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Abong’o B, Agumba S, Moshi V, Simwero J, Otima J, Ochomo E. Insecticide treated eaves screens provide additional marginal protection compared to untreated eave screens under semi-field conditions in western Kenya. MALARIAWORLD JOURNAL 2024; 15:1. [PMID: 38322708 PMCID: PMC10842374 DOI: 10.5281/zenodo.10567425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Introduction Human habitats remain the main point of human-vector interaction leading to malaria transmission despite the sustained use of insecticide-treated nets and indoor residual spraying. Simple structural modifications involving screening of doors, windows and eaves have great potential for reducing indoor entry of mosquitoes. Moreover, insecticide treatment of the screen material may provide additional benefit in mosquito population reduction. Materials and Methods Four huts, each constructed inside a semi-field structure, were used in the study. Two had untreated eave and door screens and screened air cavities in place of windows (experiment 1) or were similar but with the eave screens treated with Actellic® 300CS insecticide (experiment 2). The other two huts remained unscreened throughout the study. Two hundred, 3-day old adults of F1 generation Anopheles funestus collected by aspiration or F0 reared from An. arabiensis larvae or An. arabiensis (Dongola strain) were released in each semi-field structure at dusk and recaptured the following morning. A single volunteer slept in each hut under an untreated bednet each night of the study. Recaptured mosquitoes were counted and recorded by location, either indoor or outdoor of each hut in the different semi-field structures. Results Based on modelled estimates, significantly fewer, 10% An. arabiensis from Ahero, 11% An. arabiensis Dongola strain and 10% An. funestus from Siaya were observed inside modified huts compared to unmodified ones. Treating of eave screen material with Actellic® 300CS significantly reduced indoor numbers of An. arabiensis from Ahero, to nearly 0%, and An. arabiensis Dongola strain, to 3%, compared to huts with untreated eave screens, while eliminating An. funestus indoors. These modifications cost US$180 /structure and have been observed to last more than 15 years in a different location. Conclusions Eave, door and window screening are effective ways of reducing mosquito entry into houses. Additionally, treatment of eave screen material with an effective insecticide further reduces the Anopheles population in and around the screened huts under semi-field conditions and could greatly complement existing vector control efforts.
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Affiliation(s)
- Bernard Abong’o
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
- Research World Limited, Kisumu, Kenya
| | - Silas Agumba
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Vincent Moshi
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Jacob Simwero
- Habitat for Humanity International, Lenana Road, Nairobi
| | - Jane Otima
- Habitat for Humanity International, Lenana Road, Nairobi
| | - Eric Ochomo
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
- Research World Limited, Kisumu, Kenya
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Hasyim H, Dewi WC, Lestari RAF, Flora R, Novrikasari N, Liberty IA, Marini H, Elagali A, Herlinda S, Maharani FE. Risk factors of malaria transmission in mining workers in Muara Enim, South Sumatra, Indonesia. Sci Rep 2023; 13:14755. [PMID: 37679466 PMCID: PMC10484942 DOI: 10.1038/s41598-023-40418-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 08/09/2023] [Indexed: 09/09/2023] Open
Abstract
Eliminating malaria by 2030 is stated as goal three in the UN's Sustainable Development Goals (SDGs). However, malaria still remains a significant public health problem. This study aims to identify the factors determining malaria transmission in artisanal or small-scale miner (ASM) communities in three villages: Tanjung Agung, Tanjung Lalang, and Penyandingan, located in the Tanjung Enim District, Muara Enim, South Sumatra, Indonesia. Researchers conducted a cross-sectional study involving 92 participants from the study area. They used a logistic regression model to investigate the risk factors related to malaria occurrence. The multivariable analysis revealed that age (Adjusted Prevalence Ratio (APR) = 7.989 with 95% CI 1.724-37.002) and mosquito breeding (APR = 7.685 with 95% CI 1.502-39.309) were risk factors for malaria. On the other hand, higher education (APR = 0.104 with 95% CI 0.027-0.403), the use of mosquito repellent (APR = 0.138 with 95% CI 0.035-0.549), and the condition of house walls (APR = 0.145 with 95% CI 0.0414-0.511) were identified as protective factors. The current study highlights age and mosquito breeding sites as risk factors for malaria. Additionally, higher education, insect repellent use, and the condition of house walls are protective factors against malaria. Therefore, reducing risk factors and increasing protective measures through effective communication, information, and education are highly recommended to eliminate malaria in mining areas.
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Affiliation(s)
- Hamzah Hasyim
- Faculty of Public Health, Universitas Sriwijaya, Palembang, Indonesia.
