Epidemiological profiles of recurrent malaria episodes in an endemic area along the Thailand-Myanmar border: a prospective cohort study
Abstract Background In low malaria transmission areas, many people acquire multiple malaria infections within a single season. This study aimed to describe the pattern and epidemiological profile of malaria recurrence in a hypoendemic area of western Thailand and identify factors associated with hav...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2019-04-01
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| Series: | Malaria Journal |
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| Online Access: | http://link.springer.com/article/10.1186/s12936-019-2763-5 |
| _version_ | 1818941069861060608 |
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| author | Saranath Lawpoolsri Jetsumon Sattabongkot Jeeraphat Sirichaisinthop Liwang Cui Kirakorn Kiattibutr Nattawan Rachaphaew Kritsana Suk-uam Amnat Khamsiriwatchara Jaranit Kaewkungwal |
| author_facet | Saranath Lawpoolsri Jetsumon Sattabongkot Jeeraphat Sirichaisinthop Liwang Cui Kirakorn Kiattibutr Nattawan Rachaphaew Kritsana Suk-uam Amnat Khamsiriwatchara Jaranit Kaewkungwal |
| author_sort | Saranath Lawpoolsri |
| collection | DOAJ |
| description | Abstract Background In low malaria transmission areas, many people acquire multiple malaria infections within a single season. This study aimed to describe the pattern and epidemiological profile of malaria recurrence in a hypoendemic area of western Thailand and identify factors associated with having multiple malaria episodes. Methods An open cohort of 7000 residents in seven clusters along the Thai-Myanmar border was followed during a 6.5-year period (2011–mid 2017). Symptomatic and asymptomatic malaria infections were detected by passive case detection (PCD), weekly household visit, and mass blood surveys every 4–6 months. Malaria recurrence was defined as subsequent parasitaemic episodes occurred later than 7 days after receiving anti-malarial treatment. This study focused on analysis of recurrent episodes that occurred within 1 year after treatment. Numbers of malaria cases with single and multiple episodes were compared between clusters. Kaplan–Meier curve was performed to determine the intervals of recurrent episodes by Plasmodium species and age groups. The ordinal logistic model was used to determine factors associated with multiple malaria episodes, and to compare with single episodes, and those with no malaria infection. Results The cumulative incidence of malaria in the study area was 5.2% over the 6.5 years. Overall, 410 malaria patients were detected. Of these patients, 20% and 16% had multiple malaria episodes during the entire period and within 1 year after initial treatment, respectively. About 80% of repeated malaria episodes were caused by the same Plasmodium species as the primary infections. The median interval and interquartile range (IQR) between the first and second episode was 88 (43–175) days for all parasites, 56 (35–133) days for two Plasmodium falciparum episodes, and 90 (59–204) days for two Plasmodium vivax episodes. The interval between the episodes was increased with age. Factors significantly associated with multiple episodes of malaria infection included male sex, young age, Karen ethnicity, forest-related occupation, and having other malaria infected persons in the same house in the same period. Conclusions People who have multiple malaria episodes may play an important role in maintaining malaria transmission in the area. Understanding epidemiological profiles of this group is important for planning strategies to achieve the elimination goal. |
| first_indexed | 2024-12-20T06:49:41Z |
| format | Article |
| id | doaj.art-9d953f103bfa46828ed3e159ac7ba30d |
| institution | Directory Open Access Journal |
| issn | 1475-2875 |
| language | English |
| last_indexed | 2024-12-20T06:49:41Z |
| publishDate | 2019-04-01 |
| publisher | BMC |
| record_format | Article |
| series | Malaria Journal |
| spelling | doaj.art-9d953f103bfa46828ed3e159ac7ba30d2022-12-21T19:49:35ZengBMCMalaria Journal1475-28752019-04-0118111110.1186/s12936-019-2763-5Epidemiological profiles of recurrent malaria episodes in an endemic area along the Thailand-Myanmar border: a prospective cohort studySaranath Lawpoolsri0Jetsumon Sattabongkot1Jeeraphat Sirichaisinthop2Liwang Cui3Kirakorn Kiattibutr4Nattawan Rachaphaew5Kritsana Suk-uam6Amnat Khamsiriwatchara7Jaranit Kaewkungwal8Center of Excellence in Biomedical and Public Health Informatics (BIOPHICS), Faculty of Tropical Medicine, Mahidol UniversityMahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBureau of Vector-Borne Diseases, Department of Disease Control, Ministry of Public HealthDivision of Infectious Diseases and