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Aarumugam P, Kovendan K, Kamalakannan S, Jebanesan A. Chemical Exposure of Synthetic Pyrethroid on Deltamethrin Under the Selection Pressure over the Generations: A Reproductive Potential Study of Anopheles stephensi. Appl Biochem Biotechnol 2024:10.1007/s12010-024-04911-9. [PMID: 38512550 DOI: 10.1007/s12010-024-04911-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2024] [Indexed: 03/23/2024]
Abstract
Biochemical synthetic pyrethroids, deltamethrin are presently used insecticides for the control of mosquito vector-borne diseases in worldwide. Mosquito re-emergence with diseases becoming a serious problem due to development of insecticide resistance. The comprehensive knowledge on the underlying mechanisms of resistance against deltamethrin is required for implementation of an efficient vector control programme. The assessment of the biological fitness of a mosquito strain exposed to insecticide pressure is extremely vital because it provides information on the development of resistance. In the present study, the adult stage of malaria vector, Anopheles stephensi, was designated for the study of deltamethrin resistance (F40 generations). The non-blood-fed, laboratory-reared females to sub-lethal doses of deltamethrin (0.004%, 0.005%, 0.007%, or 0.01%) exposed to every generation for up to F40. The adult mosquito susceptibility was performed by WHO standard method for evaluation. After 24 h, mortality was recorded in both treated and control groups. Therefore, the biological fitness characteristics such as feeding, fecundity, hatchability, egg retention, immature duration, adult emergence, and adult life span were studied to assess the exposed deltamethrin under selection pressure as compared to the unexposed (control) population. The laboratory selection of An. stephensi exposed deltamethrin over the generations were diminished its biological fitness. Information on biological fitness including reproductive potential of mosquito strain under selection pressure against deltamethrin is incredibly necessary because it would facilitate in resistance management. Baseline information gives in this experiment will guide for future studies on the susceptibilities of wild malaria mosquito populations in India.
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Affiliation(s)
- Palani Aarumugam
- P.G and Research Department of Zoology, Sri Vijay Vidyalaya College of Arts and Science, Nallampalli Papparapatty Road, Balajangamanhalli, Dharmapuri, 636 807, Tamil Nadu, India
| | - Kalimuthu Kovendan
- Division of Vector Biology and Control, Department of Zoology, Faculty of Science, Annamalai University, Annamalainagar, 608 002, Tamil Nadu, India.
| | - Siva Kamalakannan
- National Centre for Disease Control, Ministry of Health and Family Welfare, 22-Sham Nath Marg, Civil Line, Delhi, 110 054, India
| | - Arulsamy Jebanesan
- Division of Vector Biology and Control, Department of Zoology, Faculty of Science, Annamalai University, Annamalainagar, 608 002, Tamil Nadu, India
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Pimnon S, Bhumiratana A, Intarapuk A, Ritthison W. Effect of expanding farmlands with domestication of animals in the vicinity of disturbed swamps and built-up farmland ponds on population dispersion and decline of locally adapted Mansonia vectors ( Diptera: Culicidae). Vet World 2024; 17:564-576. [PMID: 38680151 PMCID: PMC11045523 DOI: 10.14202/vetworld.2024.564-576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/29/2024] [Indexed: 05/01/2024] Open
Abstract
Background and Objectives The adaptive processes and resilience of Mansonia vectors responsible for bioindicators can change in response to climate, land use, and environmental changes. This study evaluated the effects of expanding farmlands with the domestication of animals in the vicinity of either disturbed swamps or built-up farmland ponds on the population dispersion and decline of locally adapted Mansonia faunas as a result of expanding farmlands in Thailand. Materials and Methods Based on environmental surveys, four different geographically defined study sites were selected: I - the expanding farmlands with domestication of livestock and pet animals in the vicinity of low-lying swamp with habitat fragmentation and aquatic vegetation; II - the expanding farmlands with domestication of pet animals in the vicinity of elevated swamp with habitat destruction and aquatic vegetation; III - the expanding farmlands with domestication of livestock and pet animals in the vicinity of low-lying farmland ponds with restoration and aquatic vegetation; and IV - the expanding farmlands with domestication of pet animals in the vicinity of elevated farmland ponds with restoration and aquatic vegetation. Human landing catch collection method was used to periodically assess the species composition and abundance of Mansonia vectors. Results Aggregated distributions and seasonal abundances of Mansonia faunas (Mansonia uniformis, Mansonia indiana, Mansonia annulifera, Mansonia annulata, Mansonia bonneae, and Mansonia dives) with variable proportions were observed at all the study sites. A decline in the population of Mansonia faunas, except for Ma. uniformis, was observed at study sites I and II. Conclusion The anticipated effects of expanding farmlands affected the population dispersion and decline of locally adapted Mansonia faunas, thus representing a diverse assemblage of Mansonia species with different adaptations, ecological tolerances, and host exploitation strategies in life. These effects depended either on the function of disturbed swamps or on the development of farmland ponds, whether they provided a wide range of freshwater habitats, or on the domestication of animals, whether they provided animal blood meal sources.
