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Liao JR, Tu WC, Chiu MC, Kuo MH, Cheng HC, Chan CC, Dai SM. Joint influence of architectural and spatiotemporal factors on the presence of Aedes aegypti in urban environments. PEST MANAGEMENT SCIENCE 2023; 79:4367-4375. [PMID: 37384574 DOI: 10.1002/ps.7634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 06/22/2023] [Accepted: 06/29/2023] [Indexed: 07/01/2023]
Abstract
BACKGROUND Urbanization has led to the proliferation of high-rise buildings, which have substantially influenced the distribution of dengue vectors, such as Aedes aegypti (L.). However, knowledge gaps exist regarding the individual and combined effects of architectural and spatiotemporal factors on dengue vector. This study investigated the interrelationship between Ae. aegypti presence, building architectural features, and spatiotemporal factors in urban environments. RESULTS The mosquito Ae. aegypti presence varied by location and seasons, being higher in outdoor environments than in indoor environments. Lingya (Kaohsiung City, Taiwan) had the highest mosquito numbers, particularly in basement and first floor areas. Ae. aegypti was found on multiple floors within buildings, and their presence was greater in summer and autumn. The XGBoost model revealed that height within a building, temperature, humidity, resident density, and rainfall were key factors influencing mosquito presence, whereas openness had a relatively minor impact. CONCLUSION To effectively address the problems caused by urbanization, the three-dimensional distribution of Ae. aegypti, including their spatial distribution across heights and areas within the urban environment, must be considered. By incorporating these multiple factors, this approach provides valuable insights for those responsible for urban planning and disease management strategies. Understanding the interplay between architectural features, environmental conditions, and the presence of Ae. aegypti is essential for developing targeted interventions and mitigating the adverse impacts of urbanization on public health. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Jhih-Rong Liao
- Department of Entomology, National Chung Hsing University, Taichung City, Taiwan
- Systematic Zoology Laboratory, Department of Biological Sciences, Tokyo Metropolitan University, Hachioji City, Tokyo, Japan
| | - Wu-Chun Tu
- Department of Entomology, National Chung Hsing University, Taichung City, Taiwan
- School of Life Sciences and Technology, Institut Teknologi Bandung, Bandung, West Java, Indonesia
| | - Ming-Chih Chiu
- Department of Entomology, National Chung Hsing University, Taichung City, Taiwan
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama City, Ehime, Japan
| | - Mei-Hwa Kuo
- Department of Entomology, National Chung Hsing University, Taichung City, Taiwan
| | - Hui-Ching Cheng
- National Mosquito-Borne Diseases Control Research Center, National Health Research Institutes, Kaohsiung City, Taiwan
| | - Chia-Chun Chan
- Department of Entomology, National Chung Hsing University, Taichung City, Taiwan
| | - Shu-Mei Dai
- Department of Entomology, National Chung Hsing University, Taichung City, Taiwan
- Center for Dengue Fever Control and Research, Kaohsiung Medical University, Kaohsiung City, Taiwan
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Aung SH, Mon Kyaw AM, Jittamala P, Lawpoolsri S, Soonthornworasiri N, Sriwichai P, Phuanukoonnon S. Efficacy of household Aedes larval control practices in a peri-urban township, Yangon, Myanmar: Implication for entomological surveillance. Heliyon 2023; 9:e18083. [PMID: 37483793 PMCID: PMC10362226 DOI: 10.1016/j.heliyon.2023.e18083] [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: 01/21/2022] [Revised: 06/18/2023] [Accepted: 07/06/2023] [Indexed: 07/25/2023] Open
Abstract
Dengue is a major public health concern in Myanmar. We carried out a cross-sectional study to investigate the efficacy of larval control practices in household water containers, such as the use of the larvicide, temephos, covering the containers with lids and weekly cleaning. We surveyed 300 households in Kaw Hmu Township, a peri-urban community in the Yangon region. We inspected 1,892 water storage containers and 342 non-water storage/household waste containers during the rainy season and 1,866 water storage containers and 287 non-water storage/household waste containers during the dry season. The presence of Aedes larvae and larval control measures were recorded for each container. Results revealed that larval indices were higher than World Health Organization standard indices, and infestations in water storage containers were more common in the rainy season (6.6%) than in the dry season (5.7%). Infestations were also more likely in containers of non-potable water (9.1%-9.9%) than in containers of potable water (0.1%-0.7%). Two thirds of water storage containers were treated with temephos. Containers most likely to contain Aedes larvae were cement basins and barrels. Temephos was effective in controlling infestations in cement basins, while weekly cleaning was effective in controlling infestations in barrels. Combinations of control methods were more effective at larval control than the use of a single method. Larval infestations were high (18.4% in the rainy season) in unused containers and in containers which were household waste. Overall, we found a complex interaction between household water use, container characteristics, and larval control practices. Larval control strategies in Myanmar will require ongoing entomological surveillance and the identification of key breeding sources and optimal control methods.
