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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Doum D, Mclver DJ, Hustedt J, Hii J, Sovannaroth S, Lek D, Richardson JH, Tatarsky A, Lobo NF. An active and targeted survey reveals asymptomatic malaria infections among high-risk populations in Mondulkiri, Cambodia. Malar J 2023; 22:193. [PMID: 37353790 DOI: 10.1186/s12936-023-04630-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/20/2023] [Indexed: 06/25/2023] Open
Abstract
BACKGROUND Malaria is a mosquito-borne disease that is one of the most serious public health issues globally and a leading cause of mortality in many developing countries worldwide. Knowing the prevalence of both symptomatic and asymptomatic malaria on a subnational scale allows for the estimation of the burden of parasitaemia present in the transmission system, enabling targeting and tailoring of resources towards greater impact and better use of available capacity. This study aimed to determine the PCR-based point prevalence of malaria infection, by parasite species, among three high-risk populations in Mondulkiri province, Cambodia: forest rangers, forest dwellers, and forest goers. METHODS A cross-sectional survey was performed during the transmission season in November and December 2021. Blood samples collected on filter paper from participants (n = 1301) from all target groups were screened for Plasmodium spp using PCR. RESULTS Malaria prevalence among all study participants was 6.7% for any Plasmodium species. Malaria prevalence in the forest ranger group was 8.1%, was 6.8% in forest goers, and 6.4% in forest dwellers; all infections were asymptomatic. Plasmodium vivax was detected in all participant groups, while the few Plasmodium falciparum infections were found in goers and dwellers. 81% of all infections were due to P. vivax, 9% were due to P. falciparum, 3% due to Plasmodium cynomolgi, and the rest (7%) remained undefined. Gender was associated with malaria infection prevalence, with male participants having higher odds of malaria infection than female participants (OR = 1.69, 95% CI 1.08-2.64). Passively collected malaria incidence data from the Cambodian government were also investigated. Health facility-reported malaria cases, based on rapid diagnostic tests, for the period Jan-Dec 2021 were 521 Plasmodium vivax (0.89% prevalence), 34 P. falciparum (0.06%) and four P. falciparum + mixed (0.01%)-a total of 559 cases (0.95%) for all of Mondulkiri. CONCLUSION This reservoir of asymptomatic parasitaemia may be perpetuating low levels of transmission, and thus, new strategies are required to realize the goal of eliminating malaria in Cambodia by 2025.
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Affiliation(s)
- Dyna Doum
- Health Forefront Organization, Phnom Penh, Cambodia
| | - David J Mclver
- Malaria Elimination Initiative, University of California, San Francisco, CA, USA.
| | - John Hustedt
- Health Forefront Organization, Phnom Penh, Cambodia
| | - Jeffrey Hii
- Malaria Elimination Initiative, University of California, San Francisco, CA, USA
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Dysoley Lek
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | | | - Allison Tatarsky
- Malaria Elimination Initiative, University of California, San Francisco, CA, USA
| | - Neil F Lobo
- Malaria Elimination Initiative, University of California, San Francisco, CA, USA
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, USA
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3
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Chen I, Doum D, Mannion K, Hustedt J, Sovannaroth S, McIver D, Macdonald M, Lobo NF, Tatarsky A, Handley M, Neukom J. Applying the COM-B behavior model to inform the delivery of spatial repellents and insecticide-treated clothing among forest exposed populations in Mondulkiri Province, Cambodia. Res Sq 2023:rs.3.rs-2874672. [PMID: 37205382 PMCID: PMC10187415 DOI: 10.21203/rs.3.rs-2874672/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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 (VSPR) 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. Mixed methods were used to understand their experience, attitudes, and preferences regarding the products trialed. Quantitative data was summarized and qualitative insights were analyzed using thematic analysis, applying the Capability, Opportunity, Motivation Behavior Change (COM-B) model and Behavior 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 odor 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 ads, and enablement to guarantee 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 in Cambodia, while research efforts can aim to develop products that are rainproof, easy to use in forest settings, and have favorable odor profiles to target users.
