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Lek D, Sokomar N, Samphornarann T, Rideout J, Hassan SED, Bunkea T, Ath SS, Seng R, Hustedt J, Peto TJ, Hughes J, Kimmen K, Dy K, Adhikari B. Impact of targeted drug administration and intermittent preventive treatment for forest goers using artesunate-pyronaridine to control malaria outbreaks in Cambodia. Trop Med Health 2024; 52:42. [PMID: 38863067 PMCID: PMC11165738 DOI: 10.1186/s41182-024-00607-2] [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: 04/01/2024] [Accepted: 05/29/2024] [Indexed: 06/13/2024] Open
Abstract
INTRODUCTION The national malaria programme of Cambodia targets the rapid elimination of all human malaria by 2025. As clinical cases decline to near-elimination levels, a key strategy is the rapid identification of malaria outbreaks triggering effective action to interrupt local transmission. We report a comprehensive, multipronged management approach in response to a 2022 Plasmodium falciparum outbreak in Kravanh district, western Cambodia. METHODS The provincial health department of Pursat in conjunction with the Center for Parasitology, Entomology and Malaria Control (CNM) identified villages where transmission was occurring using clinical records, and initiated various interventions, including the distribution of insecticide-treated bed nets, running awareness campaigns, and implementing fever screening with targeted drug administration. Health stations were set up at forest entry points, and later, targeted drug administrations with artesunate-pyronaridine (Pyramax) and intermittent preventive treatment for forest goers (IPTf) were implemented in specific village foci. Data related to adherence and adverse events from IPTf and TDA were collected. The coverage rates of interventions were calculated, and local malaria infections were monitored. RESULTS A total of 942 individuals were screened through active fever surveillance in villages where IPTf and TDA were conducted. The study demonstrated high coverage and adherence rates in the targeted villages, with 92% (553/600) coverage in round one and 65% (387/600) in round two. Adherence rate was 99% (551/553) in round one and 98% (377/387) in round two. The study found that forest goers preferred taking Pyramax over repeated testing consistent with the coverage rates: 92% in round one compared to 65% in round two. All individuals reachable through health stations or mobile teams reported complete IPTf uptake. No severe adverse events were reported. Only six individuals reported mild adverse events, such as loss of energy, fever, abdominal pain, diarrhoea, and muscle aches. Two individuals attributed their symptoms to heavy alcohol intake following prophylaxis. CONCLUSIONS The targeted malaria outbreak response demonstrated high acceptability, safety, and feasibility of the selected interventions. Malaria transmission was rapidly controlled using the available community resources. This experience suggests the effectiveness of the programmatic response for future outbreaks.
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Affiliation(s)
- Dysoley Lek
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia.
- School of Public Health, National Institute of Public Health, Phnom Penh, Cambodia.
| | - Nguon Sokomar
- Cambodia Malaria Elimination Project2, University Research Company Ltd., Phnom Penh, Cambodia
| | - Top Samphornarann
- Cambodia Malaria Elimination Project2, University Research Company Ltd., Phnom Penh, Cambodia
| | - Jeanne Rideout
- Cambodia Malaria Elimination Project2, University Research Company Ltd., Phnom Penh, Cambodia
| | - Saad El-Din Hassan
- Cambodia Malaria Elimination Project2, University Research Company Ltd., Phnom Penh, Cambodia
| | - Tol Bunkea
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Saing Sam Ath
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Rothpisey Seng
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - John Hustedt
- Cambodia Malaria Elimination Project2, University Research Company Ltd., Phnom Penh, Cambodia
- FHI 360, Phnom Penh, Cambodia
| | - 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
| | - Jayme Hughes
- Clinton Health Access Initiative, Phnom Penh, Cambodia
| | - Ke Kimmen
- Provincial Health Department, Pursat, Cambodia
| | - Khoy Dy
- Clinton Health Access Initiative, Phnom Penh, Cambodia
| | - Bipin Adhikari
- 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.
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2
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Iv S, Nguon C, Kong P, Sieng T, Srun S, Christiansen-Jucht C, Kul C, Lorn T, Chy S, Popovici J, Vantaux A, Witkowski B, Berry A, Piola P, Flamand C. Intermittent preventive treatment for forest goers by forest malaria workers: an observational study on a key intervention for malaria elimination in Cambodia. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2024; 47:101093. [PMID: 38799614 PMCID: PMC11127514 DOI: 10.1016/j.lanwpc.2024.101093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/04/2024] [Accepted: 05/01/2024] [Indexed: 05/29/2024]
Abstract
Background Cambodia targets P. falciparum malaria elimination by 2023 and all human malaria species by 2025, aligning with WHO's Mekong Malaria Elimination program. The Intermittent Preventive Treatment for Forest Goers (IPTf) project aimed at forest-specific malaria elimination. The study aims to pinpoint the main factors driving malaria transmission in Cambodian forests and evaluate the initial implementation and effectiveness of IPTf in accelerating the elimination of malaria by treating and preventing infections among at-risk populations in these areas. Methods From March 11, 2019, to January 30, 2021, a malaria intervention program took place in isolated forests in Northeast Cambodia. The first phase focused on observing forest goers (FGs) within the forests, documenting their malaria risk. In the second phase, a monthly artesunate-mefloquine IPTf was implemented by trained forest malaria workers who were former FGs conducting interviews, blood collection, and IPTf administration. Findings Throughout the two-year period, 2198 FGs were involved in 3579 interviews, with 284 in both the observation and intervention phases. Following IPTf implementation, PCR-confirmed malaria prevalence significantly decreased from 2.9% to 0.5% for P. falciparum and from 21.0% to 4.7% for P. vivax. Among the 284 participants tracked through both phases, malaria prevalence fell from 2.5% to 0.3% for P. falciparum and from 22.5% to 3.7% for P. vivax. The intervention phase demonstrated a rapid decline in P. falciparum prevalence among mobile and previously inaccessible populations, while also revealing a higher P. falciparum infection risk associated with activities inaccurately labelled as farming, underscoring the need for customized interventions. Interpretation The successful implementation of IPTf in Cambodia's remote forests has markedly decreased malaria prevalence among high-risk groups. Cambodia's National Malaria Program has acknowledged this strategy as essential for malaria elimination intervention, endorsing forest-specific approaches to meet the 2025 goal of eradicating all human malaria species in Cambodia. Funding The study received funding from the French 5% Initiative (Initiative Canal 2-17SANIN205).
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Affiliation(s)
- Sophea Iv
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
- UMR 1043 – INFINITY – Institut Toulousain des Maladies Infectieuses et Inflammatoires, Toulouse, France
| | - Chea Nguon
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Phanith Kong
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Téphanie Sieng
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Sreynet Srun
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | | | - Chanvong Kul
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Thornleaksmey Lorn
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Sophy Chy
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Jean Popovici
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
- G5 Épidémiologie et Analyse des Maladies Infectieuse, Département de Santé Globale, Institut Pasteur, F-75015, Paris, France
| | - Amélie Vantaux
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Benoit Witkowski
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Antoine Berry
- UMR 1043 – INFINITY – Institut Toulousain des Maladies Infectieuses et Inflammatoires, Toulouse, France
| | - Patrice Piola
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Claude Flamand
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
- Mathematical Modelling of Infectious Diseases Unit, Institut Pasteur, UMR2000, CNRS, Paris, France
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3
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Manzoni G, Try R, Guintran JO, Christiansen-Jucht C, Jacoby E, Sovannaroth S, Zhang Z, Banouvong V, Shortus MS, Reyburn R, Chanthavisouk C, Linn NYY, Thapa B, Khine SK, Sudathip P, Gopinath D, Thieu NQ, Ngon MS, Cong DT, Hui L, Kelley J, Valecha NNK, Bustos MD, Rasmussen C, Tuseo L. Progress towards malaria elimination in the Greater Mekong Subregion: perspectives from the World Health Organization. Malar J 2024; 23:64. [PMID: 38429807 PMCID: PMC10908136 DOI: 10.1186/s12936-024-04851-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: 11/09/2023] [Accepted: 01/11/2024] [Indexed: 03/03/2024] Open
Abstract
Malaria remains a global health challenge, disproportionately affecting vulnerable communities. Despite substantial progress, the emergence of anti-malarial drug resistance poses a constant threat. The Greater Mekong Subregion (GMS), which includes Cambodia, China's Yunnan province, Lao People's Democratic Republic, Myanmar, Thailand, and Viet Nam has been the epicentre for the emergence of resistance to successive generations of anti-malarial therapies. From the perspective of the World Health Organization (WHO), this article considers the collaborative efforts in the GMS, to contain Plasmodium falciparum artemisinin partial resistance and multi-drug resistance and to advance malaria elimination. The emergence of artemisinin partial resistance in the GMS necessitated urgent action and regional collaboration resulting in the Strategy for Malaria Elimination in the Greater Mekong Subregion (2015-2030), advocating for accelerated malaria elimination interventions tailored to country needs, co-ordinated and supported by the WHO Mekong malaria elimination programme. The strategy has delivered substantial reductions in malaria across all GMS countries, with a 77% reduction in malaria cases and a 97% reduction in malaria deaths across the GMS between 2012 and 2022. Notably, China was certified malaria-free by WHO in 2021. Countries' ownership and accountability have been pivotal, with each GMS country outlining its priorities in strategic and annual work plans. The development of strong networks for anti-malarial drug resistance surveillance and epidemiological surveillance was essential. Harmonization of policies and guidelines enhanced collaboration, ensuring that activities were driven by evidence. Challenges persist, particularly in Myanmar, where security concerns have limited recent progress, though an intensification and acceleration plan aims to regain momentum. Barriers to implementation can slow progress and continuing innovation is needed. Accessing mobile and migrant populations is key to addressing remaining transmission foci, requiring effective cross-border collaboration. In conclusion, the GMS has made significant progress towards malaria elimination, particularly in the east where several countries are close to P. falciparum elimination. New and persisting challenges require sustained efforts and continued close collaboration. The GMS countries have repeatedly risen to every obstacle presented, and now is the time to re-double efforts and achieve the 2030 goal of malaria elimination for the region.