- Faculty of Medicine, Institute for Occupational Medicine, Social Medicine and Environmental Medicine, Goethe University, Frankfurt Am Main, Germany.
| | - Wita Citra Dewi
- Faculty of Public Health, Universitas Sriwijaya, Palembang, Indonesia
| | | | - Rostika Flora
- Faculty of Public Health, Universitas Sriwijaya, Palembang, Indonesia
| | | | - Iche Andriyani Liberty
- Faculty of Medicine, Department of Public Health and Community Medicine, Universitas Sriwijaya, Palembang, Indonesia
| | - Heni Marini
- Faculty of Public Health, Universitas Sriwijaya, Palembang, Indonesia
| | - Ahmed Elagali
- School of Biological Sciences, The University of Western Australia, Perth, Australia
- Minderoo Foundation, Perth, Australia
| | - Siti Herlinda
- Faculty of Agriculture, Department of Plant Protection, Universitas Sriwijaya, Palembang, Indonesia
- Research Center for Sub-Optimal Lands (PUR-PLSO), Universitas Sriwijaya, Palembang, Indonesia
| | - Fadhilah Eka Maharani
- Faculty of Mathematics and Natural Sciences, Biology Department, Universitas Sriwijaya, Palembang, Indonesia
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van Dijk N, Carter J, Omondi W, Mens P, Schallig H. Clinical features, immunological interactions and household determinants of visceral leishmaniasis and malaria coinfections in West Pokot, Kenya: protocol for an observational study. BMJ Open 2023; 13:e068679. [PMID: 37068901 PMCID: PMC10111886 DOI: 10.1136/bmjopen-2022-068679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/19/2023] Open
Abstract
INTRODUCTION Visceral leishmaniasis (VL) and malaria are two deadly parasitic diseases that coexist in West Pokot County, Kenya. The local population is at considerable risk of coinfection with VL and malaria; however, few studies have described the clinical implications of this comorbidity. Questions remain regarding the immune responses responsible for possible predisposing or protective effects. Moreover, characterisation of environmental and household risk factors for co-acquiring VL and malaria is warranted to increase awareness and guide implementation of targeted control strategies. This protocol intends to address these knowledge gaps concerning VL-malaria coinfections. METHODS AND ANALYSIS This observational research project will have a multimethod approach, starting with a cross-sectional study at Kacheliba Sub-County Hospital in West Pokot, Kenya. Patients with laboratory confirmation of a VL and/or malaria infection will be clinically assessed and symptomatology of monoinfections and coinfections will be compared. Second, a questionnaire will be addressed to all included patients and to healthy controls in local communities. This case-control study will aim to describe household and environmental determinants associated with VL-malaria coinfection. Lastly, blood samples will be collected from a small cohort of VL and malaria monoinfected and coinfected patients during treatment of their infection(s), and from healthy controls and asymptomatic VL and malaria cases recruited in local communities. These specimens will be used for serum cytokine measurements and molecular quantitation of Plasmodium and Leishmania. In this way, the immune response and parasite dynamics during VL-malaria coinfection will be characterised longitudinally and compared with those observed in clinical and asymptomatic monoinfections. ETHICS AND DISSEMINATION Ethical approval was obtained from the Ethics and Scientific Research Committee of Amref Health Africa. The study findings will be presented at international conferences and published in open-access, peer-reviewed journals. TRIAL REGISTRATION NUMBER ISRCTN Registry (ISRCTN15023306).
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Affiliation(s)
- Norbert van Dijk
- Department of Medical Microbiology and Infection Prevention, Amsterdam University Medical Centres, Academic Medical Centre at the University of Amsterdam, Amsterdam, The Netherlands
- Infectious Diseases Programme, Amsterdam Institute for Infection and Immunity, Amsterdam, The Netherlands
| | - Jane Carter
- Clinical and Diagnostics Programme, Amref Health Africa, Nairobi, Kenya
| | - Wyckliff Omondi
- Division of Vector Borne and Neglected Tropical Diseases, Kenya Ministry of Health, Nairobi, Kenya
| | - Petra Mens
- Department of Medical Microbiology and Infection Prevention, Amsterdam University Medical Centres, Academic Medical Centre at the University of Amsterdam, Amsterdam, The Netherlands
- Infectious Diseases Programme, Amsterdam Institute for Infection and Immunity, Amsterdam, The Netherlands
| | - Henk Schallig
- Department of Medical Microbiology and Infection Prevention, Amsterdam University Medical Centres, Academic Medical Centre at the University of Amsterdam, Amsterdam, The Netherlands
- Infectious Diseases Programme, Amsterdam Institute for Infection and Immunity, Amsterdam, The Netherlands
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Ravishankaran S, Asokan A, Justin NAJA, Thomas S, Joshua V, Mathai MT, Eapen A. Does the roof type of a house influence the presence of adult Anopheles stephensi, urban malaria vector? - evidence from a few slum settings in Chennai, India. Parasitol Res 2022; 121:105-114. [PMID: 34773504 PMCID: PMC8995298 DOI: 10.1007/s00436-021-07376-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/08/2021] [Indexed: 01/03/2023]
Abstract
In an urban setting, it is a difficult task to collect adult Anopheles stephensi, unlike the immature stages, due to various reasons. A longitudinal study was undertaken from January 2016 to April 2017, with CDC light traps to collect adult Anopheles stephensi and other mosquito species in houses located in a few slums of Chennai, India. A total of 203 trap collections were made indoors from human dwellings having different roof types, as well as outdoors. Three to four trap collections were made at night (18:00 to 06:00 h) once a week. Overall, Culex quinquefasciatus (64%) was the predominant mosquito species captured, followed by An. stephensi (24%). In 98 of the 203 trap collections (48.3%), at least one female An. stephensi was trapped. In all, 224 female An. stephensi were trapped, of which the majority were collected during monsoon and winter seasons. Compared to outdoors, 10% more An. stephensi, the majority of them unfed, were collected indoors, with relatively more contribution coming from asbestos-roofed houses (71.4%), followed by thatched-roof houses (47.3%). Overall, 2.2% positivity for Plasmodium vivax was detected in An. stephensi through Circumsporozoite-ELISA. Binary logistic regression model indicated that season (winter and monsoon), asbestos-roofed dwelling, lesser number of rooms in a house, and more members in a family were significant predictor variables for the odds of trapping an An. stephensi. The study brought out significant factors associated with the presence of An. stephensi in urban slums setting in Chennai, where malaria is declining. The findings would help in devising targeted, effective vector control interventions for malaria elimination in urban settings.
