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Cáceres Carrera L, Santamaría AM, Castillo AM, Romero L, Urriola E, Torres-Cosme R, Calzada JE. Detection through the use of RT-MqPCR of asymptomatic reservoirs of malaria in samples of patients from the indigenous Comarca of Guna Yala, Panama: Essential method to achieve the elimination of malaria. PLoS One 2024; 19:e0305558. [PMID: 39046959 PMCID: PMC11268588 DOI: 10.1371/journal.pone.0305558] [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: 07/15/2023] [Accepted: 06/02/2024] [Indexed: 07/27/2024] Open
Abstract
BACKGROUND Plasmodium vivax is the main causative agent of malaria in Panama. However, the prevalence of asymptomatic infections in the different endemic regions remains unknown. Understanding the epidemiological behavior of asymptomatic infections is essential for the elimination of malaria. This study aimed to determine the prevalence of asymptomatic malarial infections in one of the main endemic regions of Panama using multiplex real-time reverse transcription RT-MqPCR. METHODS A cross-sectional study was conducted in three communities in the Guna Yala Comarca. A total of 551 thick blood smears and their respective samples on filter paper were collected from volunteers of different ages and sexes from June 20 to 25, 2016. Infections by the Plasmodium spp. were diagnosed using microscopy and RT-MqPCR. All statistical analyses were performed using the R software. RESULTS The average prevalence of asymptomatic infections by P. vivax in the three communities detected by RT-MqPCR was 9.3%, with Ukupa having the highest prevalence (13.4%), followed by Aidirgandi (11.1%) and Irgandi (3.3%). A total of 74 samples were diagnosed as asymptomatic infections using RT-MqPCR. Light microscopy (LM) detected that 17.6% (13/74) of the asymptomatic samples and 82.4% (61/74) were diagnosed as false negatives. A 100% correlation was observed between samples diagnosed using LM and RT-MqPCR. A total of 52.7% (39/74) of the asymptomatic patients were female and 85.1% (63/74) were registered between the ages of 1 and 21 years. Factors associated with asymptomatic infection were community (aOR = 0.38 (95% CI 0.17-0.83), p < 0.001) and age aOR = 0.98 (95% CI 0.97-1.00), p < 0.05); F = 5.38; p < 0.05). CONCLUSIONS This study provides novel evidence of the considerable prevalence of asymptomatic P. vivax infections in the endemic region of Kuna Yala, representing a new challenge that requires immediate attention from the National Malaria Program. The results of this study provide essential information for the health authorities responsible for developing new policies. Furthermore, it will allow program administrators to reorient and design effective malaria control strategies that consider asymptomatic infections as a fundamental part of malaria control and move towards fulfilling their commitment to eliminate it.
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Affiliation(s)
- Lorenzo Cáceres Carrera
- Departmento de Entomología Médica del Instituto Conmemorativo Gorgas de Estudios de la Salud, Ciudad de Panamá, Panamá
| | - Ana María Santamaría
- Departmento de Parasitología del Instituto Conmemorativo Gorgas de Estudios de la Salud, Ciudad de Panamá, Panamá
| | - Anakena Margarita Castillo
- Departmento de Entomología Médica del Instituto Conmemorativo Gorgas de Estudios de la Salud, Ciudad de Panamá, Panamá
| | - Luis Romero
- Laboratorio Central de Referencia en Salud Pública del Instituto Conmemorativo Gorgas de Estudios de la Salud, Ciudad de Panamá, Panamá
| | - Eduardo Urriola
- Facultad de Ciencias Biomédicas, Universidad Latina de Panamá, Ciudad de Panamá, Panamá
| | - Rolando Torres-Cosme
- Departmento de Entomología Médica del Instituto Conmemorativo Gorgas de Estudios de la Salud, Ciudad de Panamá, Panamá
| | - José Eduardo Calzada
- Departmento de Parasitología del Instituto Conmemorativo Gorgas de Estudios de la Salud, Ciudad de Panamá, Panamá
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Kaewkungwal J, Roobsoong W, Lawpoolsri S, Nguitragool W, Thammapalo S, Prikchoo P, Khamsiriwatchara A, Pawarana R, Jarujareet P, Parker DM, Sripoorote P, Kengganpanich M, Ngamjarus C, Sattabongkot J, Cui L. Effectiveness, Safety, and Acceptability of Primaquine Mass Drug Administration in Low-Endemicity Areas in Southern Thailand: Proof-of-Concept Study. JMIR Public Health Surveill 2024; 10:e51993. [PMID: 38922648 PMCID: PMC11237773 DOI: 10.2196/51993] [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: 08/19/2023] [Revised: 01/28/2024] [Accepted: 05/14/2024] [Indexed: 06/27/2024] Open
Abstract
BACKGROUND A challenge in achieving the malaria-elimination target in the Greater Mekong Subregion, including Thailand, is the predominance of Plasmodium vivax malaria, which has shown extreme resilience to control measures. OBJECTIVE This proof-of-concept study aimed to provide evidence for implementing primaquine mass drug administration (pMDA) as a strategy for P. vivax elimination in low-endemicity settings. METHODS The study employed a mixed-methods trial to thoroughly evaluate the effectiveness, safety, acceptability, and community engagement of pMDA. The quantitative part was designed as a 2-period cluster-crossover randomized controlled trial. The intervention was pMDA augmented to the national prevention and control standards with directly observed treatment (DOT) by village health volunteers. The qualitative part employed in-depth interviews and brainstorming discussions. The study involved 7 clusters in 2 districts of 2 southern provinces in Thailand with persistently low P. vivax transmission. In the quantitative part, 5 cross-sectional blood surveys were conducted in both the pMDA and control groups before and 3 months after pMDA. The effectiveness of pMDA was determined by comparing the proportions of P. vivax infections per 1000 population between the 2 groups, with a multilevel zero-inflated negative binomial model adjusted for cluster and time as covariates and the interaction. The safety data comprised adverse events after drug administration. Thematic content analysis was used to assess the acceptability and engagement of stakeholders. RESULTS In the pre-pMDA period, the proportions of P. vivax infections in the pMDA (n=1536) and control (n=1577) groups were 13.0 (95% CI 8.2-20.4) and 12.0 (95% CI 7.5-19.1), respectively. At month 3 post-pMDA, these proportions in the pMDA (n=1430) and control (n=1420) groups were 8.4 (95% CI 4.6-15.1) and 5.6 (95% CI 2.6-11.5), respectively. No statistically significant differences were found between the groups. The number of malaria cases reduced in all clusters in both groups, and thus, the impact of pMDA was inconclusive. There were no major safety concerns. Acceptance among the study participants and public health care providers at local and national levels was high, and they believed that pMDA had boosted awareness in the community. CONCLUSIONS pMDA was associated with high adherence, safety, and tolerability, but it may not significantly impact P. vivax transmission. As this was a proof-of-concept study, we decided not to scale up the intervention with larger clusters and samples. An alternative approach involving a targeted primaquine treatment strategy with primaquine and DOT is currently being implemented. We experienced success regarding effective health care workforces at point-of-care centers, effective collaborations in the community, and commitment from authorities at local and national levels. Our efforts boosted the acceptability of the malaria-elimination initiative. Community engagement is recommended to achieve elimination targets. TRIAL REGISTRATION Thai Clinical Trials Registry TCTR20190806004; https://www.thaiclinicaltrials.org/show/TCTR20190806004.
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Affiliation(s)
| | - Wanlapa Roobsoong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Wang Nguitragool
- Department of Molecular Tropical Medicine and Genetics, 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
| | - Rungrawee Pawarana
- Center of Excellence for Biomedical and Public Health Informatics (BIOPHICS), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Pawinee Jarujareet
- Center of Excellence for Biomedical and Public Health Informatics (BIOPHICS), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Daniel M Parker
- Department of Population Health and Disease Prevention, University of California, Irvine, Irvine, CA, United States
- Department of Epidemiology and Biostatistics, University of California, Irvine, Irvine, CA, United States
| | - Piyarat Sripoorote
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mondha Kengganpanich
- Department of Health Education and Behavioral Sciences, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Chetta Ngamjarus
- Department of Epidemiology and Biostatistics, Faculty of Public Health, Khon Kaen University, Khon Kaen, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Liwang Cui
- Division of Infectious Diseases and Internal Medicine, Department of Internal Medicine, University of South Florida, Tampa, FL, United States
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Sattabongkot J, Cui L, Bantuchai S, Chotirat S, Kaewkungwal J, Khamsiriwatchara A, Kiattibutr K, Kyaw MP, Lawpoolsri S, Linn NYY, Menezes L, Miao J, Nguitragool W, Parker D, Prikchoo P, Roobsoong W, Sa-Angchai P, Samung Y, Sirichaisinthop J, Sriwichai P, Suk-Uam K, Thammapalo S, Wang B, Zhong D. Malaria Research for Tailored Control and Elimination Strategies in the Greater Mekong Subregion. Am J Trop Med Hyg 2022; 107:152-159. [PMID: 36228914 DOI: 10.4269/ajtmh.21-1268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 05/28/2022] [Indexed: 11/07/2022] Open
Abstract
The malaria landscape in the Greater Mekong Subregion has experienced drastic changes with the ramp-up of the control efforts, revealing formidable challenges that slowed down the progress toward malaria elimination. Problems such as border malaria and cross-border malaria introduction, multidrug resistance in Plasmodium falciparum, the persistence of Plasmodium vivax, the asymptomatic parasite reservoirs, and insecticide resistance in primary vectors require integrated strategies tailored for individual nations in the region. In recognition of these challenges and the need for research, the Southeast Asian International Center of Excellence for Malaria Research has established a network of researchers and stakeholders and conducted basic and translational research to identify existing and emerging problems and develop new countermeasures. The installation of a comprehensive disease and vector surveillance system at sentinel sites in border areas with the implementation of passive/active case detection and cross-sectional surveys allowed timely detection and management of malaria cases, provided updated knowledge for effective vector control measures, and facilitated the efficacy studies of antimalarials. Incorporating sensitive molecular diagnosis to expose the significance of asymptomatic parasite reservoirs for sustaining transmission helped establish the necessary evidence to guide targeted control to eliminate residual transmission. In addition, this program has developed point-of-care diagnostics to monitor the quality of artemisinin combination therapies, delivering the needed information to the drug regulatory authorities to take measures against falsified and substandard antimalarials. To accelerate malaria elimination, this program has actively engaged with stakeholders of all levels, fostered vertical and horizontal collaborations, and enabled the effective dissemination of research findings.
