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Win KM, Show KL, Sattabongkot J, Aung PL. Ownership and use of insecticide-treated nets in Myanmar: insights from a nationally representative demographic and health survey. Malar J 2024; 23:167. [PMID: 38807175 PMCID: PMC11135007 DOI: 10.1186/s12936-024-04994-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 05/21/2024] [Indexed: 05/30/2024] Open
Abstract
BACKGROUND Malaria poses a substantial public health threat in Myanmar, indicating the need for rigorous efforts to achieve elimination of the disease nationwide by 2030. The use of insecticide-treated nets (ITNs) forms part of a pivotal strategy for preventing transmission. This study explored the ownership and use of ITNs in Myanmar and identified factors associated with non-use of ITNs. METHODS Household datasets from the 2015-2016 Myanmar Demographic and Health Survey were utilised, which encompassed all household members except children under the age of five. Descriptive statistics and inferential tests, including simple and multiple logistics regression models and Pearson correlations, were employed for analysis. All analyses, taking the two-stage stratified cluster sampling design into account, used weighting factors and the "svyset" command in STATA. The ownership and use of bed nets were also visualised in QGIS maps. RESULTS Among the 46,507 participants, 22.3% (95% CI 20.0%, 24.5%) had access to ITNs, with only 15.3% (95% CI 13.7, 17.1%) sleeping under an ITN the night before the survey. Factors associated with the non-use of ITNs included age category (15-34 years-aOR: 1.17, 95% CI 1.01, 1.30; 50+ years-aOR: 1.19, 95% CI 1.06, 1.33), location (delta or lowland-aOR: 5.39, 95% CI 3.94, 7.38; hills-aOR: 1.80, 95% CI 1.20, 2.71; plains-aOR: 3.89, 95% CI 2.51, 6.03), urban residency (aOR: 1.63, 95% CI 1.22, 2.17), and wealth quintile (third-aOR: 1.38, 95% CI 1.08, 1.75; fourth-aOR: 1.65, 95% CI 1.23, 2.23; fifth-aOR: 1.47, 95% CI 1.02, 2.13). A coherent distribution of the ownership and use of ITNs was seen across all states/regions, and a strong correlation existed between the ownership and use of ITNs (r: 0.9795, 95% CI 0.9377, 0.9933, alpha < 0.001). CONCLUSIONS This study identified relatively low percentages of ITN ownership and use, indicating the need to increase the distribution of ITNs to achieve the target of at least one ITN per every two people. Strengthening the use of ITNs requires targeted health promotion interventions, especially among relatively affluent individuals residing in delta or lowland areas, hills, and plains.
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Affiliation(s)
- Kyawt Mon Win
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Pyae Linn Aung
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Wang Y, Chitnis N, Fairbanks EL. Optimizing malaria vector control in the Greater Mekong Subregion: a systematic review and mathematical modelling study to identify desirable intervention characteristics. Parasit Vectors 2024; 17:162. [PMID: 38553759 PMCID: PMC10981350 DOI: 10.1186/s13071-024-06234-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/04/2024] [Indexed: 04/01/2024] Open
Abstract
BACKGROUND In the Greater Mekong Subregion (GMS), new vector-control tools are needed to target mosquitoes that bite outside during the daytime and night-time to advance malaria elimination. METHODS We conducted systematic literature searches to generate a bionomic dataset of the main malaria vectors in the GMS, including human blood index (HBI), parity proportion, sac proportion (proportion with uncontracted ovary sacs, indicating the amount of time until they returned to host seeking after oviposition) and the resting period duration. We then performed global sensitivity analyses to assess the influence of bionomics and intervention characteristics on vectorial capacity. RESULTS Our review showed that Anopheles minimus, An. sinensis, An. maculatus and An. sundaicus display opportunistic blood-feeding behaviour, while An. dirus is more anthropophilic. Multivariate regression analysis indicated that environmental, climatic and sampling factors influence the proportion of parous mosquitoes, and resting duration varies seasonally. Sensitivity analysis highlighted HBI and parity proportion as the most influential bionomic parameters, followed by resting duration. Killing before feeding is always a desirable characteristic across all settings in the GMS. Disarming is also a desirable characteristic in settings with a low HBI. Repelling is only an effective strategy in settings with a low HBI and low parity proportion. Killing after feeding is only a desirable characteristic if the HBI and parity proportions in the setting are high. CONCLUSIONS Although in general adopting tools that kill before feeding would have the largest community-level effect on reducing outdoor transmission, other modes of action can be effective. Current tools in development which target outdoor biting mosquitoes should be implemented in different settings dependent on their characteristics.
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Affiliation(s)
- Yuqian Wang
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Kreuzstrasse 2, Allschwill, 4123, Basel, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Nakul Chitnis
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Kreuzstrasse 2, Allschwill, 4123, Basel, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Emma L Fairbanks
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Kreuzstrasse 2, Allschwill, 4123, Basel, Switzerland.
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland.
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Phasomkusolsil S, Tawong J, Monkanna N, Kornkan T, Jitbantrengphan T, Chaiyasab M, Pongda N, Kamram T, Lindroth EJ. The effects of human and rhesus macaque blood meal sources on mosquito reproduction and adult survival under laboratory conditions. Exp Parasitol 2023; 253:108591. [PMID: 37558194 DOI: 10.1016/j.exppara.2023.108591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/29/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023]
Abstract
Mass rearing of mosquitoes as required to fulfil research studies is a technically challenging endeavor. Blood meal source has been recognized as a key consideration in mass rearing of mosquitoes that affects colony health and fecundity. Four species of laboratory-colonized mosquitoes from the Department of Entomology, US Army Medical Directorate - Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS); Anopheles cracens, An. dirus, An. minimus and An. sawadwongporni were fed blood meals from human and rhesus macaque sources using an artificial membrane feeder. The effects of different blood meal sources were evaluated concerning blood-feeding, survival and reproduction (fecundity and hatching rates). Adult survival was monitored at days 7, 14 and 21 post blood-feeding. Although the mosquitoes fed on human blood exhibited higher rates of engorgement, there were no significant differences in blood-feeding rates in An. cracens (P = 0.08) and An. dirus (P = 0.91) between rhesus macaque and human blood sources. Twenty-one days post-feeding, no significant differences were observed in the survival rates of mosquitoes fed on human versus rhesus macaque blood. Except for An. dirus, which had better survival rates with human blood (97.5%) than after feeding on rhesus macaque blood (95.4%). All mosquito species fed on human blood produced significantly more eggs when compared to those fed on rhesus macaque blood. However, there was no statistical difference in hatching rates between blood sources, except for An. dirus, which had better hatching rates with human blood. These results indicate that human and rhesus macaque blood may be a viable alternative for maintaining Anopheles mosquitoes in colony.
