO2 when people enter a building and (5) using hot-wire anemometers. Experiment 2 used CO2 data loggers to compare ventilation in a reference metal-roofed house with closed eaves and badly-fitting doors with a similar house with (1) thatched roof and open eaves, (2) eaves tubes, (3) screened doors and (4) screened doors and windows. RESULTS In experiment 1, CO2 data loggers placed indoors in two identical houses showed similar changes in airflow (p > 0.05) for all three methods recording either decreasing or increasing CO2. Blower doors were unable to measure airflow in houses with open eaves or screened windows and the anemometers broke down under field conditions. In experiment 2, open eaves in thatched houses, screened doors alone, and screened doors and windows increased indoor ventilation compared to the reference metal-roofed house with closed eaves and badly fitting doors (p < 0.05). Eaves tubes did not increase ventilation in comparison to the reference house. CONCLUSION CO2 data loggers proved to be a simple and efficient method for measuring ventilation in rural houses at night. Ventilation of metal-roofed houses can be improved by adding two screened doors and windows on opposite walls. Improved ventilation will result in increased thermal comfort making it more likely that people will sleep under a bed net.
Collapse
Affiliation(s)
- Jakob B Knudsen
- Schools of Architecture, Design and Conservation, The Royal Danish Academy of Fine Arts, Philip de Langes Allé 10, 1435, Copenhagen K, Denmark.
| | - Margaret Pinder
- Medical Research Council Unit, The Gambia at the London School of Hygiene & Tropical Medicine, Fajara, The Gambia.,Department of Biosciences, Durham University, Durham, UK
| | - Ebrima Jatta
- Department of Biosciences, Durham University, Durham, UK.,National Malaria Control Programme, Banjul, The Gambia
| | - Musa Jawara
- Medical Research Council Unit, The Gambia at the London School of Hygiene & Tropical Medicine, Fajara, The Gambia
| | - Mahamed A Yousuf
- Schools of Architecture, Design and Conservation, The Royal Danish Academy of Fine Arts, Philip de Langes Allé 10, 1435, Copenhagen K, Denmark
| | - Amalie T Søndergaard
- Schools of Architecture, Design and Conservation, The Royal Danish Academy of Fine Arts, Philip de Langes Allé 10, 1435, Copenhagen K, Denmark
| | - Steve W Lindsay
- Department of Biosciences, Durham University, Durham, UK.,London School of Hygiene & Tropical Medicine, London, UK
| |
Collapse
|
27
|
Odufuwa OG, Ross A, Mlacha YP, Juma O, Mmbaga S, Msellemu D, Moore S. Household factors associated with access to insecticide-treated nets and house modification in Bagamoyo and Ulanga districts, Tanzania. Malar J 2020; 19:220. [PMID: 32576180 PMCID: PMC7313165 DOI: 10.1186/s12936-020-03303-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 06/18/2020] [Indexed: 08/29/2023] Open
Abstract
BACKGROUND Insecticide-treated nets (ITNs) and house modifications are proven vector control tools, yet in most regions, full coverage has not been achieved. This study investigates household factors associated with access to ITNs and house modification in Tanzania. METHODS Baseline cross-sectional survey data from previous studies on spatial repellants and indoor residual spray evaluation was analysed from 6757 households in Bagamoyo (60 km north of Dar es Salaam) and 1241 households in Ulanga (a remote rural area in southeast Tanzania), respectively. Regression models were used to estimate the associations between the outcomes: population access to ITNs, access to ITN per sleeping spaces, window screens and closed eaves, and the covariates household size, age, gender, pregnancy, education, house size, house modification (window screens and closed eaves) and wealth. RESULTS Population access to ITNs (households with one ITN per two people that stayed in the house the previous night of the survey) was 69% (n = 4663) and access to ITNs per sleeping spaces (households with enough ITNs to cover all sleeping spaces used the previous night of the survey) was 45% (n = 3010) in Bagamoyo, 3 years after the last mass campaign. These findings are both lower than the least 80% coverage target of the Tanzania National Malaria Strategic Plan (Tanzania NMSP). In Ulanga, population access to ITNs was 92% (n = 1143) and ITNs per sleeping spaces was 88% (n = 1093), 1 year after the last Universal Coverage Campaign (UCC). Increased household size was significantly associated with lower access to ITNs even shortly after UCC. House modification was common in both areas but influenced by wealth. In Bagamoyo, screened windows were more common than closed eaves (65% vs 13%), whereas in Ulanga more houses had closed eaves than window screens (55% vs 12%). CONCLUSION Population access to ITNs was substantially lower than the targets of the Tanzania NMSP after 3 years and lower among larger households after 1 year following ITN campaign. House modification was common in both areas, associated with wealth. Improved access to ITNs and window screens through subsidies and Behaviour Change Communication (BCC) strategies, especially among large and poor households and those headed by people with a low level of education, could maximize the uptake of a combination of these two interventions.