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Affiliation(s)
| | | | | | - John Hustedt
- United States Agency for International Development
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Hustedt J, Prasetyo DB, Fiorenzano JM, von Fricken ME, Hertz JC. Correction: Phlebotomine sand flies (Diptera: Psychodidae) and sand fly-borne pathogens in the Greater Mekong Subregion: a systematic review. Parasit Vectors 2022; 15:432. [DOI: 10.1186/s13071-022-05550-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Hustedt J, Prasetyo DB, Fiorenzano JM, von Fricken ME, Hertz JC. Phlebotomine sand flies (Diptera: Psychodidae) and sand fly-borne pathogens in the Greater Mekong Subregion: a systematic review. Parasit Vectors 2022; 15:355. [PMID: 36199150 PMCID: PMC9533508 DOI: 10.1186/s13071-022-05464-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 09/03/2022] [Indexed: 11/20/2022] Open
Abstract
Phlebotomine sand flies are proven or suspected vectors of several pathogens of importance, including leishmaniasis, bartonellosis and sand fly fevers. Although sand flies have a worldwide distribution, there has been limited research published on sand flies and sand fly-borne pathogens throughout the Greater Mekong Sub-region (GMS). This review followed the PRISMA guidelines to determine the biodiversity and presence of phlebotomine sand flies and their associated pathogens in the GMS, specifically Cambodia, Thailand, the Lao People’s Democratic Republic (Laos), Malaysia and Vietnam. A total of 1472 records were identified by searching electronic databases, scanning reference lists of articles and consulting experts in the field. After screening of title and abstracts, 178 records remained and were further screened for original data (n = 34), not having regional data (n = 14), duplication of data (n = 4), records not available (n = 4) and no language translation available (n = 2). A total of 120 studies were then included for full review, with 41 studies on sand fly-related disease in humans, 33 studies on sand fly-related disease in animals and 54 entomological studies focused on sand flies (5 papers contained data on > 1 category), with a majority of the overall data from Thailand. There were relatively few studies on each country, with the exception of Thailand, and the studies applied different methods to investigate sand flies and sand fly-borne diseases, impacting the ability to conduct meaningful meta-analysis. The findings suggest that leishmaniasis in humans and the presence of sand fly vectors have been reported across several GMS countries over the past 100 years, with local transmission in humans confirmed in Thailand and Vietnam. Additionally, local Mundinia species are likely transmitted by biting midges. Findings from this study provide a framework for future investigations to determine the geographic distribution and risk profiles of leishmaniasis and other associated sand fly-borne disease throughout the GMS. It is recommended that researchers expand surveillance efforts across the GMS, with an emphasis placed on entomological surveys, syndromic and asymptomatic monitoring in both humans and animals and molecular characterization of sand flies and sand fly-borne pathogens, particularly in the understudied countries of Cambodia, Vietnam and Laos.
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Affiliation(s)
- John Hustedt
- Vysnova Partners, AXA Tower, 8 Shenton Way, Level 34-01, Singapore, Singapore.
| | - Didot Budi Prasetyo
- Entomology Division, Emerging Infections Department, U.S. Naval Medical Research Unit Two, Sembawang, Singapore, Singapore
| | - Jodi M Fiorenzano
- Entomology Division, Emerging Infections Department, U.S. Naval Medical Research Unit Two, Sembawang, Singapore, Singapore
| | - Michael E von Fricken
- Department of Global and Community Health, College of Health and Human Services, George Mason University, Fairfax, VA, USA
| | - Jeffrey C Hertz
- Entomology Division, Emerging Infections Department, U.S. Naval Medical Research Unit Two, Sembawang, Singapore, Singapore
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Bigio J, Braack L, Chea T, Set S, Suon S, Echaubard P, Hustedt J, Debackere M, Ramirez B, Prasetyo DB, Bunleng S, Wharton-Smith A, Hii J. Entomological outcomes of cluster-randomised, community-driven dengue vector-suppression interventions in Kampong Cham province, Cambodia. PLoS Negl Trop Dis 2022; 16:e0010028. [PMID: 35077452 PMCID: PMC8789142 DOI: 10.1371/journal.pntd.0010028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/24/2021] [Indexed: 11/18/2022] Open
Abstract
Cambodia has one of the highest dengue infection rates in Southeast Asia. Here we report quantitative entomological results of a large-scale cluster-randomised trial assessing the impact on vector populations of a package of vector control interventions including larvivorous guppy fish in household water containers, mosquito trapping with gravid-ovitraps, solid waste management, breeding-container coverage through community education and engagement for behavioural change, particularly through the participation of school children. These activities resulted in major reductions in Container Index, House Index, Breteau Index, Pupal Index and Adult Index (all p-values 0.002 or lower) in the Intervention Arm compared with the Control Arm in a series of household surveys conducted over a follow-up period of more than one year, although the project was not able to measure the longer-term sustainability of the interventions. Despite comparative reductions in Adult Index between the study arms, the Adult Index was higher in the Intervention Arm in the final household survey than in the first household survey. This package of biophysical and community engagement interventions was highly effective in reducing entomological indices for dengue compared with the control group, but caution is required in extrapolating the reduction in household Adult Index to a reduction in the overall population of adult Aedes mosquitoes, and in interpreting the relationship between a reduction in entomological indices and a reduction in the number of dengue cases. The package of interventions should be trialled in other locations.