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Affiliation(s)
- Siriporn Phasomkusolsil
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand.
| | - Jaruwan Tawong
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Nantaporn Monkanna
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Tanaporn Kornkan
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Thanin Jitbantrengphan
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Marisa Chaiyasab
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Natchanida Pongda
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Thinadda Kamram
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Erica J Lindroth
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
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Aung PL, Soe MT, Oo TL, Aung KT, Lin KK, Thi A, Menezes L, Parker DM, Cui L, Kyaw MP. Spatiotemporal dynamics of malaria in Banmauk Township, Sagaing region of Northern Myanmar: characteristics, trends, and risk factors. BMC Infect Dis 2022; 22:653. [PMID: 35902825 PMCID: PMC9331130 DOI: 10.1186/s12879-022-07634-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 07/19/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND While national malaria incidence has been declining in Myanmar, some subregions within the nation continue to have high burdens of malaria morbidity and mortality. This study assessed the malaria situation in one of these regions, Banmauk Township, located near the Myanmar-India border. Our goal was to provide a detailed description of the malaria epidemiology in this township and to provide some evidence-based recommendations to formulate a strategy for reaching the national malaria elimination plan. Banmauk consistently has one of the highest malaria burdens in Myanmar. METHODS With the implementation of strengthened malaria control and surveillance activities after the endorsement of a national malaria elimination plan in 2015, detailed incidence data were obtained for 2016-2018 for Banmauk Township. The data include patient demographics, parasite species, disease severity, and disease outcome. Data were analyzed to identify characteristics, trends, distribution, and risk factors. RESULTS During 2016-2018, 2,402 malaria cases were reported, with Plasmodium falciparum accounting for 83.4% of infections. Both P. falciparum and P. vivax were transmitted more frequently during the rainy season (May-October). Despite intensified control, the annual parasite incidence rate (API) in 2017 (11.0) almost doubled that in 2016 (6.5). In total, 2.5% (59/2042) of the cases, of which 54 P. falciparum and 5 P. vivax, were complicated cases, resulting in 5 deaths. Malaria morbidity was high in children < 15 years and accounted for 33.4% of all cases and about 47% of the complicated cases. Older age groups and males living with poor transportation conditions were more likely to test positive especially in rainy and cold seasons. Despite the clear seasonality of malaria, severe cases were found among young children even more common in the dry season, when malaria incidence was low. CONCLUSIONS Despite the declining trend, the malaria burden remained high in Banmauk Township. Our study also documented severe cases and deaths from both falciparum and vivax malaria. P. falciparum remained the predominant parasite species, demanding increased efforts to achieve the goal of elimination of P. falciparum by 2025. As P. falciparum cases decreased, the proportion of cases attributable to P. vivax increased. In order to eliminate malaria, it will likely be important to increasingly target this species as well.
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Affiliation(s)
| | - Myat Thu Soe
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Thit Lwin Oo
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Kyaw Thu Aung
- Township Health Department, Banmauk Township, Sagaing, Myanmar
| | - Kyaw Kyaw Lin
- Township Health Department, Banmauk Township, Sagaing, Myanmar
| | - Aung Thi
- Department of Public Health, Ministry of Health, NayPyiTaw, Myanmar
| | - Lynette Menezes
- 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
| | - Daniel M Parker
- Department of Population Health and Disease Prevention, University of California, Irvine, CA, USA.
| | - 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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Feng X, Feng J, Zhang L, Tu H, Xia Z. Vector control in China, from malaria endemic to elimination and challenges ahead. Infect Dis Poverty 2022; 11:54. [PMID: 35562786 PMCID: PMC9102289 DOI: 10.1186/s40249-022-00971-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 04/09/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Vector control is an important approach to preventing and controlling malaria. From the malaria epidemic to malaria elimination in China, vector control has played an essential and irreplaceable role in the historical process. This review systematically summarizes the evolution, adjustment, and optimization of vector control strategy towards elimination and discusses the challenges ahead. MAIN TEXT This review first summarizes the evolution of vector control strategies during different stages of malaria epidemic, control, elimination, and post-elimination in China. We then distill the vector control experience and lessons in different stages. We discuss the current and future challenges and propose future research directions and developments for novel malaria vector control strategies. RESULTS Vector control has played an invaluable role in achieving malaria elimination. China adopted different prevention and control measures in response to the different malaria-endemic situations and vector distributions. Firstly, baseline surveys were initiated to establish the entomological data and helped clarify the prevention priorities and targets. Secondly, targeted and adjusted vector control strategies were conducted in various regions according to the local epidemic characteristics and different vector species. Thirdly, scientific research facilitated efficient vector-control strategies. In addition, the overall economic and social development have promoted environmental improvement, personal protection, and health care. Prediction of the vector distribution was integrated into risk assessment strategies, allowing for sustaining achievements in risk areas. CONCLUSIONS The tailored and adapted vector control strategies have played a critical role in China's malaria prevention, control, and elimination. Achievements and lessons learned on vector control from this progress would provide a practical reference in coping with the challenges and potential barriers other countries face in the global effort to eliminate malaria.
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Affiliation(s)
- Xinyu Feng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research On Tropical Diseases, Shanghai, 200025, China
| | - Jun Feng
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai, 200336, China
| | - Li Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research On Tropical Diseases, Shanghai, 200025, China
| | - Hong Tu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research On Tropical Diseases, Shanghai, 200025, China
| | - Zhigui Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research On Tropical Diseases, Shanghai, 200025, China.
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6
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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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Huang F, Li S, Tian P, Pu LJS, Cui Y, Liu H, Yang L, Bi DY. Genetic polymorphisms in genes associated with drug resistance in Plasmodium vivax parasites from northeastern Myanmar. Malar J 2022; 21:66. [PMID: 35241080 PMCID: PMC8892751 DOI: 10.1186/s12936-022-04084-y] [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: 10/11/2021] [Accepted: 02/11/2022] [Indexed: 11/10/2022] Open
Abstract
Background Anti-malarial drug resistance is still a major threat to malaria elimination in the Great Mekong Sub-region. Plasmodium vivax parasites resistant to anti-malarial drugs are now found in Myanmar. Molecular surveillance on drug resistance genes in P. vivax parasites from northeastern Myanmar was aimed at estimating the underlying drug resistance in this region. Methods Blood samples from patients with vivax malaria were collected from Laiza city in northeastern Myanmar in 2020. Drug resistance genes including Pvcrt-o, Pvmdr1, Pvdhfr and Pvdhps were amplified and sequenced. Genetic polymorphisms and haplotypes were analysed to evaluate the prevalence of mutant alleles associated with drug resistance. Results A total of 149 blood samples from P. vivax patients were collected. The prevalence of Pvmdr1 mutations at codons 958 and 1076 was 100.0% and 52.0%, respectively, whereas no single nucleotide polymorphism was present at codon 976. The proportions of single and double mutant types were 48.0% and 52.0%, respectively. A K10 “AAG” insertion in the Pvcrt-o gene was not detected. Mutations in Pvdhfr at codons 57, 58, 61, 99 and 117 were detected in 29.9%, 54.3%, 27.6%, 44.9% and 55.1% of the samples, respectively. Wild type was predominant (46.3%), followed by quadruple and double mutant haplotypes. Of three types of tandem repeat variations of Pvdhfr, Type B, with three copies of GGDN repeats, was the most common. Pvdhps mutations were only detected at codons 383 and 553 and the wild type Pvdhps was dominant (78.0%). Eleven haplotypes were identified when combining the mutations of Pvdhfr and Pvdhps, among which the predominant one was the wild type (33.9%), followed by double mutant alleles S58R/S117N /WT (24.6%). Conclusions This study demonstrated resistant P. vivax phenotypes exists in northeastern Myanmar. Continued surveillance of drug resistance markers is needed to update treatment guidelines in this region. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04084-y.
