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Duong HD, Taniguchi Y, Takashima Y, Sekiguchi S, Aye KM, Ahmadi P, Bui LK, Irie T, Nagayasu E, Yoshida A. Diagnostic value of recombinant nanoluciferase fused Toxoplasma gondii antigens in Luciferase-linked Antibody Capture Assay (LACA) for Toxoplasma infection in pigs. J Vet Med Sci 2022; 84:905-913. [PMID: 35584943 PMCID: PMC9353080 DOI: 10.1292/jvms.22-0099] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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] [Indexed: 11/22/2022] Open
Abstract
Toxoplasmosis is a widespread protozoan zoonosis. Since ingesting undercooked meat harboring Toxoplasma gondii cyst is considered one of the major transmission routes to
humans, the screening of T. gondii in meat-producing animals can reduce the risk of food-borne toxoplasmosis in humans. Among serological diagnostic methods,
Luciferase-linked Antibody Capture Assay (LACA) has been found to be a promising platform with high sensitivity and specificity. In this study, we aimed to evaluate recombinant
nanoluciferase fused-T. gondii antigens (rNluc-GRA6, rNluc-GRA7, rNluc-GRA8 and rNluc-BAG1) for their potential use in LACA for pigs. As a result, the sensitivity of GRA6-,
GRA7-, GRA8- and BAG1-LACA were 70.0%, 80.0%, 80.0% and 30.0% with specificity 87.0%, 81.5%, 74.1% and 50.0%, respectively. The cocktail LACA using a mixture of rNluc-GRA6, rNluc-GRA7 and
rNluc-GRA8 indicated higher sensitivity (90.0%) and a similar specificity (96.3%) in comparison with the commercial ELISA kit. Compared to the Dye-Test as a reference test, cocktail LACA
showed strong agreement (kappa value=0.811) when we assessed pig sera collected at the slaughterhouse. In addition, we also successfully established the rapid LACA format for the detection
of Toxoplasma infection in pigs (called Rapid-LACA) in which the test could be performed within 30 min. In Rapid-LACA, the protein A pre-coated/blocked plates could be
preserved at −30°C, 4°C or room temperature conditions for at least two months without compromising on the quality of assay.
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Affiliation(s)
- Hieu Duc Duong
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki.,Department of Veterinary Parasitology, Faculty of Veterinary Medicine, Vietnam National University of Agriculture
| | - Yuji Taniguchi
- Department of Veterinary Parasitology, Faculty of Applied Biological Sciences, Gifu University
| | - Yasuhiro Takashima
- Department of Veterinary Parasitology, Faculty of Applied Biological Sciences, Gifu University
| | - Satoshi Sekiguchi
- Laboratory of Animal Infectious Disease and Prevention, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki.,Centre for Animal Diseases Control (CADIC), University of Miyazaki
| | - Khin Myo Aye
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki.,Parasitology Research Division, Department of Medical Research
| | - Parnian Ahmadi
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki
| | - Linh Khanh Bui
- Department of Veterinary Parasitology, Faculty of Veterinary Medicine, Vietnam National University of Agriculture
| | - Takao Irie
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki.,Centre for Animal Diseases Control (CADIC), University of Miyazaki
| | - Eiji Nagayasu
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki
| | - Ayako Yoshida
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki.,Centre for Animal Diseases Control (CADIC), University of Miyazaki
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Nyunt MH, Aye KM, Naing ST, Mon AS, Htwe MM, Win SM, Thwe WM, Zaw NN, Kyaw MP, Thi A. Residual malaria among migrant workers in Myanmar: why still persistent and how to eliminate it? BMC Infect Dis 2021; 21:1146. [PMID: 34758727 PMCID: PMC8579646 DOI: 10.1186/s12879-021-06839-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 03/09/2021] [Accepted: 11/02/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Residual malaria is probably an important source for the re-emergence of malaria infection in the elimination era. Assessment to identify the factors influencing residual malaria in high-risk groups is needed to develop evidence-based decisions by stakeholders and policymakers. METHODS This study was conducted to explore the factors influencing the residual malaria infection among migrant workers in two sentinel sites (endemic vs. pre-elimination areas) in Myanmar using the mixed-model method. RESULTS A total of 102 migrant respondents (65 in Bamauk and 37 in Shwegyin) were included for the quantitative assessment using pretested questionnaires during household visits. Although 87.3% of them had insecticidal bed nets (ITNs/LLINs), only 68.3% of the migrants in Bamauk and 57.9% in Shwegyin used it regularly. The use of any bed net was high (79.9% in Bamauk vs. 91.0% in Shwegyin). The mean LLINs in their families were 1.64 (95%CI: 1.48-1.81) in Bamauk and 2.89 (95%CI: 2.67-3.11) in Shwegyin. Most of them received no health information for malaria prevention within the last year and their knowledge about malaria was low. Their working nature was a challenge for control measures against malaria in migrants. CONCLUSION The strategy for distributing LLINs and health promotion activities for mobile/migrant populations should be reviewed, and an appropriate action plan should be developed for the specific migrant group. Moreover, health promotion activities for behavior change communication should be strengthened in the migrant population in Myanmar.