Collapse
Affiliation(s)
| | - Amanda Ross
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Yeromin P Mlacha
- Ifakara Health Institute, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Omary Juma
- Ifakara Health Institute, Bagamoyo, Tanzania
| | | | - Daniel Msellemu
- Ifakara Health Institute, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Sarah Moore
- Ifakara Health Institute, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| |
Collapse
|
28
|
Kweka EJ, Mazigo HD, Lyaruu LJ, Mausa EA, Venter N, Mahande AM, Coetzee M. Anopheline Mosquito Species Composition, Kdr Mutation Frequency, and Parasite Infectivity Status in Northern Tanzania. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:933-938. [PMID: 31923308 DOI: 10.1093/jme/tjz245] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Indexed: 06/10/2023]
Abstract
The scaling-up of malaria control interventions in northern Tanzania has resulted in a decline in malaria prevalence and vector species composition. Despite this achievement, residual malaria transmission remains a concern in the area. The main aim of this study was to investigate malaria vector species composition, parasite infectivity rates, and the presence of insecticide knockdown resistance (kdr) mutations in three sites that have experienced a significant decline in malaria in northern Tanzania. Adult mosquitoes were sampled using light traps in houses and hand-aspirators in cowsheds, whereas the standard dipping method was used for sampling mosquito larvae. Adult mosquitoes identified as Anopheles gambiae s.l. and An. funestus s.l. and larval stages III and IV of An. gambiae s.l. were stored in absolute ethanol for further laboratory molecular identification. The identified species in the An. gambiae complex were An. gambiae s.s., An. merus, An. quadriannulatus, and An. arabiensis, whereas the An. funestus group comprised An. funestus s.s., An. rivulorum, and An. leesoni. For An. gambiae s.s. analyzed from Zeneth, 47.6% were kdr-East homozygous susceptible, 35.7% kdr-East heterozygous resistant, 9.6% kdr-East homozygous resistant, and 7.1% undefined, whereas specimens from Kwakibuyu were 45.5% kdr-East homozygous susceptible, 32.7% kdr-East heterozygous resistant, 16.3% kdr-East homozygous resistant, and 5.5% undefined. There were no kdr-West alleles identified from any specimen. The overall malaria parasite infectivity rate was 0.75%. No infections were found in Moshi. The findings indicate that populations of the major malaria vector mosquitoes are still present in the study area, with An. funestus taking a lead in malaria transmission.
Collapse
Affiliation(s)
- Eliningaya J Kweka
- Division of Livestock and Human Diseases Vector Control, Tropical Pesticides Research Institute, Arusha, Tanzania
- Department of Medical Parasitology and Entomology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Humphrey D Mazigo
- Department of Medical Parasitology and Entomology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Lucile J Lyaruu
- Division of Livestock and Human Diseases Vector Control, Tropical Pesticides Research Institute, Arusha, Tanzania
| | - Emmanuel A Mausa
- National Plant Genetic Resource Centre, Tropical Pesticides Research Institute, Arusha, Tanzania
| | - Nelius Venter
- Wits Research Institute for Malaria and Wits/MRC Collaborating Centre for Multi-disciplinary Research on Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Centre for Emerging, Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Aneth M Mahande
- Mabogini Field Station, Tropical Pesticides Research Institute, Moshi, Tanzania
| | - Maureen Coetzee
- Wits Research Institute for Malaria and Wits/MRC Collaborating Centre for Multi-disciplinary Research on Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Centre for Emerging, Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| |
Collapse
|
29
|
Tusting LS, Bradley J, Bhatt S, Gibson HS, Weiss DJ, Shenton FC, Lindsay SW. Environmental temperature and growth faltering in African children: a cross-sectional study. Lancet Planet Health 2020; 4:e116-e123. [PMID: 32220673 PMCID: PMC7232952 DOI: 10.1016/s2542-5196(20)30037-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Child growth faltering persists in sub-Saharan Africa despite the scale-up of nutrition, water, and sanitation interventions over the past 2 decades. High temperatures have been hypothesised to contribute to child growth faltering via an adaptive response to heat, reduced appetite, and the energetic cost of thermoregulation. We did a cross-sectional study to assess whether child growth faltering is related to environmental temperature in sub-Saharan Africa. METHODS Data were extracted from 52 Demographic and Heath Surveys, dating from 2003 to 2016, that recorded anthropometric data in children aged 0-5 years, and were linked with remotely sensed monthly mean daytime land surface temperature for 2000-16. The odds of stunting (low height-for-age), wasting (low weight-for-height), and underweight (low weight-for-age) relative to monthly mean daytime land surface temperature were determined using multivariable logistic regression. FINDINGS The study population comprised 656 107 children resident in 373 012 households. Monthly mean daytime land surface temperature above 35°C was associated with increases in the odds of wasting (odds ratio 1·27, 95% CI 1·16-1·38; p<0·0001), underweight (1·09, 1·02-1·16; p=0·0073), and concurrent stunting with wasting (1·23, 1·07-1·41; p=0·0037), but a reduction in stunting (0·90, 0·85-0·96; p=0·00047) compared with a monthly mean daytime land surface temperature of less than 30°C. INTERPRETATION Children living in hotter parts of sub-Saharan Africa are more likely to be wasted, underweight, and concurrently stunted and wasted, but less likely to be stunted, than in cooler areas. Studies are needed to further investigate the relationship between temperature and child growth, including whether there is a direct effect not mediated by food security, regional wealth, and other environmental variables. Rising temperature, linked to anthropogenic climate change, might increase child growth faltering in sub-Saharan Africa. FUNDING UK Medical Research Council and UK Global Challenges Research Fund.
