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Muñoz-Ortiz A, Beltrán M, Vargas Durango J, Mestre G, Santamaria Herreño E, Escovar JE. Spatio-Temporal distribution of a vector of cutaneous leishmaniasis: Pintomyia longiflocosa, in a population from the Colombian Andean Mountains. PLoS Negl Trop Dis 2024; 18:e0012237. [PMID: 38885272 PMCID: PMC11213335 DOI: 10.1371/journal.pntd.0012237] [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: 06/16/2023] [Revised: 06/28/2024] [Accepted: 05/22/2024] [Indexed: 06/20/2024] Open
Abstract
BACKGROUND Leishmaniasis, a neglected disease and public health concern, is associated with various factors such as biological, social, economical conditions and climate, increasing the risk of human infection. Understanding the population dynamics of the vectors, like Pintomyia longiflocosa, and its relationship with ecological variables is crucial for developing effective strategies to control sand fly populations and combat cutaneous leishmaniasis in a tropical country like Colombia. METHODOLOGY Adult sand flies were collected in three different sample locations: outdoor, indoor, and peri-domestic areas in three houses located in the rural settlement of Campoalegre (Huila) between February 2020 and February 2021, using the CDC light traps. The sand fly density was quantified and associated with the sample locations and the sampling months using Analysis of Variance and Pearson correlations. PRINCIPAL FINDINGS In the period of the sample, 98.86% of sand fly collected was identified as Pi. longiflocosa. The density of this species was significantly different between males and females, the latter contributing more to density in all sample locations (P<0.0001). The outdoor was the sample location with the highest and most significative density in this study (70%, P = 0.04). The density of these sand flies is related to the seasonality of Campoalegre, revealing a density peak from February and June to October (P < 0.05). Finally, precipitation is the environmental variable prominently linked to the density pattern, showing a negative correlation with it. Months with the highest precipitations show the lowest values of Pi. longiflocosa abundance. CONCLUSIONS/SIGNICANCE Our investigation reveals a inverse correlation between precipitation levels and the abundance of Pi. longiflocosa in Campoalegre (Huila), particularly in outdoor areas. This suggests that vector control strategies to periods of reduced precipitation in outdoor settings could offer an effective approach to minimizing cases of cutaneous leishmaniasis in the region.
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Affiliation(s)
- Astrid Muñoz-Ortiz
- Escuela de Ciencias Básicas y Aplicadas, Universidad de La Salle, Bogotá D.C., Colombia
| | - Miguel Beltrán
- Escuela de Ciencias Básicas y Aplicadas, Universidad de La Salle, Bogotá D.C., Colombia
| | | | - Gelys Mestre
- Escuela de Ciencias Básicas y Aplicadas, Universidad de La Salle, Bogotá D.C., Colombia
| | | | - Jesús E. Escovar
- Escuela de Ciencias Básicas y Aplicadas, Universidad de La Salle, Bogotá D.C., Colombia
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Mazarire TT, Lobb L, Newete SW, Munhenga G. The Impact of Climatic Factors on Temporal Mosquito Distribution and Population Dynamics in an Area Targeted for Sterile Insect Technique Pilot Trials. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2024; 21:558. [PMID: 38791773 PMCID: PMC11121319 DOI: 10.3390/ijerph21050558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/20/2024] [Accepted: 04/24/2024] [Indexed: 05/26/2024]
Abstract
It is widely accepted that climate affects the mosquito life history traits; however, its precise role in determining mosquito distribution and population dynamics is not fully understood. This study aimed to investigate the influence of various climatic factors on the temporal distribution of Anopheles arabiensis populations in Mamfene, South Africa between 2014 and 2019. Time series analysis, wavelet analysis, cross-correlation analysis, and regression model combined with the autoregressive integrated moving average (ARIMA) model were utilized to assess the relationship between climatic factors and An. arabiensis population density. In total 3826 adult An. arabiensis collected was used for the analysis. ARIMA (0, 1, 2) (0, 0, 1)12 models closely described the trends observed in An. arabiensis population density and distribution. The wavelet coherence and time-lagged correlation analysis showed positive correlations between An. arabiensis population density and temperature (r = 0.537 ), humidity (r = 0.495) and rainfall (r = 0.298) whilst wind showed negative correlations (r = -0.466). The regression model showed that temperature (p = 0.00119), rainfall (p = 0.0436), and humidity (p = 0.0441) as significant predictors for forecasting An. arabiensis abundance. The extended ARIMA model (AIC = 102.08) was a better fit for predicting An. arabiensis abundance compared to the basic model. Anopheles arabiensis still remains the predominant malaria vector in the study area and climate variables were found to have varying effects on the distribution and abundance of An. arabiensis. This necessitates other complementary vector control strategies such as the Sterile Insect Technique (SIT) which involves releasing sterile males into the environment to reduce mosquito populations. This requires timely mosquito and climate information to precisely target releases and enhance the effectiveness of the program, consequently reducing the malaria risk.
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Affiliation(s)
- Theresa Taona Mazarire
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg 2131, South Africa; (L.L.); (G.M.)
- Wits Research Institute for Malaria, School of Pathology, University of the Witwatersrand, Johannesburg 2050, South Africa
- Geoinformatics Division, Agricultural Research Council-Natural Resource and Engineering, Arcadia, Pretoria 0083, South Africa;
| | - Leanne Lobb
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg 2131, South Africa; (L.L.); (G.M.)
| | - Solomon Wakshom Newete
- Geoinformatics Division, Agricultural Research Council-Natural Resource and Engineering, Arcadia, Pretoria 0083, South Africa;
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Bramfontein, Johannesburg 2050, South Africa
| | - Givemore Munhenga
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg 2131, South Africa; (L.L.); (G.M.)
- Wits Research Institute for Malaria, School of Pathology, University of the Witwatersrand, Johannesburg 2050, South Africa
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Lin ZR, Yin SS, Yang J, Guo XR, Dong CL, Lin YK, Ding CL, Sun XD, Yan RX, Yang SL, Zhou XH, Xu JW. The public health response to an outbreak of border-spill malaria along China-Myanmar border. PLoS One 2022; 17:e0275932. [PMID: 36525438 PMCID: PMC9757579 DOI: 10.1371/journal.pone.0275932] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 09/27/2022] [Indexed: 12/23/2022] Open
Abstract
INTRODUCTION Malaria importation can be caused by cross-border movement either of both people and anopheline mosquitoes. However, there still lacks robust evidence of imported malaria caused by Plasmodium spp. infected anopheles along international border areas (border-spill malaria). The objectives of this study were to confirm whether an outbreak of Plasmodium vivax malaria is border-spill malaria and assess the effects of China's public health response along China-Myanmar border. METHODS Epidemiological, parasitological and entomological investigations were conducted to investigate the outbreak of border-spill malaria. Meanwhile, comprehensive interventions were carried out to prevent further transmission and reintroduction of malaria. RESULTS Rapid diagnostic testing, microscopy and polymerase chain reaction were performed and the infections were confirmed as P. vivax. A total of 22 (9.21%) of 239 workers contracted P. vivax during the outbreak. Multivariate logistic regression analysis identified that the distance of worker shelters in China within 300 meters to the internally displaced person (IDP) camps in Myanmar was a risk factors associated with malaria infection (adjusted odds ratio 7.5920; 95% confidence interval, 2.6079-22.1013; P = 0.0002). After comprehensive interventions, malaria transmission was successfully interpreted and prevented at the project site till the completion of project on 14 January 2020, and recurrence of P. vivax malaria was not detected by the end of 2020. CONCLUSION This study provided robust evidence of border-spill malaria along China-Myanmar border. Malaria parasite reservoir and distance travelled by female anopheline mosquitoes are two determinants for border-spill malaria. The public health response to the outbreak indicates that the malaria surveillance and response system works well in preventing reintroduction of malaria. However, prevention of border-spill malaria is still a major challenge in the Yunnan border area, China.