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Affiliation(s)
- Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | | | - Sadudee Chotirat
- 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
| | | | | | - Nay Yi Yi Linn
- Department of Public Health, Ministry of Health, Nay Pyi Taw, Myanmar
| | - Lynette Menezes
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Jun Miao
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Wang Nguitragool
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Daniel Parker
- Department of Epidemiology, University of California at Irvine, Irvine, California
| | - Pathomporn Prikchoo
- Office of Disease Prevention and Control 12, Ministry of Public Health, Songkla, Thailand
| | - Wanlapa Roobsoong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Yudthana Samung
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jeeraphat Sirichaisinthop
- Vector-Borne Disease Control Center, Department of Disease Control, Ministry of Public Health, Bangkok, Thailand
| | - Patchara Sriwichai
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kritsana Suk-Uam
- Vector Borne Disease Control Center 2.3, Ministry of Public Health, Tak, Thailand
| | - Suwich Thammapalo
- Vector-Borne Disease Control Center, Department of Disease Control, Ministry of Public Health, Bangkok, Thailand
| | - Baomin Wang
- College of Agriculture and Biotechnology, China Agricultural University, Beijing, China
| | - Daibin Zhong
- Program in Public Health, University of California at Irvine, Irvine, California
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Lin ZR, Li SG, Sun XD, Guo XR, Zheng Z, Yang J, Pian HR, Tian P, Chen QY, Sun XY, Ding CL, Duan KX, Chen HW, Bee DY, Zhou HN. Effectiveness of joint 3 + 1 malaria strategy along China-Myanmar cross border areas. BMC Infect Dis 2021; 21:1246. [PMID: 34906092 PMCID: PMC8670156 DOI: 10.1186/s12879-021-06920-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 11/29/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cross-border malaria in Laiza City of Myanmar seriously affected Yingjiang County of China and compromised reaching the goal of malaria elimination by 2020. Since 2017, a pilot project on 3 + 1 strategy of joint cross-border malaria prevention and control was carried out for building a malaria buffer in these border areas. Here, 3 were the three preventive lines in China where different focalized approaches of malaria elimination were applied and + 1 was a defined border area in Myanmar where the integrated measures of malaria control were adopted. METHODS A 5-year retrospective analysis (2015 to 2019) was conducted that included case detection, parasite prevalence and vector surveillance. Descriptive statistics was used and the incidence or rates were compared. The annual parasite incidence and the parasite prevalence rate in + 1 area of Myanmar, the annual importation rate in Yingjiang County of China and the density of An. minimus were statistically significant indictors to assess the effectiveness of the 3 + 1 strategy. RESULTS In + 1 area of Myanmar from 2015 to 2019, the averaged annual parasite incidence was (59.11 ± 40.73)/1000 and Plasmodium vivax accounted for 96.27% of the total confirmed cases. After the pilot project, the annual parasite incidence dropped 89% from 104.77/1000 in 2016 to 12.18/1000 in 2019, the microscopic parasite prevalence rate dropped 100% from 0.34% in 2017 to zero in 2019 and the averaged density of An. Minimus per trap-night dropped 93% from 1.92 in June to 0.13 in September. The submicroscopic parasite prevalence rate increased from 1.15% in 2017 to 1.66% in 2019 without significant difference between the two surveys (P = 0.084). In Yingjiang County of China, neither indigenous nor introduced case was reported and 100% cases were imported from Myanmar since 2017. The averaged annual importation rate from 2015 to 2019 was (0.47 ± 0.15)/1000. After the pilot project, the annual importation rate dropped from 0.59/1000 in 2016 to 0.28/1000 in 2019 with an overall reduction of 53% in the whole county. The reduction was 67% (57.63/1000 to 18.01/1000) in the first preventive line, 52% (0.20/1000 to 0.10/1000) in the second preventive line and 36% (0.32/1000 to 0.22/1000) in the third preventive line. The averaged density of An. Minimus per trap-night in the first preventive line dropped 94% from 2.55 in June to 0.14 in September, without significant difference from that of + 1 area of Myanmar (Z value = - 1.18, P value = 0.24). CONCLUSION The pilot project on 3 + 1 strategy has been significantly effective in the study areas and a buffer zone of border malaria was successfully established between Laiza City of Myanmar and Yingjiang County of China.
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Affiliation(s)
- Zu-Rui Lin
- Yunnan Institute of Parasitic Diseases; Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Collaborative Innovation Centre for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Pu'er, 665000, China
| | - Shi-Gang Li
- Yangjiang Centre for Disease Control and Prevention, Yangjiang, 679300, China
| | - Xiao-Dong Sun
- Yunnan Institute of Parasitic Diseases; Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Collaborative Innovation Centre for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Pu'er, 665000, China.
| | - Xiang-Rui Guo
- Yangjiang Centre for Disease Control and Prevention, Yangjiang, 679300, China
| | - Zhi Zheng
- Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100730, China.
| | - Jie Yang
- Dehong Centre for Disease Control and Prevention, Mangshi, 678400, China
| | - Hong-Ru Pian
- Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100730, China
| | - Peng Tian
- Yunnan Institute of Parasitic Diseases; Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Collaborative Innovation Centre for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Pu'er, 665000, China
| | - Qi-Yan Chen
- Yunnan Institute of Parasitic Diseases; Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Collaborative Innovation Centre for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Pu'er, 665000, China
| | | | - Chun-Li Ding
- Yunnan Institute of Parasitic Diseases; Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Collaborative Innovation Centre for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Pu'er, 665000, China
| | - Kai-Xia Duan
- Yunnan Institute of Parasitic Diseases; Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Collaborative Innovation Centre for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Pu'er, 665000, China
| | - Hong-Wei Chen
- Nangbang Township Central Hospital, Yingjiang, 679300, China
| | - Dakhidam Yaw Bee
- Malaria Project Office, Health Department of Kachin Special Region II, Laiza City, Myanmar
| | - Hong-Ning Zhou
- Yunnan Institute of Parasitic Diseases; Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Collaborative Innovation Centre for Public Health and Disease Prevention and Control, Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research, Pu'er, 665000, China.
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Cantor D, Swartz J, Roberts B, Abbara A, Ager A, Bhutta ZA, Blanchet K, Madoro Bunte D, Chukwuorji JC, Daoud N, Ekezie W, Jimenez-Damary C, Jobanputra K, Makhashvili N, Rayes D, Restrepo-Espinosa MH, Rodriguez-Morales AJ, Salami B, Smith J. Understanding the health needs of internally displaced persons: A scoping review. J Migr Health 2021; 4:100071. [PMID: 34820657 PMCID: PMC8600058 DOI: 10.1016/j.jmh.2021.100071] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 11/01/2022] Open
Abstract
We seek to strengthen understanding of the health needs of internally displaced persons (IDPs) in contexts of conflict or violence. Based upon a scoping review, our paper identified limited evidence on IDP health, but nevertheless indicates that IDPs tend to experience worse health outcomes than other conflict-affected populations across a range of health issues; and this is due to the particularly vulnerable situation of IDPs relative to these other populations, including reduced access to health services. Further research is required to better understand these needs and the interventions that can most effectively address these needs.
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Affiliation(s)
- David Cantor
- Internal Displacement Research Programme, School of Advanced Study, University of London, UK
| | | | - Bayard Roberts
- Health Services Research and Policy Department, London School of Hygiene and Tropical Medicine, UK
| | - Aula Abbara
- Department of Infectious Disease, Imperial College London, London, UK; Syria Public Health Network
| | - Alastair Ager
- Institute for Global Health & Development, Queen Margaret University, Edinburgh, UK
- Mailman School of Public Health, Columbia University, USA
| | | | - Karl Blanchet
- Geneva Centre of Humanitarian Studies, University of Geneva, Switzerland
| | | | | | - Nihaya Daoud
- Department of Public Health, Ben-Gurion University of the Negev, Israel
| | | | | | | | | | - Diana Rayes
- Johns Hopkins Bloomberg School of Public Health, USA
| | | | - Alfonso J. Rodriguez-Morales
- Grupo de Investigación Biomedicina, Fundacion Universitaria Autónoma de las Americas, Colombia
- Universidad Cientifica del Sur, Peru
| | | | - James Smith
- Elrha; Health in Humanitarian Crises Centre, London School of Hygiene and Tropical Medicine, UK
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Yang H, Wang J, Liu H, Zhao Y, Lakshmi S, Li X, Nie R, Li C, Wang H, Cao Y, Menezes L, Cui L. Efficacy and Safety of a Naphthoquine-Azithromycin Coformulation for Malaria Prophylaxis in Southeast Asia: A Phase 3, Double-blind, Randomized, Placebo-controlled Trial. Clin Infect Dis 2021; 73:e2470-e2476. [PMID: 32687174 DOI: 10.1093/cid/ciaa1018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A prophylactic antimalarial drug that is both effective for protection and improves compliance is in high demand. METHODS We conducted a randomized, placebo-controlled, double-blinded phase 3 trial to evaluate the 1:1 fixed-dose combination of naphthoquine-azithromycin (NQAZ) for safety and protection against Plasmodium infections in villages along the China-Myanmar border. A total of 631 residents, 5-65 years of age, were randomized into the drug group (n = 319) and the placebo group (n = 312) to receive NZAQ and placebo, respectively, as a single-dose monthly treatment. Follow-ups were conducted weekly to monitor for adverse events and malaria infections. RESULTS Of the 531 subjects completing the trial, there were 46 and 3 blood smear-positive Plasmodium infections in the placebo and treatment groups, respectively. For the intent-to-treat analysis, the single-dose monthly NQAZ treatment had 93.62% protective efficacy (95% confidence interval [CI]: 91.72%-95.52%). For the per-protocol analysis, NQAZ treatment provided a 93.04% protective efficacy (95% CI: 90.98%-95.1%). Three smear-positive cases in the NQAZ group were all due to acute falciparum malaria. In comparison, NQAZ treatment provided 100% protection against the relapsing malaria Plasmodium vivax and Plasmodium ovale. The treatment group had 5.6% of participants experiencing transient elevation of liver aminotransferases compared with 2.2% in the placebo group (P > .05). CONCLUSIONS Monthly prophylaxis with NQAZ tablets was well tolerated and highly effective for preventing Plasmodium infections. It may prove useful for eliminating P. vivax in areas with a high prevalence of glucose-6-phosphate dehydrogenase deficiency in the population. CLINICAL TRIALS REGISTRATION ChiCTR1800020140.
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Affiliation(s)
- Henglin Yang
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Pu'er, Yunnan, China
| | - Jingyan Wang
- Institute of Microbiology and Epidemiology, Chinese Academy of Military Medical Sciences, Beijing, China
| | - Hui Liu
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Pu'er, Yunnan, China
| | - Yan Zhao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Seetha Lakshmi
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Xingliang Li
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Pu'er, Yunnan, China
| | - Renhua Nie
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Pu'er, Yunnan, China
| | - Chunfu Li
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Pu'er, Yunnan, China
| | - Hengye Wang
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Center of Malaria Research, Pu'er, Yunnan, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Lynette Menezes
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
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Ekezie W, Myles P, Murray RL, Bains M, Timmons S, Pritchard C. Self-reported diseases and their associated risk factors among camp-dwelling conflict-affected internally displaced populations in Nigeria. J Public Health (Oxf) 2021; 43:e171-e179. [PMID: 32776153 DOI: 10.1093/pubmed/fdaa114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 06/11/2020] [Accepted: 06/26/2020] [Indexed: 11/14/2022] Open
Abstract
Background Conflict in Nigeria displaced millions of people, and some settled in camp-like locations within the country. Evidence on the association between living conditions and health outcomes among these populations are limited. This study investigated the risk factors associated with illnesses among camp-dwelling internally displaced persons (IDPs) in northern Nigeria. Methods A cross-sectional study was conducted in nine camps in 2016. Self-reported data on socio-demography, resource utilization and disease outcomes were collected. Association between health conditions and various factors, including sanitation and healthcare access, was investigated. Results Data from 2253 IDPs showed 81.1% (CI = 79.5-82.7) experienced one or more health conditions; however, over 20% did not access healthcare services. Most common diseases were malaria, fever, typhoid and diarrhoea. Multivariable logistic regression presented as adjusted odds ratios(aOR) and 95% confidence intervals(CIs) showed factors significantly associated with increased likelihood of illnesses included being female (aOR = 1.53;CI = 1.19-1.96), overcrowding (aOR = 1.07;CI = 1.00-1.36), long-term conditions (aOR = 2.72;CI = 1.88-3.94), outdoor defecation (aOR = 2.37;CI = 1.14-4.94) and presence of disease-causing vectors (aOR = 3.71;CI = 1.60-8.60). Conclusion Most diseases in the camps were communicable. Modifiable risk factors such as overcrowding and poor toilet facilities were associated with increased poor health outcomes. This evidence highlights areas of high priority when planning humanitarian public health interventions.