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Affiliation(s)
- Giulia Manzoni
- WHO Mekong Malaria Elimination Programme, Phnom Penh, Cambodia.
- Independent Consultant, Antananarivo, Madagascar.
| | - Rady Try
- WHO Mekong Malaria Elimination Programme, Phnom Penh, Cambodia
| | - Jean Olivier Guintran
- World Health Organization Country Office, Phnom Penh, Cambodia
- Independent Consultant, Le Bar sur Loup, France
| | | | - Elodie Jacoby
- WHO Mekong Malaria Elimination Programme, Phnom Penh, Cambodia
- Independent Consultant, Ho Chi Minh, Viet Nam
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Zaixing Zhang
- World Health Organization Country Office, Phnom Penh, Cambodia
| | | | | | - Rita Reyburn
- World Health Organization Country Office, Vientiane, Lao PDR
| | | | - Nay Yi Yi Linn
- National Malaria Control Programme, Nay Pyi Taw, Myanmar
| | - Badri Thapa
- World Health Organization Country Office, Yangon, Myanmar
| | | | - Prayuth Sudathip
- Division of Vector Borne Diseases, Department of Disease Control, Bangkok, Thailand
| | - Deyer Gopinath
- World Health Organization Country Office, Bangkok, Thailand
| | - Nguyen Quang Thieu
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Viet Nam
| | | | | | - Liu Hui
- Yunnan Institute of Parasitic Diseases, Yunnan, China
| | - James Kelley
- World Health Organization, Regional Office for the Western Pacific, Manila, Philippines
| | | | - Maria Dorina Bustos
- World Health Organization, Regional Office for South-East Asia, New Delhi, India
| | | | - Luciano Tuseo
- WHO Mekong Malaria Elimination Programme, Phnom Penh, Cambodia
- World Health Organization, Regional Office for the Western Pacific, Manila, Philippines
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St Laurent B. Genomic complexity of parasites and vectors challenges malaria control in Southeast Asia. CURRENT OPINION IN INSECT SCIENCE 2023; 60:101113. [PMID: 37690774 DOI: 10.1016/j.cois.2023.101113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 09/02/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023]
Abstract
Southeast Asia is a uniquely complex region of malaria transmission that maintains an astounding level of species diversity among potential malaria vectors and also generates drug-resistant and quickly diverging populations of malaria parasites. All five human malaria species circulate in Southeast Asia with over 50 Anopheles species that vary in their ability to transmit these pathogens. The intricate relationships of these parasites and vectors are not well-understood. Human activity in Southeast Asian countries has created an increasingly fragmented landscape, bringing humans and mosquitoes into more frequent contact, sustaining malaria transmission in a region where few control tools are effective. Genomic shifts at the species, population, and individual level in parasites and vectors introduce variation that has produced drug- and insecticide resistance. The goal of this review is to highlight genomic studies of Southeast Asian malaria parasites and vectors that demonstrate how diversity in these organisms presents unique challenges and opportunities for global malaria control and eradication efforts.
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Emiru T, Getachew D, Murphy M, Sedda L, Ejigu LA, Bulto MG, Byrne I, Demisse M, Abdo M, Chali W, Elliott A, Vickers EN, Aranda-Díaz A, Alemayehu L, Behaksera SW, Jebessa G, Dinka H, Tsegaye T, Teka H, Chibsa S, Mumba P, Girma S, Hwang J, Yoshimizu M, Sutcliffe A, Taffese HS, Bayissa GA, Zohdy S, Tongren JE, Drakeley C, Greenhouse B, Bousema T, Tadesse FG. Evidence for a role of Anopheles stephensi in the spread of drug- and diagnosis-resistant malaria in Africa. Nat Med 2023; 29:3203-3211. [PMID: 37884028 PMCID: PMC10719088 DOI: 10.1038/s41591-023-02641-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023]
Abstract
Anopheles stephensi, an Asian malaria vector, continues to expand across Africa. The vector is now firmly established in urban settings in the Horn of Africa. Its presence in areas where malaria resurged suggested a possible role in causing malaria outbreaks. Here, using a prospective case-control design, we investigated the role of An. stephensi in transmission following a malaria outbreak in Dire Dawa, Ethiopia in April-July 2022. Screening contacts of patients with malaria and febrile controls revealed spatial clustering of Plasmodium falciparum infections around patients with malaria in strong association with the presence of An. stephensi in the household vicinity. Plasmodium sporozoites were detected in these mosquitoes. This outbreak involved clonal propagation of parasites with molecular signatures of artemisinin and diagnostic resistance. To our knowledge, this study provides the strongest evidence so far for a role of An. stephensi in driving an urban malaria outbreak in Africa, highlighting the major public health threat posed by this fast-spreading mosquito.
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Affiliation(s)
- Tadele Emiru
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Maxwell Murphy
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Luigi Sedda
- Lancaster Ecology and Epidemiology Group, Lancaster Medical School, Lancaster University, Lancaster, UK
| | | | | | - Isabel Byrne
- London School of Hygiene and Tropical Medicine, London, UK
| | | | - Melat Abdo
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Wakweya Chali
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
- Radboudumc, Nijmegen, the Netherlands
| | - Aaron Elliott
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Eric Neubauer Vickers
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Andrés Aranda-Díaz
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Lina Alemayehu
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Gutema Jebessa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Hunduma Dinka
- Adama Science and Technology University, Adama, Ethiopia
| | - Tizita Tsegaye
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Hiwot Teka
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Sheleme Chibsa
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Peter Mumba
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Samuel Girma
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Jimee Hwang
- U.S. President's Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Alice Sutcliffe
- U.S. President's Malaria Initiative, Entomology Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | | | - Sarah Zohdy
- U.S. President's Malaria Initiative, Entomology Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jon Eric Tongren
- U.S. President's Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | - Bryan Greenhouse
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | | | - Fitsum G Tadesse
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
- London School of Hygiene and Tropical Medicine, London, UK.
- Radboudumc, Nijmegen, the Netherlands.
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Chen I, Doum D, Mannion K, Hustedt J, Sovannaroth S, McIver D, Macdonald M, Lobo N, Tatarsky A, Handley MA, Neukom J. Applying the COM-B behaviour change model to a pilot study delivering volatile pyrethroid spatial repellents and insecticide-treated clothing to forest-exposed populations in Mondulkiri Province, Cambodia. Malar J 2023; 22:251. [PMID: 37658337 PMCID: PMC10472618 DOI: 10.1186/s12936-023-04685-1] [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: 04/28/2023] [Accepted: 08/22/2023] [Indexed: 09/03/2023] Open
Abstract
BACKGROUND Southeast Asia is making tremendous progress towards their 2030 malaria elimination goal but needs new interventions to stop forest malaria. This study trials two new vector control tools, a volatile pyrethroid spatial repellent (VPSR) and insecticide-treated clothing (ITC), amongst forest-exposed populations in Mondulkiri Province Cambodia to inform their potential use for eliminating forest malaria. METHODS 21 forest-exposed individuals were given a questionnaire on their perceptions of malaria and preventive practices used, after which they trialed two products sequentially. Clothes was treated with ITC by the study team. Mixed methods were used to understand their experience, attitudes, and preferences regarding the products trialed. Quantitative data was summarized and qualitative insights were analysed using thematic analysis, applying the Capability, Opportunity, and Motivation Behaviour Change (COM-B) model and Behaviour Change Wheel Framework to identify intervention functions to support tailored product rollout amongst these populations. RESULTS Study participants reported a need for protection from mosquito bites in outdoor and forest-exposed settings and perceived both products trialed to be effective for this purpose. The VPSR product was preferred when travel was not required, whereas ITC was preferred for ease of use when going to the forest, especially in rainy conditions. COM-B analysis identified that key enablers for use of both products included their perceived efficacy and ease of use, which required no skill or preparation. For barriers to use, the odour of ITC was sometimes perceived as being toxic, as well as its inability to protect uncovered skin from mosquito bites, while the perceived usefulness of the VPSR product trialed was limited by its water sensitivity in rainy forest settings. Intervention components to encourage appropriate and sustained use of these products include education about how to use these products and what to expect, persuasion to use them from community leaders and targeted channels, and enablement to facilitate convenient and affordable access. CONCLUSION The rollout of VPSRs and ITC amongst forest-exposed populations can be useful for eliminating malaria in Southeast Asia. Study findings can be applied to increase product uptake among forest exposed populations in Cambodia, while manufacturers can aim to develop products that are rainproof, easy to use in forest settings, and have favourable odour profiles to target users.