Collapse
Affiliation(s)
- Lucy S Tusting
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK.
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, UK
| | - Samir Bhatt
- Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Harry S Gibson
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Daniel J Weiss
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | | | | |
Collapse
|
30
|
Wilson AL, Davies M, Lindsay SW. Revisiting an old idea: engineering against vector-borne diseases in the domestic environment. Trans R Soc Trop Med Hyg 2020; 113:53-55. [PMID: 30239923 PMCID: PMC6364793 DOI: 10.1093/trstmh/try103] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/22/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Anne L Wilson
- Department of Biosciences, Durham University, Stockton Road, Durham, UK
| | - Mike Davies
- Institute for Environmental Design and Engineering, Faculty of the Built Environment, University College London, 14 Upper Woburn Place, London, UK
| | - Steve W Lindsay
- Department of Biosciences, Durham University, Stockton Road, Durham, UK
| |
Collapse
|
31
|
von Seidlein L, Wood H, Brittain OS, Tusting L, Bednarz A, Mshamu S, Kahabuka C, Deen J, Bell D, Lindsay SW, Knudsen J. Knowledge gaps in the construction of rural healthy homes: A research agenda for improved low-cost housing in hot-humid Africa. PLoS Med 2019; 16:e1002909. [PMID: 31600205 PMCID: PMC6786526 DOI: 10.1371/journal.pmed.1002909] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lorenz von Seidlein and colleagues discuss improving house designs in rural Africa to benefit health.
Collapse
Affiliation(s)
- Lorenz von Seidlein
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Hannah Wood
- Ingvartsen Architects, Copenhagen K, Denmark
| | | | - Lucy Tusting
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Alexa Bednarz
- Bill and Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Salum Mshamu
- CSK Research Solutions Ltd., Dar es Salaam, Tanzania
| | | | | | - David Bell
- Independent Consultant, Issaquah, Washington, United States of America
| | - Steve W. Lindsay
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Jakob Knudsen
- Ingvartsen Architects, Copenhagen K, Denmark
- School of Architecture, The Royal Danish Academy of Fine Arts, Copenhagen, Denmark
| |
Collapse
|
32
|
Rehman AM, Maiteki-Sebuguzi C, Gonahasa S, Okiring J, Kigozi SP, Chandler CIR, Drakeley C, Dorsey G, Kamya MR, Staedke SG. Intermittent preventive treatment of malaria delivered to primary schoolchildren provided effective individual protection in Jinja, Uganda: secondary outcomes of a cluster-randomized trial (START-IPT). Malar J 2019; 18:318. [PMID: 31533845 PMCID: PMC6751800 DOI: 10.1186/s12936-019-2954-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/07/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Intermittent preventive treatment (IPT) of malaria is recommended as policy for certain high-risk populations, but not currently for schoolchildren. A cluster-randomized trial was conducted to evaluate the effect of IPT with dihydroartemisinin-piperaquine (DP) on primary schoolchildren in Jinja, Uganda. Results of the impact of IPT of schoolchildren on community-level transmission have been reported previously. Here, secondary outcomes from a school-based survey are presented. METHODS Eighty-four clusters (one primary school plus 100 households) were randomized to intervention and control (1:1 ratio). Participants from intervention schools received monthly IPT with DP for up to 6 rounds (June-December 2014). At endline (November-December 2014), randomly selected children from all 84 schools were surveyed (13 per school) and thick blood smears were done. Those with fever or history of fever were tested with rapid diagnostic tests (RDTs) for malaria. Haemoglobin was measured in every fifth participant. Outcome measures included prevalence of asexual parasites and gametocytes (by microscopy), and prevalence of anaemia. Prevalence outcomes were analysed using generalized linear Poisson models with log link function, incorporating a cluster-level random intercept and quantified using prevalence risk ratios. RESULTS Among 23,280 students listed on the 42 intervention school registers, 10,079 (43.3%) aged 5-20 years were enrolled into the IPT intervention and received at least one dose of DP; of these, 9286 (92.1%) received at least one full (3-day) course. In total, 1092 children were enrolled into the final school survey (546 per arm) and had a thick blood smear done; of these, 255 had haemoglobin measured (129 intervention, 126 control). Children in the intervention arm were less likely to have asexual parasites (9.2% intervention vs 44.1% control, adjusted risk ratio [aRR] 0.22 [95% CI 0.16-0.30] p < 0.001), gametocytes (3.1% intervention vs 9.5% control, aRR 0.34 [95% CI 0.20-0.56] p < 0.001), fever (20.2% intervention vs 56.2% control, aRR 0.35 [95% CI 0.25-0.50] p < 0.001), or symptomatic malaria (5.1% intervention vs 35.7% control, aRR 0.14 [95% CI 0.08-0.26] p < 0.001). Prevalence of anaemia and mean haemoglobin were similar in both study arms. CONCLUSIONS School-aged children are a major reservoir of malaria parasites. Delivering IPT to schoolchildren would benefit individual children and may reduce transmission. School-based IPT could help to intensify malaria control toward elimination, and should be considered for policies and programmes. Trial registration Clinicaltrials.gov (NCT02009215), Registered 11 December 2013. https://clinicaltrials.gov/ct2/show/NCT02009215.