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Affiliation(s)
- Myat Htut Nyunt
- Department of Medical Research, Ministry of Health and Sports, Yangon, Republic of the Union of Myanmar.
| | - Khin Myo Aye
- Department of Medical Research, Ministry of Health and Sports, Yangon, Republic of the Union of Myanmar
| | - Shine Thura Naing
- Department of Medical Research, Ministry of Health and Sports, Yangon, Republic of the Union of Myanmar
| | - Aye Su Mon
- Department of Medical Research, Ministry of Health and Sports, Yangon, Republic of the Union of Myanmar
| | - Mi Mi Htwe
- Department of Medical Research, Ministry of Health and Sports, Yangon, Republic of the Union of Myanmar
| | - Su Mon Win
- Department of Medical Research, Ministry of Health and Sports, Yangon, Republic of the Union of Myanmar
| | - Wai Myat Thwe
- Department of Medical Research, Ministry of Health and Sports, Yangon, Republic of the Union of Myanmar
| | - Ni Ni Zaw
- Department of Medical Research, Ministry of Health and Sports, Yangon, Republic of the Union of Myanmar
| | - Myat Phone Kyaw
- Department of Medical Research, Ministry of Health and Sports, Yangon, Republic of the Union of Myanmar
| | - Aung Thi
- Department of Public Health, National Malaria Control Programme, Ministry of Health and Sports, Nay Pyi Taw, Republic of the Union of Myanmar
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Aye KM, Nagayasu E, Nyunt MH, Zaw NN, Thant KZ, Kyaw MP, Maruyama H. Seroprevalence of toxoplasmosis among reproductive-aged women in Myanmar and evaluation of luciferase immunoprecipitation system assay. BMC Infect Dis 2020; 20:906. [PMID: 33256616 PMCID: PMC7706230 DOI: 10.1186/s12879-020-05650-y] [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: 07/14/2020] [Accepted: 11/22/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUNDS Primary infection with Toxoplasma gondii during pregnancy can pose serious health problems for the fetus. However, the epidemiological status of toxoplasmosis among reproductive-aged population in Myanmar is largely unknown. Although luciferase immunoprecipitation system (LIPS) assays for serodiagnosis of toxoplasmosis was developed mostly using mouse infection model, had not been tested by using field-derived human samples. METHODS A total of 251 serum samples were collected from reproductive-aged women, residing in Shwegyin township, Bago region, Myanmar and analyzed with a commercial ELISA kit, as well as in-house LIPS assays. RESULTS The overall seroprevalence for Toxoplasma gondii infection by the commercial ELISA was 11.5%. No clear risk factor was identified except for being in the younger age group (15-30 years old). Overall, LIPS assays showed low sensitivity when the commercial ELSA was used as a reference test. CONCLUSION We identified the epidemiological situation of toxoplasmosis in some rural communities in Myanmar. The data obtained here will serve as a primary information for the effort to reduce toxoplasmosis in this region. Although looked promising in the previous experiments with mouse infection model, we found that the reported LIPS procedures need further improvements to increase the sensitivities.
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Affiliation(s)
- Khin Myo Aye
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar.,Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Kiyotake, Japan
| | - Eiji Nagayasu
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Kiyotake, Japan.
| | - Myat Htut Nyunt
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Ni Ni Zaw
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Kyaw Zin Thant
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Myat Phone Kyaw
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Haruhiko Maruyama
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Kiyotake, Japan
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Duong HD, Appiah-Kwarteng C, Takashima Y, Aye KM, Nagayasu E, Yoshida A. A novel luciferase-linked antibody capture assay (LACA) for the diagnosis of Toxoplasma gondii infection in chickens. Parasitol Int 2020; 77:102125. [PMID: 32311471 DOI: 10.1016/j.parint.2020.102125] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/20/2020] [Accepted: 04/14/2020] [Indexed: 12/17/2022]
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite that causes the most common parasitic zoonosis worldwide in multiples species of mammals and birds. Although free-range chickens may play a role as an important reservoir for T. gondii, there is no reliable and commercially available diagnostic test for this disease in chickens. In this study, we aimed to develop a novel Luciferase-linked Antibody Capture Assay (LACA) for the serodiagnosis of Toxoplasma infection in chickens. Recombinant nanoluciferase fused-T. gondii dense granule antigen 8 (rNluc-GRA8) was produced and applied to LACA assay as a diagnostic antigen. GRA8-LACA was tested with the sera from uninfected and experimentally infected chickens with T. gondii and other parasitic pathogens and showed unexpectedly high sensitivity (90.5%) and specificity (95.4%). Interestingly, E. coli lysate expressing rNluc-GRA8 could be applied in GRA8-LACA with 85.7% sensitivity and an increased specificity (96.9%) that gave better diagnostic performance compared to conventional ELISA. We applied our diagnostic system to examine 267 free-range chicken sera collected from 12 farms and 100 closed-house broiler chicken sera from local poultry abattoirs. The overall seroprevalence of toxoplasmosis in free-range chickens was 10.9% (95% CI: 10.6%-11.1%), while no positive case was found in broiler chickens. GRA8-LACA could be a useful diagnostic technique for T. gondii infection in chickens. The detection of T. gondii seropositive chickens in this study warns a potential risk of Toxoplasma transmission by the consumption of raw or undercooked chicken meat.