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Affiliation(s)
- Suntorn Pimnon
- Faculty of Public Health, Bangkokthonburi University, Bangkok 10170, Thailand
| | - Adisak Bhumiratana
- Thammasat University Research Unit in One Health and EcoHealth, Pathum Thani, Thailand
- Faculty of Public Health, Thammasat University, Rangsit Campus, Pathum Thani 12121, Thailand
| | - Apiradee Intarapuk
- Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok 10530, Thailand
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Bhumiratana A, Nunthawarasilp P, Intarapuk A, Pimnon S, Ritthison W. Emergence of zoonotic Brugia pahangi parasite in Thailand. Vet World 2023; 16:752-765. [PMID: 37235155 PMCID: PMC10206978 DOI: 10.14202/vetworld.2023.752-765] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/09/2023] [Indexed: 05/28/2023] Open
Abstract
Zoonotic Brugia pahangi parasite infections in humans have emerged over two decades in Southeast Asia (SEA), including Malaysia and Thailand. The species is commonly found in domestic cats and dogs as the natural reservoir hosts. The sporadic transmission pattern of B. pahangi zoonosis causes childhood infections in Thailand and adulthood infections in Malaysia. It is crucial to understand the vulnerability in how zoonotic B. pahangi parasite is transmitted to susceptible persons in receptive settings and the exposure to the infection under impoverished environment to which the human-vector-animal interactions are related. This acquisition of knowledge will help multiple health science professions to apply One Health approach to strengthening the capacity in diagnosis and surveillance, and hence detecting and monitoring the "lingering" zoonotic B. pahangi infections present in vulnerable populations in Thailand and elsewhere in SEA. In this review article, the authors focused on articulating the concepts of plantation-related zoonotic B. pahangi filariasis by updating current knowledge of B. pahangi life cycle, vector's life cycle and current state of research on the epidemiology and ecology of B. pahangi zoonosis.