Collapse
Affiliation(s)
- Andrea M Rehman
- Department of Infectious Disease Epidemiology, LSHTM, London, UK
| | | | - Samuel Gonahasa
- Infectious Diseases Research Collaboration, PO Box 7475, Kampala, Uganda
| | - Jaffer Okiring
- Infectious Diseases Research Collaboration, PO Box 7475, Kampala, Uganda
| | - Simon P Kigozi
- Infectious Diseases Research Collaboration, PO Box 7475, Kampala, Uganda
| | - Clare I R Chandler
- Department of Global Health & Development, Department of Clinical Research, LSHTM, London, UK
| | | | - Grant Dorsey
- Department of Medicine, University of California, San Francisco, USA
| | - Moses R Kamya
- School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Sarah G Staedke
- Infectious Diseases Research Collaboration, PO Box 7475, Kampala, Uganda.
- Department of Clinical Research, London School of Hygiene & Tropical Medicine (LSHTM), London, UK.
| |
Collapse
|
33
|
Furnival‐Adams J, Olanga EA, Napier M, Garner P. Housing interventions for preventing malaria. Cochrane Database Syst Rev 2019; 2019:CD013398. [PMCID: PMC6691978 DOI: 10.1002/14651858.cd013398] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: Primary To assess the effects of different structural house modifications on malaria disease burden. Secondary To explore whether effects vary with level of transmission.
Collapse
Affiliation(s)
| | - Evelyn A Olanga
- Malaria Alert Centre of the College of MedicineQueen Elizabeth Hospital Grounds, Ginnery cornerBlantyreMalawi
| | - Mark Napier
- Council for Scientific and Industrial ResearchBuilt EnvironmentPretoriaSouth Africa
| | - Paul Garner
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesLiverpoolUK
| |
Collapse
|
34
|
Nieto-Sanchez C, Bates BR, Guerrero D, Jimenez S, Baus EG, Peeters Grietens K, Grijalva MJ. Home improvement and system-based health promotion for sustainable prevention of Chagas disease: A qualitative study. PLoS Negl Trop Dis 2019; 13:e0007472. [PMID: 31194754 PMCID: PMC6592574 DOI: 10.1371/journal.pntd.0007472] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 06/25/2019] [Accepted: 05/16/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Human transmission of Chagas disease (CD) most commonly occurs in domiciliary spaces where triatomines remain hidden to feed on blood sources during inhabitants' sleep. Similar to other neglected tropical diseases (NTDs), sustainable control of CD requires attention to the structural conditions of life of populations at risk, in this case, the conditions of their living environments. Considering socio-cultural and political dynamics involved in dwellings' construction, this study aimed to explore social factors that contribute or limit sustainability of CD's prevention models focused on home improvement. METHODS AND MAIN FINDINGS Using Healthy Homes for Healthy Living (HHHL)-a health promotion strategy focused on improvement of living environments and system-based health promotion-as a reference, a qualitative study was conducted. Research participants were selected from three rural communities of a CD endemic region in southern Ecuador involved in HHHL's refurbishment and reconstruction interventions between 2013 and 2016. Folowing an ethnographic approach, data were collected through interviews, participant observation, informal conversations and document analysis. Our results indicate that the HHHL model addressed risk factors for CD at the household level, while simultaneously promoting wellbeing at emotional, economic and social levels in local communities. We argue that sustainability of the CD prevention model proposed by HHHL is enhanced by the confluence of three factors: systemic improvement of families' quality of life, perceived usefulness of control measures, and flexibility to adapt to emerging dynamics of the context. CONCLUSION HHHL's proposed home improvement, facilitated through system-based rather than disease specific health promotion processes, enhances agency in populations at risk and facilitates community partnerships forged around CD prevention. Although an independent analysis of cost-effectiveness is recommended, structural poverty experienced by local families is still the most important factor to consider when evaluating the sustainability and scalability of this model.