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Affiliation(s)
- Hieu Duc Duong
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan; Department of Veterinary Parasitology, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Viet Nam
| | - Cornelia Appiah-Kwarteng
- Department of Veterinary Parasitology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Yasuhiro Takashima
- Department of Veterinary Parasitology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Khin Myo Aye
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; Parasitology Research Division, Department of Medical Research, Yangon, Myanmar
| | - Eiji Nagayasu
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Ayako Yoshida
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan; Centre for Animal Diseases Control (CADIC), University of Miyazaki, Miyazaki, Japan.
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5
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Aye KM, Nagayasu E, Baba M, Yoshida A, Takashima Y, Maruyama H. Evaluation of LIPS (luciferase immunoprecipitation system) for serodiagnosis of Toxoplasmosis. J Immunol Methods 2018; 462:91-100. [PMID: 30201391 DOI: 10.1016/j.jim.2018.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 08/17/2018] [Accepted: 09/06/2018] [Indexed: 01/05/2023]
Abstract
Development of reliable, quantitative technologies for serodiagnosis of Toxoplasma gondii infection remains desirable. The luciferase immunoprecipitation system (LIPS) is a relatively simple, highly sensitive, and rapid quantitative immunoassay. The major advantages of this assay over ELISA are a wider dynamic range, shorter overall assay time, and less sample volume. In this study, we aimed to use this method for the serodiagnosis of toxoplasmosis. Recombinant Toxoplasma antigens (dense granule antigens GRA6, GRA7, and GRA8 and bradyzoite antigen BAG1) fused with nanoluciferase (Nluc, a small luciferase enzyme) were expressed in Escherichia coli, purified, and tested in LIPS assays with sera from experimental mice infected with T. gondii and a WHO standard anti-Toxoplasma human immunoglobulin (TOXM). In the experimentally infected mice, LIPS assays detected antibodies against Nluc-GRA6, Nluc-GRA7, and Nluc-GRA8 as early as day 14, whereas antibodies against Nluc-BAG1 remained undetected until day 21 and then showed significant elevation on day 60. In TOXM sera, LIPS assays with each Nluc recombinant protein produced reliable standard curves with a coefficient of determination (R2) of 0.980-0.989 for GRA6, 0.986-0.990 for GRA7, 0.998-0.999 for GRA8, and 0.942-0.987 for BAG1. The detection limits were estimated to be 3.9, 2, 1, and 1 IU/ml for rGRA6, rGRA7, rGRA8, and rBAG1, respectively. The LIPS assay for toxoplasmosis could detect antibodies against T. gondii in the mouse and human sera with a reasonably high sensitivity. We consider the LIPS assay to be a promising alternative tool for screening, diagnosing, and monitoring toxoplasmosis. In particular, detection of antibodies against BAG1 may be useful for a longitudinal seroprevalence study in suspected high-risk areas on the basis of its elevated serum concentration in the chronic phase.
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Affiliation(s)
- Khin Myo Aye
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; Parasitology Research Division, Department of Medical Research, Yangon, Myanmar.
| | - Eiji Nagayasu
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
| | - Minami Baba
- Department of Veterinary Parasitology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan; Proteo-Science Center, Division of Molecular Parasitology, Ehime University, Toon, Japan.
| | - Ayako Yoshida
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan; Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan.
| | - Yasuhiro Takashima
- Department of Veterinary Parasitology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan; Center for Highly Advanced Integration of Nano and Life Sciences, Gifu University (G-CHAIN), Gifu, Japan.
| | - Haruhiko Maruyama
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
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Oo SZM, Thaung S, Maung YNM, Aye KM, Aung ZZ, Thu HM, Thant KZ, Minakawa N. Effectiveness of a novel long-lasting pyriproxyfen larvicide (SumiLarv®2MR) against Aedes mosquitoes in schools in Yangon, Myanmar. Parasit Vectors 2018; 11:16. [PMID: 29306333 PMCID: PMC5756364 DOI: 10.1186/s13071-017-2603-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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: 09/19/2017] [Accepted: 12/20/2017] [Indexed: 11/16/2022] Open
Abstract
Background Mosquito-borne diseases are prevalent in Myanmar, with the number of dengue cases showing a significant increase in recent years. Dengue vectors have developed resistance to insecticides and currently used larvicides show only short-term effectiveness. As a result, an alternative larvicide is urgently needed. The present study evaluated the larvicidal effectiveness of long-lasting pyriproxyfen resin discs (SumiLarv®2MR) against dengue virus vectors in schools in Hlaing Thar Yar Township, Yangon. Results The proportion of Aedes mosquito-infested containers was significantly reduced in the schools applied with the larvicide (OR: 0.24, 95% CI: 0.12–0.48) while there was little reduction noted in the control schools (OR: 0.97, 95% CI: 0.55–1.72). The density of infested containers was also significantly reduced in the intervention schools (Beta: -1.50, 95% CI: -1.98– -1.04), but there was no significant reduction in density in the control schools (Beta: -0.19, 95% CI: -0.53–0.14). The proportion of adult emergence was less than 20% in the treated water collected from the intervention schools for six months, while the proportion was over 90% in the untreated water. In addition, eight-month-old SumiLarv®2MR resin discs were still 100% effective when tested in the laboratory. More than 50% of the discs disappeared from treated containers within two months of intervention. Conclusions SumiLarv®2MR was effective in reducing Aedes-infested containers at least six months after its application in schools. This new pyriproxyfen formulation has great potential for improving the current dengue vector control program in Myanmar.