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Affiliation(s)
- Winifred Ekezie
- Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham NG5 1PB, UK
| | - Puja Myles
- Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham NG5 1PB, UK
| | - Rachael L Murray
- Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham NG5 1PB, UK
| | - Manpreet Bains
- Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham NG5 1PB, UK
| | - Stephen Timmons
- Nottingham University Business School, University of Nottingham, Nottingham NG8 1BB, UK
| | - Catherine Pritchard
- Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham NG5 1PB, UK
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Cheng B, Htoo SN, Mhote NPP, Davison CM. Association between biological sex and insecticide-treated net use among household members in ethnic minority and internally displaced populations in eastern Myanmar. PLoS One 2021; 16:e0252896. [PMID: 34143807 PMCID: PMC8213136 DOI: 10.1371/journal.pone.0252896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 05/25/2021] [Indexed: 11/25/2022] Open
Abstract
Malaria prevalence in Myanmar is highest among remote and ethnic minority populations living near forest fringes along the country’s international borders. Insecticide-treated nets (ITNs) are a key intervention used to prevent malaria transmission, but insufficient ITN availability and low use can hinder effectiveness. This study assessed age and sex disparities in ITN possession, access, and use among household members of ethnic minority and internally displaced populations in eastern Myanmar. Cross-sectional data from the 2013 Eastern Burma Retrospective Mortality Survey were used to describe prevalence of ITN possession, access, and use. The association between a household member’s biological sex and their ITN use was assessed using multilevel log binomial regression. Age and household ITN supply were tested as potential effect modifiers. Of 37927 household members, 89.8% (95% CI: 89.5, 90.1) of people lived in households with at least one ITN. Approximately half belonged to households with sufficient ITN supply and used an ITN. Pregnant women and children under five had the highest proportion of ITN use regardless of sufficient household ITN status. Female adults aged 15 to 49 years old (Risk ratio or RR: 1.4, 95% CI: 1.29, 1.52) were more likely to use ITNs. This relationship did not differ by sufficient household ITN status. The findings suggest that among ethnic minority populations in areas where ITN use is indicated, many households do not have adequate ITN supply, and many individuals are not using ITNs. Children under five and pregnant women appear to be prioritized for ITN use and overall, women are slightly more likely to use ITNs than men. This study’s findings can support efforts ensuring that all household members belonging to ethnic minority and displaced populations in Eastern Myanmar benefit from sufficient ITN access and use for malaria prevention.
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Affiliation(s)
- Breagh Cheng
- Department of Public Health Sciences, Queen’s University, Kingston, Ontario, Canada
| | | | | | - Colleen M. Davison
- Department of Public Health Sciences, Queen’s University, Kingston, Ontario, Canada
- * E-mail:
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9
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Huang F, Jacob CG, Takala-Harrison S, Adams M, Yang HL, Liu H, Xia ZG, Zhou SS, Tang LH, Plowe CV. Genomic Epidemiology of Antimalarial Drug Resistance in Plasmodium falciparum in Southern China. Front Cell Infect Microbiol 2021; 10:610985. [PMID: 33489939 PMCID: PMC7820777 DOI: 10.3389/fcimb.2020.610985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/20/2020] [Indexed: 12/05/2022] Open
Abstract
Emerging artemisinin resistance in Southeast Asia poses a significant risk to malaria control and eradication goals, including China’s plan to eliminate malaria nationwide by 2020. Plasmodium falciparum was endemic in China, especially in Southern China. Parasites from this region have shown decreased susceptibility to artemisinin and delayed parasite clearance after artemisinin treatment. Understanding the genetic basis of artemisinin resistance and identifying specific genetic loci associated with this phenotype is crucial for surveillance and containment of resistance. In this study, parasites were collected from clinical patients from Yunnan province and Hainan island. The parasites were genotyped using a P. falciparum-specific single nucleotide polymorphism (SNP) microarray. The SNP profiles examined included a total of 27 validated and candidate molecular markers of drug resistance. The structure of the parasite population was evaluated by principal component analysis by using the EIGENSOFT program, and ADMIXTURE was used to calculate maximum likelihood estimates for the substructure analysis. Parasites showed a high prevalence of resistance haplotypes of pfdhfr and pfdhps and moderate prevalence of pfcrt. There was no mutation identified on pfmdr1. Candidate SNPs on chromosomes 10, 13, and 14 that were associated with delayed parasite clearance showed a low prevalence of mutants. Parasites from Southern China were clustered and separated from those from Southeast Asia. Parasites from Yunnan province were substructured from parasites from Hainan island. This study provides evidence for a genomic population with drug resistance in Southern China and also illustrates the utility of SNP microarrays for large-scale parasite molecular epidemiology.
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Affiliation(s)
- Fang Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, Key Laboratory of Parasite and Vector Biology, Ministry of Health, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | | | - Shannon Takala-Harrison
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Heng-Lin Yang
- Malaria Department, Yunnan Institute of Parasitic Diseases, Puer, China
| | - Hui Liu
- Malaria Department, Yunnan Institute of Parasitic Diseases, Puer, China
| | - Zhi-Gui Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, Key Laboratory of Parasite and Vector Biology, Ministry of Health, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | - Shui-Sen Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, Key Laboratory of Parasite and Vector Biology, Ministry of Health, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | - Lin-Hua Tang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, Key Laboratory of Parasite and Vector Biology, Ministry of Health, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
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10
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Wang S, Xu S, Geng J, Si Y, Zhao H, Li X, Yang Q, Zeng W, Xiang Z, Chen X, Zhang Y, Li C, Kyaw MP, Cui L, Yang Z. Molecular Surveillance and in vitro Drug Sensitivity Study of Plasmodium falciparum Isolates from the China-Myanmar Border. Am J Trop Med Hyg 2020; 103:1100-1106. [PMID: 32588794 DOI: 10.4269/ajtmh.20-0235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The emergence and spread of resistance in Plasmodium falciparum to the frontline treatment artemisinin-based combination therapies in Southeast Asia require close monitoring of the situation. Here, we collected 36 clinical samples of P. falciparum from the China-Myanmar border in 2014-2016, adapted these parasites to continuous culture, and performed in vitro drug assays on seven antimalarial drugs. Data for 23 parasites collected in 2010 and 2012 from the same area reported in an early study were used to assess longitudinal changes in drug sensitivity. Parasites remained highly resistant to chloroquine (CQ) and pyrimethamine, whereas they were generally sensitive to mefloquine (MFQ), lumefantrine (LMF), naphthoquine (NQ), and pyronaridine (PND). Parasites showed a similar temporal trend in sensitivity to CQ, NQ, and PND, with gradual reduction in the half-maximal inhibitory concentrations (IC50s) after 2012. The IC50s to the aminoalcohol drugs MFQ, LMF, and quinine (QN) all significantly declined in 2014, followed by various degrees of increase in 2016. Pyrimethamine displayed a continuous increase in IC50 over the years. The Dd2-like P. falciparum chloroquine-resistant transporter mutations were fixed or nearly fixed in the parasite population. The P. falciparum multidrug resistance 1 F1226Y mutation was detected in 80% parasites in 2016 and associated with reduced sensitivity to LMF and QN (P < 0.05). The N51I in P. falciparum dihydrofolate reductase and K540E/N and A581G in P. falciparum dihydropteroate synthase that are associated with antifolate resistance were either fixed or were approaching fixation in recent years. This study provides an updated picture and temporal trend of antimalarial drug resistance in the China-Myanmar border region, which will serve as a reference for antimalarial treatment.
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Affiliation(s)
- Siqi Wang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Shiling Xu
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Jinting Geng
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Yu Si
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Hui Zhao
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Xinxin Li
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Qi Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Weilin Zeng
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Zheng Xiang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Xi Chen
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Yanmei Zhang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Cuiying Li
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | | | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
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11
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Zhao Y, Wang L, Soe MT, Aung PL, Wei H, Liu Z, Ma T, Huang Y, Menezes LJ, Wang Q, Kyaw MP, Nyunt MH, Cui L, Cao Y. Molecular surveillance for drug resistance markers in Plasmodium vivax isolates from symptomatic and asymptomatic infections at the China-Myanmar border. Malar J 2020; 19:281. [PMID: 32758218 PMCID: PMC7409419 DOI: 10.1186/s12936-020-03354-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 07/28/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND In the Greater Mekong sub-region, Plasmodium vivax has become the predominant species and imposes a major challenge for regional malaria elimination. This study aimed to investigate the variations in genes potentially related to drug resistance in P. vivax populations from the China-Myanmar border area. In addition, this study also wanted to determine whether divergence existed between parasite populations associated with asymptomatic and acute infections. METHODS A total of 66 P. vivax isolates were obtained from patients with acute malaria who attended clinics at the Laiza area, Kachin State, Myanmar in 2015. In addition, 102 P. vivax isolates associated with asymptomatic infections were identified by screening of volunteers without signs or symptoms from surrounding villages. Slide-positive samples were verified with nested PCR detecting the 18S rRNA gene. Multiclonal infections were further excluded by genotyping at msp-3α and msp-3β genes. Parasite DNA from 60 symptomatic cases and 81 asymptomatic infections was used to amplify and sequence genes potentially associated with drug resistance, including pvmdr1, pvcrt-o, pvdhfr, pvdhps, and pvk12. RESULTS The pvmdr1 Y976F and F1076L mutations were present in 3/113 (2.7%) and 97/113 (85.5%) P. vivax isolates, respectively. The K10 insertion in pvcrt-o gene was found in 28.2% of the parasites. Four mutations in the two antifolate resistance genes reached relatively high levels of prevalence: pvdhfr S58R (53.4%), S117N/T (50.8%), pvdhps A383G (75.0%), and A553G (36.3%). Haplotypes with wild-type pvmdr1 (976Y/997K/1076F) and quadruple mutations in pvdhfr (13I/57L/58R/61M/99H/117T/173I) were significantly more prevalent in symptomatic than asymptomatic infections, whereas the pvmdr1 mutant haplotype 976Y/997K/1076L was significantly more prevalent in asymptomatic than symptomatic infections. In addition, quadruple mutations at codons 57, 58, 61 and 117 of pvdhfr and double mutations at codons 383 and 553 of pvdhps were found both in asymptomatic and symptomatic infections with similar frequencies. No mutations were found in the pvk12 gene. CONCLUSIONS Mutations in pvdhfr and pvdhps were prevalent in both symptomatic and asymptomatic P. vivax infections, suggestive of resistance to antifolate drugs. Asymptomatic carriers may act as a silent reservoir sustaining drug-resistant parasite transmission necessitating a rational strategy for malaria elimination in this region.