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Affiliation(s)
- Fang Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China. .,Chinese Center for Tropical Diseases Research, Shanghai, China. .,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China. .,WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China.
| | - Shigang Li
- Yingjiang County Center for Disease Control and Prevention, Yingjiang, Yunnan, China
| | - Peng Tian
- Yunnan Institute of Parasitic Diseases, Pu'er, Yunnan, China
| | | | - Yanwen Cui
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China.,Chinese Center for Tropical Diseases Research, Shanghai, China.,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China.,WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China
| | - Hui Liu
- Yunnan Institute of Parasitic Diseases, Pu'er, Yunnan, China
| | - Lianzhi Yang
- Nabang Township Hospital, Yingjiang, Yunnan, China
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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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Yang HL, Baloch Z, Xu JW, Sun XD, Lin ZR, Zhou YW, Zhao XT, Lv Q, Xu SY, Ding CL, Chen QY, Tian P, Dung KX, Xia XS, Zhou HN. Malaria: elimination tale from Yunnan Province of China and new challenges for reintroduction. Infect Dis Poverty 2021; 10:101. [PMID: 34289905 PMCID: PMC8293506 DOI: 10.1186/s40249-021-00866-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 05/21/2021] [Indexed: 12/16/2022] Open
Abstract
Background Eradication of infectious disease is the sanctified public health and sustainable development goal around the world. Main body Three antimalarial barriers were developed to control imported malarial cases, and an effective surveillance strategy known as the “1–3–7 approach” was developed to eliminate malaria from the Chinese population. From 2011 to 2019, 5254 confirmed malaria cases were reported and treated in Yunnan Province, China. Among them, 4566 cases were imported from other countries, and 688 cases were indigenous from 2011 to 2016. Since 2017, no new local malarial case has been reported in China. Thus, malaria has been completely eliminated in Yunnan Province. However, malaria is detected in overseas travellers on a regular basis, such as visitors from neighbouring Myanmar. Conclusion Hence, the strategies should be further strengthened to maintain a robust public health infrastructure for disease surveillance and vector control programs in border areas. Such programs should be supported technically and financially by the government to avert the possibility of a malarial resurgence in Yunnan Province. Graphic Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s40249-021-00866-9.
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Affiliation(s)
- Heng-Lin Yang
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China.
| | - Zulqarnain Baloch
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, Yunnan, China
| | - Jian-Wei Xu
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Xiao-Dong Sun
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Zu-Rui Lin
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Yao-Wu Zhou
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Xiao-Tao Zhao
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Quan Lv
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Shi-Yuan Xu
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Chun-Li Ding
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Qi-Yan Chen
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Peng Tian
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Kai-Xia Dung
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China
| | - Xue-Shan Xia
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, Yunnan, China.
| | - Hong-Ning Zhou
- Yunnan Provincial Key Laboratory of Vector-Borne Diseases Control and Research & Yunnan Innovative Team of Key Techniques for Vector-Borne Disease Control of Yunnan Institute of Parasitic Diseases, Pu'er, 665000, Yunnan, China.
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10
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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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11
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Li XH, Zhou HN, Xu JW, Lin ZR, Sun XD, Li JY, Lin XX, Xie Y, Alonso P, Yang HL. Seven decades towards malaria elimination in Yunnan, China. Malar J 2021; 20:147. [PMID: 33711990 PMCID: PMC7953382 DOI: 10.1186/s12936-021-03672-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/25/2021] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Yunnan Province was considered the most difficult place in China for malaria elimination because of its complex malaria epidemiology, heterogeneous ecological features, relatively modest economic development, and long, porous border with three malaria endemic countries: Lao People's Democratic Republic, Myanmar, and Viet Nam. METHODS Academic publications and grey literature relevant to malaria elimination in Yunnan covering the period from 1950 until 2020 inclusive were considered. The following academic indexes were searched: China Science Periodical Database, China National Knowledge Infrastructure Database, and MEDLINE. Grey literature sources were mainly available from the National Institute of Parasitic Diseases (NIPD), the Chinese Center for Diseases Control and Prevention, and the Yunnan Institute of Parasitic Diseases (YIPD). RESULTS A malaria elimination campaign in the 1950-1960s, based mainly on mass administration of antimalarial drugs and large-scale vector control, reduced morbidity and mortality from malaria and interrupted transmission in some areas, although elimination was not achieved. Similar strategies were used to contain outbreaks and a resurgence of disease during the 1970s, when malaria services were discontinued. From the 1980s, malaria incidence declined, despite the challenges of large numbers of mobile and migrant populations and an unstable primary health care system in rural areas following economic transformation. Launch of the national malaria elimination programme in 2010 led to adoption of the '1-3-7' surveillance and response strategy specifying timely detection of and response for every case, supported by the establishment of a real-time web-based disease surveillance system and a new primary health care system in rural areas. Border malaria was addressed in Yunnan by strengthening the surveillance system down to the lowest level, cross-border collaboration with neighbouring countries and non-governmental organizations, and the involvement of other sectors. CONCLUSIONS Seven decades of work to eliminate malaria in Yunnan have shown the importance of political commitment, technically sound strategies with high quality implementation, a robust surveillance and response system at all levels, community participation and effective management of border malaria. The experiences and lessons learned from elimination remain important for prevention re-establishment of malaria transmission in the Province.
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Affiliation(s)
- Xiao-Hong Li
- Global Malaria Programme, World Health Organization, Geneva, Switzerland.