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Affiliation(s)
- Zu-Rui Lin
- Malaria Division, Yunnan Institute of Parasitic Diseases, Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Key Laboratory of Vector-borne Disease Control and Research, Yunnan Institute of Parasitic Diseases Innovative Team of Key Techniques for Vector Borne Disease Control and Prevention, Training Base of International Scientific Exchange and Education in Tropical Diseases for South and Southeast Asia, Pu’er, Yunnan, China
| | - Shan-Shan Yin
- Parasitic Disease Section, Yingjiang County Center for Disease Control and Prevention, Yingjiang, Yunnan, China
| | - Jie Yang
- Parasitic Disease Section, Donghong Prefecture Center for Disease Control and Prevention, Mangshi, Yunnan, China
| | - Xiang-Rui Guo
- Parasitic Disease Section, Yingjiang County Center for Disease Control and Prevention, Yingjiang, Yunnan, China
| | - Chao-Liang Dong
- Parasitic Disease Section, Donghong Prefecture Center for Disease Control and Prevention, Mangshi, Yunnan, China
| | - Ying-Kun Lin
- Parasitic Disease Section, Donghong Prefecture Center for Disease Control and Prevention, Mangshi, Yunnan, China
| | - Chun-Li Ding
- Malaria Division, Yunnan Institute of Parasitic Diseases, Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Key Laboratory of Vector-borne Disease Control and Research, Yunnan Institute of Parasitic Diseases Innovative Team of Key Techniques for Vector Borne Disease Control and Prevention, Training Base of International Scientific Exchange and Education in Tropical Diseases for South and Southeast Asia, Pu’er, Yunnan, China
| | - Xiao-Dong Sun
- Malaria Division, Yunnan Institute of Parasitic Diseases, Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Key Laboratory of Vector-borne Disease Control and Research, Yunnan Institute of Parasitic Diseases Innovative Team of Key Techniques for Vector Borne Disease Control and Prevention, Training Base of International Scientific Exchange and Education in Tropical Diseases for South and Southeast Asia, Pu’er, Yunnan, China
| | - Run-Xian Yan
- Parasitic Disease Section, Yingjiang County Center for Disease Control and Prevention, Yingjiang, Yunnan, China
| | - Suo-Lan Yang
- Parasitic Disease Section, Yingjiang County Center for Disease Control and Prevention, Yingjiang, Yunnan, China
| | - Xian-Hua Zhou
- Parasitic Disease Section, Yingjiang County Center for Disease Control and Prevention, Yingjiang, Yunnan, China
| | - Jian-Wei Xu
- Malaria Division, Yunnan Institute of Parasitic Diseases, Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Key Laboratory of Vector-borne Disease Control and Research, Yunnan Institute of Parasitic Diseases Innovative Team of Key Techniques for Vector Borne Disease Control and Prevention, Training Base of International Scientific Exchange and Education in Tropical Diseases for South and Southeast Asia, Pu’er, Yunnan, China
- * E-mail:
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Furlong M, Adamu A, Hickson RI, Horwood P, Golchin M, Hoskins A, Russell T. Estimating the Distribution of Japanese Encephalitis Vectors in Australia Using Ecological Niche Modelling. Trop Med Infect Dis 2022; 7:tropicalmed7120393. [PMID: 36548648 PMCID: PMC9782987 DOI: 10.3390/tropicalmed7120393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/12/2022] [Accepted: 11/15/2022] [Indexed: 11/25/2022] Open
Abstract
Recent Japanese encephalitis virus (JEV) outbreaks in southeastern Australia have sparked interest into epidemiological factors surrounding the virus' novel emergence in this region. Here, the geographic distribution of mosquito species known to be competent JEV vectors in the country was estimated by combining known mosquito occurrences and ecological drivers of distribution to reveal insights into communities at highest risk of infectious disease transmission. Species distribution models predicted that Culex annulirostris and Culex sitiens presence was mostly likely along Australia's eastern and northern coastline, while Culex quinquefasciatus presence was estimated to be most likely near inland regions of southern Australia as well as coastal regions of Western Australia. While Culex annulirostris is considered the dominant JEV vector in Australia, our ecological niche models emphasise the need for further entomological surveillance and JEV research within Australia.
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Affiliation(s)
- Morgan Furlong
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
- Correspondence: (M.F.); (P.H.)
| | - Andrew Adamu
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
| | - Roslyn I. Hickson
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
- Commonwealth Scientific Industrial Research Organisation (CSIRO), Townsville, QLD 4811, Australia
| | - Paul Horwood
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
- Correspondence: (M.F.); (P.H.)
| | - Maryam Golchin
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
- Commonwealth Scientific Industrial Research Organisation (CSIRO), Townsville, QLD 4811, Australia
| | - Andrew Hoskins
- Commonwealth Scientific Industrial Research Organisation (CSIRO), Townsville, QLD 4811, Australia
| | - Tanya Russell
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
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Cui L, Sattabongkot J, Aung PL, Brashear A, Cao Y, Kaewkungwal J, Khamsiriwatchara A, Kyaw MP, Lawpoolsri S, Menezes L, Miao J, Nguitragool W, Parker D, Phuanukoonnon S, Roobsoong W, Siddiqui F, Soe MT, Sriwichai P, Yang Z, Zhao Y, Zhong D. Multidisciplinary Investigations of Sustained Malaria Transmission in the Greater Mekong Subregion. Am J Trop Med Hyg 2022; 107:138-151. [PMID: 36228909 DOI: 10.4269/ajtmh.21-1267] [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
In the course of malaria elimination in the Greater Mekong Subregion (GMS), malaria epidemiology has experienced drastic spatiotemporal changes with residual transmission concentrated along international borders and the rising predominance of Plasmodium vivax. The emergence of Plasmodium falciparum parasites resistant to artemisinin and partner drugs renders artemisinin-based combination therapies less effective while the potential spread of multidrug-resistant parasites elicits concern. Vector behavioral changes and insecticide resistance have reduced the effectiveness of core vector control measures. In recognition of these problems, the Southeast Asian International Center of Excellence for Malaria Research (ICEMR) has been conducting multidisciplinary research to determine how human migration, antimalarial drug resistance, vector behavior, and insecticide resistance sustain malaria transmission at international borders. These efforts allow us to comprehensively understand the ecology of border malaria transmission and develop population genomics tools to identify and track parasite introduction. In addition to employing in vivo, in vitro, and molecular approaches to monitor the emergence and spread of drug-resistant parasites, we also use genomic and genetic methods to reveal novel mechanisms of antimalarial drug resistance of parasites. We also use omics and population genetics approaches to study insecticide resistance in malaria vectors and identify changes in mosquito community structure, vectorial potential, and seasonal dynamics. Collectively, the scientific findings from the ICEMR research activities offer a systematic view of the factors sustaining residual malaria transmission and identify potential solutions to these problems to accelerate malaria elimination in the GMS.