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Affiliation(s)
- Sai Zaw Min Oo
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.,Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.,Department of Medical Research, Ministry of Health and Sports, 11191, Ziwaka Road, Dagon Township, Yangon, Myanmar
| | - Sein Thaung
- Department of Medical Research, Ministry of Health and Sports, 11191, Ziwaka Road, Dagon Township, Yangon, Myanmar
| | - Yan Naung Maung Maung
- Department of Medical Research, Ministry of Health and Sports, 11191, Ziwaka Road, Dagon Township, Yangon, Myanmar
| | - Khin Myo Aye
- Department of Medical Research, Ministry of Health and Sports, 11191, Ziwaka Road, Dagon Township, Yangon, Myanmar
| | - Zar Zar Aung
- Department of Medical Research, Ministry of Health and Sports, 11191, Ziwaka Road, Dagon Township, Yangon, Myanmar
| | - Hlaing Myat Thu
- Department of Medical Research, Ministry of Health and Sports, 11191, Ziwaka Road, Dagon Township, Yangon, Myanmar
| | - Kyaw Zin Thant
- Department of Medical Research, Ministry of Health and Sports, 11191, Ziwaka Road, Dagon Township, Yangon, Myanmar
| | - Noboru Minakawa
- Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
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Htun MW, Mon NCN, Aye KM, Hlaing CM, Kyaw MP, Handayuni I, Trimarsanto H, Bustos D, Ringwald P, Price RN, Auburn S, Thriemer K. Chloroquine efficacy for Plasmodium vivax in Myanmar in populations with high genetic diversity and moderate parasite gene flow. Malar J 2017; 16:281. [PMID: 28693552 PMCID: PMC5504659 DOI: 10.1186/s12936-017-1912-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [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: 04/13/2017] [Accepted: 06/26/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Plasmodium vivax malaria remains a major public health burden in Myanmar. Resistance to chloroquine (CQ), the first-line treatment for P. vivax, has been reported in the country and has potential to undermine local control efforts. METHODS Patients over 6 years of age with uncomplicated P. vivax mono-infection were enrolled into clinical efficacy studies in Myawaddy in 2014 and Kawthoung in 2012. Study participants received a standard dose of CQ (25 mg/kg over 3 days) followed by weekly review until day 28. Pvmdr1 copy number (CN) and microsatellite diversity were assessed on samples from the patients enrolled in the clinical study and additional cross-sectional surveys undertaken in Myawaddy and Shwegyin in 2012. RESULTS A total of 85 patients were enrolled in the CQ clinical studies, 25 in Myawaddy and 60 in Kawthoung. One patient in Myawaddy (1.2%) had an early treatment failure and two patients (2.3%) in Kawthoung presented with late treatment failures on day 28. The day 28 efficacy was 92.0% (95% CI 71.6-97.9) in Myawaddy and 98.3% (95% CI 88.7-99.8) in Kawthoung. By day 2, 92.2% (23/25) in Myawaddy and 85.0% (51/60) in Kawthoung were aparasitaemic. Genotyping and pvmdr1 CN assessment was undertaken on 43, 52 and 46 clinical isolates from Myawaddy, Kawthoung and Shwegyin respectively. Pvmdr1 amplification was observed in 3.2% (1/31) of isolates in Myawaddy, 0% (0/49) in Kawthoung and 2.5% (1/40) in Shwegyin. Diversity was high in all sites (H E 0.855-0.876), with low inter-population differentiation (F ST 0.016-0.026, P < 0.05). CONCLUSIONS Treatment failures after chloroquine were observed following chloroquine monotherapy, with pvmdr1 amplification present in both Myawaddy and Shwegyin. The results emphasize the importance of ongoing P. vivax drug resistance surveillance in Myanmar, particularly given the potential connectivity between parasite population at different sites.