| | - Hong-Ning Zhou
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Key Laboratory of Vector-Borne Disease Control and Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Pu'er City, China
| | - Jian-Wei Xu
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Key Laboratory of Vector-Borne Disease Control and Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Pu'er City, China
| | - Zu-Rui Lin
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Key Laboratory of Vector-Borne Disease Control and Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Pu'er City, China
| | - Xiao-Dong Sun
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Key Laboratory of Vector-Borne Disease Control and Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Pu'er City, China
| | - Jia-Yin Li
- Yunnan Representative Office, Health Poverty Action (UK), Kunming, China
| | - Xian-Xian Lin
- Yunnan Representative Office, Health Poverty Action (UK), Kunming, China
| | - Yan Xie
- School of Public Health, Peking University, Beijing, China
| | - Pedro Alonso
- Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | - Heng-Lin Yang
- Yunnan Institute of Parasitic Diseases, Yunnan Provincial Centre of Malaria Research, Yunnan Provincial Key Laboratory of Vector-Borne Disease Control and Research, Yunnan Provincial Collaborative Innovation Center for Public Health and Disease Prevention and Control, Pu'er City, China
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12
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Wang X, Ruan W, Zhou S, Feng X, Yan H, Huang F. Prevalence of molecular markers associated with drug resistance of Plasmodium vivax isolates in Western Yunnan Province, China. BMC Infect Dis 2020; 20:307. [PMID: 32334523 PMCID: PMC7183581 DOI: 10.1186/s12879-020-05032-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 04/15/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Plasmodium vivax is the most widely distributed malaria parasite, and its drug resistance poses unique challenges to malaria elimination. The Greater Mekong Subregion (GMS) is known as the global epicenter of multidrug resistance. Surveillance of molecular markers associated with drug resistance in this area will help to inform drug policy. METHODS Dry blood spots from 58 patients out of 109 with P. vivax infection between 2017, December and 2019, March were obtained from Yingjiang County, Yunnan Province, along the China-Myanmar border. Pvdhfr, Pvdhps, Pvmdr1 and Pvcrt-o were amplified and sequenced to assess gene mutations. The polymorphism and prevalence of these molecular markers were analyzed. RESULTS Mutations in Pvdhfr at codons 57, 58, 61, 99 and 117 were detected in 27.59, 48.28, 27.59, 32.76 and 48.28% of the isolates, respectively. Single mutant haplotype (I13F57S58T61S99S117I173) was the most frequent (29.31%, 17/58), followed by double mutant haplotype (20.69%, 12/58). Of three types of tandem repeat variations of Pvdhfr, deletion type was the most common. Pvdhps showed a lower prevalence among mutation genotypes. Single mutant was dominant and accounted for 34.48% (20/58). Prevalence of Pvmdr1 mutations at codons 958 and 1076 were 100.00% and 84.48%, respectively. The proportion of double and single mutant types was 84.48% (49/58) and 15.52% (9/58), respectively. Eleven samples (18.97%, 11/58) showed K10 "AAG" insertion in chloroquine resistance transporter gene Pvcrt-o. CONCLUSIONS There was moderate diversity of molecular patterns of resistance markers of Pvdhfr, Pvdhps, Pvmdr1 and Pvcrt-o in imported P. vivax cases to Yingjiang county in Western Yunnan, along the China-Myanmar border. Prevalence and molecular pattern of candidate drug resistance markers Pvdhfr, Pvdhps, Pvmdr1 and Pvcrt-o were demonstrated in this current study, which would help to update drug policy.
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Affiliation(s)
- Xiaoxiao Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, and WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People’s Republic of China
- Zhejiang Provincial Center for Disease Control and Prevention, Zhejiang, People’s Republic of China
| | - Wei Ruan
- Zhejiang Provincial Center for Disease Control and Prevention, Zhejiang, People’s Republic of China
| | - Shuisen Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, and WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People’s Republic of China
| | - Xinyu Feng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, and WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People’s Republic of China
| | - He Yan
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, and WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People’s Republic of China
| | - Fang Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, and WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People’s Republic of China
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13
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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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14
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Monitoring of malaria vectors at the China-Myanmar border while approaching malaria elimination. Parasit Vectors 2018; 11:511. [PMID: 30219093 PMCID: PMC6139178 DOI: 10.1186/s13071-018-3073-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/21/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Tengchong County was one of the counties located at the China-Myanmar border with high malaria incidence in the previous decades. As the pilot county for malaria elimination at the border area, Tengchong County is aiming to be the first county to achieve malaria elimination goal. A cross-sectional entomological survey was carried out to evaluate the feasibility of elimination approach and assess the receptivity of malaria reintroduction. METHODS Light traps associated with live baits were used to investigate the abundance of adult mosquitoes in nine villages in Tengchong County. Light traps were set to collect adult mosquitoes in both human houses and cowsheds from dusk till dawn in each site. RESULTS A total of 4948 adult Anopheles mosquitoes were collected from May to December in two villages. Of the mosquitoes were captured, 24.2% were in human houses and 75.8% in cowsheds. The peak of abundance occurred in July for An. sinensis and in September-October for An. minimus (s.l.) Ten Anopheles species were collected, the most prevalent being An. sinensis (50.3%), An. peditaeniatus (31.6%) and An. minimus (s.l.) (15.8%), contributing to 97.6% of the sample. Potential breeding sites were also investigated and a total of 407 larvae were collected, with An. sinensis (50.1%) and An. minimus (s.l.) (46.2%) as predominant species. Ponds and rice fields were the two preferred breeding sites for Anopheles mosquitoes; however, the difference between the number of adults and larvae captured suggest other breeding sites might exist. Both An. sinensis and An. minimus (s.l.) were found zoophilic with human blood index as 0.21 and 0.26, respectively. No Plasmodium positive Anopheles specimens were found by PCR among 4,000 trapped mosquitoes. CONCLUSIONS Although no indigenous malaria cases have been reported in Tengchong County since 2013, there is still a risk from the presence of vectors in the context of human population movements from neighboring malaria endemic areas. The presence of An. sinensis, associated to rice fields, is particularly worrying. Sustained entomological surveillance is strongly suggested even after malaria elimination certification.
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15
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Badhan R, Zakaria Z, Olafuyi O. The Repurposing of Ivermectin for Malaria: A Prospective Pharmacokinetics-Based Virtual Clinical Trials Assessment of Dosing Regimen Options. J Pharm Sci 2018; 107:2236-2250. [DOI: 10.1016/j.xphs.2018.03.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 02/09/2018] [Accepted: 03/30/2018] [Indexed: 12/30/2022]
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16
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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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17
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Zhang S, Guo S, Feng X, Afelt A, Frutos R, Zhou S, Manguin S. Anopheles Vectors in Mainland China While Approaching Malaria Elimination. Trends Parasitol 2017; 33:889-900. [PMID: 28734898 DOI: 10.1016/j.pt.2017.06.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/22/2017] [Accepted: 06/29/2017] [Indexed: 01/27/2023]
Abstract
China is approaching malaria elimination; however, well-documented information on malaria vectors is still missing, which could hinder the development of appropriate surveillance strategies and WHO certification. This review summarizes the nationwide distribution of malaria vectors, their bionomic characteristics, control measures, and related studies. After several years of effort, the area of distribution of the principal malaria vectors was reduced, in particular for Anopheles lesteri (synonym: An. anthropophagus) and Anopheles dirus s.l., which nearly disappeared from their former endemic regions. Anopheles sinensis is becoming the predominant species in southwestern China. The bionomic characteristics of these species have changed, and resistance to insecticides was reported. There is a need to update surveillance tools and investigate the role of secondary vectors in malaria transmission.
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Affiliation(s)
- Shaosen Zhang
- National Institute of Parasitic Diseases, Chinese Centre for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Tropical Diseases, National Centre for International Research on Tropical Diseases, Shanghai, China; Université de Montpellier, IES-Institut d'Electronique et des Systèmes, UMR5214, CNRS-UM, 860 rue de Saint-Priest, Bât 5, 34095 Montpellier, France; Cirad, UMR 17, Intertryp, Campus international de Baillarguet, 34398 Montpellier, Cedex 5, France; Institut de Recherche pour le Développement (IRD France), LIPMC, UMR-MD3, Faculté de Pharmacie, 34093 Montpellier, France
| | - Shaohua Guo
- National Institute of Parasitic Diseases, Chinese Centre for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Tropical Diseases, National Centre for International Research on Tropical Diseases, Shanghai, China; Jiading District Center for Disease Control and Prevention, Shanghai, China
| | - Xinyu Feng
- National Institute of Parasitic Diseases, Chinese Centre for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Tropical Diseases, National Centre for International Research on Tropical Diseases, Shanghai, China
| | - Aneta Afelt
- Interdisciplinary Center for Mathematical and Computational Modelling, University of Warsaw, Prosta 69, 00-838, Warsaw, Poland
| | - Roger Frutos
- Université de Montpellier, IES-Institut d'Electronique et des Systèmes, UMR5214, CNRS-UM, 860 rue de Saint-Priest, Bât 5, 34095 Montpellier, France; Cirad, UMR 17, Intertryp, Campus international de Baillarguet, 34398 Montpellier, Cedex 5, France
| | - Shuisen Zhou
- National Institute of Parasitic Diseases, Chinese Centre for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Tropical Diseases, National Centre for International Research on Tropical Diseases, Shanghai, China.