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Affiliation(s)
- Yan Zhao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Lin Wang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Myat Thu Soe
- Myanmar Health Network Organization, Yangon, Myanmar
| | | | - Haichao Wei
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Ziling Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Tongyu Ma
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Yuanyuan Huang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Lynette J Menezes
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Qinghui Wang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | | | | | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA.
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
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12
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Edosomwan EU, Evbuomwan IO, Agbalalah C, Dahunsi SO, Abhulimhen-Iyoha BI. Malaria coinfection with Neglected Tropical Diseases (NTDs) in children at Internally Displaced Persons (IDP) camp in Benin City, Nigeria. Heliyon 2020; 6:e04604. [PMID: 32793830 PMCID: PMC7408312 DOI: 10.1016/j.heliyon.2020.e04604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/03/2020] [Accepted: 07/28/2020] [Indexed: 11/05/2022] Open
Abstract
Malaria and Neglected Tropical Diseases (NTDs) are highly endemic in poorer countries of the world. The research investigated the prevalence of parasitic infections among children in Internally Displaced Persons (IDP) camp in Benin City. Faecal, urine and blood specimen were collected from 184 children (100 males and 84 females) aged 6–15. Blood samples were prepared using thick film method and analyzed microscopically. Direct smear technique was employed for faecal sample and sedimentation method to concentrate ova from the urine sample. Ten species of parasites were identified in this study. The predominant species were Plasmodium falciparum (67.93%), Entamoeba histolytica (67.93%) and Giardia duodenalis (59.78%). Plasmodium falciparum and E. histolytica were most prevalent in both sexes, with P. falciparum infecting 68% males and 67.86% females while E. histolytica infected 66% males and 70.24% females (P = 0.24). Mixed infections with blood and intestinal parasites were recorded in 41.18% in age group 5–10 and 47.90% in age group 11–15 (P < 0.5). Also, mixed infections with blood and intestinal parasites were detected in 45% males and 50% females (P = 0.51). Urinary schistosomiasis was recorded in 28.80% of the participants. Parasitic infections especially P. falciparum malaria and amoebiasis were predominant among the children. Therefore, our findings call for specific intervention programmes to reduce parasite intensity and morbidity in the children. Environmental and personal hygiene should be implemented in order to curb parasitosis in the study area.
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Affiliation(s)
- Evelyn U Edosomwan
- Department of Animal and Environmental Biology, University of Benin, Benin City, Nigeria
| | - Ikponmwosa O Evbuomwan
- Applied Biology and Biotechnology Programme, Department of Microbiology, Landmark University, Omu-Aran, Kwara State, Nigeria
| | - Cynthia Agbalalah
- Department of Animal and Environmental Biology, University of Benin, Benin City, Nigeria
| | - Samuel O Dahunsi
- Department of Microbiology, Landmark University, Omu-Aran, Kwara State, Nigeria
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13
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Brashear AM, Fan Q, Hu Y, Li Y, Zhao Y, Wang Z, Cao Y, Miao J, Barry A, Cui L. Population genomics identifies a distinct Plasmodium vivax population on the China-Myanmar border of Southeast Asia. PLoS Negl Trop Dis 2020; 14:e0008506. [PMID: 32745103 PMCID: PMC7425983 DOI: 10.1371/journal.pntd.0008506] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 08/13/2020] [Accepted: 06/22/2020] [Indexed: 01/31/2023] Open
Abstract
Plasmodium vivax has become the predominant malaria parasite and a major challenge for malaria elimination in the Greater Mekong Subregion (GMS). Yet, our knowledge about the evolution of P. vivax populations in the GMS is fragmental. We performed whole genome sequencing on 23 P. vivax samples from the China-Myanmar border (CMB) and used 21 high-coverage samples to compare to over 200 samples from the rest of the GMS. Using genome-wide single nucleotide polymorphisms (SNPs), we analyzed population differentiation, genetic structure, migration and potential selection using an array of methods. The CMB parasites displayed a higher proportion of monoclonal infections, and 52% shared over 90% of their genomes in identity-by-descent segments with at least one other sample from the CMB, suggesting preferential expansion of certain parasite strains in this region, likely resulting from the P. vivax outbreaks occurring during this study period. Principal component, admixture, fixation index and phylogenetic analyses all identified that parasites from the CMB were genetically distinct from parasites from eastern parts of the GMS (Cambodia, Laos, Vietnam, and Thailand), whereas the eastern GMS parasite populations were largely undifferentiated. Such a genetic differentiation pattern of the P. vivax populations from the GMS parasite was largely explainable through geographic distance. Using the genome-wide SNPs, we narrowed down to a set of 36 SNPs for differentiating parasites from different areas of the GMS. Genome-wide scans to determine selection in the genome with two statistical methods identified genes potentially under drug selection, including genes associated with antifolate resistance and genes linked to chloroquine resistance in Plasmodium falciparum.
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Affiliation(s)
- Awtum M. Brashear
- Department of Internal Medicine, University of South Florida, Tampa, Florida, United States of America
- Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Qi Fan
- Dalian Institute of Technology, Dalian, Liaoning Province, China
| | - Yubing Hu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Yuling Li
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Yan Zhao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Zenglei Wang
- MHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Beijing Union Medical College, Beijing, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Jun Miao
- Department of Internal Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Alyssa Barry
- Infection Systems Epidemiology, School of Medicine, Faculty of Health, Deakin University, Geelong, VIC, Australia
| | - Liwang Cui
- Department of Internal Medicine, University of South Florida, Tampa, Florida, United States of America
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14
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Xu S, Zeng W, Ngassa Mbenda HG, Liu H, Chen X, Xiang Z, Li C, Zhang Y, Baird JK, Yang Z, Cui L. Efficacy of directly-observed chloroquine-primaquine treatment for uncomplicated acute Plasmodium vivax malaria in northeast Myanmar: A prospective open-label efficacy trial. Travel Med Infect Dis 2020; 36:101499. [PMID: 31604130 PMCID: PMC7816571 DOI: 10.1016/j.tmaid.2019.101499] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 10/02/2019] [Accepted: 10/03/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND Chloroquine (CQ) and primaquine (PQ) remain the frontline drugs for radical cure of uncomplicated P. vivax malaria in the Greater Mekong Sub-region (GMS). Recent reports of decreased susceptibility of P. vivax to CQ in many parts of the GMS raise concerns. METHODS From April 2014 to September 2016, 281 patients with uncomplicated P. vivax infection attending clinics in border settlements for internally displaced people in northeast Myanmar were recruited into this study. Patients were treated with standard regimen of 3-day CQ and concurrent 14-day PQ (3.5 mg/kg total dose) as directly observed therapy, and followed for recurrent parasitemia within 28 days post-patency. RESULTS Within the 28-day follow-up period, seven patients developed recurrent parasitemia, resulting in a cumulative rate of parasite recurrence of 2.6%. Five of the seven parasitemias recurred within two weeks, and two of those failed to clear within seven days, indicating high-grade resistance. CONCLUSION Although failure of CQ/PQ treatment of P. vivax was relatively infrequent in northeast Myanmar, this study nonetheless confirms that CQ/PQ-resistant strains do circulate in this area, some of them of a highly resistant phenotype. It is thus recommended that patients who acquire vivax malaria in Myanmar be treated an artemisinin-combination therapy along with hypnozoitocidal primaquine therapy to achieve radical cure.
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Affiliation(s)
- Shiling Xu
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan, 650500, PR China
| | - Weilin Zeng
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan, 650500, PR China
| | - Huguette Gaelle Ngassa Mbenda
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Blvd, Suite 304, Tampa, FL, 33612, USA
| | - Huaie Liu
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan, 650500, PR China
| | - Xi Chen
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan, 650500, PR China
| | - Zheng Xiang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan, 650500, PR China
| | - Cuiying Li
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan, 650500, PR China
| | - Yanmei Zhang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan, 650500, PR China
| | - J Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Jalan Diponegoro No. 69, Jakarta, 10430, Indonesia; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan, 650500, PR China.
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Blvd, Suite 304, Tampa, FL, 33612, USA.
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15
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The health beliefs, dengue knowledge and control behaviors among internally displaced persons versus local residents in Kachin Special Region II, Myanmar. PLoS Negl Trop Dis 2020; 14:e0008321. [PMID: 32584822 PMCID: PMC7343181 DOI: 10.1371/journal.pntd.0008321] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 07/08/2020] [Accepted: 04/24/2020] [Indexed: 12/03/2022] Open
Abstract
Dengue fever (DF) is one of main public health problems along the China-Myanmar border, however, data about DF is still lacking in Kachin Special Region II (KSR2), Myanmar. To understand health beliefs in general, and knowledge and treatment-seeking and prevention behaviors related to DF among the neglected population, the study was carried out by using a combination of quantitative household questionnaire surveys (HHSs) and qualitative semi-structured in-depth interviews (SDIs). The HHS questionnaire was administered to a total of 258 household heads. The 215 (83.3%) HHS respondents believed in Christianity and Catholicism. However, the 141 (54.7%,) of the total respondents thought that people with evil practices might be punished by diseases. More respondents believed that too rainy weather and water were more related to disease in the internally displaced person (IDP) camp than the local community (P<0.01). Most of the HHS respondents had sound knowledge of dengue symptoms, causes, vectors, transmission and prevention. The 257 (99.6%) HHS respondents reported that their families went to the public health facilities first to seek treatment. The 210 (84.1%) respondents reported that they turned containers upside down within five days. The key informants (n = 18) identified that the appropriate knowledge and behaviors were attributable to formal school education and specific health education campaign during the outbreak response in 2017, and that Kachin people enjoy conversing with each other, neighbors talked about the dengue information they received. The study results indicated that Kachin people have a good knowledge and behaviors of dengue control. The actual situation of dengue is still not clear due to lacking data of laboratory test. In the context of resources shortage, more international assistance is still needed to promote local dengue control and prevention efforts. The conflict between the Kachin Independence Army and the Myanmar government armed forces has lasted for more than eight years in the Kachin State (since 9th June 2011). Control of vector-borne diseases is especially important in emergency settings of tropical regions. In 2017, a dengue outbreak occurred and then was successfully controlled in Kachin Special Region (KSR2), Myanmar. To understand further preparedness at the community level for future possible re-emergence of DF, one IDP camp and a local community were sampled to investigate people’s health beliefs in general, knowledge and treatment-seeking and prevention behaviors related to dengue control from August to December, the local dengue transmission season in 2018. This study found that the IDPs and local Kachin residents have sound knowledge about dengue, treatment-seeking and prevention behaviors; an inconsistency exists between their religious and health beliefs due to pressure from various diseases and health problems. The community members perceived DF as a serious and life-threatening disease; however, the local health authority did not think dengue was a priority health problem. The actual situation of dengue is still not clear due to lacking laboratory test and surveillance data. In the emergency context, dengue may still be a local health threat and dengue control is particularly important. The local capacity for dengue laboratory testing and control and prevention activities should be promoted urgently. This should get more international attention and assistance.