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Affiliation(s)
- Sangamithra Ravishankaran
- ICMR-National Institute of Malaria Research, Field Unit, NIE Campus, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India,Department of Zoology, Madras Christian College, Tambaram, Chennai-600 059, Tamil Nadu, India
| | - Aswin Asokan
- ICMR-National Institute of Malaria Research, Field Unit, NIE Campus, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India
| | - N A Johnson Amala Justin
- Regional Office for Health and Family Welfare, A-2A, Rajaji Bhavan, Besant Nagar, Chennai- 600 090, Tamil Nadu, India
| | - Shalu Thomas
- ICMR-National Institute of Malaria Research, Field Unit, NIE Campus, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India,Department of Zoology, Madras Christian College, Tambaram, Chennai-600 059, Tamil Nadu, India
| | - Vasna Joshua
- ICMR-National Institute of Epidemiology, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India
| | - Manu Thomas Mathai
- Department of Zoology, Madras Christian College, Tambaram, Chennai-600 059, Tamil Nadu, India
| | - Alex Eapen
- ICMR-National Institute of Malaria Research, Field Unit, NIE Campus, 2 Main Road, TNHB, Ayapakkam, Chennai-600 077, Tamil Nadu, India,Corresponding author:
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Kawada H, Nakazawa S, Ohashi K, Kambewa EA, Pemba DF. Indoor environmental factors and house structures affect vaporization of active ingredient from spatial repellent devices placed in typical rural houses in south eastern Malawi. Jpn J Infect Dis 2021; 75:288-295. [PMID: 34853193 DOI: 10.7883/yoken.jjid.2021.584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The use of a metofluthrin-impregnated spatial repellent device (MSRD) is a new, practically effective method for preventing mosquito blood feeding. Indoor environmental factors such as room temperature and ventilation rate are thought to be important for MSRD activity. Measurements of room temperature and vaporization of metofluthrin from MSRD in typical rural metal-roof houses and thatched-roof houses in southeastern Malawi were conducted. The relationship between house structure and number of collected Anopheline mosquitoes with and without MSRD treatment was also investigated. The difference between daytime room temperature and nighttime room temperature was significantly higher in metal-roof houses than thatched-roof houses. The vaporization of metofluthrin from the MSRD was not accelerated by the high room temperature, but by the high indoor air flow by ventilation. The number of mosquito collections was significantly higher in thatched-roof houses than in metal-roof houses. MSRD-treated thatched-roof houses have a higher probability of mosquito infestation, but the vaporization of metofluthrin is also higher due to indoor air flow, resulting in a reduction in mosquito numbers. Metal-roof houses with closed eaves reduce the probability of mosquito invasion, and a longer predicted effectiveness occurs with MSRD because of the controlled release of metofluthrin through lower indoor air flow.
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Affiliation(s)
- Hitoshi Kawada
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, JAPAN
| | - Shusuke Nakazawa
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, JAPAN
| | - Kazunori Ohashi
- Health and Crop Sciences Research Laboratory, Sumitomo Chemical Co., Ltd., JAPAN
| | - Eggrey Aisha Kambewa
- Vector Borne Disease Laboratory, Chancellor College, University of Malawi, Republic of Malawi
| | - Dylo Foster Pemba
- Vector Borne Disease Laboratory, Chancellor College, University of Malawi, Republic of Malawi
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Kaindoa EW, Mmbando AS, Shirima R, Hape EE, Okumu FO. Insecticide-treated eave ribbons for malaria vector control in low-income communities. Malar J 2021; 20:415. [PMID: 34688285 PMCID: PMC8542300 DOI: 10.1186/s12936-021-03945-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/06/2021] [Indexed: 12/03/2022] Open
Abstract
Supplementary tools are required to address the limitations of insecticide-treated nets (ITNs) and indoor residual spraying (IRS), which are currently the core vector control methods against malaria in Africa. The eave ribbons technology exploits the natural house-entry behaviours of major malaria vectors to deliver mosquitocidal or repellent actives around eave spaces through which the Anopheles mosquitoes usually enter human dwellings. They confer protection by preventing biting indoors and in the peri-domestic outdoor spaces, and also killing a significant proportion of the mosquitoes. Current versions of eave ribbons are made of low-cost hessian fabric infused with candidate insecticides and can be easily fitted onto multiple house types without any additional modifications. This article reviews the evidence for efficacy of the technology, and discusses its potential as affordable and versatile supplementary approach for targeted and efficient control of mosquito-borne diseases, particularly malaria. Given their simplicity and demonstrated potential in previous studies, future research should investigate ways to optimize scalability and effectiveness of the ribbons. It is also important to assess whether the ribbons may constitute a less-cumbersome, but more affordable substitute for other interventions, such as IRS, by judiciously using lower quantities of selected insecticides targeted around eave spaces to deliver equivalent or greater suppression of malaria transmission.