| | - Sylvie Manguin
- Institut de Recherche pour le Développement (IRD France), LIPMC, UMR-MD3, Faculté de Pharmacie, 34093 Montpellier, France
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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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19
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Yang D, Xu C, Wang J, Zhao Y. Spatiotemporal epidemic characteristics and risk factor analysis of malaria in Yunnan Province, China. BMC Public Health 2017; 17:66. [PMID: 28077125 PMCID: PMC5225622 DOI: 10.1186/s12889-016-3994-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 12/23/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria remains an important public health concern in China and is particularly serious in Yunnan, a China's provincial region of high malaria burden with an incidence of 1.79/105 in 2012. This study aims to examine the epidemiologic profile and spatiotemporal aspects of epidemics of malaria, and to examine risk factors which may influence malaria epidemics in Yunnan Province. METHODS The data of malaria cases in 2012 in 125 counties of Yunnan Province was used in this research. The epidemical characteristics of cases were revealed, and time and space clusters of malaria were detected by applying scan statistics method. In addition, we applied the geographically weighted regression (GWR) model in identifying underlying risk factors. RESULTS There was a total of 821 cases of malaria, and male patients accounted for 83.9% (689) of the total cases. The incidence in the group aged 20-30 years was the highest, at 3.00/105. The majority (84.1%) of malaria cases occurred in farmers and migrant workers, according to occupation statistics. On a space-time basis, epidemics of malaria of varying severity occurred in the summer and autumn months, and the high risk regions were mainly distributed in the southwest counties. Annual average temperature, annual cumulative rainfall, rice yield per square kilometer and proportion of rural employees mainly showed a positive association with the malaria incidence rate, according to the GWR model. CONCLUSIONS Malaria continues to be one of serious public health issues in Yunnan Province, especially in border counties in southwestern Yunnan. Temperature, precipitation, rice cultivation and proportion of rural employees were positively associated with malaria incidence. Individuals, and disease prevention and control departments, should implement more stringent preventative strategies in locations with hot and humid environmental conditions to control malaria.
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Affiliation(s)
- Dongyang Yang
- School of Geographic Sciences, East China Normal University, Shanghai, 200241, China.,State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chengdong Xu
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jinfeng Wang
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, 100101, China. .,Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
| | - Yong Zhao
- College of Environment and Planning, Henan University, Kaifeng, 475004, Henan, China
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20
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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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21
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Hundessa SH, Williams G, Li S, Guo J, Chen L, Zhang W, Guo Y. Spatial and space-time distribution of Plasmodium vivax and Plasmodium falciparum malaria in China, 2005-2014. Malar J 2016; 15:595. [PMID: 27993171 PMCID: PMC5168843 DOI: 10.1186/s12936-016-1646-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 12/05/2016] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Despite the declining burden of malaria in China, the disease remains a significant public health problem with periodic outbreaks and spatial variation across the country. A better understanding of the spatial and temporal characteristics of malaria is essential for consolidating the disease control and elimination programme. This study aims to understand the spatial and spatiotemporal distribution of Plasmodium vivax and Plasmodium falciparum malaria in China during 2005-2009. METHODS Global Moran's I statistics was used to detect a spatial distribution of local P. falciparum and P. vivax malaria at the county level. Spatial and space-time scan statistics were applied to detect spatial and spatiotemporal clusters, respectively. RESULTS Both P. vivax and P. falciparum malaria showed spatial autocorrelation. The most likely spatial cluster of P. vivax was detected in northern Anhui province between 2005 and 2009, and western Yunnan province between 2010 and 2014. For P. falciparum, the clusters included several counties of western Yunnan province from 2005 to 2011, Guangxi from 2012 to 2013, and Anhui in 2014. The most likely space-time clusters of P. vivax malaria and P. falciparum malaria were detected in northern Anhui province and western Yunnan province, respectively, during 2005-2009. CONCLUSION The spatial and space-time cluster analysis identified high-risk areas and periods for both P. vivax and P. falciparum malaria. Both malaria types showed significant spatial and spatiotemporal variations. Contrary to P. vivax, the high-risk areas for P. falciparum malaria shifted from the west to the east of China. Further studies are required to examine the spatial changes in risk of malaria transmission and identify the underlying causes of elevated risk in the high-risk areas.
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Affiliation(s)
- Samuel H. Hundessa
- Division of Epidemiology and Biostatistics, School of Public Health, University of Queensland, Herston Rd, Herston, QLD 4006 Australia
| | - Gail Williams
- Division of Epidemiology and Biostatistics, School of Public Health, University of Queensland, Herston Rd, Herston, QLD 4006 Australia
| | - Shanshan Li
- Division of Epidemiology and Biostatistics, School of Public Health, University of Queensland, Herston Rd, Herston, QLD 4006 Australia
| | - Jinpeng Guo
- Institute for Disease Control and Prevention, Academy of Military Medical Science, Beijing, People’s Republic of China
| | - Linping Chen
- Division of Epidemiology and Biostatistics, School of Public Health, University of Queensland, Herston Rd, Herston, QLD 4006 Australia
| | - Wenyi Zhang
- Institute for Disease Control and Prevention, Academy of Military Medical Science, Beijing, People’s Republic of China
| | - Yuming Guo
- Division of Epidemiology and Biostatistics, School of Public Health, University of Queensland, Herston Rd, Herston, QLD 4006 Australia
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22
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Chaumeau V, Andolina C, Fustec B, Tuikue Ndam N, Brengues C, Herder S, Cerqueira D, Chareonviriyaphap T, Nosten F, Corbel V. Comparison of the Performances of Five Primer Sets for the Detection and Quantification of Plasmodium in Anopheline Vectors by Real-Time PCR. PLoS One 2016; 11:e0159160. [PMID: 27441839 PMCID: PMC4956213 DOI: 10.1371/journal.pone.0159160] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/28/2016] [Indexed: 02/07/2023] Open
Abstract
Quantitative real-time polymerase chain reaction (qrtPCR) has made a significant improvement for the detection of Plasmodium in anopheline vectors. A wide variety of primers has been used in different assays, mostly adapted from molecular diagnosis of malaria in human. However, such an adaptation can impact the sensitivity of the PCR. Therefore we compared the sensitivity of five primer sets with different molecular targets on blood stages, sporozoites and oocysts standards of Plasmodium falciparum (Pf) and P. vivax (Pv). Dilution series of standard DNA were used to discriminate between methods at low concentrations of parasite and to generate standard curves suitable for the absolute quantification of Plasmodium sporozoites. Our results showed that the best primers to detect blood stages were not necessarily the best ones to detect sporozoites. Absolute detection threshold of our qrtPCR assay varied between 3.6 and 360 Pv sporozoites and between 6 and 600 Pf sporozoites per mosquito according to the primer set used in the reaction mix. In this paper, we discuss the general performance of each primer set and highlight the need to use efficient detection methods for transmission studies.