Internal Medicine, Department of Internal Medicine, University of South FloridaMahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol UniversityMahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol UniversityVector-Borne Disease Control Center 2.3, Ministry of Public HealthCenter of Excellence in Biomedical and Public Health Informatics (BIOPHICS), Faculty of Tropical Medicine, Mahidol UniversityCenter of Excellence in Biomedical and Public Health Informatics (BIOPHICS), Faculty of Tropical Medicine, Mahidol UniversityAbstract Background In low malaria transmission areas, many people acquire multiple malaria infections within a single season. This study aimed to describe the pattern and epidemiological profile of malaria recurrence in a hypoendemic area of western Thailand and identify factors associated with having multiple malaria episodes. Methods An open cohort of 7000 residents in seven clusters along the Thai-Myanmar border was followed during a 6.5-year period (2011–mid 2017). Symptomatic and asymptomatic malaria infections were detected by passive case detection (PCD), weekly household visit, and mass blood surveys every 4–6 months. Malaria recurrence was defined as subsequent parasitaemic episodes occurred later than 7 days after receiving anti-malarial treatment. This study focused on analysis of recurrent episodes that occurred within 1 year after treatment. Numbers of malaria cases with single and multiple episodes were compared between clusters. Kaplan–Meier curve was performed to determine the intervals of recurrent episodes by Plasmodium species and age groups. The ordinal logistic model was used to determine factors associated with multiple malaria episodes, and to compare with single episodes, and those with no malaria infection. Results The cumulative incidence of malaria in the study area was 5.2% over the 6.5 years. Overall, 410 malaria patients were detected. Of these patients, 20% and 16% had multiple malaria episodes during the entire period and within 1 year after initial treatment, respectively. About 80% of repeated malaria episodes were caused by the same Plasmodium species as the primary infections. The median interval and interquartile range (IQR) between the first and second episode was 88 (43–175) days for all parasites, 56 (35–133) days for two Plasmodium falciparum episodes, and 90 (59–204) days for two Plasmodium vivax episodes. The interval between the episodes was increased with age. Factors significantly associated with multiple episodes of malaria infection included male sex, young age, Karen ethnicity, forest-related occupation, and having other malaria infected persons in the same house in the same period. Conclusions People who have multiple malaria episodes may play an important role in maintaining malaria transmission in the area. Understanding epidemiological profiles of this group is important for planning strategies to achieve the elimination goal.http://link.springer.com/article/10.1186/s12936-019-2763-5Recurrent malariaThai-Myanmar borderAnti-malarial drug resistanceMultiple episodesLow malaria transmissionMalaria elimination |
| spellingShingle | Saranath Lawpoolsri Jetsumon Sattabongkot Jeeraphat Sirichaisinthop Liwang Cui Kirakorn Kiattibutr Nattawan Rachaphaew Kritsana Suk-uam Amnat Khamsiriwatchara Jaranit Kaewkungwal Epidemiological profiles of recurrent malaria episodes in an endemic area along the Thailand-Myanmar border: a prospective cohort study Malaria Journal Recurrent malaria Thai-Myanmar border Anti-malarial drug resistance Multiple episodes Low malaria transmission Malaria elimination |
| title | Epidemiological profiles of recurrent malaria episodes in an endemic area along the Thailand-Myanmar border: a prospective cohort study |
| title_full | Epidemiological profiles of recurrent malaria episodes in an endemic area along the Thailand-Myanmar border: a prospective cohort study |
| title_fullStr | Epidemiological profiles of recurrent malaria episodes in an endemic area along the Thailand-Myanmar border: a prospective cohort study |
| title_full_unstemmed | Epidemiological profiles of recurrent malaria episodes in an endemic area along the Thailand-Myanmar border: a prospective cohort study |
| title_short | Epidemiological profiles of recurrent malaria episodes in an endemic area along the Thailand-Myanmar border: a prospective cohort study |
| title_sort | epidemiological profiles of recurrent malaria episodes in an endemic area along the thailand myanmar border a prospective cohort study |
| topic | Recurrent malaria Thai-Myanmar border Anti-malarial drug resistance Multiple episodes Low malaria transmission Malaria elimination |
| url | http://link.springer.com/article/10.1186/s12936-019-2763-5 |
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