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Affiliation(s)
- Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | | | | | - Awtum Brashear
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Yaming Cao
- Department of Immunology, China Medical University, Shenyang, China
| | | | | | | | | | - 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, Mahidol University, Bangkok, Thailand
| | - Daniel Parker
- Department of Epidemiology, University of California at Irvine, Irvine, California
| | | | | | - Faiza Siddiqui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Myat Thu Soe
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Patchara Sriwichai
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Yan Zhao
- Department of Immunology, China Medical University, Shenyang, China
| | - Daibin Zhong
- Program in Public Health, University of California at Irvine, Irvine, California
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Li Y, Huang Y, Chen R, Huang W, Xu H, Ye R, Huang S, Zhen J, Wen X, Wang G, Liu Y, Li H, Zheng Z, Wang J, Wang G, Chen C, Zeng W, Meng F, Huang X, Wang G, Yang B, Chen Y. An innovative three-layer strategy in response to a quartan malaria outbreak among forest goers in Hainan Island, China: a retrospective study. Infect Dis Poverty 2022; 11:97. [PMID: 36104737 PMCID: PMC9473465 DOI: 10.1186/s40249-022-01015-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 08/12/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An outbreak of Plasmodium malariae infection among forest goers in Sanya City of Hainan Island, China was reported in 2015. In response to this outbreak, an innovative three-layer strategy (TLS) targeted forest goers was adapted based on the 1-3-7 approach. MAIN TEXT Key elements of TLS are: (i) The village with five malaria cases and adjacent villages were set as the first layer. All residents including forest goers were taken as the high-risk population (HRP). Active case detection (ACD) by blood smear microscopy and PCR was selected as the primary measure, and passive case detection (PCD) as complementary measure. One case was identified under TLS implementation. (ii) The township with cases (Gaofeng Town) and the nearby towns were chosen as the second layer. Only forest goers were screened by ACD, while PCD as a routine screening method. 7831 blood smears collected by ACD and PCD and tested with negative results. (iii) The city with cases (Sanya City) and others 12 counties/county-level cities were selected as the third layer. Malaria cases were monitored passively. A total of 77,555 blood slides were screened by PCD with zero positive sample. For each layer, the malaria vector mosquitoes were monitored using light traps, cattle-baited/human-bait traps. Anopheles minimus (dominant species), An. sinensis and An. dirus were captured. Vector control measures mainly include insecticide residual spraying and long-lasting insecticide nets. The capacity of clinicians, public health practitioners and laboratory technicians has been improved through training. During 2016‒2018, TLS and chemoprophylaxis were implemented in the same areas. In the first layer, all residents were monitored by ACD, and malaria chemoprophylaxis were distributed, 89.5% of forest goers were using chemoprophylaxis against malaria. The blood smears (3126 by ACD plus 1516 by PCD) were with zero positive results. Chemoprophylaxis and ACD were offered to forest goers once a year, and PCD in residents as a complementary measure in the second and third layer, 77.8% and 95.1% of forest goers received chemoprophylaxis. In each layer, vector surveillance and control of malaria and trainings for medical staff were still in place. CONCLUSIONS TLS was effective in blocking the outbreak by P. malariae among forest goers in Hainan in malaria elimination stage. However, whether it could prevent the malaria resurgence in the post-elimination phase needs to be further assessed.
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Affiliation(s)
- Yuchun Li
- Hainan Provincial Center for Disease Control and Prevention, No. 40 Haifu Road, Haikou, 570203, People's Republic of China
| | - Yingjuan Huang
- Sanya City's Center for Disease Control and Prevention, No.674, Jiefang Third Road, Sanya, 570203, People's Republic of China
| | - Renqiang Chen
- Sanya City's Center for Disease Control and Prevention, No.674, Jiefang Third Road, Sanya, 570203, People's Republic of China
| | - Weizhen Huang
- Wuzhishan City's Center for Disease Control and Prevention, No. 26, Aoya Road, Wuzhishan, 572200, People's Republic of China
| | - Huanzhi Xu
- Wuzhishan City's Center for Disease Control and Prevention, No. 26, Aoya Road, Wuzhishan, 572200, People's Republic of China
| | - Rongshen Ye
- Baoting County's Center for Disease Control and Prevention, No. 2 Wenquan South Road, Baoting County, 572300, People's Republic of China
| | - Shaoling Huang
- Wanning City's Center for Disease Control and Prevention, No.70 Guangming South Road, Wanning City, 571500, People's Republic of China
| | - Ji Zhen
- Dongfang City's Center for Disease Control and Prevention, Intersection of Liberation West Road and Harvest Road, Dongfang City, 572600, People's Republic of China
| | - Xiaodan Wen
- Danzhou City's Center for Disease Control and Prevention, No. 2000 Zhongxing Avenue, Danzhou City, 571700, People's Republic of China
| | - Guoyi Wang
- Qiongzhong County's Center for Disease Control and Prevention, Intersection of Baihua Road and Education Road, Qiongzhong County, 572900, People's Republic of China
| | - Yong Liu
- Tunchang County's Center for Disease Control and Prevention, No. 6 Jiefang Road, Tunchang County, 571600, People's Republic of China
| | - Haishan Li
- Ledong County's Center for Disease Control and Prevention, Nearby Secondary Health Vocational and Technical School, Ledong County, 572500, People's Republic of China
| | - Zaichun Zheng
- Changjiang County's Center for Disease Control and Prevention, Intersection People North Road and Huimin Road, Changjiang County, 572700, People's Republic of China
| | - Jian Wang
- Baisha County's Center for Disease Control and Prevention, Weisheng Road, Baisha County, 572800, People's Republic of China
| | - Guoshen Wang
- Qionghai County's Center for Disease Control and Prevention, No. 17 Fuhaiheng South Road, Qionghai County, 571400, People's Republic of China
| | - Chong Chen
- Lingshui County's Institute of Health Supervision, Shuangyong Road, Lingshui County, 572400, People's Republic of China
| | - Wen Zeng
- Hainan Provincial Center for Disease Control and Prevention, No. 40 Haifu Road, Haikou, 570203, People's Republic of China
| | - Feng Meng
- Hainan Provincial Center for Disease Control and Prevention, No. 40 Haifu Road, Haikou, 570203, People's Republic of China
| | - Xiaoming Huang
- Hainan Provincial Center for Disease Control and Prevention, No. 40 Haifu Road, Haikou, 570203, People's Republic of China
| | - Guangze Wang
- Hainan Provincial Center for Disease Control and Prevention, No. 40 Haifu Road, Haikou, 570203, People's Republic of China.
| | - Bing Yang
- Hainan Provincial Center for Disease Control and Prevention, No. 40 Haifu Road, Haikou, 570203, People's Republic of China.
| | - Yan Chen
- Hainan Provincial Center for Disease Control and Prevention, No. 40 Haifu Road, Haikou, 570203, People's Republic of China.
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Srisuka W, Sulin C, Sommitr W, Rattanarithikul R, Aupalee K, Saeung A, Harbach RE. Mosquito (Diptera: Culicidae) Diversity and Community Structure in Doi Inthanon National Park, Northern Thailand. INSECTS 2022; 13:814. [PMID: 36135515 PMCID: PMC9505505 DOI: 10.3390/insects13090814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/31/2022] [Accepted: 09/03/2022] [Indexed: 06/16/2023]
Abstract
Urbanization and human activities create new suitable aquatic habitats for the immature stages of mosquitoes in many countries. This also applies to Doi Inthanon National Park in northern Thailand, which is named for the highest mountain in the country. Despite its popularity, there is no information regarding mosquito diversity and community structure in the different ecosystems of the park. Monthly collections of immature stages from various habitats were conducted from August 2004 to December 2005 using dipping and sucking methods. The specimens collected from each habitat were reared to adults and identified based on their morphology. Diversity parameters and community structure were statistically analyzed. A total of 140 species (3795 specimens) belonging to 15 genera were identified. Among these, four genera (Culex, Aedes, Anopheles, and Uranotaenia) had high species richness, each represented by 48, 27, 19, and 15 species, respectively. Aedes albopictus was the most relatively abundant species, representing 6.7% of the total number of captured specimens, followed by Tripteroides aranoides (5.6%) and Cx. mimulus (5%). Species richness in natural habitats was significantly higher than in artificial containers. Species richness and abundance were highest in the rainy season. In comparison to agricultural areas and villages, mosquito diversity was found to be higher in forest areas. Ground pools, stream pools, rock pools, bamboo stumps, bamboo internode, and rice fields were the most preferred natural habitats. The results indicate that Doi Inthanon National Park has a high mosquito diversity. Each species exhibits differences in abundance and distribution in different habitats, which is useful information for planning conservation measures and vector control in the park.
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Affiliation(s)
- Wichai Srisuka
- Entomology Section, Queen Sirikit Botanic Garden, P.O. Box 7, Chiang Mai 50180, Thailand
| | - Chayanit Sulin
- Entomology Section, Queen Sirikit Botanic Garden, P.O. Box 7, Chiang Mai 50180, Thailand
| | - Wirat Sommitr
- Entomology Section, Queen Sirikit Botanic Garden, P.O. Box 7, Chiang Mai 50180, Thailand
| | | | - Kittipat Aupalee
- Center of Insect Vector Study, Department of Parasitology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Atiporn Saeung
- Center of Insect Vector Study, Department of Parasitology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Ralph E. Harbach
- Scientific Associate, Natural History Museum, London SW7 5BD, UK
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Yukich JO, Lindblade K, Kolaczinski J. Receptivity to malaria: meaning and measurement. Malar J 2022; 21:145. [PMID: 35527264 PMCID: PMC9080212 DOI: 10.1186/s12936-022-04155-0] [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: 05/12/2021] [Accepted: 04/07/2022] [Indexed: 01/13/2023] Open
Abstract
"Receptivity" to malaria is a construct developed during the Global Malaria Eradication Programme (GMEP) era. It has been defined in varied ways and no consistent, quantitative definition has emerged over the intervening decades. Despite the lack of consistency in defining this construct, the idea that some areas are more likely to sustain malaria transmission than others has remained important in decision-making in malaria control, planning for malaria elimination and guiding activities during the prevention of re-establishment (POR) period. This manuscript examines current advances in methods of measurement. In the context of a decades long decline in global malaria transmission and an increasing number of countries seeking to eliminate malaria, understanding and measuring malaria receptivity has acquired new relevance.