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Affiliation(s)
- Jacob Bigio
- Research Institute of the McGill University Health Centre, Montreal, Canada
- McGill International TB Centre, Montreal, Canada
| | - Leo Braack
- Malaria Consortium, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- UP Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Thy Chea
- Malaria Consortium, Phnom Penh, Cambodia
| | - Srun Set
- Malaria Consortium, Phnom Penh, Cambodia
| | - Sokha Suon
- Malaria Consortium, Phnom Penh, Cambodia
| | | | - John Hustedt
- Malaria Consortium, Phnom Penh, Cambodia
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Bernadette Ramirez
- Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
| | | | - Sam Bunleng
- National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Alexandra Wharton-Smith
- Department for Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jeffrey Hii
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, James Cook University, Australia
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Abstract
Background Despite substantial reductions in malaria burden and improvement in case management, malaria remains a major public health challenge in the Asia-Pacific region. Residual malaria transmission (RMT) is the fraction of total transmission that persists after achievement of full operational coverage with effective insecticide-treated bed nets (ITNs)/long-lasting insecticidal nets (LLINs) and/or indoor residual spray interventions. There is a critical need to standardize and share best practices for entomological, anthropological, and product development investigative protocols to meet the challenges of RMT and elimination goals. Methods A systematic review was conducted to describe when and where RMT is occurring, while specifically targeting ownership and usage of ITN/LLINs, indoor residual spray application, insecticide susceptibility of vectors, and human and vector biting behavior, with a focus on nighttime activities. Results Sixty-six publications from 1995 to present met the inclusion criteria for closer review. Associations between local vector control coverage and use with behaviors of human and mosquito vectors varied by locality and circumstance. Consequently, the magnitude of RMT is insufficiently studied and analyzed with sparse estimates of individual exposure in communities, insufficient or incomplete observations of ITN/LLIN use, and the local human population movement into and from high-risk areas. Conclusions This review identified significant gaps or deficiencies that require urgent attention, namely, developing standardized procedures and methods to estimate risk exposure beyond the peridomestic setting, analytical approaches to measure key human-vector interactions, and seasonal location-specific agricultural or forest use calendars, and establishing the collection of longitudinal human and vector data close in time and location.