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16
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Li J, Zhang J, Li Q, Hu Y, Ruan Y, Tao Z, Xia H, Qiao J, Meng L, Zeng W, Li C, He X, Zhao L, Siddiqui FA, Miao J, Yang Z, Fang Q, Cui L. Ex vivo susceptibilities of Plasmodium vivax isolates from the China-Myanmar border to antimalarial drugs and association with polymorphisms in Pvmdr1 and Pvcrt-o genes. PLoS Negl Trop Dis 2020; 14:e0008255. [PMID: 32530913 PMCID: PMC7314094 DOI: 10.1371/journal.pntd.0008255] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 06/24/2020] [Accepted: 03/26/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Vivax malaria is an important public health problem in the Greater Mekong Subregion (GMS), including the China-Myanmar border. Previous studies have found that Plasmodium vivax has decreased sensitivity to antimalarial drugs in some areas of the GMS, but the sensitivity of P. vivax to antimalarial drugs is unclear in the China-Myanmar border. Here, we investigate the drug sensitivity profile and genetic variations for two drug resistance related genes in P. vivax isolates to provide baseline information for future drug studies in the China-Myanmar border. METHODOLOGY/PRINCIPAL FINDINGS A total of 64 P. vivax clinical isolates collected from the China-Myanmar border area were assessed for ex vivo susceptibility to eight antimalarial drugs by the schizont maturation assay. The medians of IC50 (half-maximum inhibitory concentrations) for chloroquine, mefloquine, pyronaridine, piperaquine, quinine, artesunate, artemether, dihydroartemisinin were 84.2 nM, 34.9 nM, 4.0 nM, 22.3 nM, 41.4 nM, 2.8 nM, 2.1 nM and 2.0 nM, respectively. Twelve P. vivax clinical isolates were found over the cut-off IC50 value (220 nM) for chloroquine resistance. In addition, sequence polymorphisms in pvmdr1 (P. vivax multidrug resistance-1), pvcrt-o (P. vivax chloroquine resistance transporter-o), and difference in pvmdr1 copy number were studied. Sequencing of the pvmdr1 gene in 52 samples identified 12 amino acid substitutions, among which two (G698S and T958M) were fixed, M908L were present in 98.1% of the isolates, while Y976F and F1076L were present in 3.8% and 78.8% of the isolates, respectively. Amplification of the pvmdr1 gene was only detected in 4.8% of the samples. Sequencing of the pvcrt-o in 59 parasite isolates identified a single lysine insertion at position 10 in 32.2% of the isolates. The pvmdr1 M908L substitutions in pvmdr1 in our samples was associated with reduced sensitivity to chloroquine, mefloquine, pyronaridine, piperaquine, quinine, artesunate and dihydroartemisinin. CONCLUSIONS Our findings depict a drug sensitivity profile and genetic variations of the P. vivax isolates from the China-Myanmar border area, and suggest possible emergence of chloroquine resistant P. vivax isolates in the region, which demands further efforts for resistance monitoring and mechanism studies.
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Affiliation(s)
- Jiangyan Li
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, Anhui Province, China
- Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Jie Zhang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan Province, China
| | - Qian Li
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, Anhui Province, China
- Xiangtan Blood Center, Xiangtan, Hunan Province, China
| | - Yue Hu
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan Province, China
| | - Yonghua Ruan
- Department of Pathology, Kunming Medical University, Kunming, Yunnan Province, China
| | - Zhiyong Tao
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, Anhui Province, China
- Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Hui Xia
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, Anhui Province, China
- Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Jichen Qiao
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, Anhui Province, China
- Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Lingwen Meng
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, Anhui Province, China
- Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, Anhui Province, China
| | - Weilin Zeng
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan Province, China
| | - Cuiying Li
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan Province, China
| | - Xi He
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan Province, China
| | - Luyi Zhao
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan Province, China
| | - Faiza A. Siddiqui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Jun Miao
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan Province, China
- * E-mail: (ZY); (QF)
| | - Qiang Fang
- Department of Microbiology and Parasitology, Bengbu Medical College, Bengbu, Anhui Province, China
- Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, Bengbu, Anhui Province, China
- * E-mail: (ZY); (QF)
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
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Zhao X, Thanapongtharm W, Lawawirojwong S, Wei C, Tang Y, Zhou Y, Sun X, Sattabongkot J, Kaewkungwal J. Spatiotemporal Trends of Malaria in Relation to Economic Development and Cross-Border Movement along the China-Myanmar Border in Yunnan Province. THE KOREAN JOURNAL OF PARASITOLOGY 2020; 58:267-278. [PMID: 32615740 PMCID: PMC7338897 DOI: 10.3347/kjp.2020.58.3.267] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 03/02/2020] [Accepted: 04/06/2020] [Indexed: 12/01/2022]
Abstract
The heterogeneity and complexity of malaria involves political and natural environments, socioeconomic development, cross-border movement, and vector biology; factors that cannot be changed in a short time. This study aimed to assess the impact of economic growth and cross-border movement, toward elimination of malaria in Yunnan Province during its pre-elimination phase. Malaria data during 2011-2016 were extracted from 18 counties of Yunnan and from 7 villages, 11 displaced person camps of the Kachin Special Region II of Myanmar. Data of per-capita gross domestic product (GDP) were obtained from Yunnan Bureau of Statistics. Data were analyzed and mapped to determine spatiotemporal heterogeneity at county and village levels. There were a total 2,117 malaria cases with 85.2% imported cases; most imported cases came from Myanmar (78.5%). Along the demarcation line, malaria incidence rates in villages/camps in Myanmar were significantly higher than those of the neighboring villages in China. The spatial and temporal trends suggested that increasing per-capita GDP may have an indirect effect on the reduction of malaria cases when observed at macro level; however, malaria persists owing to complex, multi-faceted factors including poverty at individual level and cross-border movement of the workforce. In moving toward malaria elimination, despite economic growth, cooperative efforts with neighboring countries are critical to interrupt local transmission and prevent reintroduction of malaria via imported cases. Cross-border workers should be educated in preventive measures through effective behavior change communication, and investment is needed in active surveillance systems and novel diagnostic and treatment services during the elimination phase.
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Affiliation(s)
- Xiaotao Zhao
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Yunnan Institute of Parasitic Diseases, Puer, Yunnan, China
| | - Weerapong Thanapongtharm
- Veterinary Epidemiological Center, Bureau of Disease Control and Veterinary Services, Department of Livestock Development, Bangkok, Thailand
| | - Siam Lawawirojwong
- Geo-Informatics and Space Technology Development Agency, Bangkok, Thailand
| | - Chun Wei
- Yunnan Institute of Parasitic Diseases, Puer, Yunnan, China
| | - Yerong Tang
- Yunnan Institute of Parasitic Diseases, Puer, Yunnan, China
| | - Yaowu Zhou
- Yunnan Institute of Parasitic Diseases, Puer, Yunnan, China
| | - Xiaodong Sun
- Yunnan Institute of Parasitic Diseases, Puer, Yunnan, China
| | - Jestumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jaranit Kaewkungwal
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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18
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Li Y, Hu Y, Zhao Y, Wang Q, Ngassa Mbenda HG, Kittichai V, Lawpoolsri S, Sattabongkot J, Menezes L, Liu X, Cui L, Cao Y. Dynamics of Plasmodium vivax populations in border areas of the Greater Mekong sub-region during malaria elimination. Malar J 2020; 19:145. [PMID: 32268906 PMCID: PMC7140319 DOI: 10.1186/s12936-020-03221-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 04/03/2020] [Indexed: 12/18/2022] Open
Abstract
Background Countries within the Greater Mekong Sub-region (GMS) of Southeast Asia have committed to eliminating malaria by 2030. Although the malaria situation has greatly improved, malaria transmission remains at international border regions. In some areas, Plasmodium vivax has become the predominant parasite. To gain a better understanding of transmission dynamics, knowledge on the changes of P. vivax populations after the scale-up of control interventions will guide more effective targeted control efforts. Methods This study investigated genetic diversity and population structures in 206 P. vivax clinical samples collected at two time points in two international border areas: the China-Myanmar border (CMB) (n = 50 in 2004 and n = 52 in 2016) and Thailand-Myanmar border (TMB) (n = 50 in 2012 and n = 54 in 2015). Parasites were genotyped using 10 microsatellite markers. Results Despite intensified control efforts, genetic diversity remained high (HE = 0.66–0.86) and was not significantly different among the four populations (P > 0.05). Specifically, HE slightly decreased from 0.76 in 2004 to 0.66 in 2016 at the CMB and increased from 0.80 in 2012 to 0.86 in 2015 at the TMB. The proportions of polyclonal infections varied significantly among the four populations (P < 0.05), and showed substantial decreases from 48.0% in 2004 to 23.7 at the CMB and from 40.0% in 2012 to 30.7% in 2015 at the TMB, with corresponding decreases in the multiplicity of infection. Consistent with the continuous decline of malaria incidence in the GMS over time, there were also increases in multilocus linkage disequilibrium, suggesting more fragmented and increasingly inbred parasite populations. There were considerable genetic differentiation and sub-division among the four tested populations. Temporal genetic differentiation was observed at each site (FST = 0.081 at the CMB and FST = 0.133 at the TMB). Various degrees of clustering were evident between the older parasite samples collected in 2004 at the CMB and the 2016 CMB and 2012 TMB populations, suggesting some of these parasites had shared ancestry. In contrast, the 2015 TMB population was genetically distinctive, which may reflect a process of population replacement. Whereas the effective population size (Ne) at the CMB showed a decrease from 4979 in 2004 to 3052 in 2016 with the infinite allele model, the Ne at the TMB experienced an increase from 6289 to 10,259. Conclusions With enhanced control efforts on malaria, P. vivax at the TMB and CMB showed considerable spatial and temporal differentiation, but the presence of large P. vivax reservoirs still sustained genetic diversity and transmission. These findings provide new insights into P. vivax transmission dynamics and population structure in these border areas of the GMS. Coordinated and integrated control efforts on both sides of international borders are essential to reach the goal of regional malaria elimination.
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Affiliation(s)
- Yuling Li
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.,Emergency Department, The First Affiliated Hospital of Dalian Medical University, Dalian, 116011, Liaoning, China
| | - Yubing Hu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Yan Zhao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Qinghui Wang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Huguette Gaelle Ngassa Mbenda
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Veerayuth Kittichai
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Saranath Lawpoolsri
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Lynette Menezes
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Xiaoming Liu
- Center for Global Health and Infectious Disease Research, College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Liwang Cui
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA. .,Center for Global Health and Infectious Disease Research, College of Public Health, University of South Florida, Tampa, FL, 33612, USA.