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Affiliation(s)
- Ingrid Chen
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA.
| | - Dyna Doum
- Health Forefront Organization, Phnom Penh, Cambodia
| | - Kylie Mannion
- Menzies School of Health Research, Charles Darwin University, Casuarina, Australia
| | - John Hustedt
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - David McIver
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | | | - Neil Lobo
- University of Notre Dame, Notre Dame, IN, USA
| | - Allison Tatarsky
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Margaret A Handley
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Josselyn Neukom
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
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7
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Conradis-Jansen F, Tripura R, Peto TJ, Callery JJ, Adhikari B, Ean M, Jongdeepaisal M, Pell C, Khonputsa P, Murgia R, Sovannaroth S, Müller O, Cheah PY, Dondorp AM, von Seidlein L, Maude RJ. Community engagement among forest goers in a malaria prophylaxis trial: implementation challenges and implications. Malar J 2023; 22:178. [PMID: 37291578 DOI: 10.1186/s12936-023-04610-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 05/26/2023] [Indexed: 06/10/2023] Open
Abstract
BACKGROUND Malaria transmission in Southeast Asia is increasingly confined to forests, where marginalized groups are exposed primarily through their work. Anti-malarial chemoprophylaxis may help to protect these people. This article examines the effectiveness and practical challenges of engaging forest-goers to participate in a randomized controlled clinical trial of anti-malarial chemoprophylaxis with artemether-lumefantrine (AL) versus a control (multivitamin, MV) for malaria in northeast Cambodia. METHODS The impact of engagement in terms of uptake was assessed as the proportion of people who participated during each stage of the trial: enrolment, compliance with trial procedures, and drug intake. During the trial, staff recorded the details of engagement meetings, including the views and opinions of participants and community representatives, the decision-making processes, and the challenges addressed during implementation. RESULTS In total, 1613 participants were assessed for eligibility and 1480 (92%) joined the trial, 1242 (84%) completed the trial and received prophylaxis (AL: 82% vs MV: 86%, p = 0.08); 157 (11%) were lost to follow-up (AL: 11% vs MV: 11%, p = 0.79); and 73 (5%) discontinued the drug (AL-7% vs MV-3%, p = 0.005). The AL arm was associated with discontinuation of the study drug (AL: 48/738, 7% vs 25/742, 3%; p = 0.01). Females (31/345, 9%) were more likely (42/1135, 4%) to discontinue taking drugs at some point in the trial (p = 0.005). Those (45/644, 7%) who had no previous history of malaria infection were more likely to discontinue the study drug than those (28/836, 3%) who had a history of malaria (p = 0.02). Engagement with the trial population was demanding because many types of forest work are illegal; and the involvement of an engagement team consisting of representatives from the local administration, health authorities, community leaders and community health workers played a significant role in building trust. Responsiveness to the needs and concerns of the community promoted acceptability and increased confidence in taking prophylaxis among participants. Recruitment of forest-goer volunteers to peer-supervise drug administration resulted in high compliance with drug intake. The development of locally-appropriate tools and messaging for the different linguistic and low-literacy groups was useful to ensure participants understood and adhered to the trial procedures. It was important to consider forest-goers` habits and social characteristics when planning the various trial activities. CONCLUSIONS The comprehensive, participatory engagement strategy mobilized a wide range of stakeholders including study participants, helped build trust, and overcame potential ethical and practical challenges. This locally-adapted approach was highly effective as evidenced by high levels of trial enrolment, compliance with trial procedures and drug intake.
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Affiliation(s)
- Franca Conradis-Jansen
- Heidelberg Institute of Global Health, Medical School, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - 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 Clinical 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 Clinical Medicine, University of Oxford, Oxford, UK
| | - James J Callery
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Bipin Adhikari
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Mom Ean
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Monnaphat Jongdeepaisal
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Christopher Pell
- Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
- Amsterdam UMC, Department of Global Health, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Public Health Research Institute, Global Health Program, Amsterdam, The Netherlands
| | - Panarasri Khonputsa
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Riccardo Murgia
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Siv Sovannaroth
- Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Olaf Müller
- Heidelberg Institute of Global Health, Medical School, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - Phaik Yeong Cheah
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Arjen M 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 Clinical Medicine, University of Oxford, Oxford, UK
| | - 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 Clinical Medicine, University of Oxford, Oxford, UK
| | - Richard J 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 Clinical Medicine, University of Oxford, Oxford, UK.
- The Open University, Milton Keynes, UK.
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8
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Yan C, Hii J, Ngoen-Klan R, Ahebwa A, Saeung M, Chareonviriyaphap T. The effect of transfluthrin-treated jute and cotton emanator vests on human landing and fecundity of Anopheles minimus in Thailand. Acta Trop 2023; 242:106904. [PMID: 36967063 DOI: 10.1016/j.actatropica.2023.106904] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 03/17/2023] [Accepted: 03/18/2023] [Indexed: 04/03/2023]
Abstract
Complementary approaches to tackle outdoor and early evening biting mosquitoes are urgently required. Transfluthrin (TFT) is a volatile pyrethroid capable of altering mosquito feeding behavior. This study investigated the efficacy of TFT-treated jute (TFT-J) and cotton (TFT-C) fabrics on human landing activity, feeding and fecundity of Anopheles minimus in Thailand. Jute and cotton fabrics each measuring 1024 cm2 were impregnated with 7.34 × 10-4 g/cm2 TFT (20%, w/v), and evaluated in a semi-field screen house system. Two collectors, wearing an untreated control or TFT-treated vests, conducted human-landing collections of released 100 laboratory-reared adult females of An. minimus from 18:00-00:00 h for 16 consecutive nights. Recaptured mosquitoes were given a blood meal for 30 min. with a membrane feeding system for assessment of blood feeding and fecundity. TFT-J, relative to control, significantly reduced human landings (Odds Ratio (OR) =0.27 (95% Confidence Interval (CI) [0.10-0.74], p = 0.011)), however no significant reduction was observed for TFT-C (OR=0.67 [95% CI 0.24-1.82], p = 0.43). Blood feeding was significantly lower among mosquitoes exposed to TFT-J (12.45% [95% CI, 2.04-22.85], p = 0.029) and TFT-C (13% [95% CI, 0.99-26.84], p = 0.016) relative to control. Impregnated fabrics had no effect on the mean number of egg oviposition. However, egg hatchability was reduced in TFT-J (49.5% [95% CI, 21.74-77.26], p = 0.029) and TFT-C (40.2% [95% CI, 17.21-63.19], p = 0.008) relative to control. TFT-J significantly reduced the landing, blood feeding, and fertility of An. minimus. Further studies are needed to evaluate different treatment methods on fabrics and their incorporation in integrated mosquito management.
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Affiliation(s)
- Chanly Yan
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
| | - Jeffrey Hii
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand; College of Public Health, Medical & Veterinary Sciences, James Cook University, North Queensland, QLD 4810, Australia
| | - Ratchadawan Ngoen-Klan
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
| | - Alex Ahebwa
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
| | - Manop Saeung
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
| | - Theeraphap Chareonviriyaphap
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand; Royal Society of Thailand, Thailand.
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9
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Understanding work-related travel and its relation to malaria occurrence in Thailand using geospatial maximum entropy modelling. Malar J 2023; 22:52. [PMID: 36782196 PMCID: PMC9924182 DOI: 10.1186/s12936-023-04478-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 02/01/2023] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND Estimating malaria risk associated with work locations and travel across a region provides local health officials with information useful to mitigate possible transmission paths of malaria as well as understand the risk of exposure for local populations. This study investigates malaria exposure risk by analysing the spatial pattern of malaria cases (primarily Plasmodium vivax) in Ubon Ratchathani and Sisaket provinces of Thailand, using an ecological niche model and machine learning to estimate the species distribution of P. vivax malaria and compare the resulting niche areas with occupation type, work locations, and work-related travel routes. METHODS A maximum entropy model was trained to estimate the distribution of P. vivax malaria for a period between January 2019 and April 2020, capturing estimated malaria occurrence for these provinces. A random simulation workflow was developed to make region-based case data usable for the machine learning approach. This workflow was used to generate a probability surface for the ecological niche regions. The resulting niche regions were analysed by occupation type, home and work locations, and work-related travel routes to determine the relationship between these variables and malaria occurrence. A one-way analysis of variance (ANOVA) test was used to understand the relationship between predicted malaria occurrence and occupation type. RESULTS The MaxEnt (full name) model indicated a higher occurrence of P. vivax malaria in forested areas especially along the Thailand-Cambodia border. The ANOVA results showed a statistically significant difference between average malaria risk values predicted from the ecological niche model for rubber plantation workers and farmers, the two main occupation groups in the study. The rubber plantation workers were found to be at higher risk of exposure to malaria than farmers in Ubon Ratchathani and Sisaket provinces of Thailand. CONCLUSION The results from this study point to occupation-related factors such as work location and the routes travelled to work, being risk factors in malaria occurrence and possible contributors to transmission among local populations.