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Affiliation(s)
- Jeffrey Hii
- Malaria Consortium Asia, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
| | | | - Michael J Bangs
- Public Health and Malaria Control Department, PT Freeport Indonesia, International SOS, Jl. Kertajasa, Kuala Kencana, Papua, Indonesia.,Department of Entomology, Faculty of Agriculture, Kasertart University, Bangkok, Thailand
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Hustedt J, Doum D, Keo V, Ly S, Sam B, Chan V, Boyer S, Liverani M, Alexander N, Bradley J, Prasetyo DB, Rachmat A, Lopes S, Leang R, Hii J. Ability of the Premise Condition Index to Identify Premises with Adult and Immature Aedes Mosquitoes in Kampong Cham, Cambodia. Am J Trop Med Hyg 2020; 102:1432-1439. [PMID: 32274992 PMCID: PMC7253129 DOI: 10.4269/ajtmh.19-0453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Aedes-transmitted diseases, especially dengue, are increasing throughout the world and the main preventive methods include vector control and the avoidance of mosquito bites. A simple Premise Condition Index (PCI) categorizing shade, house, and yard conditions was previously developed to help prioritize households or geographical areas where resources are limited. However, evidence about the accuracy of the PCI is mixed. The current study aimed to contribute to a better understanding of the relevance by collecting data from 2,400 premises at four time points over 1 year in Kampong Cham, Cambodia. Regression models were then used to identify associations between PCI and Aedes adult female mosquitoes and pupae. In addition, receiver operating characteristic curves were used to measure the ability of PCI to identify premises in the top quartile of mosquito abundance. The density of adult Aedes females was positively associated with PCI at the household (ratio of means = 1.16 per point on the PCI scale) and cluster level (ratio of means = 1.54). However, the number of Aedes pupae was negatively associated with PCI at the household level (rate ratio = 0.74) and did not have a statistically significant association at the cluster level. Receiver operating characteristic curves suggest the PCI score had “rather low accuracy” (area under the ROC curve = 0.52 and 0.54) at identifying top-quartile premises in terms of adult female Aedes and pupae, respectively. These results suggest that caution is warranted in the programmatic use of PCI in areas of similar geography and mosquito abundance.
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Affiliation(s)
- John Hustedt
- London School of Hygiene and Tropical Medicine, London, United Kingdom.,Malaria Consortium, Phnom Penh Center, Phnom Penh, Cambodia
| | - Dyna Doum
- Malaria Consortium, Phnom Penh Center, Phnom Penh, Cambodia
| | - Vanney Keo
- Malaria Consortium, Phnom Penh Center, Phnom Penh, Cambodia
| | - Sokha Ly
- Cambodian National Dengue Control Program, Phnom Penh, Cambodia
| | - BunLeng Sam
- Cambodian National Dengue Control Program, Phnom Penh, Cambodia
| | - Vibol Chan
- World Health Organization, Phnom Penh, Cambodia
| | | | - Marco Liverani
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Neal Alexander
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - John Bradley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Agus Rachmat
- US Naval Medical Research Unit-2, Phnom Penh, Cambodia
| | - Sergio Lopes
- Malaria Consortium, Phnom Penh Center, Phnom Penh, Cambodia
| | - Rithea Leang
- Cambodian National Dengue Control Program, Phnom Penh, Cambodia
| | - Jeffrey Hii
- Malaria Consortium, Phnom Penh Center, Phnom Penh, Cambodia
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Shafique M, Lopes S, Doum D, Keo V, Sokha L, Sam B, Vibol C, Alexander N, Bradley J, Liverani M, Hii J, Rithea L, Aryal S, Hustedt J. Implementation of guppy fish (Poecilia reticulata), and a novel larvicide (Pyriproxyfen) product (Sumilarv 2MR) for dengue control in Cambodia: A qualitative study of acceptability, sustainability and community engagement. PLoS Negl Trop Dis 2019; 13:e0007907. [PMID: 31738759 PMCID: PMC6886868 DOI: 10.1371/journal.pntd.0007907] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 12/02/2019] [Accepted: 11/05/2019] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND In Cambodia dengue vector control activities are focused on larviciding with temephos and pyrethroid based adulticide sprays to which Aedes have been shown to be increasingly resistant. A cluster randomized trial assessed the impact of using biological control tools (guppy fish, pyriproxyfen (PPF), and Communication for Behavioral Impact (COMBI) activities in combination), which would be used in a value comparison to traditional chemical control tools. Given these new intervention methods, a qualitative assessment was designed in order to represent the quality of understanding, acceptance, and implementation by participants. METHODOLOGY/PRINCIPAL FINDINGS A total of 103 participants in 12 Focus Group Discussions (FGDs) and nine In-Depth Interviews (IDIs) were included in the study. The majority of participants in intervention villages (50 out of 80) preferred guppy fish over other vector control methods due to ease of use and rearing, quick reproduction and propensity to eat larvae. A substantial number of participants (11 out of 40) in intervention villages with PPF favored it due to long-lasting effectiveness, lack of smell and easy maintenance. Participants showed high demand for both interventions and were willing to pay between 100-500 riel (0.03-0.13 USD). Nearly all participants perceived that the interventions resulted in a reduction in Aedes mosquitos (both adults and immatures) and dengue cases. The presence of larvae in the water despite the use of PPF was a source of concern for some participants, although this was overcome in some cases with proper health education through health volunteers. Interpersonal communication through health volunteers was the most favorite method of transmitting prevention messages. CONCLUSIONS/SIGNIFICANCE The community led COMBI strategy resulted in high acceptance and perceived effectiveness of the interventions in target villages. Health volunteers are an effective and accepted channel of communication to engage communities, disseminate information and promote behavioral change at the household and community level. If shown effective through corresponding entomological surveys, the interventions should be continued and further strengthened to ensure they are accessible, available and affordable.