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Affiliation(s)
- Joshua O. Yukich
- grid.265219.b0000 0001 2217 8588Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA USA
| | - Kim Lindblade
- grid.3575.40000000121633745Global Malaria Programme, World Health Organization, Geneva, CH USA
| | - Jan Kolaczinski
- grid.3575.40000000121633745Global Malaria Programme, World Health Organization, Geneva, CH USA
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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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Zheng J, Shi B, Xia S, Yang G, Zhou XN. Spatial patterns of <em>Plasmodium vivax</em> transmission explored by multivariate auto-regressive state-space modelling - A case study in Baoshan Prefecture in southern China. GEOSPATIAL HEALTH 2021; 16. [PMID: 33733649 DOI: 10.4081/gh.2021.879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/21/2020] [Indexed: 06/12/2023]
Abstract
The transition from the control phase to elimination of malaria in China through the national malaria elimination programme has focussed attention on the need for improvement of the surveillance- response systems. It is now understood that routine passive surveillance is inadequate in the parasite elimination phase that requires supplementation by active surveillance in foci where cluster cases have occurred. This study aims to explore the spatial clusters and temporal trends of malaria cases by the multivariate auto-regressive state-space model (MARSS) along the border to Myanmar in southern China. Data for indigenous cases spanning the period from 2007 to 2010 were extracted from the China's Infectious Diseases Information Reporting Management System (IDIRMS). The best MARSS model indicated that malaria transmission in the study area during 36 months could be grouped into three clusters. The estimation of malaria transmission patterns showed a downward trend across all clusters. The proposed methodology used in this study offers a simple and rapid, yet effective way to categorize patterns of foci which provide assistance for active monitoring of malaria in the elimination phase.
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Affiliation(s)
- Jinxin Zheng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai, China; National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China; Chinese Center for Tropical Diseases Research, Shanghai.
| | - Benyun Shi
- School of Computer Science and Technology, Nanjing Tech University, Nanjing, Jiangsu.
| | - Shang Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai, China; National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China; Chinese Center for Tropical Diseases Research, Shanghai.
| | - Guojing Yang
- Hainan Medical University, Laboratory of Tropical Environment and Health, Haikou, Hainan, China; Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute; University of Basel, Basel.
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai, China; National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China; Chinese Center for Tropical Diseases Research, Shanghai.
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Brown R, Chua TH, Fornace K, Drakeley C, Vythilingam I, Ferguson HM. Human exposure to zoonotic malaria vectors in village, farm and forest habitats in Sabah, Malaysian Borneo. PLoS Negl Trop Dis 2020; 14:e0008617. [PMID: 32886679 PMCID: PMC7497982 DOI: 10.1371/journal.pntd.0008617] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 09/17/2020] [Accepted: 07/20/2020] [Indexed: 12/27/2022] Open
Abstract
The zoonotic malaria parasite, Plasmodium knowlesi, is now a substantial public health problem in Malaysian Borneo. Current understanding of P. knowlesi vector bionomics and ecology in Sabah comes from a few studies near the epicentre of human cases in one district, Kudat. These have incriminated Anopheles balabacensis as the primary vector, and suggest that human exposure to vector biting is peri-domestic as well as in forest environments. To address the limited understanding of vector ecology and human exposure risk outside of Kudat, we performed wider scale surveillance across four districts in Sabah with confirmed transmission to investigate spatial heterogeneity in vector abundance, diversity and infection rate. Entomological surveillance was carried out six months after a cross-sectional survey of P. knowlesi prevalence in humans throughout the study area; providing an opportunity to investigate associations between entomological indicators and infection. Human-landing catches were performed in peri-domestic, farm and forest sites in 11 villages (3-4 per district) and paired with estimates of human P. knowlesi exposure based on sero-prevalence. Anopheles balabacensis was present in all districts but only 6/11 villages. The mean density of An. balabacensis was relatively low, but significantly higher in farm (0.094/night) and forest (0.082/night) than peri-domestic areas (0.007/night). Only one An. balabacensis (n = 32) was infected with P. knowlesi. Plasmodium knowlesi sero-positivity in people was not associated with An. balabacensis density at the village-level however post hoc analyses indicated the study had limited power to detect a statistical association due low vector density. Wider scale sampling revealed substantial heterogeneity in vector density and distribution between villages and districts. Vector-habitat associations predicted from this larger-scale surveillance differed from those inferred from smaller-scale studies in Kudat; highlighting the importance of local ecological context. Findings highlight potential trade-offs between maximizing temporal versus spatial breadth when designing entomological surveillance; and provide baseline entomological and epidemiological data to inform future studies of entomological risk factors for human P. knowlesi infection.
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Affiliation(s)
- Rebecca Brown
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
| | - Tock H. Chua
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Kimberly Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Heather M. Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Li Y, Zhou G, Zhong S, Wang X, Zhong D, Hemming-Schroeder E, Yi G, Fu F, Fu F, Cui L, Cui G, Yan G. Spatial heterogeneity and temporal dynamics of mosquito population density and community structure in Hainan Island, China. Parasit Vectors 2020; 13:444. [PMID: 32887654 PMCID: PMC7650291 DOI: 10.1186/s13071-020-04326-5] [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: 06/10/2020] [Accepted: 08/30/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Mosquitoes are vectors of many tropical diseases. Understanding the ecology of local mosquito vectors, such as species composition, distributions, population dynamics, and species diversity is important for designing the optimal strategy to control the mosquito-borne diseases. METHODS Entomological surveillance of adult mosquitoes was conducted in five sites representing different ecological settings across Hainan Island from January to December of 2018 using BG Sentinel (BGS) traps and Centers for Disease Prevention and Control (CDC) light traps. In each site, we selected three areas representing urban, suburban and rural settings. Eighteen trap-days were sampled in each setting at each site, and CDC light traps and BGS traps were setup simultaneously. Mosquito species composition, distribution, population dynamics, and species diversity were analyzed. Mosquito densities were compared between different study sites and between different settings. RESULTS Nine species of mosquitoes belonging to four genera were identified. Culex quinquefasciatus (80.8%), Armigeres subalbatus (13.0%) and Anopheles sinensis (3.1%) were the top three species collected by CDC light traps; Cx. quinquefasciatus (91.9%), Ae. albopictus (5.1%), and Ar. subalbatus (2.8%) were the top three species collected by BGS traps. Predominant species varied among study sites. The population dynamics of Ae. albopictus, An. sinensis and Cx. quinquefasciatus showed clear seasonal variation regardless of study sites with a varied peak season for different species. Mosquito abundance of all species showed significant differences among different study sites and among urban, suburban and rural areas. Danzhou had the highest mosquito biodiversity, with an α, β, and Gini-Simpson biodiversity index of 8, 1.13 and 0.42, respectively. BGS traps captured Aedes mosquito at a higher efficiency than CDC light traps, whereas CDC light traps captured significantly more Anopheles and Armigeres mosquitoes than BGS traps. CONCLUSIONS Mosquitoes were abundant on Hainan Island with clear seasonality and spatial heterogeneity. Population density, species composition, distribution, and species diversity were strongly affected by the natural environment. Different tools are required for the surveillance of different mosquito species.