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10
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Rerolle F, Dantzer E, Phimmakong T, Lover A, Hongvanthong B, Phetsouvanh R, Marshall J, Sturrock H, Bennett A. Characterizing mobility patterns of forest goers in southern Lao PDR using GPS loggers. Malar J 2023; 22:38. [PMID: 36732769 PMCID: PMC9893532 DOI: 10.1186/s12936-023-04468-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 01/24/2023] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND In the Greater Mekong Subregion (GMS), forest-going populations are considered high-risk populations for malaria and are increasingly targeted by national control programmes' elimination efforts. A better understanding of forest-going populations' mobility patterns and risk associated with specific types of forest-going trips is necessary for countries in the GMS to achieve their objective of eliminating malaria by 2030. METHODS Between March and November 2018, as part of a focal test and treat intervention (FTAT), 2,904 forest-goers were recruited in southern Lao PDR. A subset of forest-goers carried an "i-Got-U" GPS logger for roughly 2 months, configured to collect GPS coordinates every 15 to 30 min. The utilization distribution (UD) surface around each GPS trajectory was used to extract trips to the forest and forest-fringes. Trips with shared mobility characteristics in terms of duration, timing and forest penetration were identified by a hierarchical clustering algorithm. Then, clusters of trips with increased exposure to dominant malaria vectors in the region were further classified as high-risk. Finally, gradient boosting trees were used to assess which of the forest-goers' socio-demographic and behavioural characteristics best predicted their likelihood to engage in such high-risk trips. RESULTS A total of 122 forest-goers accepted carrying a GPS logger resulting in the collection of 803 trips to the forest or forest-fringes. Six clusters of trips emerged, helping to classify 385 (48%) trips with increased exposure to malaria vectors based on high forest penetration and whether the trip happened overnight. Age, outdoor sleeping structures and number of children were the best predictors of forest-goers' probability of engaging in high-risk trips. The probability of engaging in high-risk trips was high (~ 33%) in all strata of the forest-going population. CONCLUSION This study characterized the heterogeneity within the mobility patterns of forest-goers and attempted to further segment their role in malaria transmission in southern Lao People's Democratic Republic (PDR). National control programmes across the region can leverage these results to tailor their interventions and messaging to high-risk populations and accelerate malaria elimination.
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Affiliation(s)
- Francois Rerolle
- grid.266102.10000 0001 2297 6811Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, CA USA ,grid.266102.10000 0001 2297 6811Department of Epidemiology and Biostatistics, University of California, San Francisco, CA USA
| | - Emily Dantzer
- grid.266102.10000 0001 2297 6811Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, CA USA
| | - Toula Phimmakong
- grid.415768.90000 0004 8340 2282Center for Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Lao People’s Democratic Republic
| | - Andrew Lover
- grid.266683.f0000 0001 2166 5835Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA USA
| | - Bouasy Hongvanthong
- grid.415768.90000 0004 8340 2282Center for Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Lao People’s Democratic Republic
| | - Rattanaxay Phetsouvanh
- grid.415768.90000 0004 8340 2282Center for Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Lao People’s Democratic Republic
| | - John Marshall
- grid.47840.3f0000 0001 2181 7878Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA USA
| | - Hugh Sturrock
- grid.266102.10000 0001 2297 6811Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, CA USA ,grid.266102.10000 0001 2297 6811Department of Epidemiology and Biostatistics, University of California, San Francisco, CA USA
| | - Adam Bennett
- grid.266102.10000 0001 2297 6811Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, CA USA ,grid.266102.10000 0001 2297 6811Department of Epidemiology and Biostatistics, University of California, San Francisco, CA USA ,grid.415269.d0000 0000 8940 7771Malaria and Neglected Tropical Diseases, PATH, Seattle, WA USA
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11
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Rahim MAFA, Chuangchaiya S, Chanpum P, Palawong L, Kantee P, Dian ND, Lubis IND, Divis PCS, Kaneko A, Tetteh KKA, Idris ZM. Seroepidemiological surveillance, community perceptions and associated risk factors of malaria exposure among forest-goers in Northeastern Thailand. Front Cell Infect Microbiol 2022; 12:953585. [PMID: 36093204 PMCID: PMC9450859 DOI: 10.3389/fcimb.2022.953585] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/03/2022] [Indexed: 12/02/2022] Open
Abstract
Malaria remains a major public health challenge in Thailand. Continuous assessment and understanding of the behavior and perceptions related to malaria exposure in the high-risk group are necessary to achieve the elimination goal. This study aimed to investigate the parasite prevalence, seroprevalence rate, knowledge, attitudes, and practices (KAP), and malaria risk factors in rural communities living close to a forested area in the northeastern part of Thailand. A community-based cross-sectional survey was conducted in three forest-goer communities (i.e., Ban Khok, Ban Koh, and Dong Yang) located in Khamcha-i district, Mukdahan Province, Thailand, from July to August 2019. Demographic, socioeconomic information and KAP data were collected using a structured questionnaire. Parasite prevalence was determined by microscopy. Seroprevalence was determined via ELISA using two Plasmodium falciparum (PfAMA-1 and PfMSP-119) and two Plasmodium vivax (PvAMA-1 and PvMSP-119) antigens. Age-adjusted antibody responses were analyzed using a reversible catalytic model to calculate seroconversion rate (SCR). Malaria parasite was not detected in any of the 345 participants. The overall malaria seroprevalence was 72.2% for PfAMA-1, 18.8% for PfMSP-119, 32.5% for PvAMA-1, and 4.4% for PvMSP-119. The proportion of seroprevalence for P. falciparum and P. vivax antigens was significantly highest in Ban Koh (35.1%, P < 0.001) and Don Yang (18.8%, P < 0.001), respectively. For all parasite antigens except PvMSP-119, the proportion of seropositive individuals significantly increased with age (P < 0.001). Based on the SCRs, there was a higher level of P. falciparum transmission than P. vivax. Regarding KAP, almost all respondents showed adequate knowledge and awareness about malaria. Nevertheless, significant effort is needed to improve positive attitudes and practices concerning malaria prevention measures. Multivariate regression analyses showed that living in Ban Koh was associated with both P. falciparum (adjusted odds ratio [aOR] 12.87, P < 0.001) and P. vivax (aOR 9.78, P < 0.001) seropositivities. We also found significant associations between age and seropositivity against P. falciparum and P. vivax antigens. The data suggest that seroepidemiological surveillance using AMA-1 and MSP-119 antigens may provide further evidence to reconstruct malaria exposure history. The absence of weak evidence of recent malaria transmission in Mukdahan Province is promising in the context of the disease elimination program.
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Affiliation(s)
- Mohd Amirul Fitri A. Rahim
- Deparment of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Sriwipa Chuangchaiya
- Faculty of Public Health, Kasetsart University, Chalermphrakiat Sakon Nakhon Province Campus, Sakon Nakhon, Thailand
- *Correspondence: Zulkarnain Md Idris, ; Sriwipa Chuangchaiya,
| | - Paisit Chanpum
- Vector Borne Disease Unit, Ban Koh Sub-District Health Promoting Hospital, Mukdahan, Thailand
| | - Laun Palawong
- Vector Borne Disease Unit, Ban Koh Sub-District Health Promoting Hospital, Mukdahan, Thailand
| | - Panuwat Kantee
- Vector Borne Disease Unit, Ban Koh Sub-District Health Promoting Hospital, Mukdahan, Thailand
| | - Nor Diyana Dian
- Deparment of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Inke Nadia D. Lubis
- Department of Paediatric, Faculty of Medicine, Universitas Sumatera Utara, Medan, Indonesia
| | - Paul C. S. Divis
- Malaria Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia
| | - Akira Kaneko
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Department of Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | - Kevin K. A. Tetteh
- Department of Infection Biology, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Zulkarnain Md Idris
- Deparment of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
- *Correspondence: Zulkarnain Md Idris, ; Sriwipa Chuangchaiya,
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12
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Jongdeepaisal M, Khonputsa P, Prasert O, Maneenet S, Pongsoipetch K, Jatapai A, Rotejanaprasert C, Sudathip P, Maude RJ, Pell C. Forest malaria and prospects for anti-malarial chemoprophylaxis among forest goers: findings from a qualitative study in Thailand. Malar J 2022; 21:47. [PMID: 35164759 PMCID: PMC8845363 DOI: 10.1186/s12936-022-04070-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/30/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Across the Greater Mekong Subregion, malaria remains a dangerous infectious disease, particularly for people who visit forested areas where residual transmission continues. Because vector control measures offer incomplete protection to forest goers, chemoprophylaxis has been suggested as a potential supplementary measure for malaria prevention and control. To implement prophylaxis effectively, additional information is needed to understand forest goers' activities and their willingness to use malaria prevention measures, including prophylaxis, and how it could be delivered in communities. Drawing on in-depth interviews with forest goers and stakeholders, this article examines the potential acceptability and implementation challenges of malaria prophylaxis for forest goers in northeast Thailand. METHODS In-depth interviews were conducted with forest goers (n = 11) and stakeholders (n = 16) including healthcare workers, community leaders, and policymakers. Interviews were audio-recorded, transcribed and coded using NVivo, employing an inductive and deductive approach, for thematic analysis. RESULTS Forest goers were well aware of their (elevated) malaria risk and reported seeking care for malaria from local health care providers. Forest goers and community members have a close relationship with the forest but are not a homogenous group: their place and time-at-risk varied according to their activities and length of stay in the forest. Among stakeholders, the choice and cost of anti-malarial prophylactic regimen-its efficacy, length and complexity, number of tablets, potential side effects, and long-term impact on users-were key considerations for its feasibility. They also expressed concern about adherence to the preventive therapy and potential difficulty treating malaria patients with the same regimen. Prophylaxis was considered a low priority in areas with perceived accessible health system and approaching malaria elimination. CONCLUSIONS In the context of multi-drug resistance, there are several considerations for implementing malaria prophylaxis: the need to target forest goers who are at-risk with a clear period of exposure, to ensure continued use of vector control measures and adherence to prophylactic anti-malarials, and to adopt an evidence-based approach to determine an appropriate regimen. Beyond addressing current intervention challenges and managing malaria incidence in low-transmission setting, it is crucial to keep malaria services available and accessible at the village level especially in areas home to highly mobile populations.