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Affiliation(s)
- Emmanuel W Kaindoa
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania. .,School of Life Science and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, Tanzania.
| | - Arnold S Mmbando
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania.,Department of Biosciences, Durham University, DH13LE, Durham, UK
| | - Ruth Shirima
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Emmanuel E Hape
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, G12 8QQ, Glasgow, UK
| | - Fredros O Okumu
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, G12 8QQ, Glasgow, UK.,School of Life Science and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, Tanzania
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7
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Investigating differences in village-level heterogeneity of malaria infection and household risk factors in Papua New Guinea. Sci Rep 2021; 11:16540. [PMID: 34400687 PMCID: PMC8367982 DOI: 10.1038/s41598-021-95959-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/27/2021] [Indexed: 11/13/2022] Open
Abstract
Malaria risk is highly heterogeneous. Understanding village and household-level spatial heterogeneity of malaria risk can support a transition to spatially targeted interventions for malaria elimination. This analysis uses data from cross-sectional prevalence surveys conducted in 2014 and 2016 in two villages (Megiar and Mirap) in Papua New Guinea. Generalised additive modelling was used to characterise spatial heterogeneity of malaria risk and investigate the contribution of individual, household and environmental-level risk factors. Following a period of declining malaria prevalence, the prevalence of P. falciparum increased from 11.4 to 19.1% in Megiar and 12.3 to 28.3% in Mirap between 2014 and 2016, with focal hotspots observed in these villages in 2014 and expanding in 2016. Prevalence of P. vivax was similar in both years (20.6% and 18.3% in Megiar, 22.1% and 23.4% in Mirap) and spatial risk heterogeneity was less apparent compared to P. falciparum. Within-village hotspots varied by Plasmodium species across time and between villages. In Megiar, the adjusted odds ratio (AOR) of infection could be partially explained by household factors that increase risk of vector exposure, such as collecting outdoor surface water as a main source of water. In Mirap, increased AOR overlapped with proximity to densely vegetated areas of the village. The identification of household and environmental factors associated with increased spatial risk may serve as useful indicators of transmission hotspots and inform the development of tailored approaches for malaria control.
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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.
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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
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Sikalima J, Schue JL, Hill SE, Mulenga M, Handema R, Daka V, Chileshe J, Kasongo W, Chaponda M, Bukasa Kabuya JB, Moss WJ, Ippolito MM. House Structure Is Associated with Malaria among Febrile Patients in a High-Transmission Region of Zambia. Am J Trop Med Hyg 2021; 104:2131-2138. [PMID: 33844650 PMCID: PMC8176472 DOI: 10.4269/ajtmh.20-1378] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/10/2021] [Indexed: 11/07/2022] Open
Abstract
Since the late nineteenth century, the importance of house structure as a determinant of malaria risk has been recognized. Few studies to date have examined the association of housing and malaria in clinical populations. We conducted a cross-sectional study of febrile patients (n = 282) at two rural health clinics in a high malaria-transmission area of northern Zambia. Participants underwent testing for Plasmodium falciparum infection by PCR. Demographic and other risk factors including house structure, indoor residual spraying (IRS), bed net use, education level, and household income were collected. Data were fitted to logistic regression models for relational and mediation analyses. Residing in a house with a thatch roof was associated with higher odds of malaria than residing in a house with corrugated metal (odds ratio: 2.6; 95% CI: 1.0-6.3, P = 0.04). Lower income and educational attainment were also associated with greater odds of malaria. Living under a thatch roof accounted for 24% (95% CI: 14-82) of the effect of household income on malaria risk, and income accounted for 11% (95% CI: 8-19) of the effect of education. Neither IRS nor bed net use was associated with malaria risk despite large, local investments in these vector control interventions. The findings testify to malaria as a disease of rural poverty and contribute further evidence to the utility of housing improvements in vector control programs.