Collapse
Affiliation(s)
- Claudia Nieto-Sanchez
- Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
- Infectious and Tropical Disease Institute, Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, United States of America
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Benjamin R. Bates
- Infectious and Tropical Disease Institute, Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, United States of America
- School of Communication Studies, Ohio University, Athens, Ohio, United States of America
| | - Darwin Guerrero
- Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Sylvia Jimenez
- Facultad de Arquitectura, Arte y Diseño, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Esteban G. Baus
- Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Koen Peeters Grietens
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Mario J. Grijalva
- Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
- Infectious and Tropical Disease Institute, Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, United States of America
| |
Collapse
|
35
|
von Seidlein L, Peto TJ, Tripura R, Pell C, Yeung S, Kindermans JM, Dondorp A, Maude R. Novel Approaches to Control Malaria in Forested Areas of Southeast Asia. Trends Parasitol 2019; 35:388-398. [PMID: 31076353 DOI: 10.1016/j.pt.2019.03.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/24/2019] [Accepted: 03/27/2019] [Indexed: 12/27/2022]
Abstract
The emergence and spread of drug resistance in the Greater Mekong Subregion (GMS) have added urgency to accelerate malaria elimination while reducing the treatment options. The remaining foci of malaria transmission are often in forests, where vectors tend to bite during daytime and outdoors, thus reducing the effectiveness of insecticide-treated bed nets. Limited periods of exposure suggest that chemoprophylaxis could be a promising strategy to protect forest workers against malaria. Here we discuss three major questions in optimizing malaria chemoprophylaxis for forest workers: which antimalarial drug regimens are most appropriate, how frequently the chemoprophylaxis should be delivered, and how to motivate forest workers to use, and adhere to, malaria prophylaxis.
Collapse
Affiliation(s)
- Lorenz von Seidlein
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Thomas J Peto
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rupam Tripura
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Christopher Pell
- Centre for Social Sciences and Global Health, University of Amsterdam, Amsterdam, The Netherlands; Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
| | - Shunmay Yeung
- London School of Hygiene and Tropical Medicine, London, UK
| | | | - Arjen Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Richard Maude
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
| |
Collapse
|
36
|
Ricotta E, Oppong S, Yukich JO, Briët OJT. Determinants of bed net use conditional on access in population surveys in Ghana. Malar J 2019; 18:63. [PMID: 30849976 PMCID: PMC6408824 DOI: 10.1186/s12936-019-2700-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/01/2019] [Indexed: 12/02/2022] Open
Abstract
Background Insecticide-treated nets (ITNs) are one of the most effective and widely available methods for preventing malaria, and there is interest in understanding the complexities of behavioural drivers of non-use among those with access. This analysis evaluated net use behaviour in Ghana by exploring how several household and environmental variables relate to use among Ghanaians with access to a net. Methods Survey data from the Ghana 2014 Demographic and Health Survey and the 2016 Malaria Indicator Survey were used to calculate household members’ access to space under a net as well as the proportion of net use conditional on access (NUCA). Geospatial information on cluster location was obtained, as well as average humidex, a measure of how hot it feels, for the month each cluster was surveyed. The relationship between independent variables and net use was assessed via beta-binomial regression models that controlled for spatially correlated random effects using non-Gaussian kriging. Results In both surveys, increasing wealth was associated with decreased net use among those with access in households when compared to the poorest category. In 2014, exposure to messages about bed net use for malaria prevention was associated with increased net use (OR 2.5, 95% CrI 1.5–4.2), as was living in a rural area in both 2014 (OR 2.5, 95% CrI 1.5–4.3) and 2016 (OR 1.6, 95% CrI 1.1–2.3). The number of nets per person was not associated with net use in either survey. Model fit was improved for both surveys by including a spatial random effect for cluster, demonstrating some spatial autocorrelation in the proportion of people using a net. Humidex, electricity in the household and IRS were not associated with NUCA. Conclusion Net use conditional on access is affected by household characteristics and is also spatially-dependent in Ghana. Setting (whether the household was urban or rural) plays a role, with wealthier and more urban households less likely to use nets when they are available. It will likely be necessary in the future to focus on rural settings, urban settings, and wealth status independently, both to better understand predictors of household net use in these areas and to design more targeted interventions to ensure consistent use of vector control interventions that meet specific needs of the population. Electronic supplementary material The online version of this article (10.1186/s12936-019-2700-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Emily Ricotta
- Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box CH-4002, Basel, Switzerland. .,University of Basel, Petersplatz 1, P.O. Box CH-4001, Basel, Switzerland.