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Affiliation(s)
- Monnaphat Jongdeepaisal
- 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
| | - Panarasri Khonputsa
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Orathai Prasert
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Suphitsara Maneenet
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kulchada Pongsoipetch
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Anchalee Jatapai
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chawarat Rotejanaprasert
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Prayuth Sudathip
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | - Richard J 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 TH Chan School of Public Health, Harvard University, Boston, USA.
- The Open University, Milton Keynes, UK.
| | - Christopher Pell
- Amsterdam Institute for Global Health and Development (AIGHD), Amsterdam, The Netherlands
- Department of Global Health, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Centre for Social Science and Global Health, University of Amsterdam, Amsterdam, The Netherlands
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13
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Nguyen TT, Gryseels C, Tran DT, Smekens T, Gerrets R, Nguyen XX, Peeters Grietens K. Understanding Malaria Persistence: A Mixed-Methods Study on the Effectiveness of Malaria Elimination Strategies in South-Central Vietnam. Front Public Health 2021; 9:742378. [PMID: 34950624 PMCID: PMC8688690 DOI: 10.3389/fpubh.2021.742378] [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: 11/02/2021] [Indexed: 11/17/2022] Open
Abstract
Despite the scale-up of vector control, diagnosis and treatment, and health information campaigns, malaria persists in the forested areas of South-Central Vietnam, home to ethnic minority populations. A mixed-methods study using an exploratory sequential design was conducted in 10 Ra-glai villages in Bac Ai district of Ninh Thuan province to examine which social factors limited the effectiveness of the national malaria elimination strategy in the local setting. Territorial arrangements and mobility were found to directly limit the effectiveness of indoor residual spraying and long-lasting insectidical treated nets (LLINs). Households (n=410) were resettled in the “new villages” by the government, where they received brick houses (87.1%) and sufficient LLINs (97.3%). However, 97.6% of households went back to their “old villages” to continue slash-and-burn agriculture. In the old village, 48.5% of households lived in open-structured plot huts and only 5.7% of them had sufficient LLIN coverage. Household representatives believed malaria could be cured with antimalarials (57.8%), but also perceived non-malarial medicines, rituals, and vitamin supplements to be effective against malaria. Household members (n = 1,957) used public health services for their most recent illness (62.9%), but also reported to buy low-cost medicines from the private sector to treat fevers and discomfort as these were perceived to be the most cost-effective treatment option for slash-and-burn farmers. The study shows the relevance of understanding social factors to improve the uptake of public health interventions and calls for contextually adapted strategies for malaria elimination in ethnic minority populations in Vietnam and similar settings.
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Affiliation(s)
- Thuan Thi Nguyen
- Department of Malaria Epidemiology, National Institute of Malariology, Parasitology and Entomology (NIMPE), Hanoi, Vietnam.,Unit of Socio-Ecological Health Research, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.,Faculty of Social and Behavioural Sciences, Amsterdam Institute for Social Science Research (AISSR), University of Amsterdam, Amsterdam, Netherlands
| | - Charlotte Gryseels
- Unit of Socio-Ecological Health Research, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Duong Thanh Tran
- Department of Malaria Epidemiology, National Institute of Malariology, Parasitology and Entomology (NIMPE), Hanoi, Vietnam
| | - Tom Smekens
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - René Gerrets
- Faculty of Social and Behavioural Sciences, Amsterdam Institute for Social Science Research (AISSR), University of Amsterdam, Amsterdam, Netherlands.,Amsterdam Institute for Global Health and Development (AIGHD), Amsterdam, Netherlands
| | - Xa Xuan Nguyen
- Department of Malaria Epidemiology, National Institute of Malariology, Parasitology and Entomology (NIMPE), Hanoi, Vietnam
| | - Koen Peeters Grietens
- Unit of Socio-Ecological Health Research, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.,School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
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14
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The use of respondent‑driven sampling to assess febrile illness treatment-seeking behaviours among forest-goers in Cambodia and Vietnam. Malar J 2021; 20:477. [PMID: 34930264 PMCID: PMC8686608 DOI: 10.1186/s12936-021-04001-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 12/01/2021] [Indexed: 12/01/2022] Open
Abstract
Background Countries in the Greater Mekong sub-region (GMS) aim to eliminate all forms of malaria by 2030. In Cambodia and Vietnam, forest-goers are at an increased risk of malaria. Universal access to prompt diagnosis and treatment is a core malaria intervention. This can only be achieved by understanding the healthcare-seeking behaviour among the most vulnerable groups and eliminating barriers to prompt and effective treatment. This study aimed to explore healthcare-seeking behaviours for febrile illness among populations at risk for malaria in Cambodia and Vietnam. Methods In 2019, researchers from Population Services International (PSI) conducted a population-based survey of forest-goers in Cambodia and Vietnam using respondent-driven sampling (RDS) In Cambodia two operational districts, Oral and Phnom Srouch in Kampong Speu Province were included in the study. In Vietnam, communes located within 15 km of the forest edge in Binh Phuoc and Gia Lai Provinces were selected. Adults who had spent at least one night per week or four nights per month in the forest over the previous three months were eligible for the study. Results Some 75% of forest-goers in Cambodia and 65% in Vietnam sought treatment for illness outside the home. In Cambodia, 39% sought treatment from the private sector, 32% from community health workers, and 24% from public health facilities. In Vietnam, 62% sought care from community facilities, 29.3% from the private sector, and 6.9% went to a public facility. Among forest-goers who sought care, 33% in Cambodia and 52% in Vietnam did so within 24 h. Conclusions This study is consistent with others that show that early diagnosis and treatment of malaria remains an obstacle to malaria elimination. This study also demonstrates that there are gaps in timeliness of care seeking among forest-goers. The findings from this study around provider preference and delays in treatment-seeking can be used to strengthen the design and targeting of malaria interventions and social and behaviour change strategies to accelerate malaria elimination in Cambodia and Vietnam. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-04001-9.
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15
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Jongdeepaisal M, Ean M, Heng C, Buntau T, Tripura R, Callery JJ, Peto TJ, Conradis-Jansen F, von Seidlein L, Khonputsa P, Pongsoipetch K, Soviet U, Sovannaroth S, Pell C, Maude RJ. Acceptability and feasibility of malaria prophylaxis for forest goers: findings from a qualitative study in Cambodia. Malar J 2021; 20:446. [PMID: 34823527 PMCID: PMC8613728 DOI: 10.1186/s12936-021-03983-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/12/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND In the Greater Mekong Subregion, adults are at highest risk for malaria, particularly those who visit forests. The absence of effective vector control strategies and limited periods of exposure during forest visits suggest that chemoprophylaxis could be an appropriate strategy to protect forest goers against malaria. METHODS Alongside a clinical trial of anti-malarial chemoprophylaxis in northern Cambodia, qualitative research was conducted, including in-depth interviews and observation, to explore the acceptability of malaria prophylaxis for forest goers, the implementation opportunities, and challenges of this strategy. RESULTS Prophylaxis with artemether-lumefantrine for forest goers was found to be acceptable under trial conditions. Three factors played a major role: the community's awareness and perception of the effectiveness of prophylaxis, their trust in the provider, and malaria as a local health concern. The findings highlight how uptake and adherence to prophylaxis are influenced by the perceived balance between benefits and burden of anti-malarials which are modulated by the seasonality of forest visits and its influence on malaria risk. CONCLUSIONS The implementation of anti-malarial prophylaxis needs to consider how the preventive medication can be incorporated into existing vector-control measures, malaria testing and treatment services. The next step in the roll out of anti-malarial prophylaxis for forest visitors will require support from local health workers.