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Affiliation(s)
- Adisak Bhumiratana
- Thammasat University Research Unit in One Health and EcoHealth, Pathum Thani, Thailand
- Faculty of Public Health, Thammasat University, Pathum Thani 12121, Thailand
| | | | - Apiradee Intarapuk
- Faculty of Veterinary Medicine, Mahanakorn University of Technology, Bangkok 10530, Thailand
| | - Suntorn Pimnon
- Faculty of Public Health, Bangkokthonburi University, Bangkok 10170, Thailand
| | - Wanapa Ritthison
- Office of Disease Prevention and Control, Region 6 Chonburi, Thailand
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Aubourg MA, Al-Amin HM, Sunkara A, Chetan S, Monroe A, Phru CS, Haque R, Khan WA, Hendershot A, Alam MS, Lobo NF. Human behaviour directs household-level exposure to malaria vectors in Bandarban, Bangladesh. Malar J 2022; 21:355. [PMID: 36443751 PMCID: PMC9706855 DOI: 10.1186/s12936-022-04375-4] [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: 04/25/2022] [Accepted: 11/09/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Bangladesh has reduced malaria incidence and mortality by over 75% between 2010 and 2020. Widespread long-lasting insecticidal net (LLIN) distribution and use is one of the measures responsible for this success. Recalcitrant malaria hotspots within the Chittagong Hill Tracts districts suggest important drivers of malaria risk may remain uncharacterized. METHODS Towards understanding how household-level human behaviour impacts exposure to mosquitoes, parallel human landing catches and human behavioural observations were conducted in four households for 6 months (May-October) over the rainy season in the Bandarban District. Analysis quantifies spatiotemporal human behaviour-adjusted exposure to Anopheles with and without LLINs. RESULTS This small-scale operational study demonstrates that human spatial and temporal presence along with LLIN use drives exposure to Anopheles. Though the four households had both outdoor and indoor exposure, especially in the evening (1800-2000 h) and early morning (0400-0500 h), data points to household-based heterogeneity in malaria exposure even with similar LLIN access. CONCLUSION Incorporating human behaviour into exposure estimates can be used to understand the efficacy and limitations of local vector control strategies and identify gaps in protection, as well as where present intervention strategies may be optimized.
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Affiliation(s)
- Matthew A Aubourg
- Department of Biological Sciences, 321 Galvin Life Science Center, University of Notre Dame, Notre Dame, IN, 46556, USA.
| | - Hasan Mohammad Al-Amin
- International Centre for Diarrheal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh.,QIMR Berghofer Medical Research Institute, Queensland, Australia
| | - Anoop Sunkara
- Department of Biological Sciences, 321 Galvin Life Science Center, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Sanjna Chetan
- Department of Biological Sciences, 321 Galvin Life Science Center, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - April Monroe
- Johns Hopkins Center for Communication Programs, Baltimore, MD, USA
| | - Ching Swe Phru
- International Centre for Diarrheal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Rashidul Haque
- International Centre for Diarrheal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Wasif A Khan
- International Centre for Diarrheal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Allison Hendershot
- Department of Biological Sciences, 321 Galvin Life Science Center, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Mohammad Shafiul Alam
- International Centre for Diarrheal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Neil F Lobo
- Department of Biological Sciences, 321 Galvin Life Science Center, University of Notre Dame, Notre Dame, IN, 46556, USA
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Ammatawiyanon L, Tongkumchum P, Lim A, McNeil D. Modelling malaria in southernmost provinces of Thailand: a two-step process for analysis of highly right-skewed data with a large proportion of zeros. Malar J 2022; 21:334. [PMID: 36380322 PMCID: PMC9664774 DOI: 10.1186/s12936-022-04363-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 11/05/2022] [Indexed: 11/16/2022] Open
Abstract
Background Malaria remains a serious health problem in the southern border provinces of Thailand. The issue areas can be identified using an appropriate statistical model. This study aimed to investigate malaria for its spatial occurrence and incidence rate in the southernmost provinces of Thailand. Methods The Thai Office of Disease Prevention and Control, Ministry of Public Health, provided total hospital admissions of malaria cases from 2008 to 2020, which were classified by age, gender, and sub-district of residence. Sixty-two sub-districts were excluded since they had no malaria cases. A logistic model was used to identify spatial occurrence patterns of malaria, and a log-linear regression model was employed to model the incidence rate after eliminating records with zero cases. Results The overall occurrence rate was 9.8% and the overall median incidence rate was 4.3 cases per 1,000 population. Malaria occurence peaked at young adults aged 20–29, and subsequently fell with age for both sexes, whereas incidence rate increased with age for both sexes. Malaria occurrence and incidence rates fluctuated; they appeared to be on the decline. The area with the highest malaria occurrence and incidence rate was remarkably similar to the area with the highest number of malaria cases, which were mostly in Yala province's sub-districts bordering Malaysia. Conclusions Malaria is a serious problem in forest-covered border areas. The correct policies and strategies should be concentrated in these areas, in order to address this condition.