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Affiliation(s)
| | - Sergio Lopes
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Dyna Doum
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Vanney Keo
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Ly Sokha
- National Dengue Control Program, National Center of Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - BunLeng Sam
- National Dengue Control Program, National Center of Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Chan Vibol
- Malaria and other Vector-borne and Parasitic diseases, World Health Organization, Phnom Penh, Cambodia
| | - Neal Alexander
- MRC Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - John Bradley
- MRC Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Marco Liverani
- Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jeffrey Hii
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Leang Rithea
- National Dengue Control Program, National Center of Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Siddhi Aryal
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - John Hustedt
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
- Malaria and other Vector-borne and Parasitic diseases, World Health Organization, Phnom Penh, Cambodia
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10
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Boyer S, Lopes S, Prasetyo D, Hustedt J, Sarady AS, Doum D, Yean S, Peng B, Bunleng S, Leang R, Fontenille D, Hii J. Resistance of Aedes aegypti (Diptera: Culicidae) Populations to Deltamethrin, Permethrin, and Temephos in Cambodia. Asia Pac J Public Health 2018; 30:158-166. [PMID: 29502428 DOI: 10.1177/1010539517753876] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Dengue fever is a major public health concern, including 185,000 annual cases in Cambodia. Aedes aegypti is the primary vector for dengue transmission and is targeted with insecticide treatments. This study characterized the insecticide resistance status of Ae aegypti from rural and urban locations. The susceptibility to temephos, permethrin, and deltamethrin of Ae aegypti was evaluated in accordance with World Health Organization instructions. All the field populations showed lower mortality rate to temephos compared with the sensitive strain with resistance ratio 50 (RR50) varying from 3.3 to 33.78 and RR90 from 4.2 to 47 compared with the sensitive strain, demonstrating a generalized resistance of larvae to the temephos in Cambodia. Ae aegypti adult populations were highly resistant to permethrin regardless of province or rural/urban classification with an average mortality of 0.02%. Seven of the 8 field populations showed resistance to deltamethrin. These results are alarming for dengue vector control, as widespread resistance may compromise the entomological impact of larval control operations. Innovative vector control tools are needed to replace ineffective pesticides in Cambodia.
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Affiliation(s)
| | - Sergio Lopes
- 2 Malaria Consortium Cambodia, Phnom Penh, Cambodia
| | - Didot Prasetyo
- 3 US Naval Medical Research Unit-2 Detachment Phnom Penh, Phnom Penh, Cambodia
| | - John Hustedt
- 2 Malaria Consortium Cambodia, Phnom Penh, Cambodia
| | | | - Dyna Doum
- 2 Malaria Consortium Cambodia, Phnom Penh, Cambodia
| | - Sony Yean
- 1 Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Borin Peng
- 1 Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Sam Bunleng
- 4 National Center for Entomology, Parasitology and Malaria Control (CNM), Phnom Penh, Cambodia
| | - Rithea Leang
- 4 National Center for Entomology, Parasitology and Malaria Control (CNM), Phnom Penh, Cambodia
| | | | - Jeffrey Hii
- 5 Malaria Consortium Asia Regional Office, Faculty of Tropical Medicine, Mahidol University Bangkok, Thailand