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
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19
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Ekezie W, Adaji EE, Murray RL. Essential healthcare services provided to conflict-affected internally displaced populations in low and middle-income countries: A systematic review. Health Promot Perspect 2020; 10:24-37. [PMID: 32104654 PMCID: PMC7036202 DOI: 10.15171/hpp.2020.06] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 11/08/2019] [Indexed: 11/29/2022] Open
Abstract
Background: Conflict and violent crises have resulted in over 40 million of internally displaced persons (IDPs). Most affected regions lack access to basic health resources and generally rely on humanitarian support. The objective of this review was to appraise primary health service interventions among conflict-induced internally displaced populations in low and middle income countries between 2000 and 2019. Methods: A systematic review of literature in the following databases: Embase, MEDLINE, PsyArticles, PsycINFO, Scopus, Web of Science, LILAC and CAB Articles, was performed to identify interventions implemented in conflict IDP settings. Results: Initial searches yielded 4578 papers and 30 studies met the inclusion criteria. Descriptivesynthesis analysis was used, and the final selections were assessed using a customized CriticalAppraisal Skills Programme (CASP) checklist. Included papers were from Sub-Saharan Africa, South Asia and the Middle East regions. Most studies were on prevention interventions, especially water treatment and maternal health. Treatment interventions mostly focused on onmalaria and mental health. Only one food and nutrition study with outcome data was identified, indicating limitations in IDP health-related intervention publications. Reported interventions were conducted between one week to five years, and the study qualities were moderate. The most effective interventions were integrated programmes and common challenges were weakstudy methodology and data reporting. Conclusion: Regardless of the intervention types and durations, the services offered were beneficial to the IDPs. More intervention evidence are, however required as shown in gaps around food and nutrition, health education and disease surveillance.
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Affiliation(s)
- Winifred Ekezie
- Division of Epidemiology and Public Health, University of Nottingham, UK
| | | | - Rachael L Murray
- Division of Epidemiology and Public Health, University of Nottingham, UK
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20
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Hu Y, Wang L, Mbenda HGN, Soe MT, Yu C, Feng H, Kyaw MP, Cui L, Zhu X, Cao Y. Genetic diversity, natural selection and haplotype grouping of Plasmodium vivax Duffy-binding protein genes from eastern and western Myanmar borders. Parasit Vectors 2019; 12:546. [PMID: 31747970 PMCID: PMC6864963 DOI: 10.1186/s13071-019-3803-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/12/2019] [Indexed: 12/17/2022] Open
Abstract
Background Merozoite proteins of the malaria parasites involved in the invasion of red blood cells are selected by host immunity and their diversity is greatly influenced by changes in malaria epidemiology. In the Greater Mekong Subregion (GMS), malaria transmission is concentrated along the international borders and there have been major changes in malaria epidemiology with Plasmodium vivax becoming the dominant species in many regions. Here, we aimed to evaluate the genetic diversity of P. vivax Duffy-binding protein gene domain II (pvdbp-II) in isolates from the eastern and western borders of Myanmar, and compared it with that from global P. vivax populations. Methods pvdbp-II sequences were obtained from 85 and 82 clinical P. vivax isolates from the eastern and western Myanmar borders, respectively. In addition, 504 pvdbp-II sequences from nine P. vivax populations of the world were retrieved from GenBank and used for comparative analysis of genetic diversity, recombination and population structure of the parasite population. Results The nucleotide diversity of the pvdbp-II sequences from the Myanmar border parasite isolates was not uniform, with the highest diversity located between nucleotides 1078 and 1332. Western Myanmar isolates had a unique R391C mutation. Evidence of positive natural selection was detected in pvdbp-II gene in P. vivax isolates from the eastern Myanmar area. P. vivax parasite populations in the GMS, including those from the eastern, western, and central Myanmar as well as Thailand showed low-level genetic differentiation (FST, 0.000–0.099). Population genetic structure analysis of the pvdbp-II sequences showed a division of the GMS populations into four genetic clusters. A total of 60 PvDBP-II haplotypes were identified in 210 sequences from the GMS populations. Among the epitopes in PvDBP-II, high genetic diversity was found in epitopes 45 (379-SIFGT(D/G)(E/K)(K/N)AQQ(R/H)(R/C)KQ-393, π = 0.029) and Ia (416-G(N/K)F(I/M)WICK(L/I)-424], Ib [482-KSYD(Q/E)WITR-490, π = 0.028) in P. vivax populations from the eastern and western borders of Myanmar. Conclusions The pvdbp-II gene is genetically diverse in the eastern and western Myanmar border P. vivax populations. Positive natural selection and recombination occurred in pvdbp-II gene. Low-level genetic differentiation was identified, suggesting extensive gene flow of the P. vivax populations in the GMS. These results can help understand the evolution of the P. vivax populations in the course of regional malaria elimination and guide the design of PvDBP-II-based vaccine.![]()
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Affiliation(s)
- Yubing Hu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Lin Wang
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Huguette Gaelle Ngassa Mbenda
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Myat Thu Soe
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Chunyun Yu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Hui Feng
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | | | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Xiaotong Zhu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China.
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China.
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21
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Naing C, Whittaker MA, Tanner M. Inter-sectoral approaches for the prevention and control of malaria among the mobile and migrant populations: a scoping review. Malar J 2018; 17:430. [PMID: 30445959 PMCID: PMC6240188 DOI: 10.1186/s12936-018-2562-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/01/2018] [Indexed: 02/05/2023] Open
Abstract
Background Malaria cases among mobile and migrant populations (MMPs) represent a large and important reservoir for transmission, if undetected or untreated. The objectives of this review were to identify which intersectoral actions have been taken and how they are applied to interventions targeted at the MMPs and also to assess the effect of interventions targeted to these special groups of population. Results A total of 36 studies met the inclusion criteria for this review. Numerous stakeholders were identified as involved in the intersectoral actions to defeat malaria amongst MMPs. Almost all studies discussed the involvement of Ministry of Health/Public Health (MOH/MOPH). The most frequently assessed intervention among the studies that were included was the coverage and utilization of insecticide-treated nets as personal protective measures (40.5%), followed by the intervention of early diagnoses and treatment of malaria (33.3%), the surveillance and response activities (13.9%) and the behaviour change communication (8.3%). There is a dearth of information on how these stakeholders shared roles and responsibilities for implementation, and about the channels of communication between-and-within the partners and with the MOH/MOPH. Despite limited details in the studies, the intermediate outcomes showed some evidence that the intersectoral collaborations contributed to improvement in knowledge about malaria, initiation and promotion of bed nets utilization, increased access to diagnosis and treatment in a surveillance context and contributed towards a reduction in malaria transmission. Overall, a high proportion of the targeted MMPs was equipped with correct knowledge about malaria transmission (70%, 95% CI 57–83%). Interventions targeting the use of bed nets utilization were two times more likely to reduce malaria incidence amongst the targeted MMPs (summary OR 2.01, 95% CI 1.43–2.6) than the non-users. The various intersectoral actions were often more vertically organized and not fully integrated in a systemic way within a given country or sub-national administrative setting. Conclusion Findings suggest that interventions supported by the multiple stakeholders had a significant impact on the reduction of malaria transmission amongst the targeted MMPs. Well-designed studies from different countries are recommended to robustly assess the role of intersectoral interventions targeted to MMPs and their impact on the reduction of transmission. Electronic supplementary material The online version of this article (10.1186/s12936-018-2562-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cho Naing
- Institute for Research, Development and Innovation (IRDI), International Medical University, Kuala Lumpur, Malaysia. .,Division of Tropical Health and Medicine, James Cook University, Townsville, QLD, Australia.
| | - Maxine A Whittaker
- Division of Tropical Health and Medicine, James Cook University, Townsville, QLD, Australia
| | - Marcel Tanner
- Swiss Tropical and Public Health Institute, Basel, Switzerland
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22
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Monitoring of malaria vectors at the China-Myanmar border while approaching malaria elimination. Parasit Vectors 2018; 11:511. [PMID: 30219093 PMCID: PMC6139178 DOI: 10.1186/s13071-018-3073-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/21/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Tengchong County was one of the counties located at the China-Myanmar border with high malaria incidence in the previous decades. As the pilot county for malaria elimination at the border area, Tengchong County is aiming to be the first county to achieve malaria elimination goal. A cross-sectional entomological survey was carried out to evaluate the feasibility of elimination approach and assess the receptivity of malaria reintroduction. METHODS Light traps associated with live baits were used to investigate the abundance of adult mosquitoes in nine villages in Tengchong County. Light traps were set to collect adult mosquitoes in both human houses and cowsheds from dusk till dawn in each site. RESULTS A total of 4948 adult Anopheles mosquitoes were collected from May to December in two villages. Of the mosquitoes were captured, 24.2% were in human houses and 75.8% in cowsheds. The peak of abundance occurred in July for An. sinensis and in September-October for An. minimus (s.l.) Ten Anopheles species were collected, the most prevalent being An. sinensis (50.3%), An. peditaeniatus (31.6%) and An. minimus (s.l.) (15.8%), contributing to 97.6% of the sample. Potential breeding sites were also investigated and a total of 407 larvae were collected, with An. sinensis (50.1%) and An. minimus (s.l.) (46.2%) as predominant species. Ponds and rice fields were the two preferred breeding sites for Anopheles mosquitoes; however, the difference between the number of adults and larvae captured suggest other breeding sites might exist. Both An. sinensis and An. minimus (s.l.) were found zoophilic with human blood index as 0.21 and 0.26, respectively. No Plasmodium positive Anopheles specimens were found by PCR among 4,000 trapped mosquitoes. CONCLUSIONS Although no indigenous malaria cases have been reported in Tengchong County since 2013, there is still a risk from the presence of vectors in the context of human population movements from neighboring malaria endemic areas. The presence of An. sinensis, associated to rice fields, is particularly worrying. Sustained entomological surveillance is strongly suggested even after malaria elimination certification.
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Randomized, Double-Blind, Placebo-Controlled Studies to Assess Safety and Prophylactic Efficacy of Naphthoquine-Azithromycin Combination for Malaria Prophylaxis in Southeast Asia. Antimicrob Agents Chemother 2018; 62:AAC.00793-18. [PMID: 29987144 DOI: 10.1128/aac.00793-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/05/2018] [Indexed: 01/01/2023] Open
Abstract
New prophylactic drugs against malaria infections are urgently needed. We conducted randomized, double-blind, placebo-controlled, phase 2 trials of a new antimalarial drug combination, naphthoquine-azithromycin (NQAZ), to determine its safety and protective efficacy in a low-endemicity area of Southeast Asia. In the first trial, 127 healthy volunteers were randomized to receive two single doses of either 400 mg of NQAZ (200 mg of each drug), 800 mg of NQAZ (400 mg of each drug), or placebo on day 0 and day 30. Weekly follow-ups were performed for 2 months, and physical and clinical laboratory exams were done during the second and eighth week. Both drug regimens were well tolerated, without any serious adverse events. Four adverse events (transient and slight elevations of serum transaminase concentrations) were found only in the two drug-treated groups and thus might be drug-related. In the second trial, 353 volunteer villagers were randomized into the same three groups as in the first trial, and malaria infections were followed for a month. For the intention-to-treat analysis, both regimens offered greater than 90% prophylactic efficacies against all malaria infections. When the analysis was done according to parasite species, 400 mg and 800 mg NQAZ provided 81.63 and 90.59% prophylactic efficacies, respectively, against Plasmodium falciparum infections, whereas both offered 100% prophylactic efficacy against Plasmodium vivax and Plasmodium ovale These trials showed that NQAZ had a good safety profile, and monthly single doses of 400 mg or 800 mg for adults offered excellent prophylaxis against malaria infections, especially the two relapsing species.