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Affiliation(s)
- V. Chaumeau
- Centre hospitalier universitaire de Montpellier, Montpellier, France
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France
- Centre for Advanced Studies for Agriculture and Food, Institute of Advanced Studies, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- * E-mail: (V. Chaumeau); (V. Corbel)
| | - C. Andolina
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - B. Fustec
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France
- Centre for Advanced Studies for Agriculture and Food, Institute of Advanced Studies, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - N. Tuikue Ndam
- Institut de Recherche pour le développement, UMR216, Mère et enfant face aux infections tropicales, Paris, France
- Communauté d’Universités et d’Etablissements Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - C. Brengues
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France
| | - S. Herder
- UMR Intertryp, Institut de Recherche pour le Développement, Montpellier, France
- Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - D. Cerqueira
- Centre for Advanced Studies for Agriculture and Food, Institute of Advanced Studies, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - T. Chareonviriyaphap
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - F. Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - V. Corbel
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France
- Centre for Advanced Studies for Agriculture and Food, Institute of Advanced Studies, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
- * E-mail: (V. Chaumeau); (V. Corbel)
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23
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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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Hua YQ, Ding YR, Yan ZT, Si FL, Luo QC, Chen B. The complete mitochondrial genome of Anopheles minimus (Diptera: Culicidae) and the phylogenetics of known Anopheles mitogenomes. INSECT SCIENCE 2016; 23:353-365. [PMID: 26852698 DOI: 10.1111/1744-7917.12326] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/28/2016] [Indexed: 06/05/2023]
Abstract
Anopheles minimus is an important vector of human malaria in southern China and Southeast Asia. The phylogenetics of mosquitoes has not been well resolved, and the mitochondrial genome (mtgenome) has proven to be an important marker in the study of evolutionary biology. In this study, the complete mtgenome of An. minimus was sequenced for the first time. It is 15 395 bp long and encodes 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs) and a non-coding region. The gene organization is consistent with those of known Anopheles mtgenomes. The mtgenome performs a clear bias in nucleotide composition with a positive AT-skew and a negative GC-skew. All 13 PCGs prefer to use the codon UUA (Leu), ATN as initiation codon but cytochrome-oxidase subunit 1 (COI) and ND5, with TCG and GTG, and TAA as termination codon, but COI, COII, COIII and ND4, all with the incomplete T. tRNAs have the typical clover-leaf structure, but tRNA(Ser(AGN)) is consistent with known Anopheles mtgenomes. The control region includes a conserved T-stretch and a (TA)n stretch, and has the highest A+T content at 93.1%. The phylogenetics of An. minimus with 18 other Anopheles species was constructed by maximum likelihood and Bayesian inference, based on concatenated PCG sequences. The subgenera, Cellia and Anopheles, and Nyssorhynchus and Kerteszia have mutually close relationships, respectively. The Punctulatus group and Leucosphyrus group of Neomyzomyia Series, and the Albitarsis group of Albitarsis Series were suggested to be monophyletic. The monophyletic status of the subgenera, Cellia, Anopheles, Nyssorhynchus and Kerteszia need to be further elucidated.
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Affiliation(s)
- Ya-Qiong Hua
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Yi-Ran Ding
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Zhen-Tian Yan
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Feng-Ling Si
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Qian-Chun Luo
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Bin Chen
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, China
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25
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Wang D, Li S, Cheng Z, Xiao N, Cotter C, Hwang J, Li X, Yin S, Wang J, Bai L, Zheng Z, Wang S. Transmission Risk from Imported Plasmodium vivax Malaria in the China-Myanmar Border Region. Emerg Infect Dis 2016; 21:1861-4. [PMID: 26401843 PMCID: PMC4593446 DOI: 10.3201/eid2110.150679] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Malaria importation and local vector susceptibility to imported Plasmodium vivax infection are a continuing risk along the China–Myanmar border. Malaria transmission has been prevented in 3 border villages in Tengchong County, Yunnan Province, China, by use of active fever surveillance, integrated vector control measures, and intensified surveillance and response.
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26
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Hu T, Liu YB, Zhang SS, Xia ZG, Zhou SS, Yan J, Cao J, Feng ZC. Shrinking the malaria map in China: measuring the progress of the National Malaria Elimination Programme. Infect Dis Poverty 2016; 5:52. [PMID: 27197517 PMCID: PMC4873993 DOI: 10.1186/s40249-016-0146-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 05/13/2016] [Indexed: 11/17/2022] Open
Abstract
Background Remarkable progress has been made towards the elimination of malaria in China since the National Malaria Elimination Programme (NMEP) was launched in 2010. The incidence of locally-acquired malaria cases has declined rapidly and endemic areas have also dramatically shrunk. In total, 3 078 malaria cases were reported in 2014, but only 56 cases were indigenous. In order to further promote the elimination programme, we reviewed the progress of and experiences associated with malaria elimination in China, and identified the challenges and priorities for the next stage of the programme. Methods Data were collected from the web-based China Information System for Disease Control and Prevention, and the China Annual Report of Malaria Elimination. The progress towards the elimination of malaria from 2010 to 2014 was measured. Results During the implementation of the NMEP from 2010 to 2014, local malaria incidence has declined continuously, only remaining in the Yunnan Province and Tibet Autonomous Region in 2014. By the end of 2015, 75.6 % (1 636/2 163) of the malaria-endemic counties passed the sub-national elimination assessment. The main challenges are cases of border malaria and imported malaria from other countries. Sustainable support and investment from the government, the establishment of an effective surveillance and response system, and risk assessments for the potential reintroduction of malaria are priorities for the next stage of the elimination programme. Conclusions The NMEP in China has been successfully implemented thus far and the malaria map has shrunk dramatically. The priorities for malaria elimination are interventions to block transmission at border areas, management of imported malaria cases, preventing malaria reintroduction, capacity building, and sustainability of malaria surveillance and response. Electronic supplementary material The online version of this article (doi:10.1186/s40249-016-0146-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tao Hu
- School of Medicine and Health Management, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.,Bureau of Disease Prevention and Control, National Health and Family Planning Commission of the People's Republic of China, Beijing, People's Republic of China
| | - Yao-Bao Liu
- Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, People's Republic of China
| | - Shao-Sen Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China
| | - Zhi-Gui Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China
| | - Shui-Sen Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China
| | - Jun Yan
- Bureau of Disease Prevention and Control, National Health and Family Planning Commission of the People's Republic of China, Beijing, People's Republic of China
| | - Jun Cao
- Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu, People's Republic of China.,Public Health Research Center, Jiangnan University, Wuxi, People's Republic of China
| | - Zhan-Chun Feng
- School of Medicine and Health Management, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
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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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28
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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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Tangena JAA, Thammavong P, Wilson AL, Brey PT, Lindsay SW. Risk and Control of Mosquito-Borne Diseases in Southeast Asian Rubber Plantations. Trends Parasitol 2016; 32:402-415. [PMID: 26907494 DOI: 10.1016/j.pt.2016.01.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/04/2016] [Accepted: 01/19/2016] [Indexed: 11/18/2022]
Abstract
Unprecedented economic growth in Southeast Asia (SEA) has encouraged the expansion of rubber plantations. This land-use transformation is changing the risk of mosquito-borne diseases. Mature plantations provide ideal habitats for the mosquito vectors of malaria, dengue, and chikungunya. Migrant workers may introduce pathogens into plantation areas, most worryingly artemisinin-resistant malaria parasites. The close proximity of rubber plantations to natural forest also increases the threat from zoonoses, where new vector-borne pathogens spill over from wild animals into humans. There is therefore an urgent need to scale up vector control and access to health care for rubber workers. This requires an intersectoral approach with strong collaboration between the health sector, rubber industry, and local communities.