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Affiliation(s)
- Myo Win Htun
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Nan Cho Nwe Mon
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Khin Myo Aye
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Chan Myae Hlaing
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Myat Phone Kyaw
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Irene Handayuni
- 0000 0000 8523 7955grid.271089.5Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810 Australia
| | - Hidayat Trimarsanto
- 0000 0004 1795 0993grid.418754.bEijkman Institute for Molecular Biology, Jl. Diponegoro 69, Central Jakarta, 10430 Indonesia ,grid.466915.9The Ministry of Research and Technology (RISTEK), Jakarta, Indonesia ,0000 0001 0746 0534grid.432292.cAgency for Assessment and Application of Technology, Jl. MH Thamrin 8, Jakarta, 10340 Indonesia
| | - Dorina Bustos
- 0000 0004 0576 2573grid.415836.dWorld Health Organization, Country Office for Thailand, Ministry of Public Health, Nonthaburi, Thailand
| | - Pascal Ringwald
- 0000000121633745grid.3575.4Global Malaria Programme, World Health Organization, 20 Avenue Appia, 1211 Geneva, 27, Switzerland
| | - Ric N. Price
- 0000 0000 8523 7955grid.271089.5Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810 Australia ,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford Old Road Campus, Oxford, UK
| | - Sarah Auburn
- 0000 0000 8523 7955grid.271089.5Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810 Australia
| | - Kamala Thriemer
- 0000 0000 8523 7955grid.271089.5Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810 Australia
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8
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Soe TN, Wu Y, Tun MW, Xu X, Hu Y, Ruan Y, Win AYN, Nyunt MH, Mon NCN, Han KT, Aye KM, Morris J, Su P, Yang Z, Kyaw MP, Cui L. Genetic diversity of Plasmodium falciparum populations in southeast and western Myanmar. Parasit Vectors 2017; 10:322. [PMID: 28676097 PMCID: PMC5496439 DOI: 10.1186/s13071-017-2254-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [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: 12/21/2016] [Accepted: 06/19/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The genetic diversity of malaria parasites reflects the complexity and size of the parasite populations. This study was designed to explore the genetic diversity of Plasmodium falciparum populations collected from two southeastern areas (Shwekyin and Myawaddy bordering Thailand) and one western area (Kyauktaw bordering Bangladesh) of Myanmar. METHODS A total of 267 blood samples collected from patients with acute P. falciparum infections during 2009 and 2010 were used for genotyping at the merozoite surface protein 1 (Msp1), Msp2 and glutamate-rich protein (Glurp) loci. RESULTS One hundred and eighty four samples were successfully genotyped at three genes. The allelic distributions of the three genes were all significantly different among three areas. MAD20 and 3D7 were the most prevalent alleles in three areas for Msp1 and Msp2, respectively. The Glurp allele with a bin size of 700-750 bp was the most prevalent both in Shwekyin and Myawaddy, whereas two alleles with bin sizes of 800-850 bp and 900-1000 bp were the most prevalent in the western site Kyauktaw. Overall, 73.91% of samples contained multiclonal infections, resulting in a mean multiplicity of infection (MOI) of 1.94. Interestingly, the MOI level presented a rising trend with the order of Myawaddy, Kyauktaw and Shwekyin, which also paralleled with the increasing frequencies of Msp1 RO33 and Msp2 FC27 200-250 bp alleles. Msp1 and Msp2 genes displayed higher levels of diversity and higher MOI rates than Glurp. PCR revealed four samples (two from Shwekyin and two from Myawaddy) with mixed infections of P. falciparum and P. vivax. CONCLUSIONS This study genotyped parasite clinical samples from two southeast regions and one western state of Myanmar at the Msp1, Msp2 and Glurp loci, which revealed high levels of genetic diversity and mixed-strain infections of P. falciparum populations at these sites. The results indicated that malaria transmission intensity in these regions remained high and more strengthened control efforts are needed. The genotypic data provided baseline information for monitoring the impacts of malaria elimination efforts in the region.
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Affiliation(s)
- Than Naing Soe
- Department of Public Health, Ministry of Health and Sports, Nay Pyi Taw, Myanmar
| | - Yanrui Wu
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China.,Department of Cell Biology & Genetics, Kunming Medical University, Kunming, China
| | - Myo Win Tun
- Department of Medical Research, Yangon city, Myanmar
| | - Xin Xu
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Yue Hu
- Department of Pathology, Kunming Medical University, Kunming, China
| | - Yonghua Ruan
- Department of Pathology, Kunming Medical University, Kunming, China
| | | | | | | | - Kay Thwe Han
- Department of Medical Research, Yangon city, Myanmar
| | - Khin Myo Aye
- Department of Medical Research, Yangon city, Myanmar
| | - James Morris
- Department of Genetics and Biochemistry, Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, SC, USA
| | - Pincan Su
- Transfusion Medicine Research Department, Yunnan Kunming Blood Center, Kunming, China
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China.
| | - Myat Phone Kyaw
- Department of Medical Research, Yangon city, Myanmar. .,Myanmar Medical Association, Yangon, Myanmar.
| | - Liwang Cui
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China. .,Department of Entomology, Pennsylvania State University, University Park city, PA, 16802, USA.
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9
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Nyunt MH, Han JH, Wang B, Aye KM, Aye KH, Lee SK, Htut Y, Kyaw MP, Han KT, Han ET. Clinical and molecular surveillance of drug resistant vivax malaria in Myanmar (2009-2016). Malar J 2017; 16:117. [PMID: 28298235 PMCID: PMC5353783 DOI: 10.1186/s12936-017-1770-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [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: 01/17/2017] [Accepted: 03/08/2017] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND One of the major challenges for control and elimination of malaria is ongoing spread and emergence of drug resistance. While epidemiology and surveillance of the drug resistance in falciparum malaria is being explored globally, there are few studies on drug resistance vivax malaria. METHODS To assess the spread of drug-resistant vivax malaria in Myanmar, a multisite, prospective, longitudinal study with retrospective analysis of previous therapeutic efficacy studies, was conducted. A total of 906 from nine study sites were included in retrospective analysis and 208 from three study sites in prospective study. Uncomplicated vivax mono-infected patients were recruited and monitored with longitudinal follow-up until day 28 after treatment with chloroquine. Amplification and sequence analysis of molecular markers, such as mutations in pvcrt-O, pvmdr1, pvdhps and pvdhfr, were done in day-0 samples in prospective study. RESULTS Clinical failure cases were found only in Kawthaung, southern Myanmar and western Myanmar sites within 2009-2016. Chloroquine resistance markers, pvcrt-O 'AAG' insertion and pvmdr1 mutation (Y976F) showed higher mutant rate in southern and central Myanmar than western site: 66.7, 72.7 vs 48.3% and 26.7, 17.0 vs 1.7%, respectively. A similar pattern of significantly higher mutant rate of antifolate resistance markers, pvdhps (S382A, K512M, A553G) and pvdhfr (F57L/I, S58R, T61M, S117T/N) were noted. CONCLUSIONS Although clinical failure rate was low, widespread distribution of chloroquine and antifolate resistance molecular makers alert to the emergence and spread of drug resistance vivax malaria in Myanmar. Proper strategy and action plan to eliminate and contain the resistant strain strengthened together with clinical and molecular surveillance on drug resistance vivax is recommended.