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Zhao Y, Zeng J, Zhao Y, Liu Q, He Y, Zhang J, Yang Z, Fan Q, Wang Q, Cui L, Cao Y. Risk factors for asymptomatic malaria infections from seasonal cross-sectional surveys along the China-Myanmar border. Malar J 2018; 17:247. [PMID: 29973194 PMCID: PMC6032786 DOI: 10.1186/s12936-018-2398-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/22/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Border malaria, a shared phenomenon in the Greater Mekong Sub-region of Southeast Asia, is a major obstacle for regional malaria elimination. Along the China-Myanmar border, an additional problem arose as a result of the settlement of internally displaced people (IDP) in the border region. Since asymptomatic malaria significantly impacts transmission dynamics, assessment of the prevalence, dynamics and risk factors of asymptomatic malaria infections is necessary. METHODS Cross-sectional surveys were carried out in 3 seasons (March and April, July and November) and 2 sites (villages and IDP camps) in 2015. A total of 1680 finger-prick blood samples were collected and used for parasite detection by microscopy and nested RT-PCR (nRT-PCR). Logistic regression models were used to explore the risk factors associated with asymptomatic malaria at individual and household levels. RESULTS The prevalence of asymptomatic Plasmodium infections was 23.3% by nRT-PCR, significantly higher than that detected by microscopy (1.5%). The proportions of Plasmodium vivax, Plasmodium falciparum and mixed-species infections were 89.6, 8.1 and 2.3%, respectively. Asymptomatic infections showed obvious seasonality with higher prevalence in the rainy season. Logistic regression analysis identified males and school children (≤ 15 years) as the high-risk populations. Vector-based interventions, including bed net and indoor residual spray, were found to have significant impacts on asymptomatic Plasmodium infections, with non-users of these measures carrying much higher risks of infection. In addition, individuals living in poorly constructed households or farther away from clinics were more prone to asymptomatic infections. CONCLUSIONS Sub-microscopic Plasmodium infections were highly prevalent in the border human populations from IDP camps and surrounding villages. Both individual- and household-level risk factors were identified, which provides useful information for identifying the high-priority populations to implement targeted malaria control.
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Affiliation(s)
- Yan Zhao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Jie Zeng
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Yonghong Zhao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Qingyang Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Yang He
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Jiaqi Zhang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Qi Fan
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Qinghui Wang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
| | - Liwang Cui
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China. .,Department of Entomology, Pennsylvania State University, University Park, State College, PA, 16802, USA.
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
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25
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Deng Z, Li Q, Yi H, Zhang Y, Yang F, Li H, Luo L, Ma L, Yang Z, He Y, Cui L. Hemoglobin E protects against acute Plasmodium vivax infections in a Kachin population at the China-Myanmar border. J Infect 2018; 77:435-439. [PMID: 29964138 DOI: 10.1016/j.jinf.2018.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/17/2018] [Accepted: 06/19/2018] [Indexed: 01/08/2023]
Abstract
OBJECTIVES Hemoglobin E (HbE, β26 Glu-Lys) is the most prevalent hemoglobinopathy in Southeast Asia. This study aimed to determine whether HbE protects against clinical Plasmodium vivax malaria in Southeast Asia. METHODS In a case-control study performed in villages along the China-Myanmar border, we determined the prevalence of HbE in 257 villagers who had acute P. vivax infections and in 157 control healthy villagers. RESULTS HbE in P. vivax patients (17.4%) was significantly less prevalent than in the healthy villager population (36.3%). Moreover, there was a complete lack of HbEE homozygotes in the vivax patients as compared to 9.5% prevalence in the healthy villagers. Using the HbAA group as the reference, both the HbEA heterozygotes and HbEE homozygotes had significantly lower odds of presenting with acute P. vivax infections. Furthermore, HbEA heterozygotes also had significantly lower P. vivax asexual parasite densities. HbEA did not affect the proportion of P. vivax patients with gametocytemia nor the gametocyte densities. CONCLUSIONS HbE offers significant protection against the occurrence and parasite density of acute P. vivax infections and provides a renewed perspective on P. vivax malaria as a potentially strong driving force behind the high frequencies of HbE in the Kachin population.
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Affiliation(s)
- Zeshuai Deng
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, Yunnan Province, China
| | - Qing Li
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, Yunnan Province, China
| | - Haoan Yi
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, Yunnan Province, China
| | - Yanjie Zhang
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, Yunnan Province, China
| | - Fang Yang
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, Yunnan Province, China
| | - Hong Li
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, Yunnan Province, China
| | - Lan Luo
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, Yunnan Province, China
| | - Limei Ma
- Department of Histology and Embryology, Kunming Medical University, Kunming, Yunnan Province, China
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, Yunnan Province, China
| | - Yongshu He
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, Yunnan Province, China.
| | - Liwang Cui
- Department of Entomology, The Pennsylvania State University, Pennsylvania, United States of America.
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26
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Malaria burden and treatment targets in Kachin Special Region II, Myanmar from 2008 to 2016: A retrospective analysis. PLoS One 2018; 13:e0195032. [PMID: 29614088 PMCID: PMC5882093 DOI: 10.1371/journal.pone.0195032] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 03/15/2018] [Indexed: 01/02/2023] Open
Abstract
Although drug-based treatment is the primary intervention for malaria control and elimination, optimal use of targeted treatments remains unclear. From 2008 to 2016, three targeted programs on treatment were undertaken in Kachin Special Region II (KR2), Myanmar. Program I (2008–2011) treated all confirmed, clinical and suspected cases; program II (2012–2013) treated confirmed and clinical cases; and program III (2014–2016) targeted confirmed cases only. This study aims to evaluate the impacts of the three programs on malaria burden individually based on the annual parasite incidence (API), slide positivity rate (SPR) and their relative values. The API is calculated from original collected data and the incidence rate ratio (IRR) for each year is calculated by using the first-year API as a reference in each program phase across the KR2. Same method is applied to calculate SPR and risk ratio (RR) at the sentinel hospital too. During program I (2008–2011), malaria burden was reduced by 61% (95%CI: 58%-74%) and the actual API decreased from 9.8 (95%CI: 9.6–10.1) per 100 person-years in 2008 to 3.8 (3.6–4.1) per 100 person-years in 2011. Amid program II (2012–2013), the malaria burden increased by 33% (95%CI: 22%-46%) and the actual API increased from 2.1(95%CI: 2.0–2.3) per 100 person-years in 2012 to 2.8 (95%CI: 2.7–2.9) per 100 person-years in 2013. During program III (2014–2016) the malaria burden increased furtherly by 60% (95%CI: 51% - 69%) and the actual API increased from 3.2(95%CI: 3.0–3.3) per 100 person-years in 2014 to 5.1 (95%CI: 4.9–5.2) per 100 person-years in 2016. Results of the slide positivity of the sentinel hospital also confirm these results. Resurgence of malaria was mainly due to Plasmodium vivax during program II and III. This study indicates that strategy adopted in program I (2008–2011) should be more appropriate for the KR2. Quality-assured treatment of all confirmed, clinical and suspected malaria cases may be helpful for the reduction of malaria burden.
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27
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Lo E, Lam N, Hemming-Schroeder E, Nguyen J, Zhou G, Lee MC, Yang Z, Cui L, Yan G. Frequent Spread of Plasmodium vivax Malaria Maintains High Genetic Diversity at the Myanmar-China Border, Without Distance and Landscape Barriers. J Infect Dis 2017; 216:1254-1263. [PMID: 28329141 DOI: 10.1093/infdis/jix106] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 03/02/2017] [Indexed: 11/13/2022] Open
Abstract
Background In Myanmar, civil unrest and the establishment of internally displaced person (IDP) settlements along the Myanmar-China border have impacted malaria transmission. Methods Microsatellite markers were used to examine source-sink dynamics for Plasmodium vivax between IDP settlements and surrounding villages in the border region. Genotypic structure and diversity were compared across the 3 years following the establishment of IDP settlements, to infer demographic history. We investigated whether human migration and landscape heterogeneity contributed to P. vivax transmission. Results P. vivax from IDP settlements and local communities consistently exhibited high genetic diversity within populations but low polyclonality within individuals. No apparent genetic structure was observed among populations and years. P. vivax genotypes in China were similar to those in Myanmar, and parasite introduction was unidirectional. Landscape factors, including distance, elevation, and land cover, do not appear to impede parasite gene flow. Conclusions The admixture of P. vivax genotypes suggested that parasite gene flow via human movement contributes to the spread of malaria both locally in Myanmar and across the international border. Our genetic findings highlight the presence of large P. vivax gene reservoirs that can sustain transmission. Thus, it is important to reinforce and improve existing control efforts along border areas.
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Affiliation(s)
- Eugenia Lo
- Program in Public Health, University of California-Irvine
| | - Nancy Lam
- Program in Public Health, University of California-Irvine
| | | | | | - Guofa Zhou
- Program in Public Health, University of California-Irvine
| | - Ming-Chieh Lee
- Program in Public Health, University of California-Irvine
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, China
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park
| | - Guiyun Yan
- Program in Public Health, University of California-Irvine
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28
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Brooks HM, Jean Paul MK, Claude KM, Mocanu V, Hawkes MT. Use and disuse of malaria bed nets in an internally displaced persons camp in the Democratic Republic of the Congo: A mixed-methods study. PLoS One 2017; 12:e0185290. [PMID: 28950001 PMCID: PMC5614551 DOI: 10.1371/journal.pone.0185290] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 09/08/2017] [Indexed: 11/18/2022] Open
Abstract
Introduction Malaria is a major cause of morbidity and mortality among displaced populations in tropical zones. Bed nets are widely used to prevent malaria; however, few data are available on bed net distribution within displaced populations. Methods Mixed methods study in a single internally displaced persons (IDP) camp and neighboring community in Eastern Democratic Republic of the Congo (DRC). Qualitative data (focus group discussions, FGDs) and quantitative data (door-to-door survey and individual testing using malaria rapid diagnostic test, RDT) were collected. Results Ten FGDs were conducted with 55 individuals. Although malaria was widely recognized as a significant threat and bed nets were freely distributed in the camp, many households did not own or use them. IDPs converged on the following reasons for low bed net ownership and use: inconvenience of net installation and sale of nets to meet immediate needs such as food. One hundred households, comprised of 411 individuals, were surveyed in Birambizo. The burden of malaria was high (45/78 (58%) of children <5 were positive for malaria by RDT) and bed net utilization was low (29/100 (29%) households owned a bed net, and 85/411 (20%) individuals slept under a bed net the previous night). Children <5 were more likely to use a bed net than older children or adults (OR 3.4 (95%CI 2.0–5.8), p<0.0001). Compared to 29 bed nets currently in use by study participants, 146 bed nets had been sold (82%) or exchanged (18%) either in the camp (27%) or in the neighbouring village market (73%). Conclusions Qualitative descriptions and quantitative analysis revealed pragmatic barriers to bed net usage and widespread sale of freely distributed bed nets within IDP camps, despite a high burden of malaria. Additional strategies, beyond bed net distribution, are warranted to combat malaria in vulnerable and hard-to-reach population.