| | - Samuel Oppong
- National Malaria Control Programme, Public Health Division, Ghana Health Service, Korle-bu, P. O. Box KB 493, Accra, Ghana
| | - Joshua O Yukich
- Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, 1440 Canal St. #8317, New Orleans, LA, 70112, USA
| | - Olivier J T Briët
- Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box CH-4002, Basel, Switzerland.,University of Basel, Petersplatz 1, P.O. Box CH-4001, Basel, Switzerland
| |
Collapse
|
37
|
Killeen GF, Govella NJ, Mlacha YP, Chaki PP. Suppression of malaria vector densities and human infection prevalence associated with scale-up of mosquito-proofed housing in Dar es Salaam, Tanzania: re-analysis of an observational series of parasitological and entomological surveys. Lancet Planet Health 2019; 3:e132-e143. [PMID: 30904112 DOI: 10.1016/s2542-5196(19)30035-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND In the city of Dar es Salaam, Tanzania, rapid and spontaneous scale-up of window screening occurred through purely horizontal commercial distribution systems without any public subsidies or promotion. Scale-up of window screening coincided with a planned evaluation of programmatic, vertically managed scale-up of regular larvicide application as an intervention against malaria vectors and transmission. We aimed to establish whether scale-up of window screening was associated with suppression of mosquito populations, especially for malaria vectors that strongly prefer humans as their source of blood. METHODS This study was a re-analysis of a previous observational series of epidemiological data plus new analyses of previously partly reported complementary entomological data, from Dar es Salaam. Between 2004 and 2008, six rounds of cluster-sampled, rolling, cross-sectional parasitological and questionnaire surveys were done in urban Dar es Salaam to assess the effect of larviciding and other determinants of malaria risk, such as use of bed nets and antimalarial drugs, socioeconomic status, age, sex, travel history, mosquito-proofed housing, and spending time outdoors. The effects of scaled-up larvicide application and window screening were estimated by fitting generalised linear mixed models that allowed for both spatial variation between survey locations and temporal autocorrelation within locations. We also conducted continuous longitudinal entomological surveys of outdoor human biting rates by mosquitoes and experimental measurements of mosquito host preferences. FINDINGS Best-fit models of Plasmodium falciparum malaria infection prevalence among humans were largely consistent with the results of the previous analyses. Re-analysis of previously reported epidemiological data revealed that most of the empirically fitted downward time trend in P falciparum malaria prevalence over the course of the study (odds ratio [OR] 0·04; 95% CI 0·03-0·06; p<0·0001), which was not previously reported numerically or attributed to any explanatory factor, could be plausibly explained by association with an upward trend in city-wide window screening coverage (OR 0·07; 0·05-0·09; p<0·0001) and progressive rollout of larviciding (OR 0·50; 0·41-0·60; p<0·0001). Increasing coverage of complete window screening was also associated with reduced biting densities of all taxonomic groups of mosquitoes (all p<0·0001), especially the Anopheles gambiae complex (relative rate [RR] 0·23; 95% CI 0·16-0·33) and Anopheles funestus group (RR 0·08; 0·04-0·16), which were confirmed as the most efficient vectors of malaria with strong preferences for humans over cattle. Larviciding was also associated with reduced biting densities of all mosquito taxa (p<0·0001), to an extent that varied consistently with the larvicide targeting scheme and known larval ecology of each taxon. INTERPRETATION Community-wide mosquito proofing of houses might deliver greater impacts on vector populations and malaria transmission than previously thought. The spontaneous nature of the scale-up observed here is also encouraging with regards to practicality, acceptability, and affordability in low-income settings. FUNDING United States Agency for International Development, Bill & Melinda Gates Foundation, Wellcome Trust, and Valent BioSciences LLC.
Collapse
Affiliation(s)
- Gerry F Killeen
- Ifakara Health Institute, Department of Environmental Health and Ecological Sciences, Dar es Salaam, Tanzania; Liverpool School of Tropical Medicine, Department of Vector Biology, Liverpool, UK.
| | - Nicodem J Govella
- Ifakara Health Institute, Department of Environmental Health and Ecological Sciences, Dar es Salaam, Tanzania
| | - Yeromin P Mlacha
- Ifakara Health Institute, Department of Environmental Health and Ecological Sciences, Dar es Salaam, Tanzania
| | - Prosper P Chaki
- Ifakara Health Institute, Department of Environmental Health and Ecological Sciences, Dar es Salaam, Tanzania
| |
Collapse
|
38
|
Jatta E, Jawara M, Bradley J, Jeffries D, Kandeh B, Knudsen JB, Wilson AL, Pinder M, D'Alessandro U, Lindsay SW. How house design affects malaria mosquito density, temperature, and relative humidity: an experimental study in rural Gambia. Lancet Planet Health 2018; 2:e498-e508. [PMID: 30396441 DOI: 10.1016/s2542-5196(18)30234-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 09/27/2018] [Accepted: 10/12/2018] [Indexed: 06/08/2023]
Abstract
INTRODUCTION Unprecedented improvements in housing are occurring across much of rural sub-Saharan Africa, but the consequences of these changes on malaria transmission remain poorly explored. We examined how different typologies of rural housing affect mosquito house entry and indoor climate. METHODS Five typologies of mud-block houses were constructed in rural Gambia: four were traditional designs with poorly fitted doors and one was a novel design with gable windows to improve ventilation. In each house, one male volunteer slept under a bednet and mosquitoes were collected indoors with a light trap. Typologies were rotated between houses weekly. Indoor conditions were monitored with data loggers and the perceived comfort of sleepers recorded with questionnaires. We used pyschrometric modelling to quantify the comfort of the indoor climate using the logger data. Primary measurements were mean number of Anopheles gambiae and mean temperature for each house typology. FINDINGS In thatched-roofed houses, closing the eaves reduced A gambiae house entry by 94% (95% CI 89-97) but increased the temperature compared with thatched-roofed houses with open eaves. In houses with closed eaves, those with metal roofs had more A gambiae, were hotter (1·5°C hotter [95% CI 1·3-1·7]) between 2100h and 2300 h, and had 25% higher concentrations of carbon dioxide (211·1 ppm higher [117·8-304·6]) than those with thatched roofs. In metal-roofed houses with closed eaves, mosquito house entry was reduced by 96% (91-98) by well fitted screened doors. Improved ventilation of metal-roofed houses made them as cool as thatched houses with open eaves. Metal-roofed houses with closed eaves were considered more uncomfortable than thatched ones with closed eaves. In metal-roofed houses, ventilated houses were more comfortable than unventilated houses before midnight, when people retired to bed. INTERPRETATION Closing the eaves reduced vector entry in thatched houses but increased entry in metal-roofed houses. Metal-roofed houses with closed eaves were, however, protected against malaria vectors by well fitted screened doors and were made comfortable by increasing ventilation. House designs that exclude mosquitoes and are comfortable to live in should be a priority in sub-Saharan Africa. FUNDING Sir Halley Stewart Trust, Global Clinical Trials, and Global Challenges Research Fund.