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Chaiphongpachara T, Changbunjong T, Sumruayphol S, Laojun S, Suwandittakul N, Kuntawong K. Geometric morphometrics versus DNA barcoding for the identification of malaria vectors Anopheles dirus and An. baimaii in the Thai-Cambodia border. Sci Rep 2022; 12:13236. [PMID: 35918453 PMCID: PMC9345986 DOI: 10.1038/s41598-022-17646-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 07/28/2022] [Indexed: 11/09/2022] Open
Abstract
Anopheles (Cellia) dirus Peyton & Harrison and Anopheles baimaii Sallum & Peyton are sibling species within the Dirus complex belonging to the Leucosphyrus group, and have been incriminated as primary vectors of malaria in Thailand. In the present study, DNA barcoding and geometric morphometrics were used to distinguish between An. dirus and An. baimaii in the international border areas, Trat Province, eastern Thailand. Our results revealed that DNA barcoding based on the cytochrome c oxidase subunit I gene could not be used to distinguish An. dirus from An. baimaii. The overlapping values between intra- and interspecific genetic divergence indicated no barcoding gap present for An. dirus and An. baimaii (ranging from 0 to 0.99%). However, the results of the geometric morphometric analysis based on the wing shape clearly distinguished An. dirus and An. baimaii, with 92.42% of specimens assigned to the correct species. We concluded that geometric morphometrics is an effective tool for the correct species identification of these two malaria vectors. Our findings could be used to make entomological surveillance information more accurate, leading to further effective mosquito control planning in Thailand and other countries in Southeast Asia.
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Affiliation(s)
- Tanawat Chaiphongpachara
- Department of Public Health and Health Promotion, College of Allied Health Sciences, Suan Sunandha Rajabhat University, Bangkok, 10300, Thailand.
| | - Tanasak Changbunjong
- Department of Pre-Clinic and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand.,The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals (MoZWE), Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Suchada Sumruayphol
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Sedthapong Laojun
- Department of Public Health and Health Promotion, College of Allied Health Sciences, Suan Sunandha Rajabhat University, Bangkok, 10300, Thailand
| | - Nantana Suwandittakul
- Department of Public Health and Health Promotion, College of Allied Health Sciences, Suan Sunandha Rajabhat University, Bangkok, 10300, Thailand
| | - Kewarin Kuntawong
- Department of Public Health and Health Promotion, College of Allied Health Sciences, Suan Sunandha Rajabhat University, Bangkok, 10300, Thailand
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7
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Hii J, Hustedt J, Bangs MJ. Residual Malaria Transmission in Select Countries of Asia-Pacific Region: Old Wine in a New Barrel. J Infect Dis 2021; 223:S111-S142. [PMID: 33906222 PMCID: PMC8079134 DOI: 10.1093/infdis/jiab004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Background Despite substantial reductions in malaria burden and improvement in case management, malaria remains a major public health challenge in the Asia-Pacific region. Residual malaria transmission (RMT) is the fraction of total transmission that persists after achievement of full operational coverage with effective insecticide-treated bed nets (ITNs)/long-lasting insecticidal nets (LLINs) and/or indoor residual spray interventions. There is a critical need to standardize and share best practices for entomological, anthropological, and product development investigative protocols to meet the challenges of RMT and elimination goals. Methods A systematic review was conducted to describe when and where RMT is occurring, while specifically targeting ownership and usage of ITN/LLINs, indoor residual spray application, insecticide susceptibility of vectors, and human and vector biting behavior, with a focus on nighttime activities. Results Sixty-six publications from 1995 to present met the inclusion criteria for closer review. Associations between local vector control coverage and use with behaviors of human and mosquito vectors varied by locality and circumstance. Consequently, the magnitude of RMT is insufficiently studied and analyzed with sparse estimates of individual exposure in communities, insufficient or incomplete observations of ITN/LLIN use, and the local human population movement into and from high-risk areas. Conclusions This review identified significant gaps or deficiencies that require urgent attention, namely, developing standardized procedures and methods to estimate risk exposure beyond the peridomestic setting, analytical approaches to measure key human-vector interactions, and seasonal location-specific agricultural or forest use calendars, and establishing the collection of longitudinal human and vector data close in time and location.