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Kumaran E, Doum D, Keo V, Sokha L, Sam B, Chan V, Alexander N, Bradley J, Liverani M, Prasetyo DB, Rachmat A, Lopes S, Hii J, Rithea L, Shafique M, Hustedt J. Dengue knowledge, attitudes and practices and their impact on community-based vector control in rural Cambodia. PLoS Negl Trop Dis 2018; 12:e0006268. [PMID: 29451879 PMCID: PMC5833285 DOI: 10.1371/journal.pntd.0006268] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 03/01/2018] [Accepted: 01/24/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Globally there are an estimated 390 million dengue infections per year, of which 96 million are clinically apparent. In Cambodia, estimates suggest as many as 185,850 cases annually. The World Health Organization global strategy for dengue prevention aims to reduce mortality rates by 50% and morbidity by 25% by 2020. The adoption of integrated vector management approach using community-based methods tailored to the local context is one of the recommended strategies to achieve these objectives. Understanding local knowledge, attitudes and practices is therefore essential to designing suitable strategies to fit each local context. METHODS AND FINDINGS A Knowledge, Attitudes and Practices survey in 600 randomly chosen households was administered in 30 villages in Kampong Cham which is one of the most populated provinces of Cambodia. KAP surveys were administered to a sub-sample of households where an entomology survey was conducted (1200 households), during which Aedes larval/pupae and adult female Aedes mosquito densities were recorded. Participants had high levels of knowledge regarding the transmission of dengue, Aedes breeding, and biting prevention methods; the majority of participants believed they were at risk and that dengue transmission is preventable. However, self-reported vector control practices did not match observed practices recorded in our surveys. No correlation was found between knowledge and observed practices either. CONCLUSION An education campaign regarding dengue prevention in this setting with high knowledge levels is unlikely to have any significant effect on practices unless it is incorporated in a more comprehensive strategy for behavioural change, such a COMBI method, which includes behavioural models as well as communication and marketing theory and practice. TRIAL REGISTRATION ISRCTN85307778.
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Affiliation(s)
- Emmanuelle Kumaran
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
- * E-mail:
| | - Dyna Doum
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Vanney Keo
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Ly Sokha
- National Dengue Control Program, National Center of Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - BunLeng Sam
- National Dengue Control Program, National Center of Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Vibol Chan
- Malaria and other Vector-borne and Parasitic diseases Office of the WHO Representative in Cambodia, World Health Organization, Phnom Penh, Cambodia
| | - Neal Alexander
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | - John Bradley
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | - Marco Liverani
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | | | - Agus Rachmat
- Data Analyst Unit, US Naval Medical Research Unit-2, Phnom Penh, Cambodia
| | - Sergio Lopes
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Jeffrey Hii
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
| | - Leang Rithea
- National Dengue Control Program, National Center of Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | | | - John Hustedt
- Technical Department, Malaria Consortium, Phnom Penh, Cambodia
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
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Hustedt J, Doum D, Keo V, Ly S, Sam B, Chan V, Alexander N, Bradley J, Prasetyo DB, Rachmat A, Muhammad S, Lopes S, Leang R, Hii J. Determining the efficacy of guppies and pyriproxyfen (Sumilarv® 2MR) combined with community engagement on dengue vectors in Cambodia: study protocol for a randomized controlled trial. Trials 2017; 18:367. [PMID: 28778174 PMCID: PMC5545006 DOI: 10.1186/s13063-017-2105-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/14/2017] [Indexed: 11/16/2022] Open
Abstract