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Affiliation(s)
- Myat Htut Nyunt
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea.,Department of Medical Research, Yangon, Myanmar
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Bo Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Anhui, China
| | | | | | - Seong-Kyun Lee
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Ye Htut
- Department of Medical Research, Yangon, Myanmar
| | | | | | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea.
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10
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Nyunt MH, Wang B, Aye KM, Aye KH, Han JH, Lee SK, Han KT, Htut Y, Han ET. Molecular surveillance of artemisinin resistance falciparum malaria among migrant goldmine workers in Myanmar. Malar J 2017; 16:97. [PMID: 28249583 PMCID: PMC5333451 DOI: 10.1186/s12936-017-1753-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [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: 11/23/2016] [Accepted: 02/25/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Artemisinin resistance has been reported in Greater Mekong Sub-region countries, including Myanmar. After discovery of artemisinin resistance marker (K13), molecular surveillance on artemisinin resistance in endemic regions have been conducted. As the migrant population represents a high percentage of malaria cases, molecular surveillance of artemisinin resistance among migrant workers is of great concern. METHODS A cross-sectional survey was conducted in Shwegyin Township, where migrants work in the goldmines. Blood samples were collected from uncomplicated Plasmodium falciparum-infected migrant workers by active and passive cases screening with rapid diagnostic testing (RDT) and microscopy. Amplification and sequence analysis of artemisinin resistance molecular markers, such as k13, pfarps10, pffd, pfmdr2, pfmrp1, pfrad5, and pfcnbp, were carried out and pfmdr1 copy number analysis was conducted by real-time PCR. RESULTS Among the 100 falciparum-infected patients, most were male (90%), of working age (20-40 years) with median parasite density of 11,166 parasites/µL (range 270-110,472 parasites/µL). Artemisinin resistance molecular marker, k13 mutations were detected in (21/100, 21.0%) in which composed of a validated marker, C580Y (9/21, 42.9%) and candidate markers such as P574L (5/21, 23.8%), P667T (5/21, 23.8%) and M476I (2/21, 9.5%). Underlying genetic markers predisposing to become k13 mutants were found as V127M of pfarps10 (41/100, 41.0%), D153Y of pffd (64/100, 64.0%), T484I of pfmdr2 (58/100, 58.0%) and F1390I of pfmrp1 (24/100, 24.0%). The pfmdr1 copy number analysis revealed six copy numbers (1/100, 1.0%), three (2/100, 2.0%), two (8/100, 8.0%) and only one copy number (89/100, 89.0%). Only one sample showed both k13 mutation (P667T) and multiple copy number of pfmdr1. CONCLUSIONS High mutant rate of artemisinin resistance markers and relatively high pfmdr1 copy number among isolates collected from migrant goldmine workers alert the importance of containment measures among this target population. Clinical and molecular surveillance of artemisinin resistance among migrants should be scaled up.
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Affiliation(s)
- Myat Htut Nyunt
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea.,Department of Medical Research, Yangon, Myanmar
| | - Bo Wang
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea.,Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Anhui, People's Republic of China
| | | | | | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Seong-Kyun Lee
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | | | - Ye Htut
- Department of Medical Research, Yangon, Myanmar
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea.