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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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8
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Jones RT, Tusting LS, Smith HMP, Segbaya S, Macdonald MB, Bangs MJ, Logan JG. The Role of the Private Sector in Supporting Malaria Control in Resource Development Settings. J Infect Dis 2021; 222:S701-S708. [PMID: 33119094 PMCID: PMC7594257 DOI: 10.1093/infdis/jiaa488] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Industrial operations of the private sector, such as extraction, agriculture, and construction, can bring large numbers of people into new settlement areas and cause environmental change that promotes the transmission of vector-borne diseases. Industry-related workers and communities unduly exposed to infection risk typically lack the knowledge and means to protect themselves. However, there is a strong business rationale for protecting local resident employees through integrated vector control programs, as well as an ethical responsibility to care for these individuals and the affected communities. We discuss the role and challenges of the private sector in developing malaria control programs, which can include extensive collaborations with the public sector that go on to form the basis of national vector control programs or more broadly support local healthcare systems.
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Affiliation(s)
- Robert T Jones
- Arthropod Control Product Test Centre, London School of Hygiene & Tropical Medicine, London, United Kingdom.,Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Lucy S Tusting
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Hugh M P Smith
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | | | - Michael J Bangs
- lnternational SOS, Ltd., Timika, Papua Province, Indonesia.,International SOS, Ltd., Kolwesi, Lualaba Province, Democratic Republic of Congo
| | - James G Logan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Shimizu S, Chotirat S, Dokkulab N, Hongchad I, Khowsroy K, Kiattibutr K, Maneechai N, Manopwisedjaroen K, Petchvijit P, Phumchuea K, Rachaphaew N, Sripoorote P, Suansomjit C, Thongyod W, Khamsiriwatchara A, Lawpoolsri S, Hanboonkunupakarn B, Sattabongkot J, Nguitragool W. Malaria cross-sectional surveys identified asymptomatic infections of Plasmodium falciparum, Plasmodium vivax and Plasmodium knowlesi in Surat Thani, a southern province of Thailand. Int J Infect Dis 2020; 96:445-451. [PMID: 32407902 DOI: 10.1016/j.ijid.2020.05.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/06/2020] [Accepted: 05/06/2020] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVES Malaria cross-sectional surveys are rarely conducted in very low transmission settings. This study aimed to determine the prevalence and risk factors of Plasmodium infection in a near-elimination setting in southern Thailand. METHODS Two cross-sectional surveys were conducted in areas of active transmission in the Surat Thani province of Thailand in January and May 2019. PCR was used to detect Plasmodium infection. RESULTS The prevalence of Plasmodium blood infection was 0.45% and 0.61% in January and May 2019, respectively. The major parasite species was Plasmodium falciparum in January and Plasmodium vivax in May. Unexpectedly, Plasmodium knowlesi infections were also detected. Most infections, including those of Plasmodium knowlesi, were asymptomatic. Being male and staying outdoors at night-time were the only significant identified risk factors. Of people infected in January 28.0% were positive in May for the same parasite species, suggesting persistent asymptomatic infections. CONCLUSIONS Despite the very low incidence rate in Surat Thani, most malaria infections were asymptomatic. Outdoor mosquito biting at night-time is likely an important mode of malaria transmission. Unexpectedly, asymptomatic Plasmodium knowlesi infection was found, confirming previous reports of such infection in mainland Southeast Asia.