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Affiliation(s)
- Yiji Li
- Department of Pathogen Biology, Hainan Medical University, Haikou, Hainan China
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA 92697 USA
| | - Guofa Zhou
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA 92697 USA
| | - Saifeng Zhong
- Department of Pathogen Biology, Hainan Medical University, Haikou, Hainan China
| | - Xiaoming Wang
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA 92697 USA
| | - Daibin Zhong
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA 92697 USA
| | | | - Guohui Yi
- Public Research Laboratory, Hainan Medical University, Haikou, Hainan China
| | - Fengyang Fu
- Department of Medical Technology, Chongqing Medical and Pharmaceutical College, Chongqing, China
| | - Faxing Fu
- Department of Pathogen Biology, Hainan Medical University, Haikou, Hainan China
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612 USA
| | - Guzhen Cui
- Key Laboratory of Medical Microbiology and Parasitology of Education Department of Guizhou, School of Basic Medical Science, Guizhou Medical University, Guiyang, China
- Key Laboratory of Endemic and Ethnic Diseases Ministry of Education, Guiyang, China
| | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA 92697 USA
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Santos EB, Favretto MA, Navarro‐Silva MA. Community structure of mosquitoes (Diptera: Culicidae) in the coast of Southern Brazil. AUSTRAL ENTOMOLOGY 2019; 58:826-835. [DOI: 10.1111/aen.12412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Affiliation(s)
- Emili B Santos
- Universidade Federal de Santa Catarina, Campus Curitibanos Km 3, Ulysses Gaboardi Road Curitibanos Santa Catarina State Brazil
| | - Mario A Favretto
- Secretaria Municipal de SaúdePrefeitura Municipal de Campos Novos Caetano Belincanta Neto Avenue Campos Novos Santa Catarina State Brazil
| | - Mario A Navarro‐Silva
- Departamento de ZoologiaUniversidade Federal do Paraná Jardim das Américas Curitiba Paraná State Brazil
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Yang D, Liu R, Ye L, Hu Q, Rui J, Zhou Y, Zhang H, Zhang X, Zhao B, Chen T. Hand, foot, and mouth disease in Changsha City, China, 2009-2017: a new method to analyse the epidemiological characteristics of the disease. Infect Dis (Lond) 2019; 52:39-44. [PMID: 31596157 DOI: 10.1080/23744235.2019.1675902] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Objectives: By adopting a new method, this study aimed to analyse the epidemiological characteristics of hand, foot, and mouth disease (HFMD) in nine districts and counties (cities) of Changsha City, China, from 2009 to 2017.Methods: The reported HFMD cases were collected in Changsha from 2009 to 2017. The traditional descriptive method and a new method (index system) including six indices (richness index N, Simpson diversity index D, Shannon diversity index H, Berger-Parker dominance index d, Shannon evenness index E, and Morisita-Horn similarity index C) were used to describe the epidemiological characteristics of HFMD in Changsha.Results: There were 214155 HFMD reported in Changsha during the study period. The incidence of the disease was higher in even-numbered years (2010, 2012, 2014, and 2016) than in uneven-numbered years (2009, 2011, 2013, 2015, and 2017), with two peaks in May to June and October to November every year. The age of onset was mainly from 0 to 5 years old, and the death was mainly from 0 to 2 years old. According to occupational classification, districts and counties (cities) had a high degree of similarity of the composition of HFMD, and there was no regional difference.Conclusions: Changsha had a yearly increasing trend of HFMD from 2009 to 2017, and the key population for prevention and control was children aged in 0-5 years old. Seasonal distribution of high incidence and peak incidence were occurred in even-numbered years. The sub-regions of the city shared moderate diversity and high similarity of occupational distribution of HFMD.
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Affiliation(s)
- Dong Yang
- Changsha Center for Disease Control and Prevention, Changsha, People's Republic of China
| | - Ruchun Liu
- Changsha Center for Disease Control and Prevention, Changsha, People's Republic of China
| | - Lan Ye
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, People's Republic of China
| | - Qingqing Hu
- Division of Public Health, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Jia Rui
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, People's Republic of China
| | - Yinzhu Zhou
- Changsha Center for Disease Control and Prevention, Changsha, People's Republic of China
| | - Heng Zhang
- Changsha Center for Disease Control and Prevention, Changsha, People's Republic of China
| | - Xixing Zhang
- Changsha Center for Disease Control and Prevention, Changsha, People's Republic of China
| | - Benhua Zhao
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, People's Republic of China
| | - Tianmu Chen
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, People's Republic of China
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Geng J, Malla P, Zhang J, Xu S, Li C, Zhao Y, Wang Q, Kyaw MP, Cao Y, Yang Z, Cui L. Increasing trends of malaria in a border area of the Greater Mekong Subregion. Malar J 2019; 18:309. [PMID: 31514740 PMCID: PMC6739967 DOI: 10.1186/s12936-019-2924-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 08/17/2019] [Indexed: 11/27/2022] Open
Abstract
Background Intensive malaria transmission along international borders is a significant impediment to malaria elimination in the Greater Mekong Subregion (GMS) of Southeast Asia. Passive case detection (PCD) was used to study the dynamics and trends of malaria transmission at the China–Myanmar border to provide epidemiologic information for improved malaria control. Methods PCD was conducted in one hospital and 12 clinics near the Laiza town in northeast Myanmar from 2011 to 2016. Clinical malaria was diagnosed by microscopy and demographic information was captured using a structured questionnaire at the time of the patient’s presentation for care. Results Over the study period, 6175 (19.7%) malaria cases were confirmed by microscopy from 31,326 suspected cases. The four human malaria parasite species were all identified, with Plasmodium vivax and Plasmodium falciparum accounting for 5607 (90.8%) and 481 (7.8%) of the confirmed cases, respectively. In contrast to the steady decline of malaria in the general GMS, the study site had an upward trend of malaria incidence with vivax malaria outbreaks in 2013 and 2016. Adult males, children under the age of 15, and those with occupations such as farming, being a soldier or student, had significantly higher risks of clinical malaria compared to having fevers from other aetiologies. A self-reported history of clinical malaria was also associated with a higher risk of confirmed malaria. Conclusions The China–Myanmar border area has experienced an overall upward trend of malaria incidence in recent years with P. vivax becoming the predominant species. Evidence-based control strategies need to focus on high-risk populations.
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Affiliation(s)
- Jinting Geng
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Pallavi Malla
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Jiaqi Zhang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Shiling Xu
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China
| | - Cuiying Li
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 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
| | | | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China.
| | - Liwang Cui
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA.
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Shen HM, Chen SB, Cui YB, Xu B, Kassegne K, Abe EM, Wang Y, Chen JH. Whole-genome sequencing and analysis of Plasmodium falciparum isolates from China-Myanmar border area. Infect Dis Poverty 2018; 7:118. [PMID: 30445995 PMCID: PMC6240207 DOI: 10.1186/s40249-018-0493-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 10/16/2018] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND China has made progress in malaria control and aims to eliminate malaria nationwide, but implementing effective interventions along the border regions remain a huge task. The Plasmodium falciparum cases imported from Southeast Asia has frequently reported especially in the China-Myanmar border (CMB) area. Though, information is scant on P. falciparum genetic variability in this area. METHODS This study reported P. falciparum isolates genome sequence of six clinical isolates in the CMB area. Furthermore, we estimated the nucleotide diversity, Watterson's estimator and Tajima's D value for the whole genome mutation rate in slide window. RESULTS Our data were aligned onto 96.05-98.61% of the reference 3D7 genome in high fold coverages. Principal component analysis result showed that P. falciparum clustered generally according to their geographic origin. A total of 91 genes were identified as positive selection with Ka/Ks ratio significantly higher than 1, and most of them were multigene families encoding variant surface antigens (VSAs) such as var, rif and stevor. The enrichment of the positive selection on VSA genes implied that the environment complexity subjected CMB's P. falciparum to more pressure for survival. CONCLUSIONS Our research suggests that greater genetic diversity in CMB area and the positive selection signals in VSA genes, which allow P. falciparum to fit the host immune system well and aggravate the difficulty of treatment. Meanwhile, results obtained from this study will provide the fundamental basis for P. falciparum population genomic research in CMB area.