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Affiliation(s)
- Monnaphat Jongdeepaisal
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mom Ean
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chhoeun Heng
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Thoek Buntau
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Rupam Tripura
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - James J. Callery
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Thomas J. Peto
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Franca Conradis-Jansen
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Lorenz von Seidlein
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Panarasri Khonputsa
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kulchada Pongsoipetch
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Ung Soviet
- Provincial Health Department, Stung Treng, Stung Treng Cambodia
| | - Siv Sovannaroth
- grid.452707.3National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Christopher Pell
- grid.450091.90000 0004 4655 0462Amsterdam Institute for Global Health and Development (AIGHD), Amsterdam, The Netherlands ,grid.509540.d0000 0004 6880 3010Department of Global Health, Amsterdam University Medical Centers - Location Academic Medical Center, Amsterdam, The Netherlands ,grid.7177.60000000084992262Centre for Social Science and Global Health, University of Amsterdam, Amsterdam, The Netherlands
| | - Richard J. Maude
- grid.501272.30000 0004 5936 4917Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK ,grid.38142.3c000000041936754XHarvard TH Chan School of Public Health, Harvard University, Boston, USA ,grid.10837.3d0000000096069301The Open University, Milton Keynes, UK
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16
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Masunaga Y, Muela Ribera J, Nguyen TT, Tesfazghi K, Peeters Grietens K. In search of the last malaria cases: ethnographic methods for community and private-sector engagement in malaria elimination in Vietnam, Laos, and Cambodia. Malar J 2021; 20:370. [PMID: 34535133 PMCID: PMC8447739 DOI: 10.1186/s12936-021-03903-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 09/02/2021] [Indexed: 08/21/2023] Open
Abstract
Background Despite significant strides made in reducing malaria morbidity and mortality in the Greater Mekong Subregion, malaria transmission continues amongst the most ‘hard-to-reach’, such as forest-goers and mobile and migrant populations, who face access obstacles to malaria diagnosis and treatment. As such, regional malaria elimination strategies endeavour to incorporate the private sector and local communities in improving surveillance and detection of the last malaria cases in remote forested areas. The question remains, however, whether such strategies can reach these hard-to-reach populations and effectively reduce their disproportionate burden of malaria. This paper evaluates the strategy of community and private sector engagement in a malaria elimination project in Vietnam, Laos, and Cambodia. Methods Ethnographic research, incorporating in-depth interviews, participant observations with informal discussions, and group discussions were conducted in Bu Gia Map commune, Binh Phuc province of Vietnam; in Phouvong district, Attapeu province of Laos; and, in nine newly established and informal communities in the provinces of Mondul Kiri, Steung Treng, Kratie, Kampong Thom, and Prah Vihear of Cambodia. Results Different types of factors limited or enhanced the effectiveness of the participatory approaches in the different settings. In Vietnam, inter-ethnic tensions and sensitivity around forest-work negatively affected local population’s health-seeking behaviour and consequent uptake of malaria testing and treatment. In Laos, the location of the project collaborative pharmacies in the district-centre were a mismatch for reaching hard-to-reach populations in remote villages. In Cambodia, the strategy of recruiting community malaria-workers, elected by the community members, did manage to reach the remote forested areas where people visited or stayed. Conclusions ‘Hard-to-reach’ populations remain hard to reach without proper research identifying the socio-economic-political environment and the key dynamics determining uptake in involved communities and populations. Solid implementation research with a strong ethnographic component is required to tailor malaria elimination strategies to local contexts.
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Affiliation(s)
- Yoriko Masunaga
- Socio-Ecological Health Research Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium. .,Faculty of Social and Behavioural Science, Department of Sociology and Anthropology, University of Amsterdam, Amsterdam, The Netherlands.
| | - Joan Muela Ribera
- PASS Suisse, Neuchâtel, Switzerland.,Universitat Rovira i Virgili, Tarragona, Spain
| | - Thuan Thi Nguyen
- Socio-Ecological Health Research Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.,Faculty of Social and Behavioural Science, Department of Sociology and Anthropology, University of Amsterdam, Amsterdam, The Netherlands.,National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
| | | | - Koen Peeters Grietens
- Socio-Ecological Health Research Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.,School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
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17
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Population size estimation of seasonal forest-going populations in southern Lao PDR. Sci Rep 2021; 11:14816. [PMID: 34285321 PMCID: PMC8292394 DOI: 10.1038/s41598-021-94413-z] [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: 03/24/2021] [Accepted: 06/02/2021] [Indexed: 11/09/2022] Open
Abstract
Forest-going populations are key to malaria transmission in the Greater Mekong Sub-region (GMS) and are therefore targeted for elimination efforts. Estimating the size of this population is essential for programs to assess, track and achieve their elimination goals. Leveraging data from three cross-sectional household surveys and one survey among forest-goers, the size of this high-risk population in a southern province of Lao PDR between December 2017 and November 2018 was estimated by two methods: population-based household surveys and capture-recapture. During the first month of the dry season, the first month of the rainy season, and the last month of the rainy season, respectively, 16.2% [14.7; 17.7], 9.3% [7.2; 11.3], and 5.3% [4.4; 6.1] of the adult population were estimated to have engaged in forest-going activities. The capture-recapture method estimated a total population size of 18,426 [16,529; 20,669] forest-goers, meaning 61.0% [54.2; 67.9] of the adult population had engaged in forest-going activities over the 12-month study period. This study demonstrates two methods for population size estimation to inform malaria research and programming. The seasonality and turnover within this forest-going population provide unique opportunities and challenges for control programs across the GMS as they work towards malaria elimination.
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18
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Rerolle F, Dantzer E, Lover AA, Marshall JM, Hongvanthong B, Sturrock HJ, Bennett A. Spatio-temporal associations between deforestation and malaria incidence in Lao PDR. eLife 2021; 10:56974. [PMID: 33686939 PMCID: PMC8024023 DOI: 10.7554/elife.56974] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 02/19/2021] [Indexed: 11/13/2022] Open
Abstract
As countries in the Greater Mekong Sub-region (GMS) increasingly focus their malaria control and elimination efforts on reducing forest-related transmission, greater understanding of the relationship between deforestation and malaria incidence will be essential for programs to assess and meet their 2030 elimination goals. Leveraging village-level health facility surveillance data and forest cover data in a spatio-temporal modeling framework, we found evidence that deforestation is associated with short-term increases, but long-term decreases confirmed malaria case incidence in Lao People’s Democratic Republic (Lao PDR). We identified strong associations with deforestation measured within 30 km of villages but not with deforestation in the near (10 km) and immediate (1 km) vicinity. Results appear driven by deforestation in densely forested areas and were more pronounced for infections with Plasmodium falciparum (P. falciparum) than for Plasmodium vivax (P. vivax). These findings highlight the influence of forest activities on malaria transmission in the GMS. Biting mosquitos spread the malaria parasite to humans. Along the Mekong River in Southeast Asia, spending time in the surrounding forest increases a person's risk of malaria. This has led to a debate about whether deforestation in this area, which is called the Greater Mekong Sub-region (GMS), will increase or decrease malaria transmission. The answer to the debate is not clear because some malaria-transmitting mosquitos thrive in heavily forested areas, in particular in the GMS, while others prefer less forested areas. Scientists studying malaria in the Amazon in South America suspect that malaria transmission increases shortly after deforestation but decreases six to eight years later. Some studies have tested this ‘frontier malaria’ theory but the results have been conflicting. Fewer studies have tested this theory in Southeast Asia. But deforestation has been blamed for recent malaria outbreaks in the GMS. Using data on malaria testing and forest cover in the GMS, Rerolle et al. show that deforestation around villages increases malaria transmission in the first two years and decreases malaria rates later. This trend was driven mostly by a type of malaria called Plasmodium falciparum and was less strong for Plasmodium vivax. The location of deforested areas also mattered. Deforestation within one to 10 kilometer of villages did not affect malaria rates. Deforestation further away in about a 30 kilometer radius did affect malaria transmission. Rerolle et al. suggest this may be because villagers have to spend longer times trekking through forests to hunt or harvest wood when the wider area is deforested. Currently, National Malaria Control Programs in the GMS focus their efforts on reducing forest-related transmission. This study strengthens the evidence supporting this approach. The results also suggest that different malaria elimination strategies may be necessary for different types of malaria parasite. Using this new information could help malaria control programs better target resources or educate villagers on how to protect themselves. The innovative methods used by Rerolle et al. reveal a more complex role of deforestation in malaria transmission and may inspire other scientists to think more carefully about environmental drivers of malaria.
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Affiliation(s)
- Francois Rerolle
- Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, San Francisco, United States.,Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, United States
| | - Emily Dantzer
- Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, San Francisco, United States
| | - Andrew A Lover
- Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, United States
| | - John M Marshall
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, United States
| | - Bouasy Hongvanthong
- Center for Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | - Hugh Jw Sturrock
- Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, San Francisco, United States.,Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, United States
| | - Adam Bennett
- Malaria Elimination Initiative, The Global Health Group, University of California, San Francisco, San Francisco, United States.,Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, United States
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19
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Stratil AS, Vernaeve L, Lopes S, Bourny Y, Mannion K, Hamade P, Roca-Feltrer A, Tibenderana JK, Sovannaroth S, Debackere M. Eliminating Plasmodium falciparum malaria: results from tailoring active case detection approaches to remote populations in forested border areas in north-eastern Cambodia. Malar J 2021; 20:108. [PMID: 33618718 PMCID: PMC7898252 DOI: 10.1186/s12936-021-03622-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 02/04/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Remaining Plasmodium falciparum cases in Cambodia are concentrated in forested border areas and in remote populations who are hard to reach through passive case detection. A key approach to reach these populations is active case detection by mobile malaria workers (MMWs). However, this is operationally challenging because of changing movement patterns of the target population moving into less accessible areas. From January 2018 to December 2020, a tailored package of active case detection approaches was implemented in forested border areas of three provinces in north-eastern Cambodia to reach remote populations and support the elimination of falciparum malaria. METHODS Key elements of this project were to tailor approaches to local populations, use responsive monitoring systems, maintain operational flexibility, build strong relationships with local communities, and implement close supervision practices. MMWs were recruited from local communities. Proactive case detection approaches included mobile malaria posts positioned at frequented locations around and within forests, and locally informed outreach activities targeting more remote locations. Reactive case detection was conducted among co-travellers of confirmed cases. Testing for malaria was conducted independent of fever symptoms. Routine monitoring of programmatic data informed tactical adaptations, while supervision exercises ensured service quality. RESULTS Despite operational challenges, service delivery sites were able to maintain consistently high testing rates throughout the implementation period, with each of 45 sites testing a monthly average of 64 (SD 6) people in 2020. In 2020, project MMWs detected only 32 P. falciparum cases. Over the project period, the P. falciparum/P. vivax ratio steadily inversed. Including data from neighbouring health centres and village malaria workers, 45% (80,988/180,732) of all people tested and 39% (1280/3243) of P. falciparum cases detected in the area can be attributed to project MMWs. Remaining challenges of the last elimination phase include maintaining intensified elimination efforts, addressing the issue of detecting low parasitaemia cases and shifting focus to P. vivax malaria. CONCLUSIONS Reaching remote populations through active case detection should remain a key strategy to eliminate P. falciparum malaria. This case study presented a successful approach combining tailored proactive and reactive strategies that could be transferred to similar settings in other areas of the Greater Mekong Subregion.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control (CNM), Phnom Penh, Cambodia
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20
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Malaria in Cambodia: A Retrospective Analysis of a Changing Epidemiology 2006-2019. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18041960. [PMID: 33670471 PMCID: PMC7922556 DOI: 10.3390/ijerph18041960] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/22/2021] [Accepted: 02/12/2021] [Indexed: 11/17/2022]
Abstract
Background: In Cambodia, malaria persists with changing epidemiology and resistance to antimalarials. This study aimed to describe how malaria has evolved spatially from 2006 to 2019 in Cambodia. Methods: We undertook a secondary analysis of existing malaria data from all government healthcare facilities in Cambodia. The epidemiology of malaria was described by sex, age, seasonality, and species. Spatial clusters at the district level were identified with a Poisson model. Results: Overall, incidence decreased from 7.4 cases/1000 population in 2006 to 1.9 in 2019. The decrease has been drastic for females, from 6.7 to 0.6/1000. Adults aged 15–49 years had the highest malaria incidence among all age groups. The proportion of Plasmodium (P.) falciparum + Mixed among confirmed cases declined from 87.9% (n = 67,489) in 2006 to 16.6% (n = 5290) in 2019. Clusters of P. falciparum + Mixed and P. vivax + Mixed were detected in forested provinces along all national borders. Conclusions: There has been a noted decrease in P. falciparum cases in 2019, suggesting that an intensification plan should be maintained. A decline in P. vivax cases was also noted, although less pronounced. Interventions aimed at preventing new infections of P. vivax and relapses should be prioritized. All detected malaria cases should be captured by the national surveillance system to avoid misleading trends.
