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Pongsoipetch K, Walshe R, Mukem S, Kamsri T, Singkham N, Sudathip P, Kitchakarn S, Maude RR, Maude RJ. Mapping malaria transmission foci in Northeast Thailand from 2011 to 2021: approaching elimination in a hypoendemic area. Malar J 2024; 23:212. [PMID: 39020432 PMCID: PMC11253324 DOI: 10.1186/s12936-024-05026-6] [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: 03/20/2024] [Accepted: 06/25/2024] [Indexed: 07/19/2024] Open
Abstract
BACKGROUND Thailand is approaching local elimination of malaria in the eastern provinces. It has successfully reduced the number of cases over the past decade, but there are persistent transmission hot spots in and around forests. This study aimed to use data from the malaria surveillance system to describe the spatiotemporal trends of malaria in Northeast Thailand and fine-scale patterns in locally transmitted cases between 2011 and 2021. METHODS Case data was stratified based on likely location of infection and parasite species. Annual Parasite Index per 1000 population (API) was calculated for different categories. Time series decomposition was performed to identify trends and seasonal patterns. Statistically significant clusters of high (hot spots) and low (cold spots) API were identified using the Getis-Ord Gi* statistic. The stability of those hot spots and the absolute change in the proportion of API density from baseline were compared by case type. RESULTS The total number of confirmed cases experienced a non-linear decline by 96.6%, from 1061 in 2011 to 36 in 2021. There has been a decline in both Plasmodium vivax and Plasmodium falciparum case numbers, with only four confirmed P. falciparum cases over the last two years-a 98.89% drop from 180 in 2011. API was generally higher in Si Sa Ket province, which had peaks every 2-3 years. There was a large outbreak in Ubon Ratchathani in 2014-2016 which had a high proportion of P. falciparum reported. The proportion of cases classified increased over the study period, and the proportion of cases classed as indigenous to the village of residence increased from 0.2% to 33.3%. There were stable hot spots of indigenous and imported cases in the south of Si Sa Ket and southeast of Ubon Ratchathani. Plasmodium vivax hot spots were observed into recent years, while those of P. falciparum decreased to zero in Ubon in 2020 and emerged in the eastern part in 2021, the same year that P. falciparum hot spots in Si Sa Ket reached zero. CONCLUSIONS There has been a large, non-linear decline in the number of malaria cases reported and an increasing proportion of cases are classed as indigenous to the patient's village of residence. Stable hot spots of ongoing transmission in the forested border areas were identified, with transmission likely persisting because of remote location and high-risk forest-going behaviours. Future efforts should include cross-border collaboration and continued targeting of high-risk behaviours to reduce the risk of imported cases seeding local transmission.
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Affiliation(s)
- Kulchada Pongsoipetch
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Rebecca Walshe
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Suwanna Mukem
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Tanong Kamsri
- Phibun Mangsahan Hospital, Ubon Ratchathani, Thailand
- Provincial Health Office, Ubon Ratchathani, Thailand
| | | | - Prayuth Sudathip
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, 11000, Thailand
| | - Suravadee Kitchakarn
- Division of Vector Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, 11000, Thailand
| | | | - Richard James 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.
- The Open University, Milton Keynes, UK.
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Sridapan T, Rattanakoch P, Kijprasong K, Srisutham S. Drug resistance markers in Plasmodium vivax isolates from a Kanchanaburi province, Thailand between January to May 2023. PLoS One 2024; 19:e0304337. [PMID: 38968216 PMCID: PMC11226124 DOI: 10.1371/journal.pone.0304337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 05/10/2024] [Indexed: 07/07/2024] Open
Abstract
BACKGROUND Plasmodium vivax has become the predominant species in the border regions of Thailand. The emergence and spread of antimalarial drug resistance in P. vivax is one of the significant challenges for malaria control. Continuous surveillance of drug resistance is therefore necessary for monitoring the development of drug resistance in the region. This study aims to investigate the prevalence of the mutation in the P. vivax multidrug resistant 1 (Pvmdr1), dihydrofolate reductase (Pvdhfr), and dihydropteroate synthetase (Pvdhps) genes conferred resistance to chloroquine (CQ), pyrimethamine (P) and sulfadoxine (S), respectively. METHOD 100 P. vivax isolates were obtained between January to May 2023 from a Kanchanaburi province, western Thailand. Nucleotide sequences of Pvmdr1, Pvdhfr, and Pvdhps genes were amplified and sequenced. The frequency of single nucleotide polymorphisms (SNPs)-haplotypes of drug-resistant alleles was assessed. The linkage disequilibrium (LD) tests were also analyzed. RESULTS In Pvmdr1, T958M, Y976F, and F1076L, mutations were detected in 100%, 21%, and 23% of the isolates, respectively. In Pvdhfr, the quadruple mutant allele (I57R58M61T117) prevailed in 84% of the samples, followed by (L57R58M61T117) in 11%. For Pvdhps, the double mutant allele (G383G553) was detected (48%), followed by the triple mutant allele (G383M512G553) (47%) of the isolates. The most prevalent combination of Pvdhfr (I57R58M61T117) and Pvdhps (G383G553) alleles was sextuple mutated haplotypes (48%). For LD analysis, the association in the SNPs pairs was found between the intragenic and intergenic regions of the Pvdhfr and Pvdhps genes. CONCLUSION The study has recently updated the high prevalence of three gene mutations associated with CQ and SP resistance. Genetic monitoring is therefore important to intensify in the regions to further assess the spread of drug resistant. Our data also provide evidence on the distribution of drug resistance for the early warning system, thereby threatening P. vivax malaria treatment policy decisions at the national level.