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Affiliation(s)
| | | | | | - Victor Mocanu
- Department of Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Michael T. Hawkes
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
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29
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Douine M, Mosnier E, Le Hingrat Q, Charpentier C, Corlin F, Hureau L, Adenis A, Lazrek Y, Niemetsky F, Aucouturier AL, Demar M, Musset L, Nacher M. Illegal gold miners in French Guiana: a neglected population with poor health. BMC Public Health 2017; 18:23. [PMID: 28716015 PMCID: PMC5513330 DOI: 10.1186/s12889-017-4557-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 06/30/2017] [Indexed: 11/17/2022] Open
Abstract
Background In French Guiana, a French overseas territory in South America, 6 to 10 thousands undocumented persons work illegally in gold mining sites in the Amazonian forest. Precarious life conditions lead to poor health but few data exist on the health status of illegal gold miners in French Guiana. The objective of this article was to describe the sociodemographic and health status of this vulnerable population. Method A prospective cross-sectional survey was conducted in 2015 on gold mine supply sites at the border between French Guiana and Suriname. Health status was assessed through medical examination, past medical history, haemoglobin concentration, and HIV and malaria testing. A questionnaire was used to collect data about the migration itinerary and life conditions on mining sites. Results Among the 421 adults included in the study, 93.8% (395/421) were Brazilian, mainly from Maranhão (55.7%, 220/395), the poorest Brazilian state. The sex ratio was 2.4. Overall, 48% of persons never went to school or beyond the primary level. The median time spent in gold mining was quite long (10 years), with a high turn-over. One third of the surveyed population (37.1%, 156/421) had high blood pressure, and only two had a medical follow-up. Most persons had experienced malaria (89.3%, 376/421). They declared frequent arboviroses and digestive disorders. Active leishmaniasis was observed in 8.3% of gold miners. Among women, 28.5% were anemic. Concerning HIV, 36.6% (154/421) of persons, mainly men, never got tested before and 6 were tested positive, which represented an HIV prevalence of 1.43% (95%CI =0.29–2.5). Conclusion These findings support the hypothesis that mining in remote areas is linked to several specific illnesses. Theoretically, gold miners would be presumed to start their economical migration to French Guiana as a healthy group. However, their strenuous working and living conditions there lead to poor health caused by infectious and non infectious diseases. This description of their health status is precious for health policy planners in French Guiana given the importance of controlling communicable disease, and the severity and range of specific illnesses acquired by this neglected population. Trial registration Clinical trial registration PRS N° NCT02903706. Retrospectively registered 09/13/2016.
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Affiliation(s)
- Maylis Douine
- Centre d'Investigation Clinique Antilles-Guyane (Inserm 1424), Cayenne Hospital, Av des Flamboyant, BP 6006, 97306 cedex, Cayenne, French Guiana, France. .,Epidemiology of Tropical Parasitoses, EA 3593, Université de Guyane, Cayenne, French Guiana, France.
| | - Emilie Mosnier
- Epidemiology of Tropical Parasitoses, EA 3593, Université de Guyane, Cayenne, French Guiana, France.,Centres Délocalisés de Prévention et de Soins, Cayenne Hospital, Cayenne, French Guiana, France
| | - Quentin Le Hingrat
- INSERM UMR1137, IAME Université Paris Diderot Sorbonne Paris Cité, AP-HP, Laboratoire de Virologie, Hôpital Bichat-Claude Bernard, Paris, France
| | - Charlotte Charpentier
- INSERM UMR1137, IAME Université Paris Diderot Sorbonne Paris Cité, AP-HP, Laboratoire de Virologie, Hôpital Bichat-Claude Bernard, Paris, France
| | - Florine Corlin
- Centre d'Investigation Clinique Antilles-Guyane (Inserm 1424), Cayenne Hospital, Av des Flamboyant, BP 6006, 97306 cedex, Cayenne, French Guiana, France
| | - Louise Hureau
- Centre d'Investigation Clinique Antilles-Guyane (Inserm 1424), Cayenne Hospital, Av des Flamboyant, BP 6006, 97306 cedex, Cayenne, French Guiana, France
| | - Antoine Adenis
- Centre d'Investigation Clinique Antilles-Guyane (Inserm 1424), Cayenne Hospital, Av des Flamboyant, BP 6006, 97306 cedex, Cayenne, French Guiana, France.,Epidemiology of Tropical Parasitoses, EA 3593, Université de Guyane, Cayenne, French Guiana, France
| | - Yassamine Lazrek
- Laboratoire de parasitologie, WHO Collaborating Center for Surveillance of Anti-Malarial Drug Resistance, Centre National de Référence du paludisme, Institut Pasteur de la Guyane, Cayenne, French Guiana, France
| | - Florence Niemetsky
- Centres Délocalisés de Prévention et de Soins, Cayenne Hospital, Cayenne, French Guiana, France
| | - Anne-Laure Aucouturier
- Centre d'Investigation Clinique Antilles-Guyane (Inserm 1424), Cayenne Hospital, Av des Flamboyant, BP 6006, 97306 cedex, Cayenne, French Guiana, France.,Centres Délocalisés de Prévention et de Soins, Cayenne Hospital, Cayenne, French Guiana, France
| | - Magalie Demar
- Academic Laboratory of Parasitology - Mycology, Cayenne Hospital, Cayenne, French Guiana, France
| | - Lise Musset
- Laboratoire de parasitologie, WHO Collaborating Center for Surveillance of Anti-Malarial Drug Resistance, Centre National de Référence du paludisme, Institut Pasteur de la Guyane, Cayenne, French Guiana, France
| | - Mathieu Nacher
- Centre d'Investigation Clinique Antilles-Guyane (Inserm 1424), Cayenne Hospital, Av des Flamboyant, BP 6006, 97306 cedex, Cayenne, French Guiana, France.,Epidemiology of Tropical Parasitoses, EA 3593, Université de Guyane, Cayenne, French Guiana, France
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30
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Zhu X, Zhao P, Wang S, Liu F, Liu J, Wang J, Yang Z, Yan G, Fan Q, Cao Y, Cui L. Analysis of Pvama1 genes from China-Myanmar border reveals little regional genetic differentiation of Plasmodium vivax populations. Parasit Vectors 2016; 9:614. [PMID: 27899135 PMCID: PMC5129220 DOI: 10.1186/s13071-016-1899-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 11/21/2016] [Indexed: 12/22/2022] Open
Abstract
Background With the premise of diminishing parasite genetic diversity following the reduction of malaria incidence, the analysis of polymorphic antigenic markers may provide important information about the impact of malaria control on local parasite populations. Here we evaluated the genetic diversity of Plasmodium vivax apical membrane antigen 1 (Pvama1) gene in a parasite population from the China-Myanmar border and compared it with global P. vivax populations. Methods We performed evolutionary analysis to examine the genetic diversity, natural selection, and population differentiation of 73 Pvama1 sequences acquired from the China-Myanmar border as well as 615 publically available Pvama1 sequences from seven global P. vivax populations. Results A total of 308 Pvama1 haplotypes were identified among the global P. vivax isolates. The overall nucleotide diversity of Pvama1 gene among the 73 China-Myanmar border parasite isolates was 0.008 with 41 haplotypes being identified (Hd = 0.958). Domain I (DI) harbored the majority (26/33) of the polymorphic sites. The McDonald Kreitman test showed a significant positive selection across the ectodomain and the DI of Pvama1. The fixation index (FST) estimation between the China-Myanmar border, Thailand (0.01) and Myanmar (0.10) showed only slight geographical genetic differentiation. Notably, the Sal-I haplotype was not detected in any of the analyzed global isolates, whereas the Belem strain was restricted to the Thai population. The detected mutations are mapped outside the overlapped region of the predicted B-cell epitopes and intrinsically unstructured/disordered regions. Conclusions This study revealed high levels of genetic diversity of Pvama1 in the P. vivax parasite population from the China-Myanmar border with DI displaying stronger diversifying selection than other domains. There were low levels of population subdivision among parasite populations from the Greater Mekong Subregion. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1899-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaotong Zhu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China
| | - Pan Zhao
- Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110122, China
| | - Si Wang
- Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110122, China
| | - Fei Liu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China
| | - Jun Liu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China
| | - Jian Wang
- Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110122, China
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, CA, USA
| | - Qi Fan
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China.
| | - Liwang Cui
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, 110122, China. .,Department of Entomology, The Pennsylvania State University, University Park, PA, 16802, USA.
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31
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Deng S, Ruan Y, Bai Y, Hu Y, Deng Z, He Y, Ruan R, Wu Y, Yang Z, Cui L. Genetic diversity of the Pvk12 gene in Plasmodium vivax from the China-Myanmar border area. Malar J 2016; 15:528. [PMID: 27809837 PMCID: PMC5096284 DOI: 10.1186/s12936-016-1592-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 10/28/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Plasmodium falciparum resistance to artemisinin emerged in the Greater Mekong Sub-region has been associated with mutations in the propeller domain of the kelch gene Pfk13. METHODS Here the polymorphisms in Pvk12 gene, the orthologue of Pfk13 in Plasmodium vivax, were determined by PCR and sequencing in 262 clinical isolates collected in recent years (2012-2015) from the China-Myanmar border area. RESULTS Sequencing of full-length Pvk12 genes from these isolates identified three synonymous mutations (N172N, S360S, S697S) and one non-synonymous mutation M124I, all of which were at very low prevalence (2.0-3.1%). Moreover, these mutations were non-overlapping between the two study sites on both sides of the border. Molecular evolutionary analysis detected signature of purifying selection on Pvk12. CONCLUSIONS There is no direct evidence that Pvk12 is involved in artemisinin resistance in P. vivax, but it remains a potential candidate requiring further investigation. Continuous monitoring of potential drug resistance in this parasite is needed in order to facilitate the regional malaria elimination campaign.
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Affiliation(s)
- Shuang Deng
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan Province, China.,Department of Pathology, Kunming Medical University, Kunming, 650500, Yunnan Province, China
| | - Yonghua Ruan
- Department of Pathology, Kunming Medical University, Kunming, 650500, Yunnan Province, China
| | - Yao Bai
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan Province, China.,Department of Pharmacology, Kunming Medical University, Kunming, 650500, Yunnan Province, China
| | - Yue Hu
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan Province, China.,Department of Pathology, Kunming Medical University, Kunming, 650500, Yunnan Province, China
| | - Zeshuai Deng
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, 650500, Yunnan Province, China
| | - Yongshu He
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, 650500, Yunnan Province, China
| | - Rui Ruan
- Department of Orthopedics, The First Affiliated Hospital, Kunming Medical University, Kunming, 650500, Yunnan Province, China
| | - Yanrui Wu
- Department of Cell Biology and Medical Genetics, Kunming Medical University, Kunming, 650500, Yunnan Province, China
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan Province, China.
| | - Liwang Cui
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan Province, China.
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