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Affiliation(s)
- Soe Htet Aung
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Aye Mon Mon Kyaw
- Central Epidemiology Unit, Department of Public Health, Yangon Region, Myanmar
| | - Podjanee Jittamala
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Saranath Lawpoolsri
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Thailand
| | | | - Patchara Sriwichai
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Suparat Phuanukoonnon
- Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Thailand
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Zeng Q, Yu X, Ni H, Xiao L, Xu T, Wu H, Chen Y, Deng H, Zhang Y, Pei S, Xiao J, Guo P. Dengue transmission dynamics prediction by combining metapopulation networks and Kalman filter algorithm. PLoS Negl Trop Dis 2023; 17:e0011418. [PMID: 37285385 DOI: 10.1371/journal.pntd.0011418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 05/24/2023] [Indexed: 06/09/2023] Open
Abstract
Predicting the specific magnitude and the temporal peak of the epidemic of individual local outbreaks is critical for infectious disease control. Previous studies have indicated that significant differences in spatial transmission and epidemic magnitude of dengue were influenced by multiple factors, such as mosquito population density, climatic conditions, and population movement patterns. However, there is a lack of studies that combine the above factors to explain their complex nonlinear relationships in dengue transmission and generate accurate predictions. Therefore, to study the complex spatial diffusion of dengue, this research combined the above factors and developed a network model for spatiotemporal transmission prediction of dengue fever using metapopulation networks based on human mobility. For improving the prediction accuracy of the epidemic model, the ensemble adjusted Kalman filter (EAKF), a data assimilation algorithm, was used to iteratively assimilate the observed case data and adjust the model and parameters. Our study demonstrated that the metapopulation network-EAKF system provided accurate predictions for city-level dengue transmission trajectories in retrospective forecasts of 12 cities in Guangdong province, China. Specifically, the system accurately predicts local dengue outbreak magnitude and the temporal peak of the epidemic up to 10 wk in advance. In addition, the system predicted the peak time, peak intensity, and total number of dengue cases more accurately than isolated city-specific forecasts. The general metapopulation assimilation framework presented in our study provides a methodological foundation for establishing an accurate system with finer temporal and spatial resolution for retrospectively forecasting the magnitude and temporal peak of dengue fever outbreaks. These forecasts based on the proposed method can be interoperated to better support intervention decisions and inform the public of potential risks of disease transmission.