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Affiliation(s)
- Jay Sikalima
- Tropical Diseases Research Centre, Ndola, Zambia
| | - Jessica L. Schue
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Sarah E. Hill
- Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Modest Mulenga
- Department of Public Health, Michael Chilufya Sata School of Medicine, Copperbelt University, Kitwe, Zambia
| | - Ray Handema
- Tropical Diseases Research Centre, Ndola, Zambia
| | - Victor Daka
- Department of Public Health, Michael Chilufya Sata School of Medicine, Copperbelt University, Kitwe, Zambia
| | | | | | | | | | - William J. Moss
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Matthew M. Ippolito
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - for the Southern and Central Africa International Centers of Excellence for Malaria Research
- Tropical Diseases Research Centre, Ndola, Zambia
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Public Health, Michael Chilufya Sata School of Medicine, Copperbelt University, Kitwe, Zambia
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Sternberg ED, Cook J, Alou LPA, Assi SB, Koffi AA, Doudou DT, Aoura CJ, Wolie RZ, Oumbouke WA, Worrall E, Kleinschmidt I, N'Guessan R, Thomas MB. Impact and cost-effectiveness of a lethal house lure against malaria transmission in central Côte d'Ivoire: a two-arm, cluster-randomised controlled trial. Lancet 2021; 397:805-815. [PMID: 33640067 PMCID: PMC7910282 DOI: 10.1016/s0140-6736(21)00250-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/15/2020] [Accepted: 01/13/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND New vector control tools are required to sustain the fight against malaria. Lethal house lures, which target mosquitoes as they attempt to enter houses to blood feed, are one approach. Here we evaluated lethal house lures consisting of In2Care (Wageningen, Netherlands) Eave Tubes, which provide point-source insecticide treatments against host-seeking mosquitoes, in combination with house screening, which aims to reduce mosquito entry. METHODS We did a two-arm, cluster-randomised controlled trial with 40 village-level clusters in central Côte d'Ivoire between Sept 26, 2016, and April 10, 2019. All households received new insecticide-treated nets at universal coverage (one bednet per two people). Suitable households within the clusters assigned to the treatment group were offered screening plus Eave Tubes, with Eave Tubes treated using a 10% wettable powder formulation of the pyrethroid β-cyfluthrin. Because of the nature of the intervention, treatment could not be masked for households and field teams, but all analyses were blinded. The primary endpoint was clinical malaria incidence recorded by active case detection over 2 years in cohorts of children aged 6 months to 10 years. This trial is registered with ISRCTN, ISRCTN18145556. FINDINGS 3022 houses received screening plus Eave Tubes, with an average coverage of 70% across the intervention clusters. 1300 eligible children were recruited for active case detection in the control group and 1260 in the intervention group. During the 2-year follow-up period, malaria case incidence was 2·29 per child-year (95% CI 1·97-2·61) in the control group and 1·43 per child-year (1·21-1·65) in the intervention group (hazard ratio 0·62, 95% CI 0·51-0·76; p<0·0001). Cost-effectiveness simulations suggested that screening plus Eave Tubes has a 74·0% chance of representing a cost-effective intervention, compared with existing healthcare activities in Côte d'Ivoire, and is similarly cost-effective to other core vector control interventions across sub-Saharan Africa. No serious adverse events associated with the intervention were reported during follow-up. INTERPRETATION Screening plus Eave Tubes can provide protection against malaria in addition to the effects of insecticide-treated nets, offering potential for a new, cost-effective strategy to supplement existing vector control tools. Additional trials are needed to confirm these initial results and further optimise Eave Tubes and the lethal house lure concept to facilitate adoption. FUNDING The Bill & Melinda Gates Foundation.
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Affiliation(s)
- Eleanore D Sternberg
- Department of Entomology, Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, USA; Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
| | - Jackie Cook
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Ludovic P Ahoua Alou
- Institut Pierre Richet, Institut National de Santé Publique, Bouaké, Côte d'Ivoire
| | - Serge Brice Assi
- Institut Pierre Richet, Institut National de Santé Publique, Bouaké, Côte d'Ivoire
| | - Alphonsine A Koffi
- Institut Pierre Richet, Institut National de Santé Publique, Bouaké, Côte d'Ivoire
| | - Dimi T Doudou
- Laboratoire de Santé, Nutrition et Hygiène, Centre de Recherche pour le Développement, Université Alassane Ouattara, Bouaké, Côte d'Ivoire
| | - Carine J Aoura
- Institut Pierre Richet, Institut National de Santé Publique, Bouaké, Côte d'Ivoire
| | - Rosine Z Wolie
- Institut Pierre Richet, Institut National de Santé Publique, Bouaké, Côte d'Ivoire; Laboratoire de genetique, Unité de Formation et de Recherche en Biosciences, Université Felix Houphouët Boigny, Abidjan, Côte d'Ivoire
| | - Welbeck A Oumbouke
- Innovative Vector Control Consortium, Liverpool School of Tropical Medicine, Liverpool, United Kingdom; Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK; Institut Pierre Richet, Institut National de Santé Publique, Bouaké, Côte d'Ivoire
| | - Eve Worrall
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Immo Kleinschmidt
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Wits Research Institute for Malaria, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa; Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
| | - Raphael N'Guessan
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK; Institut Pierre Richet, Institut National de Santé Publique, Bouaké, Côte d'Ivoire
| | - Matthew B Thomas