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11
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Nyunt MH, Aye KM, Kyaw KT, Han SS, Aye TT, Wai KT, Kyaw MP. Challenges encountered by local health volunteers in early diagnosis and prompt treatment of malaria in Myanmar artemisinin resistance containment zones. Malar J 2016; 15:308. [PMID: 27267877 PMCID: PMC4895800 DOI: 10.1186/s12936-016-1368-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [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: 02/09/2016] [Accepted: 06/02/2016] [Indexed: 11/25/2022] Open
Abstract
Background After artemisinin resistance was reported, the Myanmar artemisinin resistance containment (MARC) project was initiated in 2011. One of the activities of MARC is to train volunteers for early diagnosis and prompt treatment by providing rapid diagnostic tests (RDT) and artemisinin combination therapy. This study aimed to fulfil the gap of information on the challenges faced by malaria volunteers in artemisinin-containment areas. Methods A cross-sectional, descriptive study was conducted in 11 townships in MARC areas to assess the challenges in early diagnosis of malaria and treatment by malaria volunteers using qualitative and quantitative approaches. Results Altogether 405 volunteers participated in the study. Although 97.5 % of volunteers can interpret a positive result for malaria, only 41.2 % correctly stated the persistence of a positive result in recently infected cases. Over 80 % knew the effects of temperature and humidity on performance of the malaria RDT. Unexpectedly, 15.1 % perceived that expired RDTs can still be useful for diagnosis although 98.3 % of respondents cited that the overall results of RDTs were reliable. Although most of them knew the treatment for malaria based on RDT results, some could not give the correct answer, while a few (2 %) mentioned artesunate monotherapy for RDT-negative cases. Training received by volunteers was also varied in study sites and 92.1 % believed that it was not sufficient. A certain portion of them faced the problem of regular supply of RDTs (9.9 %) and drugs (47.5 %), interpretation of result of RDTs (30 %), and performing blood test (20 %). The median RDT tested per month (25th, 75th percentile) was 6.0 (2.0, 15.0) indicating the need for prioritization based on endemicity. Regular reporting, supervision, monitoring system, and proper refresher training using uniform content of guideline to correct misconception of the volunteers, were needed to be strengthened. Moreover, the reliable and regular supply of materials and exchange system for expired RDTs and anti-malarials was important in the effectiveness of volunteers in MARC zones. Conclusions Adequate refresher training, monitoring, supervision, and regular reliable supply of RDTs and anti-malarials were needed for capacity strengthening of volunteers in MARC zones.
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Affiliation(s)
- Myat Htut Nyunt
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Khin Myo Aye
- Department of Medical Research, Yangon, Republic of the Union of Myanmar
| | - Khin Thiri Kyaw
- Department of Medical Research, Yangon, Republic of the Union of Myanmar
| | - Soe Soe Han
- Department of Medical Research, Yangon, Republic of the Union of Myanmar
| | - Thin Thin Aye
- Department of Medical Research, Yangon, Republic of the Union of Myanmar
| | - Khin Thet Wai
- Department of Medical Research, Yangon, Republic of the Union of Myanmar
| | - Myat Phone Kyaw
- Department of Medical Research, Yangon, Republic of the Union of Myanmar
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12
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Nyunt MH, Aye KM, Kyaw MP, Wai KT, Oo T, Than A, Oo HW, Phway HP, Han SS, Htun T, San KK. Evaluation of the behaviour change communication and community mobilization activities in Myanmar artemisinin resistance containment zones. Malar J 2015; 14:522. [PMID: 26697850 PMCID: PMC4690302 DOI: 10.1186/s12936-015-1047-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [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] [Received: 05/25/2015] [Accepted: 12/11/2015] [Indexed: 11/10/2022] Open
Abstract
Background Behaviour change communication (BCC) can improve malaria prevention and treatment behaviour. As a one of the activities under Myanmar Artemisinin Resistance Containment (MARC) programme, BCC have been conducting. This study aimed to evaluate the effectiveness of the behaviour change communication and community mobilization activities in MARC zones in Myanmar. Methods A cross sectional descriptive survey was conducted in randomly selected 16 townships in Tier I and II areas of MARC zones by quantitative and qualitative approaches. Results In 832 households resided by 4664 people, there were 3797 bed nets. Around 54 % were untreated while 45.6 % were insecticide-treated nets (ITN) and 36.2 % were long-lasting insecticide-treated nets (LLINs). Proportion of households with at least one ITN was 625 (75.12 %), proportion of households with at least one ITN for every two peoples was 487 (58.53 %), and proportion of existing ITNs used in previous night was 1225 (70.65 %) respectively. Nearly 23 % of households had old nets while 52 % had new and unused extra bed nets reflecting the adequacy. Interestingly, 38 % could not mention the benefit of the use of ITN/LLINs. Although 88.2 % knew the disease “malaria”, 11.9 % could not be able to mention the symptoms. More than 80 % provided correct responses that mosquito bite can cause malaria while only 36.9 % could mention the blood test for malaria diagnosis. Only 36.6 % received malaria information within previous year but nearly 15 % could not recognize it. Mostly, 80 % of fever episodes were treated at rural health centers (38.24 %) followed by drug shops (17.65 %) and private clinics (16.18 %) respectively. Conclusions Efforts should focus on correcting misconceptions about malaria transmission, prevention and universal use of ITN/LLINs. Although BCC activities have been documented, it is still necessary to intensify community mobilization through all accessible multiple channels in MARC areas.
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Affiliation(s)
- Myat Htut Nyunt
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Khin Myo Aye
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Myat Phone Kyaw
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Khin Thet Wai
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Tin Oo
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Aye Than
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Htet Wai Oo
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Hnin Phyu Phway
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Soe Soe Han
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Thurein Htun
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
| | - Kyaw Kyaw San
- Department of Medical Research, Yangon, Republic of the Union of Myanmar.