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Affiliation(s)
- Hai-Mo Shen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Chinese Center for Tropical Diseases Research; WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
| | - Shen-Bo Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Chinese Center for Tropical Diseases Research; WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
| | - Yan-Bing Cui
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Chinese Center for Tropical Diseases Research; WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
| | - Bin Xu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Chinese Center for Tropical Diseases Research; WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
| | - Kokouvi Kassegne
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Chinese Center for Tropical Diseases Research; WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
| | - Eniola Michael Abe
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Chinese Center for Tropical Diseases Research; WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
| | - Yue Wang
- Institute of Parasitic Diseases, Zhejiang Academy of Medical Sciences, Hangzhou, 310013 China
- Department of Microbiology and Microbial Engineering, School of Life Science, Fudan University, Shanghai, 200433 China
| | - Jun-Hu Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Chinese Center for Tropical Diseases Research; WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
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Perez-Guzman PN, Carlos Junior Alcantara L, Obolski U, de Lima MM, Ashley EA, Smithuis F, Horby P, Maude RJ, Lin Z, Kyaw AMM, Lourenço J. Measuring Mosquito-borne Viral Suitability in Myanmar and Implications for Local Zika Virus Transmission. PLOS CURRENTS 2018; 10:ecurrents.outbreaks.7a6c64436a3085ebba37e5329ba169e6. [PMID: 31032144 PMCID: PMC6472868 DOI: 10.1371/currents.outbreaks.7a6c64436a3085ebba37e5329ba169e6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
INTRODUCTION In South East Asia, mosquito-borne viruses (MBVs) have long been a cause of high disease burden and significant economic costs. While in some SEA countries the epidemiology of MBVs is spatio-temporally well characterised and understood, in others such as Myanmar our understanding is largely incomplete. MATERIALS AND METHODS Here, we use a simple mathematical approach to estimate a climate-driven suitability index aiming to better characterise the intrinsic, spatio-temporal potential of MBVs in Myanmar. RESULTS Results show that the timing and amplitude of the natural oscillations of our suitability index are highly informative for the temporal patterns of DENV case counts at the country level, and a mosquito-abundance measure at a city level. When projected at fine spatial scales, the suitability index suggests that the time period of highest MBV transmission potential is between June and October independently of geographical location. Higher potential is nonetheless found along the middle axis of the country and in particular in the southern corridor of international borders with Thailand. DISCUSSION This research complements and expands our current understanding of MBV transmission potential in Myanmar, by identifying key spatial heterogeneities and temporal windows of importance for surveillance and control. We discuss our findings in the context of Zika virus given its recent worldwide emergence, public health impact, and current lack of information on its epidemiology and transmission potential in Myanmar. The proposed suitability index here demonstrated is applicable to other regions of the world for which surveillance data is missing, either due to lack of resources or absence of an MBV of interest.
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Affiliation(s)
- Pablo Noel Perez-Guzman
- Department of Global Health and Tropical Medicine, University of Oxford, UK; Department of Infectious Disease Epidemiology, Imperial College, London, UK
| | | | - Uri Obolski
- Department of Zoology, University of Oxford, UK
| | - Maricelia M de Lima
- Laboratory of Haematology, Genetics and Computational Biology, FIOCRUZ, Brazil
| | - Elizabeth A Ashley
- Myanmar-Oxford Clinical Research Unit, Yangon; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, UK
| | - Frank Smithuis
- Myanmar-Oxford Clinical Research Unit, Yangon; Nuffield Department of Medicine, University of Oxford, UK; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, UK
| | - Peter Horby
- Nuffield Department of Medicine, University of Oxford, UK
| | - Richard J Maude
- Nuffield Department of Medicine, University of Oxford, UK; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University,Thailand; Harvard TH Chan School of Public Health, Harvard University, Boston, USA
| | - Zaw Lin
- Myanmar Ministry of Health and Sports, Naypyidaw, Myanmar
| | | | - José Lourenço
- Department of Zoology, University of Oxford, Oxford, UK
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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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Chen T, Zhang S, Zhou SS, Wang X, Luo C, Zeng X, Guo X, Lin Z, Tu H, Sun X, Zhou H. Receptivity to malaria in the China-Myanmar border in Yingjiang County, Yunnan Province, China. Malar J 2017; 16:478. [PMID: 29162093 PMCID: PMC5699173 DOI: 10.1186/s12936-017-2126-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 11/16/2017] [Indexed: 11/26/2022] Open
Abstract
Background The re-establishment of malaria has become an important public health issue in and out of China, and receptivity to this disease is key to its re-emergence. Yingjiang is one of the few counties with locally acquired malaria cases in the China–Myanmar border in China. This study aimed to understand receptivity to malaria in Yingjiang County, China, from June to October 2016. Methods Light-traps were employed to capture the mosquitoes in 17 villages in eight towns which were categorized into four elevation levels: level 1, 0–599 m; level 2, 600–1199 m; level 3, 1200–1799 m; and level 4, > 1800 m. Species richness, diversity, dominance and evenness were used to picture the community structure. Similarity in species composition was compared between different elevation levels. Data of seasonal abundance of mosquitoes, human biting rate, density of light-trap-captured adult mosquitoes and larvae, parous rate, and height distribution (density) of Anopheles minimus and Anopheles sinensis were collected in two towns (Na Bang and Ping Yuan) each month from June to October, 2016. Results Over the study period, 10,053 Anopheles mosquitoes were collected from the eight towns, and 15 Anopheles species were identified, the most-common of which were An. sinensis (75.4%), Anopheles kunmingensis (15.6%), and An. minimus (3.5%). Anopheles minimus was the major malaria vector in low-elevation areas (< 600 m, i.e., Na Bang town), and An. sinensis in medium-elevation areas (600–1200 m, i.e., Ping Yuan town). In Na Bang, the peak human-biting rate of An. minimus at the inner and outer sites of the village occurred in June and August 2016, with 5/bait/night and 15/bait/night, respectively. In Ping Yuan, the peak human-biting rate of An. sinensis was in August, with 9/bait/night at the inner site and 21/bait/night at the outer site. The two towns exhibited seasonal abundance with high density of the two adult vectors: The peak density of An. minimus was in June and that of An. sinensis was in August. Meanwhile, the peak larval density of An. minimus was in July, but that of An. sinensis decreased during the investigation season; the slightly acidic water suited the growth of these vectors. The parous rates of An. sinensis and An. minimus were 90.46 and 93.33%, respectively. Conclusions The Anopheles community was spread across different elevation levels. Its structure was complex and stable during the entire epidemic season in low-elevation areas at the border. The high human-biting rates, adult and larval densities, and parous rates of the two Anopheles vectors reveal an exceedingly high receptivity to malaria in the China–Myanmar border in Yingjiang County.
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Affiliation(s)
- Tianmu Chen
- Department of Malaria, National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,Key Laboratory of Parasite and Vector Biology, Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,WHO Collaborating Centre for Tropic Diseases, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,National Center for International Research on Tropical Diseases, Ministry of Science and Technology, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China
| | - Shaosen Zhang
- Department of Malaria, National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,Key Laboratory of Parasite and Vector Biology, Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,WHO Collaborating Centre for Tropic Diseases, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,National Center for International Research on Tropical Diseases, Ministry of Science and Technology, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China
| | - Shui-Sen Zhou
- Department of Malaria, National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China. .,Key Laboratory of Parasite and Vector Biology, Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China. .,WHO Collaborating Centre for Tropic Diseases, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China. .,National Center for International Research on Tropical Diseases, Ministry of Science and Technology, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.