Background Evidence on the effectiveness of low-cost, sustainable, biological vector-control tools for the Aedes mosquitoes is limited. Therefore, the purpose of this trial is to estimate the impact of guppy fish (guppies), in combination with the use of the larvicide pyriproxyfen (Sumilarv® 2MR), and Communication for Behavioral Impact (COMBI) activities to reduce entomological indices in Cambodia. Methods/design In this cluster randomized controlled, superiority trial, 30 clusters comprising one or more villages each (with approximately 170 households) will be allocated, in a 1:1:1 ratio, to receive either (1) three interventions (guppies, Sumilarv® 2MR, and COMBI activities), (2) two interventions (guppies and COMBI activities), or (3) control (standard vector control). Households will be invited to participate, and entomology surveys among 40 randomly selected households per cluster will be carried out quarterly. The primary outcome will be the population density of adult female Aedes mosquitoes (i.e., number per house) trapped using adult resting collections. Secondary outcome measures will include the House Index, Container Index, Breteau Index, Pupae Per House, Pupae Per Person, mosquito infection rate, guppy fish coverage, Sumilarv® 2MR coverage, and percentage of respondents with knowledge about Aedes mosquitoes causing dengue. In the primary analysis, adult female Aedes density and mosquito infection rates will be aggregated over follow-up time points to give a single rate per cluster. This will be analyzed by negative binomial regression, yielding density ratios. Discussion This trial is expected to provide robust estimates of the intervention effect. A rigorous evaluation of these vector-control interventions is vital to developing an evidence-based dengue control strategy and to help direct government resources. Trial registration Current Controlled Trials, ID: ISRCTN85307778. Registered on 25 October 2015. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-2105-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- John Hustedt
- Malaria Consortium, House #91, St. 95, Boeung Trabek, Chamkar Morn, PO Box 2116, Phnom Penh, 12305, Cambodia. .,London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Dyna Doum
- Malaria Consortium, House #91, St. 95, Boeung Trabek, Chamkar Morn, PO Box 2116, Phnom Penh, 12305, Cambodia
| | - Vanney Keo
- Malaria Consortium, House #91, St. 95, Boeung Trabek, Chamkar Morn, PO Box 2116, Phnom Penh, 12305, Cambodia
| | - Sokha Ly
- Cambodian National Dengue Control Program, #477 Betong Street.(Corner St.92), Village Trapangsvay, Phnom Penh, Cambodia
| | - BunLeng Sam
- Cambodian National Dengue Control Program, #477 Betong Street.(Corner St.92), Village Trapangsvay, Phnom Penh, Cambodia
| | - Vibol Chan
- World Health Organization, No. 177-179 corner Streets Pasteur (51) and 254; Sankat Chak Tomouk Khan Daun Penh, Phnom Penh, Cambodia
| | - Neal Alexander
- London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - John Bradley
- London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Didot Budi Prasetyo
- US Naval Medical Research Unit-2, #2, St. 289, Boeung Kok 2 commune, Toul Kork district, 289 Samdach Penn Nouth, Phnom Penh, 1225, Cambodia
| | - Agus Rachmat
- US Naval Medical Research Unit-2, #2, St. 289, Boeung Kok 2 commune, Toul Kork district, 289 Samdach Penn Nouth, Phnom Penh, 1225, Cambodia
| | - Shafique Muhammad
- Malaria Consortium, House #91, St. 95, Boeung Trabek, Chamkar Morn, PO Box 2116, Phnom Penh, 12305, Cambodia
| | - Sergio Lopes
- Malaria Consortium, House #91, St. 95, Boeung Trabek, Chamkar Morn, PO Box 2116, Phnom Penh, 12305, Cambodia
| | - Rithea Leang
- Cambodian National Dengue Control Program, #477 Betong Street.(Corner St.92), Village Trapangsvay, Phnom Penh, Cambodia
| | - Jeffrey Hii
- Malaria Consortium, House #91, St. 95, Boeung Trabek, Chamkar Morn, PO Box 2116, Phnom Penh, 12305, Cambodia
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Hustedt J, Canavati SE, Rang C, Ashton RA, Khim N, Berne L, Kim S, Sovannaroth S, Ly P, Ménard D, Cox J, Meek S, Roca-Feltrer A. Reactive case-detection of malaria in Pailin Province, Western Cambodia: lessons from a year-long evaluation in a pre-elimination setting. Malar J 2016; 15:132. [PMID: 26931488 PMCID: PMC4774174 DOI: 10.1186/s12936-016-1191-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 02/23/2016] [Indexed: 12/22/2022] Open
Abstract