Collapse
Affiliation(s)
- Ebrima Jatta
- National Malaria Control Programme, Banjul, The Gambia
| | - Musa Jawara
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - John Bradley
- Tropical Epidemiology Group and Infectious Diseases Department, London School of Hygiene & Tropical Medicine, London, UK
| | - David Jeffries
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Balla Kandeh
- National Malaria Control Programme, Banjul, The Gambia
| | - Jakob B Knudsen
- The Royal Danish Academy of Fine Arts, Schools of Architecture, Design and Conservation, Copenhagen, Denmark
| | - Anne L Wilson
- Department of Biosciences, Durham University, Durham, UK
| | - Margaret Pinder
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia; Department of Biosciences, Durham University, Durham, UK
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia; Tropical Epidemiology Group and Infectious Diseases Department, London School of Hygiene & Tropical Medicine, London, UK
| | - Steve W Lindsay
- Department of Biosciences, Durham University, Durham, UK; Tropical Epidemiology Group and Infectious Diseases Department, London School of Hygiene & Tropical Medicine, London, UK.
| |
Collapse
|
39
|
Mburu MM, Juurlink M, Spitzen J, Moraga P, Hiscox A, Mzilahowa T, Takken W, McCann RS. Impact of partially and fully closed eaves on house entry rates by mosquitoes. Parasit Vectors 2018; 11:383. [PMID: 29970153 PMCID: PMC6029021 DOI: 10.1186/s13071-018-2977-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 06/25/2018] [Indexed: 12/02/2022] Open
Abstract
Background Most people infected with malaria acquire the infection indoors from mosquito vectors that entered the house through open eaves, windows and doors. Structural house improvement (e.g. closed eaves and screened windows) is an established method of reducing mosquito entry. It could be complementary to other interventions such as insecticide-treated bed nets (ITNs) for malaria control because it covers and protects all individuals in a house equally. However, when implemented at a large scale, house improvement may not be employed optimally. It is therefore critical to assess whether partial house improvement will have any effect on mosquito house entry. We investigated the effect of partial and complete eave closure on the house-entry rates of malaria vectors and other mosquitoes in southern Malawi. Methods The study was conducted for 25 nights in May-June 2016. Twenty-five traditional houses were modified according to five treatments: fully closed eaves, three different levels of partially closed eaves, and open eaves. All houses had fully screened windows and closed doors. Host-seeking mosquitoes were sampled inside these houses using Centers for Disease Control and Prevention (CDC) light traps. The effect of open eaves versus partial or complete eave closure on the number of mosquitoes trapped inside the house was estimated using a generalized linear mixed model fitted with Poisson distribution and a log-link function. Results House entry by malaria vectors was 14-times higher in houses with fully open eaves compared to houses with fully closed eaves adjusting for wall-type, number of people that slept in the house the previous night, cooking locations and presence of livestock. Houses with four small openings had 9 times more malaria vectors compared to houses with fully closed eaves. The catches of culicine mosquitoes caught in houses with fully closed eaves were not different from those caught in houses with the other treatments. Conclusions Closed eaves resulted in fewer malaria vectors in houses, with differences depending on the degree of eave closure. The ability of malaria vectors to locate any remaining entry points on improved houses, as demonstrated here, suggests that quality control must be an important component of implementing house improvement as an intervention.The lack of effect on culicine mosquitoes in this study could reduce acceptance of house improvement, as implemented here, by household residents due to continued nuisance biting. This limitation could be addressed through community engagement (e.g. encouraging people to close their doors early in the evenings) or improved designs.
Collapse
Affiliation(s)
- Monicah M Mburu
- Wageningen University and Research, Wageningen, The Netherlands. .,College of Medicine, University of Malawi, Zomba, Malawi.
| | - Malou Juurlink
- Wageningen University and Research, Wageningen, The Netherlands
| | - Jeroen Spitzen
- Wageningen University and Research, Wageningen, The Netherlands
| | - Paula Moraga
- Centre for Health Informatics, Computing and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, UK
| | | | - Themba Mzilahowa
- College of Medicine, University of Malawi, Zomba, Malawi.,MAC Communicable Diseases Action Centre, College of Medicine, Blantyre, Malawi
| | - Willem Takken
- Wageningen University and Research, Wageningen, The Netherlands
| | - Robert S McCann
- Wageningen University and Research, Wageningen, The Netherlands.,College of Medicine, University of Malawi, Zomba, Malawi
| |
Collapse
|
40
|
Cole J, Bickersteth S. What's planetary about health? An analysis of topics covered in The Lancet Planetary Health's first year. Lancet Planet Health 2018; 2:e283-e284. [PMID: 30074887 DOI: 10.1016/s2542-5196(18)30143-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 06/12/2018] [Indexed: 06/08/2023]
Affiliation(s)
- Jennifer Cole
- Rockefeller Economic Council on Planetary Health, Oxford University, Oxford Martin School, Oxford OX1 3BD, UK.