| | - Xuezhong Wang
- Yunnan Institute of Parasitic Diseases, Puer, People's Republic of China
| | - Chunhai Luo
- Yunnan Institute of Parasitic Diseases, Puer, People's Republic of China
| | - Xucan Zeng
- Yunnan Institute of Parasitic Diseases, Puer, People's Republic of China
| | - Xiangrui Guo
- Yingjiang County Center for Disease Control and Prevention, Dehong, People's Republic of China
| | - Zurui Lin
- Yunnan Institute of Parasitic Diseases, Puer, People's Republic of China
| | - Hong Tu
- Department of Malaria, National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,Key Laboratory of Parasite and Vector Biology, Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,WHO Collaborating Centre for Tropic Diseases, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,National Center for International Research on Tropical Diseases, Ministry of Science and Technology, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China
| | - Xiaodong Sun
- Yunnan Institute of Parasitic Diseases, Puer, People's Republic of China
| | - Hongning Zhou
- Yunnan Institute of Parasitic Diseases, Puer, People's Republic of China
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Shen HM, Chen SB, Wang Y, Xu B, Abe EM, Chen JH. Genome-wide scans for the identification of Plasmodium vivax genes under positive selection. Malar J 2017; 16:238. [PMID: 28587615 PMCID: PMC5461743 DOI: 10.1186/s12936-017-1882-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/27/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The current trend of Plasmodium vivax cases imported from Southeast Asia into China has sharply increased recently, especially from the China-Myanmar border (CMB) area. High recombination rates of P. vivax populations associated with varied transmission intensity might cause distinct local selective pressures. The information on the genetic variability of P. vivax in this area is scant. Hence, this study assessed the genetic diversity of P. vivax genome sequence in CMB area and aimed to provide information on the positive selection of new gene loci. RESULTS This study reports a genome-wide survey of P. vivax in CMB area, using blood samples from local patients to identify population-specific selective processes. The result showed that considerable genetic diversity and mean pair-wise divergence among the sequenced P. vivax isolates were higher in some important gene families. Using the standardized integrated haplotype score (|iHS|) for all SNPs in chromosomal regions with SNPs above the top 1% distribution, it was observed that the top score locus involved 356 genes and most of them are associated with red blood cell invasion and immune evasion. The XP-EHH test was also applied and some important genes associated with anti-malarial drug resistance were observed in high positive scores list. This result suggests that P. vivax in CMB area is facing more pressure to survive than any other region and this has led to the strong positive selection of genes that are associated with host-parasite interactions. CONCLUSIONS This study suggests that greater genetic diversity in P. vivax from CMB area and positive selection signals in invasion and drug resistance genes are consistent with the history of drug use during malaria elimination programme in CMB area. Furthermore, this result also demonstrates that haplotype-based detecting selection can assist the genome-wide methods to identify the determinants of P. vivax diversity.
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Affiliation(s)
- Hai-Mo Shen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China
| | - Shen-Bo Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China
| | - Yue Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.,Institute of Parasitic Diseases, Zhejiang Academy of Medical Sciences, Hangzhou, 310013, People's Republic of China
| | - Bin Xu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China
| | - Eniola Michael Abe
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China
| | - Jun-Hu Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology Ministry of Health, 207 Rui Jin Er Road, Shanghai, 200025, People's Republic of China.
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Yu S, Ji C, Zhu X, Xue J, Wang L, Wang Y. Impact of Bacillus sphaericus exposure on Anopheles dirus's fecundity and resistance development. Parasitol Res 2016; 116:859-864. [PMID: 28012029 DOI: 10.1007/s00436-016-5358-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 12/18/2016] [Indexed: 11/30/2022]
Abstract
Mosquitoes are important vectors of many infectious diseases. Bacillus sphaericus (Bs) is an ideal larvicide and has attracted more and more attention, recently. However, the fundamental research of its application is very limited, especially on the subsequent impact of Bs exposure on mosquito's fecundity and resistance emergence. Through bioassay, LC50 and LC95 of Bs in killing Anopheles dirus larvae were determined as 9.793 ± 1.878 IU/L and 62.4 ± 6.438 IU/L at 48 h posttreatment, 7.128 ± 0.913 IU/L and 34.385 ± 12.547 IU/L at 72 h post treatment, respectively. After being treated with a sub-lethal dose of Bs, gravidity, oviposition, hatch, pupation, and eclosion of the surviving mosquitoes were counted and analyzed to elucidate the subsequent effects of Bs exposure on the reproductive capacity of A. dirus. The result interestingly showed that the exposure of Bs significantly reduced the oviposition ability of the surviving A. dirus, without effect on egg formation/gravidity, hatch, pupation, and eclosion. The surviving mosquitoes were also maintained routinely for generations to test the sustained effect of Bs exposure on the fecundity of the offsprings. After conventional breeding for generations, the capacity of egg laying totally recovered. To explore the rules of resistance development, bioassays were performed after treatment twice with a sub-lethal dose of Bs on two continuous generations of A. dirus larvae. The killing efficacies between the Bs treated group and control group were compared. The results showed that LC50 and LC95 increased by 4.35- and 7.37-folds after treatment with the sub-lethal dose of Bs on two consecutive generations, respectively. The results indicated that A. dirus was sensitive to Bs, which could reduce oviposition of the surviving A. dirus. The subsequent effect might help to further decrease the mosquito population. However, a sub-lethal dose of Bs exposure could easily cause resistance development. Our study provides a dose standard and reference for the rational use of Bs, which will be helpful for mosquito control.
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Affiliation(s)
- Shasha Yu
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, 400038, China
| | - Chen Ji
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, 400038, China.,The 17th Students' Camp, Third Military Medical University, Chongqing, 400038, China
| | - Xiaobo Zhu
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, 400038, China.,The 17th Students' Camp, Third Military Medical University, Chongqing, 400038, China
| | - Jinwei Xue
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, 400038, China.,The 17th Students' Camp, Third Military Medical University, Chongqing, 400038, China
| | - Luhan Wang
- Chongqing Foreign Language School, Chongqing, 400039, China
| | - Ying Wang
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, 400038, China.
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22
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Zhou G, Lo E, Zhong D, Wang X, Wang Y, Malla S, Lee MC, Yang Z, Cui L, Yan G. Impact of interventions on malaria in internally displaced persons along the China-Myanmar border: 2011-2014. Malar J 2016; 15:471. [PMID: 27628040 PMCID: PMC5024476 DOI: 10.1186/s12936-016-1512-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 09/02/2016] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Internally displaced persons (IDP) represent vulnerable populations whose public health conditions merit special attention. In the China-Myanmar border area, human movement and resettlements of IDP can influence malaria transmission. Comparison of disease incidence and vector densities between IDP camps and surrounding local villages allows for better understanding of current epidemiology and to evaluate the effectiveness of interventions in the region. METHODS Malaria and vector surveillance was conducted in three IDP camps and three local villages neighbouring the camps along the China-Myanmar border in Myanmar. Clinical malaria cases were collected from seven hospitals/clinics from April 2011 to December 2014. Malaria vector population dynamics were monitored using CDC light traps. The use of malaria preventive measures and information on aid agencies and their activities was obtained through questionnaire surveys. RESULTS Malaria was confirmed in 1832 patients. Of these cases, 85.4 % were Plasmodium vivax and 11.4 % were Plasmodium falciparum malaria. Annual malaria incidence rates were 38.8 and 127.0 cases/1000 person year in IDP camps and local villages, respectively. Older children of 5-14 years had the highest incidence rate in the camps regardless of gender, while male adults had significantly higher incidence rates than females in local villages and females child-bearing age had significantly lower risk to malaria in IDP camps compare to local villages. Seasonal malaria outbreaks were observed both in the IDP camps and in the local villages from May to August 2013. The proportion of P. vivax remained unchanged in local villages but increased by approximately tenfold in IDP camps from 2011 to 2014. Anopheles vector density was tenfold higher in local villages compared to IDP camps (2.0:0.2 females/trap/night). Over 99 % of households in both communities owned bed nets. While long-lasting insecticidal nets accounted for 61 % of nets used in IDPs, nearly all residents of local villages owned regular nets without insecticide-impregnation. There were more active aid agencies in the camps than in local villages. CONCLUSION Malaria in IDP camps was significantly lower than the surrounding villages through effective control management. The observation of P. vivax outbreaks in the study area highlights the need for increased control efforts. Expansion of malaria intervention strategies in IDP camps to local surrounding villages is critical to malaria control in the border area.