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21
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Choosing interventions to eliminate forest malaria: preliminary results of two operational research studies inside Cambodian forests. Malar J 2021; 20:51. [PMID: 33472630 PMCID: PMC7818569 DOI: 10.1186/s12936-020-03572-3] [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] [Received: 10/19/2020] [Accepted: 12/24/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Rapid elimination of Plasmodium falciparum malaria in Cambodia is a goal with both national and international significance. Transmission of malaria in Cambodia is limited to forest environments, and the main population at risk consists of forest-goers who rely on forest products for income or sustenance. The ideal interventions to eliminate malaria from this population are unknown. METHODS In two forested regions of Cambodia, forest-goers were trained to become forest malaria workers (FMWs). In one region, FMWs performed mass screening and treatment, focal screening and treatment, and passive case detection inside the forest. In the other region, FMWs played an observational role for the first year, to inform the choice of intervention for the second year. In both forests, FMWs collected blood samples and questionnaire data from all forest-goers they encountered. Mosquito collections were performed in each forest. RESULTS Malaria prevalence by PCR was high in the forest, with 2.3-5.0% positive for P. falciparum and 14.6-25.0% positive for Plasmodium vivax among forest-goers in each study site. In vectors, malaria prevalence ranged from 2.1% to 9.6%, but no P. falciparum was observed. Results showed poor performance of mass screening and treatment, with sensitivity of rapid diagnostic tests equal to 9.1% (95% CI 1.1%, 29.2%) for P. falciparum and 4.4% (95% CI 1.6%, 9.2%) for P. vivax. Malaria infections were observed in all demographics and throughout the studied forests, with no clear risk factors emerging. CONCLUSIONS Malaria prevalence remains high among Cambodian forest-goers, but performance of rapid diagnostic tests is poor. More adapted strategies to this population, such as intermittent preventive treatment of forest goers, should be considered.
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22
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Reyes RA, Fornace KM, Macalinao MLM, Boncayao BL, De La Fuente ES, Sabanal HM, Bareng APN, Medado IAP, Mercado ES, Baquilod MS, Luchavez JS, Hafalla JCR, Drakeley CJ, Espino FEJ. Enhanced Health Facility Surveys to Support Malaria Control and Elimination across Different Transmission Settings in the Philippines. Am J Trop Med Hyg 2021; 104:968-978. [PMID: 33534761 PMCID: PMC7941801 DOI: 10.4269/ajtmh.20-0814] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/15/2020] [Indexed: 12/12/2022] Open
Abstract
Following substantial progress in malaria control in the Philippines, new surveillance approaches are needed to identify and target residual malaria transmission. This study evaluated an enhanced surveillance approach using rolling cross-sectional surveys of all health facility attendees augmented with molecular diagnostics and geolocation. Facility surveys were carried out in three sites representing different transmission intensities: Morong, Bataan (pre-elimination), Abra de Ilog, Occidental Mindoro (stable medium risk), and Rizal, Palawan (high risk, control). Only one rapid diagnostic test (RDT)–positive infection and no PCR confirmed infections were found in Bataan and Occidental Mindoro, suggesting the absence of transmission. In Palawan, the inclusion of all health facility attendees, regardless of symptoms, and use of molecular diagnostics identified 313 infected individuals in addition to 300 cases identified by routine screening of febrile patients with the RDT or microscopy. Of these, the majority (313/613) were subpatent infections and only detected using molecular methods. Simultaneous collection of GPS coordinates on tablet-based applications allowed real-time mapping of malaria infections. Risk factor analysis showed higher risks in children and indigenous groups, with bed net use having a protective effect. Subpatent infections were more common in men and older age-groups. Overall, malaria risks were not associated with participants’ classification, and some of the non-patient clinic attendees reported febrile illnesses (1.9%, 26/1,369), despite not seeking treatment, highlighting the widespread distribution of infection in communities. Together, these data illustrate the utility of health facility–based surveys to augment surveillance data to increase the probability of detecting infections in the wider community.
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Affiliation(s)
- Ralph A Reyes
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Kimberly M Fornace
- 2Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Beaulah L Boncayao
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Ellaine S De La Fuente
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Hennessey M Sabanal
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Alison Paolo N Bareng
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Inez Andrea P Medado
- 3Molecular Biology Laboratory, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Edelwisa S Mercado
- 3Molecular Biology Laboratory, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Mario S Baquilod
- 4Department of Health, MIMAROPA Center for Health Development, Quirino Memorial Medical Center Compound, Quezon, Philippines
| | - Jennifer S Luchavez
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Julius Clemence R Hafalla
- 2Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris J Drakeley
- 2Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Fe Esperanza J Espino
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
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23
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Nguyen TT, Nguyen XX, Ronse M, Nguyen QT, Ho PQ, Tran DT, Gerrets R, Thriemer K, Ley B, Marfurt J, Price RN, Grietens KP, Gryseels C. Diagnostic Practices and Treatment for P. vivax in the InterEthnic Therapeutic Encounter of South-Central Vietnam: A Mixed-Methods Study. Pathogens 2020; 10:pathogens10010026. [PMID: 33396538 PMCID: PMC7824694 DOI: 10.3390/pathogens10010026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/25/2020] [Accepted: 12/28/2020] [Indexed: 01/13/2023] Open
Abstract
Malaria elimination in the Greater Mekong Sub-Region is challenged by a rising proportion of malaria attributable to P. vivax. Primaquine (PQ) is effective in eliminating the parasite's dormant liver stages and can prevent relapsing infections, but it induces severe haemolysis in patients with Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, highlighting the importance of testing enzyme activity prior to treatment. A mixed-method study was conducted in south-central Vietnam to explore the factors that affect acceptability of G6PD testing, treatment-seeking behaviors, and adherence to current regimens. The majority of respondents (75.7%) were unaware of the different parasite species and rather differentiated malaria by perceived severity. People sought a diagnosis if suspected of malaria fever but not if they perceived their fevers as mild. Most respondents agreed to take prescribed medication to treat asymptomatic infection (94.1%) and to continue medication even if they felt better (91.5%). Health professionals did not have G6PD diagnostic tools nor the means to prescribe PQ safely. Adherence to treatment was linked to trust in public providers, who were perceived to make therapeutic decisions in the interest of the patient. Greater focus on providing acceptable ways of assessing G6PD deficiency will be needed to ensure the timely elimination of malaria in Vietnam.
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Affiliation(s)
- Thuan Thi Nguyen
- National Institute of Malariology, Parasitology and Entomology (NIMPE), 34 Trung Van, Trung Van Ward, Nam Tu Liem District, Hanoi 10000, Vietnam; (X.X.N.); (Q.T.N.); (P.Q.H.); (D.T.T.)
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium; (M.R.); (K.P.G.); (C.G.)