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Affiliation(s)
- Shoichi Shimizu
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sadudee Chotirat
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nichakan Dokkulab
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Isarachai Hongchad
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kessuda Khowsroy
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kirakorn Kiattibutr
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nongnuj Maneechai
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Pattamaporn Petchvijit
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kanit Phumchuea
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nattawan Rachaphaew
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Piyarat Sripoorote
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chayanut Suansomjit
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Waraporn Thongyod
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Amnat Khamsiriwatchara
- Center of Excellence for Biomedical and Public Health Informatics (BIOPHICS), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Saranath Lawpoolsri
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Borimas Hanboonkunupakarn
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wang Nguitragool
- Department of Molecular Tropical Medicine & Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Abstract
Malaria elimination is a health priority of India for the national development and to meet UN sustainable development goals. In this article, an attempt has been made to highlight some of the key issues that need attention and consideration. These include addressing the gaps in malaria burden and adopting District Health Information System (DHIS) for real time data gathering, transfer and analysis for rapid response. The article highlights threat to malaria elimination from human migration, asymptomatic malaria, P. malariae as a neglected species, need for updating vector information and devising strategies to control relay vector species especially in the high burden states of India. Additionally, scale-up of vector control interventions, integrated vector management and enhancement of vector control capacity and capability have been emphasized. It is suggested that process, performance and progress indicators for malaria elimination may be clearly spelt out and disseminated. What are the data needs for malaria elimination certification, must be well-understood? Lessons learnt by the countries that have eliminated malaria recently shall be of great value to malaria elimination efforts in India.
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Affiliation(s)
- Ashwani Kumar
- ICMR-National Institute of Malaria Research, Field Unit, Panaji, Goa, India
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11
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Edwards HM, Sriwichai P, Kirabittir K, Prachumsri J, Chavez IF, Hii J. Transmission risk beyond the village: entomological and human factors contributing to residual malaria transmission in an area approaching malaria elimination on the Thailand-Myanmar border. Malar J 2019; 18:221. [PMID: 31262309 PMCID: PMC6604376 DOI: 10.1186/s12936-019-2852-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 06/19/2019] [Indexed: 11/12/2022] Open
Abstract
Background A mixed methods study was conducted to look at the
magnitude of residual malaria transmission (RMT) and factors contributing to low (< 1% prevalence), but sustained transmission in rural communities on the Thai–Myanmar border. Methods A cross-sectional behaviour and net survey, observational surveys and entomological collections in both villages and forested farm huts frequented by community members for subsistence farming practices were conducted. Results Community members frequently stayed overnight at subsistence farm huts or in the forest. Entomological collections showed higher biting rates of primary vectors in forested farm hut sites and in a more forested village setting compared to a village with clustered housing and better infrastructure. Despite high levels of outdoor biting, biting exposure occurred predominantly indoors, particularly for non-users of long-lasting insecticidal nets (LLINs). Risk of biting exposure was exacerbated by sub-optimal coverage of LLINs, particularly in subsistence farm huts and in the forest. Furthermore, early waking hours when people had left the safety of their nets coincided with peaks in biting in later morning hours. Conclusions Entomological and epidemiological findings suggest drivers and modulators of sustained infection prevalence in the area to be: higher mosquito abundance in forested areas where LLINs were used less frequently or could not be used; late sleeping and waking times coinciding with peak biting hours; feeding preferences of Anopheles taking them away from contact with LLIN and indoor residual spraying (IRS), e.g. exophagy and zoophagy; non-use of LLIN and use of damaged/torn LLIN; high population movement across the border and into forested areas thereby increasing risk of exposure, decreasing use of protection and limiting access to healthcare; and, Plasmodium vivax predominance resulting in relapse(s) of previous infection. The findings highlight gaps in current intervention coverage beyond the village setting. Electronic supplementary material The online version of this article (10.1186/s12936-019-2852-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hannah M Edwards
- Department of Disease Epidemiology, Imperial College London, London, UK. .,Malaria Consortium Asia, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
| | - Patchara Sriwichai
- Department of Entomology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Kirakorn Kirabittir
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Jetsumon Prachumsri
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Irwin F Chavez
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Jeffrey Hii
- Department of Disease Epidemiology, Imperial College London, London, UK
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