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Affiliation(s)
- Thanawat Sridapan
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Paweesuda Rattanakoch
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | | | - Suttipat Srisutham
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
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Khulmanee T, Thita T, Kritsiriwutinan K, Boonyuen U, Saai A, Inkabjan K, Chakrabarti R, Rathod PK, Krudsood S, Mungthin M, Patrapuvich R. Low Genetic Diversity of Plasmodium vivax Circumsporozoite Surface Protein in Clinical Isolates from Southern Thailand. Trop Med Infect Dis 2024; 9:94. [PMID: 38787027 PMCID: PMC11125738 DOI: 10.3390/tropicalmed9050094] [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: 02/22/2024] [Revised: 04/13/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024] Open
Abstract
The genetic diversity within the circumsporozoite surface protein (PvCSP) of Plasmodium vivax, the predominant malaria species in Thailand, is primarily observed in the northwestern region along the Thailand-Myanmar border. However, as P. vivax cases shift to southern provinces, particularly Yala Province near the Thailand-Malaysia border, PvCSP diversity remains understudied. Between 2018 and 2020, 89 P. vivax isolates were collected in Yala Province, a significant malaria hotspot. Employing polymerase chain reaction amplification, restriction fragment length polymorphism (PCR-RFLP), and DNA sequencing, the gene encoding PvCSP (Pvcsp) was analyzed. All Yala P. vivax isolates belonged to the VK210 type, distinct from strains in the western region near the Myanmar border. The central repeat region of Pvcsp revealed two common peptide repeat motifs-GDRADGQPA and GDRAAGQPA-across all southern isolates. Sequence analysis identified two subtypes, with S1 more prevalent (92%) than S2 (8%). This study underscores the limited diversity of VK210 variants of P. vivax populations in southern Thailand. These baseline findings facilitate monitoring for potential new parasite variants, aiding in the future control and management of P. vivax in the region.
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Affiliation(s)
- Tachin Khulmanee
- Drug Research Unit for Malaria, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Thanyapit Thita
- Drug Research Unit for Malaria, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | | | - Usa Boonyuen
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | | | | | - Rimi Chakrabarti
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | | | - Srivicha Krudsood
- Clinical Malaria Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Mathirut Mungthin
- Department of Parasitology, Phramongkutklao College of Medicine, Bangkok 10400, Thailand
| | - Rapatbhorn Patrapuvich
- Drug Research Unit for Malaria, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
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Li Y, Ran Z, Tsai L, Williams S. Using call detail records to determine mobility patterns of different socio-demographic groups in the western area of Sierra Leone during early COVID-19 crisis. ENVIRONMENT AND PLANNING. B, URBAN ANALYTICS AND CITY SCIENCE 2023; 50:1298-1312. [PMID: 38603005 PMCID: PMC10247678 DOI: 10.1177/23998083231158377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Human mobility patterns created from mobile phone call detail records (CDRs) can provide an essential resource in data-poor environments to monitor the effects of health outbreaks. Analysis of this data can be instrumental for understanding the movement pattern of populations allowing governments to set and refine policies to respond to community health risks. Building on CDR mobility analysis techniques, this research set out to test whether combining CDR mobility indicators with socio-economic information can illustrate differences between different socio-economic groups' exposure risks to COVID-19. The work focuses on the Western Area of Sierra Leone which houses the capital Freetown because it lacks existing mobility data and therefore can be a great example of how CDR can be transformed for this use. To determine mobility patterns, we applied the radius of gyration, regularity of movement, and motif types analytics commonly used in CDR research. We then applied a clustering algorithm to these results to understand user trends. Then we compared the results of the three methods with socio-economic status determined from census data in the same geography. The results show the daily movement of cell phone users of lower socio-economic status covered greater distances in the Western Area before and after lockdown, thereby showing a greater risk to COVID-19. The research also shows that groups of higher social status decreased mobility significantly after lockdown and did not return to pre-COVID-19 levels, unlike lower-social status groups.
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Affiliation(s)
- Yanchao Li
- Department of Urban Studies and Planning, Massachusetts Institute of Technology, USA
| | - Ziyu Ran
- Department of Urban Studies and Planning, Massachusetts Institute of Technology, USA
| | - Lily Tsai
- Department of Political Science, Massachusetts Institute of Technology, USA
| | - Sarah Williams
- Department of Urban Studies and Planning, Massachusetts Institute of Technology, 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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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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