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Affiliation(s)
- Guofa Zhou
- University of California, Irvine, CA USA
| | - Eugenia Lo
- University of California, Irvine, CA USA
| | | | - Xiaoming Wang
- University of California, Irvine, CA USA
- Southern Medical University, Guangzhou, China
| | - Ying Wang
- Third Military Medical University, Chongqing, China
| | | | | | | | - Liwang Cui
- Pennsylvania State University, University Park, PA USA
| | - Guiyun Yan
- University of California, Irvine, CA USA
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Wang X, Zhou G, Zhong D, Wang X, Wang Y, Yang Z, Cui L, Yan G. Life-table studies revealed significant effects of deforestation on the development and survivorship of Anopheles minimus larvae. Parasit Vectors 2016; 9:323. [PMID: 27267223 PMCID: PMC4895827 DOI: 10.1186/s13071-016-1611-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/27/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Many developing countries are experiencing rapid ecological changes such as deforestation and shifting agricultural practices. These environmental changes may have an important consequence on malaria due to their impact on vector survival and reproduction. Despite intensive deforestation and malaria transmission in the China-Myanmar border area, the impact of deforestation on malaria vectors in the border area is unknown. METHODS We conducted life table studies on Anopheles minimus larvae to determine the pupation rate and development time in microcosms under deforested, banana plantation, and forested environments. RESULTS The pupation rate of An. minimus was 3.8 % in the forested environment. It was significantly increased to 12.5 % in banana plantations and to 52.5 % in the deforested area. Deforestation reduced larval-to-pupal development time by 1.9-3.3 days. Food supplementation to aquatic habitats in forested environments and banana plantations significantly increased larval survival rate to a similar level as in the deforested environment. CONCLUSION Deforestation enhanced the survival and development of An. minimus larvae, a major malaria vector in the China-Myanmar border area. Experimental determination of the life table parameters on mosquito larvae under a variety of environmental conditions is valuable to model malaria transmission dynamics and impact by climate and environmental changes.
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Affiliation(s)
- Xiaoming Wang
- School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.,Program in Public Health, University of California at Irvine, Irvine, CA, 92697, USA
| | - Guofa Zhou
- Program in Public Health, University of California at Irvine, Irvine, CA, 92697, USA
| | - Daibin Zhong
- Program in Public Health, University of California at Irvine, Irvine, CA, 92697, USA
| | - Xiaoling Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, China
| | - Ying Wang
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, 400038, China
| | - Zhaoqing Yang
- Department of Pathogen Biology, Kunming Medical University, Kunming, 650500, China
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Guiyun Yan
- School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China. .,Program in Public Health, University of California at Irvine, Irvine, CA, 92697, USA.
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24
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Zhong D, Wang X, Xu T, Zhou G, Wang Y, Lee MC, Hartsel JA, Cui L, Zheng B, Yan G. Effects of Microclimate Condition Changes Due to Land Use and Land Cover Changes on the Survivorship of Malaria Vectors in China-Myanmar Border Region. PLoS One 2016; 11:e0155301. [PMID: 27171475 PMCID: PMC4865052 DOI: 10.1371/journal.pone.0155301] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Accepted: 04/27/2016] [Indexed: 02/06/2023] Open
Abstract
In the past decade, developing countries have been experiencing rapid land use and land cover changes, including deforestation and cultivation of previously forested land. However, little is known about the impact of deforestation and land-use changes on the life history of malaria vectors and their effects on malaria transmission. This study examined the effects of deforestation and crop cultivation on the adult survivorship of major malaria mosquitoes, Anopheles sinensis and An. minimus in the China-Myanmar border region. We examined three conditions: indoor, forested, and banana plantation. Mean survival time of An. sinensis in banana plantation environment was significantly longer than those in forested environment, and mosquitoes exhibited the longest longevity in the indoor environment. This pattern held for both males and females, and also for An. minimus. To further test the effect of temperature on mosquito survival, we used two study sites with different elevation and ambient temperatures. Significantly higher survivorship of both species was found in sites with lower elevation and higher ambient temperature. Increased vector survival in the deforested area could have an important impact on malaria transmission in Southeast Asia. Understanding how deforestation impacts vector survivorship can help combat malaria transmission.
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Affiliation(s)
- Daibin Zhong
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, California, United States of America
| | - Xiaoming Wang
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, California, United States of America
- Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong Higher Institutes, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, People's Republic of China
| | - Tielong Xu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China
| | - Guofa Zhou
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, California, United States of America
| | - Ying Wang
- Department of Pathogen Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing, People's Republic of China
| | - Ming-Chieh Lee
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, California, United States of America
| | - Joshua A. Hartsel
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, California, United States of America
| | - Liwang Cui
- Department of Entomology, the Pennsylvania State University, University Park, Pennsylvania, 16802, United States of America
| | - Bin Zheng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China
| | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, California, United States of America
- * E-mail:
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Seasonal dynamics and microgeographical spatial heterogeneity of malaria along the China-Myanmar border. Acta Trop 2016; 157:12-19. [PMID: 26812008 DOI: 10.1016/j.actatropica.2016.01.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 12/29/2015] [Accepted: 01/21/2016] [Indexed: 02/04/2023]
Abstract
Malaria transmission is heterogeneous in the Greater Mekong Subregion with most of the cases occurring along international borders. Knowledge of transmission hotspots is essential for targeted malaria control and elimination in this region. This study aimed to determine the dynamics of malaria transmission and possible existence of transmission hotspots on a microgeographical scale along the China-Myanmar border. Microscopically confirmed clinical malaria cases were recorded in five border villages through a recently established surveillance system between January 2011 and December 2014. A total of 424 clinical cases with confirmed spatial and temporal information were analyzed, of which 330 (77.8%) were Plasmodium vivax and 88 (20.8%) were Plasmodium falciparum, respectively. The P. vivax and P. falciparum case ratio increased dramatically from 2.2 in 2011 to 4.7 in 2014, demonstrating that P. vivax malaria has become the predominant parasite species. Clinical infections showed a strong bimodal seasonality. There were significant differences in monthly average incidence rates among the study villages with rates in a village in China being 3-8 folds lower than those in nearby villages in Myanmar. Spatial analysis revealed the presence of clinical malaria hotspots in four villages. This information on malaria seasonal dynamics and transmission hotspots should be harnessed for planning targeted control.
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Zhu X, Zhao Z, Feng Y, Li P, Liu F, Liu J, Yang Z, Yan G, Fan Q, Cao Y, Cui L. Genetic diversity of the Plasmodium falciparum apical membrane antigen I gene in parasite population from the China-Myanmar border area. INFECTION GENETICS AND EVOLUTION 2016; 39:155-162. [PMID: 26825252 DOI: 10.1016/j.meegid.2016.01.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/20/2016] [Accepted: 01/23/2016] [Indexed: 11/28/2022]
Abstract
To investigate the genetic diversity of the Plasmodium falciparum apical membrane antigen 1 (PfAMA1) gene in Southeast Asia, we determined PfAMA1 sequences from 135 field isolates collected from the China-Myanmar border area and compared them with 956 publically available PfAMA1 sequences from seven global P. falciparum populations. This analysis revealed high genetic diversity of PfAMA1 in global P. falciparum populations with a total of 229 haplotypes identified. The genetic diversity of PfAMA1 gene from the China-Myanmar border is not evenly distributed in the different domains of this gene. Sequence diversity in PfAMA1 from the China-Myanmar border is lower than that observed in Thai, African and Oceanian populations, but higher than that in the South American population. This appeared to correlate well with the levels of endemicity of different malaria-endemic regions, where hyperendemic regions favor genetic cross of the parasite isolates and generation of higher genetic diversity. Neutrality tests show significant departure from neutrality in the entire ectodomain and Domain I of PfAMA1 in the China-Myanmar border parasite population. We found evidence supporting a substantial continent-wise genetic structure among P. falciparum populations, with the highest genetic differentiation detected between the China-Myanmar border and the South American populations. Whereas no alleles were unique to a specific region, there were considerable geographical differences in major alleles and their frequencies, highlighting further necessity to include more PfAMA1 alleles in vaccine designs.
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Affiliation(s)
- Xiaotong Zhu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning 110122, China
| | - Zhenjun Zhao
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Yonghui Feng
- Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Peipei Li
- Dalian Institute of Biotechnology, Dalian, Liaoning, 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
| | - 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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