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Affiliation(s)
- Julie-Anne A Tangena
- Laboratory of Vector-Borne Diseases, Institut Pasteur du Laos, Vientiane, Laos; School of Biological and Biomedical Sciences, Durham University, Durham, UK.
| | | | - Anne L Wilson
- School of Biological and Biomedical Sciences, Durham University, Durham, UK
| | - Paul T Brey
- Laboratory of Vector-Borne Diseases, Institut Pasteur du Laos, Vientiane, Laos
| | - Steve W Lindsay
- School of Biological and Biomedical Sciences, Durham University, Durham, UK
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30
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Li Z, Yang Y, Xiao N, Zhou S, Lin K, Wang D, Zhang Q, Jiang W, Li M, Feng X, Yu J, Ren X, Lai S, Sun J, Fang Z, Hu W, Clements ACA, Zhou X, Yu H, Yang W. Malaria imported from Ghana by returning gold miners, China, 2013. Emerg Infect Dis 2016. [PMID: 25897805 PMCID: PMC4412230 DOI: 10.3201/eid2105.141712] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
During May-August 2013, a malaria outbreak comprising 874 persons in Shanglin County, China, was detected among 4,052 persons returning from overseas. Ghana was the predominant destination country, and 92.3% of malarial infections occurred in gold miners. Preventive measures should be enhanced for persons in high-risk occupations traveling to malaria-endemic countries.
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31
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Li Z, Yang Y, Xiao N, Zhou S, Lin K, Wang D, Zhang Q, Jiang W, Li M, Feng X, Yu J, Ren X, Lai S, Sun J, Fang Z, Hu W, Clements ACA, Zhou X, Yu H, Yang W. Malaria imported from Ghana by returning gold miners, China, 2013. Emerg Infect Dis 2016; 21:864-7. [PMID: 25897805 DOI: 10.3201/2105.141712] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
During May-August 2013, a malaria outbreak comprising 874 persons in Shanglin County, China, was detected among 4,052 persons returning from overseas. Ghana was the predominant destination country, and 92.3% of malarial infections occurred in gold miners. Preventive measures should be enhanced for persons in high-risk occupations traveling to malaria-endemic countries.
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32
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Wang Y, Zhong D, Cui L, Lee MC, Yang Z, Yan G, Zhou G. Population dynamics and community structure of Anopheles mosquitoes along the China-Myanmar border. Parasit Vectors 2015; 8:445. [PMID: 26338527 PMCID: PMC4559305 DOI: 10.1186/s13071-015-1057-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 08/26/2015] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Understanding the ecology of malaria vectors such as species composition and population dynamics is essential for developing cost-effective strategies to control mosquito vector populations. METHODS Adult mosquitoes (n = 79,567) were collected in five villages along the China-Myanmar border from April 2012 to September 2014 using the CDC light trap without bait method. Mosquito community structure, Anopheles species composition and diversity were analyzed. RESULTS Twenty species of Anopheles mosquitoes were identified, with An. minimus s.l. accounting for 85% of the total collections. Mosquito densities varied from 0.05 females per trap per night (f/t/n) to 3.00 f/t/n, with strong seasonality in all sites and densities peaked from June to August. An. minimus s.l. was predominant (accounting for 54-91% of total captures) in four villages, An. maculatus s.l. was predominant (71%) in the high elevation village of Dao Nong, and An. culicifacies accounted for 15% of total captures in the peri-urban area of Simsa Lawk. All 20 species have been captured in the Mung Seng Yang village, 18 and 15 species in Ja Htu Kawng and Na Bang respectively, and nine species in both Simsa Lawk and Dao Nong. Species richness peaked from April to August. Species diversity, species dominance index, and species evenness fluctuated substantially from time to time with no clear seasonality, and varied greatly amongst villages. CONCLUSIONS Mosquitoes were abundant in the China-Myanmar bordering agricultural area with clear seasonality. Species composition and density were strongly affected by natural environments. The targeted intervention strategy should be developed and implemented so as to achieve cost-effectiveness for malaria control and elimination along the border areas.
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Affiliation(s)
- Ying Wang
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China.
| | - Daibin Zhong
- Program in Public Health, University of California at Irvine, Irvine, CA, USA.
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park, PA, USA.
| | - Ming-Chieh Lee
- Program in Public Health, University of California at Irvine, Irvine, CA, USA.
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China.
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, Irvine, CA, USA.
| | - Guofa Zhou
- Program in Public Health, University of California at Irvine, Irvine, CA, USA.
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Conn JE, Norris DE, Donnelly MJ, Beebe NW, Burkot TR, Coulibaly MB, Chery L, Eapen A, Keven JB, Kilama M, Kumar A, Lindsay SW, Moreno M, Quinones M, Reimer LJ, Russell TL, Smith DL, Thomas MB, Walker ED, Wilson ML, Yan G. Entomological Monitoring and Evaluation: Diverse Transmission Settings of ICEMR Projects Will Require Local and Regional Malaria Elimination Strategies. Am J Trop Med Hyg 2015; 93:28-41. [PMID: 26259942 PMCID: PMC4574272 DOI: 10.4269/ajtmh.15-0009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 05/20/2015] [Indexed: 01/29/2023] Open
Abstract
The unprecedented global efforts for malaria elimination in the past decade have resulted in altered vectorial systems, vector behaviors, and bionomics. These changes combined with increasingly evident heterogeneities in malaria transmission require innovative vector control strategies in addition to the established practices of long-lasting insecticidal nets and indoor residual spraying. Integrated vector management will require focal and tailored vector control to achieve malaria elimination. This switch of emphasis from universal coverage to universal coverage plus additional interventions will be reliant on improved entomological monitoring and evaluation. In 2010, the National Institutes for Allergies and Infectious Diseases (NIAID) established a network of malaria research centers termed ICEMRs (International Centers for Excellence in Malaria Research) expressly to develop this evidence base in diverse malaria endemic settings. In this article, we contrast the differing ecology and transmission settings across the ICEMR study locations. In South America, Africa, and Asia, vector biologists are already dealing with many of the issues of pushing to elimination such as highly focal transmission, proportionate increase in the importance of outdoor and crepuscular biting, vector species complexity, and "sub patent" vector transmission.