- Department of Entomology, Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, USA; York Environmental Sustainability Institute and Department of Biology, University of York, York, UK
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11
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Aung PL, Soe MT, Oo TL, Khin A, Thi A, Zhao Y, Cao Y, Cui L, Kyaw MP, Parker DM. Predictors of malaria rapid diagnostic test positivity in a high burden area of Paletwa Township, Chin State in Western Myanmar. Infect Dis Poverty 2021; 10:6. [PMID: 33431057 PMCID: PMC7802189 DOI: 10.1186/s40249-020-00787-z] [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: 07/31/2020] [Accepted: 12/16/2020] [Indexed: 12/05/2022] Open
Abstract
Background Despite major reductions in malaria burden across Myanmar, clusters of the disease continue to persist in specific subregions. This study aimed to assess the predictors of test positivity among people living in Paletwa Township of Chin State, an area of persistently high malaria burden. Methods Four villages with the highest malaria incidence from Paletwa Township were purposively selected. The characteristics of 1045 subjects seeking malaria diagnosis from the four assigned village health volunteers from January to December, 2018 were retrospectively analyzed. Their household conditions and surroundings were also recorded using a checklist. Descriptive statistics and logistic regression models were applied to investigate potential associations between individual and household characteristics and malaria diagnosis. Results In 2017, the Paletwa township presented 20.9% positivity and an annual parasite index of 46.9 cases per 1000 people. Plasmodium falciparum was the predominant species and accounted for more than 80.0% of all infections. Among 1045 people presenting at a clinic with malaria symptoms, 31.1% were diagnosed with malaria. Predictors for test positivity included living in a hut [adjusted odds ratios (a OR): 2.3, 95% confidence intervals (CI): 1.2–4.6], owning farm animals (aOR: 1.7, 95% CI: 1.1–3.6), using non-septic type of toilets (aOR: 1.9, 95% CI: 1.1–8.4), presenting with fever (aOR: 1.9, 95% CI: 1.1–3.0), having a malaria episode within the last year (aOR: 2.9, 95% CI: 1.4–5.8), traveling outside the village in the previous 14 days (aOR: 4.5, 95% CI: 1.5–13.4), and not using bed nets (a OR: 3.4, 95% CI: 2.3–5.1). There were no statistically significant differences by age or gender in this present analysis. Conclusions The results from this study, including a high proportion of P. falciparum infections, little difference in age, sex, or occupation, suggest that malaria is a major burden for these study villages. Targeted health education campaigns should be introduced to strengthen synchronous diagnosis-seeking behaviors, tighten treatment adherence, receiving a diagnosis after traveling to endemic regions, and using bed nets properly. We suggest increased surveillance, early diagnosis, and treatment efforts to control the disease and then to consider the local elimination.![]()
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Affiliation(s)
| | - Myat Thu Soe
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Thit Lwin Oo
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Aung Khin
- Myanmar Health Assistant Association, Yangon, Myanmar
| | - Aung Thi
- Department of Public Health, Ministry of Health and Sports, NayPyiTaw, Myanmar
| | - Yan Zhao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Liwang Cui
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | | | - Daniel M Parker
- Department of Population Health and Disease Prevention, Department of Epidemiology, University of California, Irvine, USA.
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12
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Murindahabi MM, Takken W, Misago X, Niyituma E, Umupfasoni J, Hakizimana E, van Vliet AJH, Poortvliet PM, Mutesa L, Murindahabi NK, Koenraadt CJM. Monitoring mosquito nuisance for the development of a citizen science approach for malaria vector surveillance in Rwanda. Malar J 2021; 20:36. [PMID: 33423679 PMCID: PMC7798336 DOI: 10.1186/s12936-020-03579-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 12/31/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Many countries, including Rwanda, have mosquito monitoring programmes in place to support decision making in the fight against malaria. However, these programmes can be costly, and require technical (entomological) expertise. Involving citizens in data collection can greatly support such activities, but this has not yet been thoroughly investigated in a rural African context. METHODS Prior to the implementation of such a citizen-science approach, a household entomological survey was conducted in October-November 2017 and repeated one year later in Busoro and Ruhuha sectors, in southern and eastern province of Rwanda, respectively. The goal was to evaluate the perception of mosquito nuisance reported by citizens as a potential indicator for malaria vector hotspots. Firstly, mosquito abundance and species composition were determined using Centers for Disease Control and Prevention (CDC) light traps inside the houses. Secondly, household members were interviewed about malaria risk factors and their perceived level of mosquito nuisance. RESULTS Tiled roofs, walls made of mud and wood, as well as the number of occupants in the house were predictors for the number of mosquitoes (Culicidae) in the houses, while the presence of eaves plus walls made of mud and wood were predictors for malaria vector abundance. Perception of mosquito nuisance reported indoors tended to be significantly correlated with the number of Anopheles gambiae sensu lato (s.l.) and Culicidae collected indoors, but this varied across years and sectors. At the village level, nuisance also significantly correlated with An. gambiae s.l. and total mosquito density, but only in 2018 while not in 2017. CONCLUSIONS Perception of mosquito nuisance denoted in a questionnaire survey could be used as a global indicator of malaria vector hotspots. Hence, involving citizens in such activities can complement malaria vector surveillance and control.