- Correspondence: ; Tel.: +324-9679-1347
| | - Xa Xuan Nguyen
- National Institute of Malariology, Parasitology and Entomology (NIMPE), 34 Trung Van, Trung Van Ward, Nam Tu Liem District, Hanoi 10000, Vietnam; (X.X.N.); (Q.T.N.); (P.Q.H.); (D.T.T.)
| | - Maya Ronse
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium; (M.R.); (K.P.G.); (C.G.)
| | - Quynh Truc Nguyen
- National Institute of Malariology, Parasitology and Entomology (NIMPE), 34 Trung Van, Trung Van Ward, Nam Tu Liem District, Hanoi 10000, Vietnam; (X.X.N.); (Q.T.N.); (P.Q.H.); (D.T.T.)
| | - Phuc Quang Ho
- National Institute of Malariology, Parasitology and Entomology (NIMPE), 34 Trung Van, Trung Van Ward, Nam Tu Liem District, Hanoi 10000, Vietnam; (X.X.N.); (Q.T.N.); (P.Q.H.); (D.T.T.)
| | - Duong Thanh Tran
- National Institute of Malariology, Parasitology and Entomology (NIMPE), 34 Trung Van, Trung Van Ward, Nam Tu Liem District, Hanoi 10000, Vietnam; (X.X.N.); (Q.T.N.); (P.Q.H.); (D.T.T.)
| | - Rene Gerrets
- Amsterdam Institute for Social Science Research (AISSR), University of Amsterdam, Postbus 15718, 1001 NE Amsterdam, The Netherlands;
- Amsterdam Institute for Global Health and Development (AIGHD), AHTC, Tower C4, Paasheuvelweg 25, 1105 BP Amsterdam, The Netherlands
| | - Kamala Thriemer
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Rocklands Drive Casuarina, Darwin Northern Territory 0810, Australia; (K.T.); (B.L.); (J.M.); (R.N.P.)
| | - Benedikt Ley
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Rocklands Drive Casuarina, Darwin Northern Territory 0810, Australia; (K.T.); (B.L.); (J.M.); (R.N.P.)
| | - Jutta Marfurt
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Rocklands Drive Casuarina, Darwin Northern Territory 0810, Australia; (K.T.); (B.L.); (J.M.); (R.N.P.)
| | - Ric N. Price
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Rocklands Drive Casuarina, Darwin Northern Territory 0810, Australia; (K.T.); (B.L.); (J.M.); (R.N.P.)
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7LG, UK
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Koen Peeters Grietens
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium; (M.R.); (K.P.G.); (C.G.)
| | - Charlotte Gryseels
- Medical Anthropology Unit, Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium; (M.R.); (K.P.G.); (C.G.)
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24
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Yeung S, McGregor D, James N, Kheang ST, Kim S, Khim N, Ly P, Sovannaroth S, Witkowski B. Performance of Ultrasensitive Rapid Diagnostic Tests for Detecting Asymptomatic Plasmodium falciparum. Am J Trop Med Hyg 2020; 102:307-309. [PMID: 31820711 PMCID: PMC7008342 DOI: 10.4269/ajtmh.19-0349] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Proposed interventions for eliminating drug-resistant Plasmodium falciparum malaria include the targeting of asymptomatic carriers through screening and treatment. We report on the diagnostic performance of the recently developed ultrasensitive rapid diagnostic test (uRDT) compared with screening with conventional RDTs (cRDT) and polymerase chain reaction (PCR) under field conditions in Cambodia in a total of 2,729 individuals. The P. falciparum positivity by quantitative PCR (qPCR) was 3.8% (26/678) in those screened during active case detection and 0.5% (10/2,051) in the cross-sectional survey. Compared with qPCR, the sensitivity of the uRDTs was 53.8% (95% CI: 33.4–73.4%) when used in active case detection and 60.0% (95% CI: 26.2–87.8%) in the cross-sectional survey. The uRDTs did not show a significant improvement in diagnostic performance over cRDTs when used for active case detection and for a malaria prevalence survey in the context of this low-transmission setting.
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Affiliation(s)
- Shunmay Yeung
- Clinical Research Department, Faculty of Infectious and Tropical Disease, Malaria Centre, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David McGregor
- Clinical Research Department, Faculty of Infectious and Tropical Disease, Malaria Centre, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Nicola James
- Clinical Research Department, Faculty of Infectious and Tropical Disease, Malaria Centre, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Soy Ty Kheang
- Health and Social Development (HSD), Phnom Penh, Cambodia
| | - Saorin Kim
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Nimol Khim
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Po Ly
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
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25
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Lek D, Callery JJ, Nguon C, Debackere M, Sovannaroth S, Tripura R, Wojnarski M, Piola P, Khean ST, Manion K, Nguon S, Kunkel A, Vernaeve L, Peto TJ, Dantzer E, Davoeung C, Etienne W, Dondorp AM, Tuseo L, von Seidlein L, Guintran JO. Tools to accelerate falciparum malaria elimination in Cambodia: a meeting report. Malar J 2020; 19:151. [PMID: 32293452 PMCID: PMC7161105 DOI: 10.1186/s12936-020-03197-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 03/20/2020] [Indexed: 02/06/2023] Open
Abstract
Cambodia targets malaria elimination by 2025. Rapid elimination will depend on successfully identifying and clearing malaria foci linked to forests. Expanding and maintaining universal access to early diagnosis and effective treatment remains the key to malaria control and ultimately malaria elimination in the Greater Mekong Subregion (GMS) in the foreseeable future. Mass Drug Administration (MDA) holds some promise in the rapid reduction of Plasmodium falciparum infections, but requires considerable investment of resources and time to mobilize the target communities. Furthermore, the most practical drug regimen for MDA in the GMS—three rounds of DHA/piperaquine—has lost some of its efficacy. Mass screening and treatment benefits asymptomatic P. falciparum carriers by clearing chronic infections, but in its current form holds little promise for malaria elimination. Hopes that “highly sensitive” diagnostic tests would provide substantial advances in screen and treat programmes have been shown to be misplaced. To reduce the burden on P. falciparum and Plasmodium vivax infections in people working in forested areas novel approaches to the use of malaria prophylaxis in forest workers should be explored. During an October 2019 workshop in Phnom Penh researchers and policymakers reviewed evidence of acceptability, feasibility and effectiveness of interventions to target malaria foci and interrupt P. falciparum transmission and discussed operational requirements and conditions for programmatic implementation.
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Affiliation(s)
- Dysoley Lek
- Centre for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - James J Callery
- Mahidol-Oxford University Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Chea Nguon
- Centre for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | | | - Siv Sovannaroth
- Centre for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Rupam Tripura
- Mahidol-Oxford University Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Marius Wojnarski
- Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | - Soy Ty Khean
- University Research Company Ltd., Phnom Penh, Cambodia.,London School of Hygiene and Tropical Medicine, London, UK
| | | | - Sokomar Nguon
- University Research Company Ltd., Phnom Penh, Cambodia
| | - Amber Kunkel
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia.,Emerging Diseases Epidemiology Unit, Institut Pasteur, Paris, France
| | | | - Thomas J Peto
- Mahidol-Oxford University Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Emily Dantzer
- University of California at San Francisco, San Francisco, USA
| | | | | | - Arjen M Dondorp
- Mahidol-Oxford University Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | | | - Lorenz von Seidlein
- Mahidol-Oxford University Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand. .,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.
| | - Jean-Olivier Guintran
- Centre for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia. .,Mahidol-Oxford University Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand.
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26
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Sanann N, Peto TJ, Tripura R, Callery JJ, Nguon C, Bui TM, Nofal SD, von Seidlein L, Lek D, Dondorp AM, Cheah PY, Pell C. Forest work and its implications for malaria elimination: a qualitative study. Malar J 2019; 18:376. [PMID: 31771587 PMCID: PMC6880349 DOI: 10.1186/s12936-019-3008-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 11/16/2019] [Indexed: 11/11/2022] Open
Abstract
Background Over the last 20 years, malaria incidence has decreased across the Greater Mekong Sub-region (GMS) and the emergence of artemisinin resistance has stimulated efforts to accelerate regional elimination. In the GMS, the malaria transmission is focused increasingly in forested zones. This article describes forest-going activities and examines forest workers’ attitudes to and experiences of malaria prevention and control in north-eastern Cambodia. Methods In Stung Treng Province, Cambodia, 19 in-depth interviews were conducted in villages with participants recently diagnosed with uncomplicated falciparum malaria who reported working in forests. Two focus group discussions with respondents’ forest-working peers were held. Interviews and focus groups were audio-recorded transcribed, and translated for thematic analysis. Results Forest work is an essential source of income for respondents. Many combine it with farming, which influences the timing and duration of forest visits. Forest activities include logging and collecting other forest products, particularly malva nuts. Men log year-round, whereas gathering forest products is seasonal and can involve entire families. Forest workers sleep chiefly in unimpregnated hammock nets in make-shift encampments. Respondents are concerned about symptomatic malaria, but unfamiliar with the concept of asymptomatic infection. They view the forest as an area of potential malaria infection and seek to protect themselves from mosquito bites through wearing long-sleeved clothes, using repellents, and lighting fires. Forest workers express a willingness to self-test and self-administer anti-malarials. Conclusions Forest workers’ behaviour and perceptions of risk indicate that improvements are needed to current control measures. There is potential to: better target distribution of impregnated hammock nets; offer curative or presumptive treatment while in forests; and expand access to screening. Establishing the efficacy and feasibility of prophylaxis for forest workers in the GMS is a priority.
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Affiliation(s)
- Nou Sanann
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,University Research Company, Phnom Penh, Cambodia
| | - 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 Clinical 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 Clinical Medicine, University of Oxford, Oxford, UK
| | - James J Callery
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chea Nguon
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Thanh Mai Bui
- Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Stephanie D Nofal
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - 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 Clinical Medicine, University of Oxford, Oxford, UK
| | - Dysoley Lek
- National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Arjen M 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 Clinical Medicine, University of Oxford, Oxford, UK
| | - Phaik Yeong Cheah
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Christopher Pell
- Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands.,Centre for Social Sciences and Global Health, University of Amsterdam, Amsterdam, The Netherlands
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27
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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.
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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
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