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13
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Andiappan H, Nissapatorn V, Sawangjaroen N, Nyunt MH, Lau YL, Khaing SL, Aye KM, Mon NCN, Tan TC, Kumar T, Onichandran S, bin Mat Adenan NA. Comparative study on Toxoplasma infection between Malaysian and Myanmar pregnant women. Parasit Vectors 2014; 7:564. [PMID: 25498432 PMCID: PMC4297455 DOI: 10.1186/s13071-014-0564-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [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] [Received: 07/04/2014] [Accepted: 11/24/2014] [Indexed: 11/13/2022] Open
Abstract
Background Toxoplasma gondii, an obligate intracellular protozoan parasite, causes a disease called toxoplasmosis which can sometimes be acquired congenitally by a newborn from an infected mother. This study aimed to determine the seroprevalence of Toxoplasma infection and its associated risks among 219 and 215 pregnant women from Malaysia and Myanmar, respectively. Methods Anti-Toxoplasma IgG and IgM antibodies were screened by using standard commercial ELISA kits. The socio-demographic, obstetrics and risk factors associated with Toxoplasma infection data were compared between the two countries. Results The overall prevalence of Toxoplasma infection in Malaysian pregnant women (42.47%; 95% CI = 36.11-49.09) was significantly higher (p < 0.05) than Myanmar pregnant women (30.70%; 95% CI = 27.92-37.16). By univariate analysis, this study identified that age group, education, parity, awareness on toxoplasmosis and consumption of undercooked meat were significantly associated (p < 0.05) with Toxoplasma seropositive Malaysian pregnant women but none of these factors associated with Toxoplasma seropositive Myanmar pregnant women. In comparison using univariate analysis between the two countries, it was found that Toxoplasma seropositive Malaysian pregnant women was associated with aged 30 years and above, secondary or lower-secondary level of education, the third trimester of pregnancy, having one child or more, lacking awareness of toxoplasmosis, absence of bad obstetrics history, having no history of close contact with cats or soil, living on a farm and also consumption of undercooked meat, unpasterized milk or untreated water. Avidity measurement was used to confirm the stages of Toxoplasma infection in pregnant women who were positive for both IgG and IgM antibodies and found all were infected in the past. Conclusion From our study, Toxoplasma screening and its risk measurement in pregnant women is firmly recommended for monitoring purposes and assisting proper management, including diagnosis and treatment during antenatal period. Also, it is necessary to initiate preventive measures for Toxoplasma infection among reproductive-age women in general and seronegative pregnant women in particular. Avidity measurement should be incorporated in Toxoplasma routine screening, especially with the availability of a single serum sample to assist in the diagnosis. Electronic supplementary material The online version of this article (doi:10.1186/s13071-014-0564-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hemah Andiappan
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Veeranoot Nissapatorn
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Nongyao Sawangjaroen
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
| | - Myat Htut Nyunt
- Department of Medical Research (Lower Myanmar), Republic of the Union of Myanmar, Yangon, Myanmar.
| | - Yee-Ling Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Si Lay Khaing
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Khin Myo Aye
- Department of Medical Research (Lower Myanmar), Republic of the Union of Myanmar, Yangon, Myanmar.
| | - Nan Cho Nwe Mon
- Department of Medical Research (Lower Myanmar), Republic of the Union of Myanmar, Yangon, Myanmar.
| | - Tian-Chye Tan
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Thulasi Kumar
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Subashini Onichandran
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Noor Azmi bin Mat Adenan
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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14
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Thu HM, Aye KM, Thein S. The effect of temperature and humidity on dengue virus propagation in Aedes aegypti mosquitos. Southeast Asian J Trop Med Public Health 1998; 29:280-4. [PMID: 9886113] [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] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The effect of temperature and relative humidity on dengue virus propagation in the mosquito as one of the possible contributing factors to dengue hemorrhagic fever (DHF) outbreaks was studied. Ae. aegypti mosquitos were reared under standard conditions and inoculated intrathoracically with dengue virus. Virus propagation in the mosquitos was determined at the temperature and relative humidity of all 3 seasons of Yangon and for the simulated temperature and relative humidity of Singapore. The virus propagation was detected by direct fluorescent antibody technique (DFAT) with mosquito head squash and the virus titer was determined by plaque forming unit test (PFUT) in baby hamster kidney-21 cells. The results show that the infected mosquitos kept under the conditions of the rainy season and under the simulated conditions of Singapore had a significantly higher virus titer (p=<0.05) when compared with the other 2 seasons of Yangon. So it is thought that the temperature and relative humidity of the rainy season of Yangon and that of Singapore favors dengue virus propagation in the mosquito and is one of the contributing factors to the occurence of DHF outbreaks.
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Affiliation(s)
- H M Thu
- Department of Medical Research, Yangon, Myanmar
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15
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Abstract
Despite a growing body of evidence predominantly, but not exclusively, from Thailand suggesting that the risk of developing dengue shock syndrome (DSS) is greatest following an anamnestic dengue infection, particularly if the most recent infection was with dengue 2 virus, there continues to be debate about the justification for these claims. This report describes a five-year, prospective study in two townships (suburbs) in Yangon (Rangoon) Myanmar (Burma) in which attempts were made to confirm the data from an earlier prospective study in Thailand and to address some of the criticism of earlier studies. This investigation found the incidence of anamnestic dengue infections in DSS patients to be significantly higher than in the community from which they were drawn and a significantly higher risk of developing DSS following an anamnestic infection (particularly with dengue 2 virus) than following a primary infection with any serotype.
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Affiliation(s)
- S Thein
- Department of Medical Research and Yangon Children's Hospital, Yangon, Myanmar
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16
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Aye KM. Intravenous drips. Trop Doct 1992; 22:88. [PMID: 1604732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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