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Affiliation(s)
- Marilyn Milumbu Murindahabi
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands.,College of Sciences and Technology, University of Rwanda, Kigali, Rwanda
| | - Willem Takken
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Xavier Misago
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Center, Kigali, Rwanda
| | - Elias Niyituma
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Center, Kigali, Rwanda
| | - Jackie Umupfasoni
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Center, Kigali, Rwanda
| | - Emmanuel Hakizimana
- Malaria and Other Parasitic Diseases Division, Rwanda Biomedical Center, Kigali, Rwanda
| | - Arnold J H van Vliet
- Environmental Systems Analysis Group, Wageningen University & Research, Wageningen, The Netherlands
| | - P Marijn Poortvliet
- Strategic Communication Group, Wageningen University & Research, Wageningen, the Netherlands
| | - Leon Mutesa
- College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
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13
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Debebe Y, Hill SR, Tekie H, Dugassa S, Hopkins RJ, Ignell R. Malaria hotspots explained from the perspective of ecological theory underlying insect foraging. Sci Rep 2020; 10:21449. [PMID: 33293574 PMCID: PMC7722757 DOI: 10.1038/s41598-020-78021-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 11/19/2020] [Indexed: 01/16/2023] Open
Abstract
Hotspots constitute the major reservoir for residual malaria transmission, with higher malaria incidence than neighbouring areas, and therefore, have the potential to form the cornerstone for successful intervention strategies. Detection of malaria hotspots is hampered by their heterogenous spatial distribution, and the laborious nature and low sensitivity of the current methods used to assess transmission intensity. We adopt ecological theory underlying foraging in herbivorous insects to vector mosquito host seeking and modelling of fine-scale landscape features at the village level. The overall effect of environmental variables on the density of indoor mosquitoes, sporozoite infected mosquitoes, and malaria incidence, was determined using generalized linear models. Spatial analyses were used to identify hotspots for malaria incidence, as well as malaria vector density and associated sporozoite prevalence. We identify household occupancy and location as the main predictors of vector density, entomological inoculation rate and malaria incidence. We propose that the use of conventional vector control and malaria interventions, integrated with their intensified application targeting predicted hotspots, can be used to reduce malaria incidence in endemic and residual malaria settings.
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Affiliation(s)
- Yared Debebe
- Department of Zoological Sciences, Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia
| | - Sharon Rose Hill
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Habte Tekie
- Department of Zoological Sciences, Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia
| | - Sisay Dugassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia
| | | | - Rickard Ignell
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
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14
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Ng'ang'a PN, Okoyo C, Mbogo C, Mutero CM. Evaluating effectiveness of screening house eaves as a potential intervention for reducing indoor vector densities and malaria prevalence in Nyabondo, western Kenya. Malar J 2020; 19:341. [PMID: 32950061 PMCID: PMC7501660 DOI: 10.1186/s12936-020-03413-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 09/10/2020] [Indexed: 11/25/2022] Open
Abstract
Background Mosquito-proofing of houses using wire mesh screens is gaining greater recognition as a practical intervention for reducing exposure to malaria transmitting mosquitoes. Screening potentially protects all persons sleeping inside the house against transmission of mosquito-borne diseases indoors. The study assessed the effectiveness of house eaves screening in reducing indoor vector densities and malaria prevalence in Nyabondo, western Kenya. Methods 160 houses were selected for the study, with half of them randomly chosen for eaves screening with fibre-glass coated wire mesh (experimental group) and the other half left without screening (control group). Randomization was carried out by use of computer-generated list in permuted blocks of ten houses and 16 village blocks, with half of them allocated treatment in a ratio of 1:1. Cross-sectional baseline entomological and parasitological data were collected before eave screening. After baseline data collection, series of sampling of indoor adult mosquitoes were conducted once a month in each village using CDC light traps. Three cross-sectional malaria parasitological surveys were conducted at three month intervals after installation of the screens. The primary outcome measures were indoor Anopheles mosquito density and malaria parasite prevalence. Results A total of 15,286 mosquitoes were collected over the two year period using CDC light traps in 160 houses distributed over 16 study villages (mean mosquitoes = 4.35, SD = 11.48). Of all mosquitoes collected, 2,872 (18.8%) were anophelines (2,869 Anopheles gambiae sensu lato, 1 Anopheles funestus and 2 other Anopheles spp). Overall, among An. gambiae collected, 92.6% were non-blood fed, 3.57% were blood fed and the remaining 0.47% were composed of gravid and half gravid females. More indoor adult mosquitoes were collected in the control than experimental arms of the study. Results from cross-sectional parasitological surveys showed that screened houses recorded relatively low malaria parasite prevalence rates compared to the control houses. Overall, malaria prevalence was 5.6% (95% CI: 4.2–7.5) n = 1,918, with baseline prevalence rate of 6.1% (95% CI: 3.9–9.4), n = 481 and 3rd follow-up survey prevalence of 3.6% (95% CI: 2.0–6.8) n = 494. At all the three parasitological follow-up survey points, house screening significantly reduced the malaria prevalence by 100% (p < 0.001), 63.6% (p = 0.026), and 100% (p < 0.001) in the 1st, 2nd and 3rd follow-up surveys respectively. Conclusions The study demonstrated that house eave screening has potential to reduce indoor vector densities and malaria prevalence in high transmission areas.
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Affiliation(s)
- Peter Njoroge Ng'ang'a
- International Centre of Insect Physiology and Ecology (ICIPE), PO Box 30772, Nairobi, Kenya. .,Jomo Kenyatta University of Agriculture and Technology, School of Public Health, PO Box 62000, Nairobi, Kenya.