| | - Sam Bickersteth
- Rockefeller Economic Council on Planetary Health, Oxford University, Oxford Martin School, Oxford OX1 3BD, UK
| |
Collapse
|
41
|
Rek JC, Alegana V, Arinaitwe E, Cameron E, Kamya MR, Katureebe A, Lindsay SW, Kilama M, Staedke SG, Todd J, Dorsey G, Tusting LS. Rapid improvements to rural Ugandan housing and their association with malaria from intense to reduced transmission: a cohort study. Lancet Planet Health 2018; 2:e83-e94. [PMID: 29615240 PMCID: PMC5887083 DOI: 10.1016/s2542-5196(18)30010-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 01/06/2018] [Accepted: 01/23/2018] [Indexed: 06/02/2023]
Abstract
BACKGROUND Rapid population growth in Africa requires an urgent expansion and improvement of housing options. Improving housing presents a promising opportunity for malaria control by reducing indoor exposure to mosquitoes. We measured recent changes in house design in rural Uganda and evaluated their association with malaria in relation to a mass scale-up of control efforts. METHODS This analysis was part of a cohort study designed to compare temporal changes in malaria incidence from a cohort of children and adults with temporal changes in malaria test positivity rate from health facility surveillance. All children aged 6 months to 10 years (n=384) living in 107 households in Nagongera sub-country, Tororo, Uganda, were given long-lasting insecticide-treated nets and followed between Aug 19, 2011, and June 30, 2017. Repeat rounds of indoor residual spraying of insecticide were initiated on Dec 5, 2014. Socioeconomic data were collected at two timepoints (Sept 25-Oct 9, 2013 and June 21-July 11, 2016) and houses were classified as modern (cement, wood, or metal walls, tiled or metal roof, and closed eaves) or traditional (all other homes). Associations between house design and three outcomes were evaluated before and after the introduction of indoor residual spraying: human biting rate estimated monthly in each household using US Centers for Disease Control and Prevention light traps; parasite prevalence measured routinely by microscopy every 3 months before indoor residual spraying and monthly after indoor residual spraying; and malaria incidence measured by passive surveillance. FINDINGS The implementation of indoor residual spraying was associated with significant declines in human biting rate (33·5 vs 2·7 Anopheles per house per night after indoor residual spraying, p<0·0001), parasite prevalence (32·0% vs 14·0%, p<0·0001), and malaria incidence (3·0 vs 0·5 episodes per person-year at risk, p<0·0001). The prevalence of modern housing increased from 23·4% in 2013 to 45·4% in 2016 (p=0·001). Compared with traditional houses, modern houses were associated with a 48% reduction in human biting rate before indoor residual spraying (adjusted incidence rate ratio [aIRR] 0·52, 95% CI 0·36-0·73, p=0·0002), and a 73% reduction after indoor residual spraying (aIRR 0·27, 0·17-0·42, p<0·0001). Before indoor residual spraying, there was no association between house type and parasite prevalence, but after indoor residual spraying there was a 57% reduction in the odds of parasitaemia in modern houses compared with traditional houses, controlling for age, sex, and socioeconomic position (adjusted odds ratio 0·43, 95% CI 0·24-0·77, p=0·004). House type was not associated with malaria incidence before or after indoor residual spraying. INTERPRETATION House design improved rapidly in rural Uganda and was associated with additional reductions in mosquito density and parasite prevalence following the introduction of indoor residual spraying. Changes to house design in endemic Africa, including closing eaves and the replacement of traditional building materials, might help further the gains achieved with more widely accepted malaria control interventions. FUNDING US National Institutes of Health, Bill & Melinda Gates Foundation, and Medical Research Council UK.
Collapse
Affiliation(s)
- John C Rek
- Infectious Disease Research Collaboration, Mulago Hospital Complex, Kampala, Uganda
| | - Victor Alegana
- Department of Geography and Environment, University of Southampton, Southampton, UK
| | - Emmanuel Arinaitwe
- Infectious Disease Research Collaboration, Mulago Hospital Complex, Kampala, Uganda; Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, UK
| | - Ewan Cameron
- Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Moses R Kamya
- Department of Medicine, Makerere University College of Health Science, Kampala, Uganda
| | - Agaba Katureebe
- Infectious Disease Research Collaboration, Mulago Hospital Complex, Kampala, Uganda
| | | | - Maxwell Kilama
- Infectious Disease Research Collaboration, Mulago Hospital Complex, Kampala, Uganda
| | - Sarah G Staedke
- Infectious Disease Research Collaboration, Mulago Hospital Complex, Kampala, Uganda; Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, UK
| | - Jim Todd
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Grant Dorsey
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Lucy S Tusting
- Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| |
Collapse
|