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Affiliation(s)
- Jan E. Conn
- *Address correspondence to Jan E. Conn, Griffin Laboratory, The Wadsworth Center, New York State Department of Health, 5668 State Farm Road, Slingerlands, NY 12159. E-mail:
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Feng J, Xia ZG, Vong S, Yang WZ, Zhou SS, Xiao N. Preparedness for malaria resurgence in China: case study on imported cases in 2000-2012. ADVANCES IN PARASITOLOGY 2015; 86:231-65. [PMID: 25476887 DOI: 10.1016/b978-0-12-800869-0.00009-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Malaria is the most important parasitic protozoan infection that has caused serious threats to human health globally. China has had success in reducing the morbidity and mortality of malaria to the lowest level through sustained and large-scale interventions. Although the total number of malaria cases declined gradually, the burden of the imported malaria cases mainly from Southeast Asian and African countries has increased substantially since 2000, posing a severe threat to public health in China. This review explores and analyses the epidemiological characteristics of the imported malaria based on data from 2000 to 2012, in order to provide theoretical bases and insights into effective prevention, avoid the resurgence of malaria in malaria-susceptible areas and develop appropriate strategies to protect people's health in China. This review also intends to offer the useful information of innovative approaches and tools that are required for malaria elimination in various settings.
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Affiliation(s)
- Jun Feng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis; Shanghai, People's Republic of China
| | - Zhi-Gui Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis; Shanghai, People's Republic of China
| | - Sirenda Vong
- World Health Organization, China Representative Office, Beijing, People's Republic of China
| | - Wei-Zhong Yang
- Chinese Preventive Medicine Association, Beijing, People's Republic of China; Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Shui-Sen Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis; Shanghai, People's Republic of China
| | - Ning Xiao
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis; Shanghai, People's Republic of China
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35
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Xia ZG, Zhang L, Feng J, Li M, Feng XY, Tang LH, Wang SQ, Yang HL, Gao Q, Kramer R, Ernest T, Yap P, Zhou XN. Lessons from malaria control to elimination: case study in Hainan and Yunnan provinces. ADVANCES IN PARASITOLOGY 2015; 86:47-79. [PMID: 25476881 DOI: 10.1016/b978-0-12-800869-0.00003-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Reduction patterns of Plasmodium falciparum and P. vivax malaria transmission and the role of an integrated strategy of case management and vector control are compared between different ecological zones. The epidemiology of malaria in Hainan and Yunnan provinces was disparate, even though distinct malaria control strategies have been adapted to different situations based on risk group, vector behaviours, local health infrastructure, and environmental conditions. The island Hainan appears to be victorious in eliminating malaria. However, there is still a long way to go to prevent the reintroduction of malaria in Hainan province and eliminating malaria in the border areas of Yunnan province. This review of the experiences and challenges from malaria control to elimination in Hainan and Yunnan provinces of southern China will provide a basis for the future elimination of malaria in the whole country.
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Affiliation(s)
- Zhi-Gui Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People's Republic of China
| | - Li Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People's Republic of China
| | - Jun Feng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People's Republic of China
| | - Mei Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People's Republic of China
| | - Xin-Yu Feng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People's Republic of China
| | - Lin-Hua Tang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People's Republic of China
| | - Shan-Qing Wang
- Hainan Provincial Center for Disease Control and Prevention, Haikou, People's Republic of China
| | - Heng-Lin Yang
- Yunnan Provincial Institute of Parasitic Diseases, Pu-er, People's Republic of China
| | - Qi Gao
- Jiangsu Provincial Institute of Parasitic Diseases, Wuxi, People's Republic of China
| | - Randall Kramer
- Duke Global Health Institute, Duke University, Durham, NC, USA
| | - Tambo Ernest
- Centre for Sustainable Malaria Control, Faculty of Natural and Environmental Science; Center for Sustainable Malaria Control, Biochemistry Department, Faculty of Natural and Agricultural Sciences,University of Pretoria, Pretoria, South Africa
| | - Peiling Yap
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH; WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, People's Republic of China
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Qian YJ, Zhang L, Xia ZG, Vong S, Yang WZ, Wang DQ, Xiao N. Preparation for malaria resurgence in China: approach in risk assessment and rapid response. ADVANCES IN PARASITOLOGY 2014; 86:267-88. [PMID: 25476888 DOI: 10.1016/b978-0-12-800869-0.00010-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
With the shrinking of indigenous malaria cases and endemic areas in the People's Republic of China (P.R. China), imported malaria predominates over all reported cases accounting for more than 90% of the total. On the way to eliminate malaria, prompt detection and rapid response to the imported cases are crucial for the prevention of secondary transmission in previous endemic areas. Through a comprehensive literature review, this chapter aims to identify risk determinants of potential local transmission caused by the imported malaria cases and discusses gaps to be addressed to reach the elimination goal by 2020. Current main gaps with respect to dealing with potential malaria resurgence in P.R. China include lack of cross-sectoral cooperation, lack of rapid response and risk assessment, poor public awareness, and inadequate research and development in the national malaria elimination programme.
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Smithuis FM, Kyaw MK, Phe UO, van der Broek I, Katterman N, Rogers C, Almeida P, Kager PA, Stepniewska K, Lubell Y, Simpson JA, White NJ. Entomological determinants of insecticide-treated bed net effectiveness in Western Myanmar. Malar J 2013; 12:364. [PMID: 24119994 PMCID: PMC4015723 DOI: 10.1186/1475-2875-12-364] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 09/20/2013] [Indexed: 11/29/2022] Open
Abstract
Background In a large cluster randomized control trial of insecticide-treated bed nets (ITN) in Western Myanmar the malaria protective effect of ITN was found to be highly variable and, in aggregate, the effect was not statistically significant. A coincident entomological investigation measured malaria vector abundance and biting behaviour and the human population sleeping habits, factors relevant to ITN effectiveness. Methods Entomological surveys were carried out using different catching methods to identify potential malaria vector species and characterise their biting habits. The salivary glands were dissected from all female anophelines caught to identify sporozoites by microscopy. Findings Between 1995 and 2000 a total of 4,824 female anopheline mosquitoes were caught with various catching methods. A total of 916 person nights yielded 3,009 female anopheline mosquitoes between 6 pm and 6 am. Except for Anopheles annularis, which showed no apparent preference (51% outdoor biting), all major species showed a strong preference for outdoor biting; Anopheles epiroticus (79%), Anopheles subpictus (72%), Anopheles maculatus (92%), Anopheles aconitus (85%) and Anopheles vagus (72%). Most human biting occurred in the early evening with the peak biting time between 6 pm and 7 pm (35%). Overall 51% (1447/2837) of all bites recorded were between 6 pm and 8 pm. A large proportion of children were not sleeping under an ITN during peak biting times. Only one An. annularis mosquito (0.02%) had malaria sporozoites identified in the salivary glands. Conclusions Peak vector biting occurred early in the evening and mainly occurred outdoors. The limited efficacy of ITN in this area of Western Myanmar may be explained by the biting behaviour of the prevalent Anopheles mosquito vectors in this area.
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Affiliation(s)
- Frank M Smithuis
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Mahidol University, Faculty of Tropical Medicine, 3rd Floor, 60th Anniversary Chalermprakiat Building, 420/6 Rajvithi Rd,, Ratchathewi District, Bangkok 10400, Thailand.
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