| | - Collins Okoyo
- Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Charles Mbogo
- Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), Nairobi, Kenya.,KEMRI-Wellcome Trust Research Programme, Public Health Unit, PO Box 43640 - 00100, Nairobi, Kenya
| | - Clifford Maina Mutero
- International Centre of Insect Physiology and Ecology (ICIPE), PO Box 30772, Nairobi, Kenya.,University of Pretoria Institute for Sustainable Malaria Control (UP ISMC, School of Health Systems and Public Health, University of Pretoria, Private Bag X363, Pretoria, 0001, South Africa
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15
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Surira MR, Ishak H, Mallongi A, Salmah AU, Syam A, Hamzah. Characteristics of home environment factors and community behavior of endemic malaria area in Jampea Island. ENFERMERIA CLINICA 2020. [DOI: 10.1016/j.enfcli.2020.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Gopal S, Ma Y, Xin C, Pitts J, Were L. Characterizing the Spatial Determinants and Prevention of Malaria in Kenya. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E5078. [PMID: 31842408 PMCID: PMC6950158 DOI: 10.3390/ijerph16245078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 11/26/2019] [Accepted: 12/05/2019] [Indexed: 01/19/2023]
Abstract
The United Nations' Sustainable Development Goal 3 is to ensure health and well-being for all at all ages with a specific target to end malaria by 2030. Aligned with this goal, the primary objective of this study is to determine the effectiveness of utilizing local spatial variations to uncover the statistical relationships between malaria incidence rate and environmental and behavioral factors across the counties of Kenya. Two data sources are used-Kenya Demographic and Health Surveys of 2000, 2005, 2010, and 2015, and the national Malaria Indicator Survey of 2015. The spatial analysis shows clustering of counties with high malaria incidence rate, or hot spots, in the Lake Victoria region and the east coastal area around Mombasa; there are significant clusters of counties with low incidence rate, or cold spot areas in Nairobi. We apply an analysis technique, geographically weighted regression, that helps to better model how environmental and social determinants are related to malaria incidence rate while accounting for the confounding effects of spatial non-stationarity. Some general patterns persist over the four years of observation. We establish that variables including rainfall, proximity to water, vegetation, and population density, show differential impacts on the incidence of malaria in Kenya. The El-Nino-southern oscillation (ENSO) event in 2015 was significant in driving up malaria in the southern region of Lake Victoria compared with prior time-periods. The applied spatial multivariate clustering analysis indicates the significance of social and behavioral survey responses. This study can help build a better spatially explicit predictive model for malaria in Kenya capturing the role and spatial distribution of environmental, social, behavioral, and other characteristics of the households.
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Affiliation(s)
- Sucharita Gopal
- Department of Earth & Environment, Boston University, Boston, MA 02215, USA; (S.G.); (Y.M.); (C.X.)
- Center for Global Development Policy, Boston University, Boston, MA 02215, USA;
| | - Yaxiong Ma
- Department of Earth & Environment, Boston University, Boston, MA 02215, USA; (S.G.); (Y.M.); (C.X.)
| | - Chen Xin
- Department of Earth & Environment, Boston University, Boston, MA 02215, USA; (S.G.); (Y.M.); (C.X.)
| | - Joshua Pitts
- Center for Global Development Policy, Boston University, Boston, MA 02215, USA;
| | - Lawrence Were
- College of Health & Rehabilitation Sciences: Sargent College, Boston University, Boston, MA 02215, USA
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17
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Saita S, Pan-Ngum W, Phuanukoonnon S, Sriwichai P, Silawan T, White LJ, Parker DM. Human population movement and behavioural patterns in malaria hotspots on the Thai-Myanmar border: implications for malaria elimination. Malar J 2019; 18:64. [PMID: 30849980 PMCID: PMC6408830 DOI: 10.1186/s12936-019-2704-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/02/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria is heterogeneously distributed across landscapes. Human population movement (HPM) could link sub-regions with varying levels of transmission, leading to the persistence of disease even in very low transmission settings. Malaria along the Thai-Myanmar border has been decreasing, but remains heterogeneous. This study aimed to measure HPM, associated predictors of travel, and HPM correlates of self-reported malaria among people living within malaria hotspots. METHODS 526 individuals from 279 households in two malaria hotspot areas were included in a prospective observational study. A baseline cross-sectional study was conducted at the beginning, recording both individual- and household-level characteristics. Individual movement and travel patterns were repeatedly observed over one dry season month (March) and one wet season month (May). Descriptive statistics, random effects logistic regressions, and logistic regressions were used to describe and determine associations between HPM patterns, individual-, household-factors, and self-reported malaria. RESULTS Trips were more common in the dry season. Malaria risk was related to the number of days doing outdoor activities in the dry season, especially trips to Myanmar, to forest areas, and overnight trips. Trips to visit forest areas were more common among participants aged 20-39, males, individuals with low income, low education, and especially among individuals with forest-related occupations. Overnight trips were more common among males, and individual with forest-related occupations. Forty-five participants reported having confirmed malaria infection within the last year. The main place of malaria blood examination and treatment was malaria post and malaria clinic, with participants usually waiting for 2-3 days from onset fever to seeking diagnosis. Individuals using bed nets, living in houses with elevated floors, and houses that received indoor residual spraying in the last year were less likely to report malaria infection. CONCLUSION An understanding of HPM and concurrent malaria dynamics is important for consideration of targeted public health interventions. Furthermore, diagnosis and treatment centres must be capable of quickly diagnosing and treating infections regardless of HPM. Coverage of diagnosis and treatment centres should be broad, maintained in areas bordering malaria hotspots, and available to all febrile individuals.
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Affiliation(s)
- Sayambhu Saita
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wirichada Pan-Ngum
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Suparat Phuanukoonnon
- Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Patchara Sriwichai
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Tassanee Silawan
- Department of Community Health, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Lisa J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Daniel M Parker
- Department of Population Health and Disease Prevention, University of California, Irvine, USA.
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