Background As momentum towards malaria elimination grows, strategies are being developed for scale-up in elimination settings. One prominent strategy, reactive case detection (RACD), involves screening and treating individuals living in close proximity to passively detected, or “index” cases. This study aims to use RACD to quantify Plasmodium parasitaemia in households of index cases, and identify risk factors for infection; these data could inform reactive screening approaches and identify target risk groups. Methods This study was conducted in the Western Cambodian province of Pailin between May 2013 and March 2014 among 440 households. Index participants/index cases (n = 270) and surrounding households (n = 110) were screened for Plasmodium infection with rapid diagnostic tests (RDT), microscopy and real-time polymerase chain reaction (PCR). Participants were interviewed to identify risk factors. A comparison group of 60 randomly-selected households was also screened, to compare infection levels of RACD and non-RACD households. In order to identify potential risk factors that would inform screening approaches and identify risk groups, multivariate logistic regression models were applied. Results Nine infections were identified in households of index cases (RACD approach) through RDT screening of 1898 individuals (seven Plasmodium vivax, two Plasmodium falciparum); seven were afebrile. Seventeen infections were identified through PCR screening of 1596 individuals (15 P. vivax, and 22 % P. falciparum/P. vivax mixed infections). In the control group, 25 P. falciparum infections were identified through PCR screening of 237 individuals, and no P. vivax was found. Plasmodium falciparum infection was associated with fever (p = 0.013), being a member of a control household (p ≤ 0.001), having a history of malaria infection (p = 0.041), and sleeping without a mosquito net (p = 0.011). Significant predictors of P. vivax infection, as diagnosed by PCR, were fever (p = 0.058, borderline significant) and history of malaria infection (p ≤ 0.001). Conclusion This study found that RACD identified very few secondary infections when targeting index and neighbouring households for screening. The results suggest RACD is not appropriate, where exposure to malaria occurs away from the community, and there is a high level of treatment-seeking from the private sector. Piloting RACD in a range of transmission settings would help to identify the ideal environment for feasible and effective reactive screening methods.
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Affiliation(s)
- John Hustedt
- Malaria Consortium Cambodia, Phnom Penh Office, House #91, St. 95, Boeung Trabek, Chamcar Morn, Phnom Penh, Cambodia.
| | - Sara E Canavati
- Malaria Consortium Cambodia, Phnom Penh Office, House #91, St. 95, Boeung Trabek, Chamcar Morn, Phnom Penh, Cambodia. .,Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok, 10400, Thailand.
| | - Chandary Rang
- Malaria Consortium Cambodia, 113 (6th floor of Parkway Square), Mao Tse Toung Blvd. Chamcar Morn, Phnom Penh, Cambodia.
| | - Ruth A Ashton
- Malaria Consortium Cambodia, Phnom Penh Office, House #91, St. 95, Boeung Trabek, Chamcar Morn, Phnom Penh, Cambodia.
| | - Nimol Khim
- Institut Pasteur in Cambodia, 5, Blvd Monivong, Phnom Penh, Cambodia.
| | - Laura Berne
- Institut Pasteur in Cambodia, 5, Blvd Monivong, Phnom Penh, Cambodia.
| | - Saorin Kim
- Institut Pasteur in Cambodia, 5, Blvd Monivong, Phnom Penh, Cambodia.
| | - Siv Sovannaroth
- The National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Corner street 92, Trapaing Svay village, Sankat Phnom Penh Thmey, Khan Sensok, Phnom Penh, Cambodia.
| | - Po Ly
- The National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Corner street 92, Trapaing Svay village, Sankat Phnom Penh Thmey, Khan Sensok, Phnom Penh, Cambodia.
| | - Didier Ménard
- Institut Pasteur in Cambodia, 5, Blvd Monivong, Phnom Penh, Cambodia.
| | - Jonathan Cox
- Malaria Consortium Cambodia, Phnom Penh Office, House #91, St. 95, Boeung Trabek, Chamcar Morn, Phnom Penh, Cambodia. .,Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Sylvia Meek
- Malaria Consortium, Development House, 56-64 Leonard Street, London, EC2A 4LT, UK.
| | - Arantxa Roca-Feltrer
- Faculty of Tropical Medicine, Malaria Consortium Asia, Mahidol University, Room 805, 420/6 Rajavidhi Road, Bangkok, 10400, Thailand.
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Hustedt J, Canavati S, Rang C, Uth S, Ly P, Sovannaroth S, Ashton R, Meek S, Felter AR. Focal screening and treatment around passively-detected malaria cases in Pailin Province, Cambodia: a feasible and effective tool to target asymptomatic infections? Malar J 2014. [PMCID: PMC4179380 DOI: 10.1186/1475-2875-13-s1-p45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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