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Affiliation(s)
- Qinghui Zeng
- Department of Preventive Medicine, Shantou University Medical College, Shantou, China
| | - Xiaolin Yu
- Department of Preventive Medicine, Shantou University Medical College, Shantou, China
| | - Haobo Ni
- Department of Preventive Medicine, Shantou University Medical College, Shantou, China
| | - Lina Xiao
- Department of Preventive Medicine, Shantou University Medical College, Shantou, China
| | - Ting Xu
- Department of Preventive Medicine, Shantou University Medical College, Shantou, China
| | - Haisheng Wu
- Department of Preventive Medicine, Shantou University Medical College, Shantou, China
| | - Yuliang Chen
- Department of Medical Quality Management, Nanfang Hospital, Guangzhou, China
| | - Hui Deng
- Institute of Vector Control, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
| | - Yingtao Zhang
- Institute of Infectious Disease Control and Prevention, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
| | - Sen Pei
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, United States of America
| | - Jianpeng Xiao
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
| | - Pi Guo
- Department of Preventive Medicine, Shantou University Medical College, Shantou, China
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou, China
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Duval P, Antonelli P, Aschan-Leygonie C, Valiente Moro C. Impact of Human Activities on Disease-Spreading Mosquitoes in Urban Areas. J Urban Health 2023:10.1007/s11524-023-00732-z. [PMID: 37277669 DOI: 10.1007/s11524-023-00732-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/25/2023] [Indexed: 06/07/2023]
Abstract
Urbanization is one of the leading global trends of the twenty-first century that has a significant impact on health. Among health challenges caused by urbanization, the relationship of urbanization between emergence and the spread of mosquito-borne infectious diseases (MBIDs) is a great public health concern. Urbanization processes encompass social, economic, and environmental changes that directly impact the biology of mosquito species. In particular, urbanized areas experience higher temperatures and pollution levels than outlying areas but also favor the development of infrastructures and objects that are favorable to mosquito development. All these modifications may influence mosquito life history traits and their ability to transmit diseases. This review aimed to summarize the impact of urbanization on mosquito spreading in urban areas and the risk associated with the emergence of MBIDs. Moreover, mosquitoes are considered as holobionts, as evidenced by numerous studies highlighting the role of mosquito-microbiota interactions in mosquito biology. Taking into account this new paradigm, this review also represents an initial synthesis on how human-driven transformations impact microbial communities in larval habitats and further interfere with mosquito behavior and life cycle in urban areas.
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Affiliation(s)
- Pénélope Duval
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, Bât. André Lwoff, 10 rue Raphaël Dubois, F-69622, Villeurbanne, France
| | - Pierre Antonelli
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, Bât. André Lwoff, 10 rue Raphaël Dubois, F-69622, Villeurbanne, France
| | - Christina Aschan-Leygonie
- University of Lyon, Université Lumière Lyon 2, UMR 5600 CNRS Environnement Ville Société, F-69007, Lyon, France
| | - Claire Valiente Moro
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, Bât. André Lwoff, 10 rue Raphaël Dubois, F-69622, Villeurbanne, France.
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Aung SH, Phuanukoonnon S, Mon Kyaw AM, Lawpoolsri S, Sriwichai P, Soonthornworasiri N, Jittamala P. Effectiveness of dengue training programmes on prevention and control among high school students in the Yangon region, Myanmar. Heliyon 2023; 9:e16759. [PMID: 37292340 PMCID: PMC10245065 DOI: 10.1016/j.heliyon.2023.e16759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/22/2023] [Accepted: 05/25/2023] [Indexed: 06/10/2023] Open
Abstract
Background Dengue is one of the health problems in Myanmar. Thus, health promotion in schools is considered a key approach for reducing risk-taking behaviours related to dengue. Objectives The study aimed to evaluate a dengue training programme for high school students to measure changes in knowledge, attitude and practices (KAP) towards dengue; evaluate the effectiveness of the programme in improving prevention and control practices among families and determining changes in larval indices in their dwelling places. Methodology The dengue school training programme was conducted for Grades 9 and 10 students in Yangon. In total, 300 students in the intervention school received training and were compared with 300 students as control. KAP was assessed using a self-administered questionnaire, whereas larval and control practice surveys were conducted at the homes of both groups 3 months before and after the programme. Results The KAP scores of the intervention group increased after the programme. Moreover, the programme improved prevention and control practices and decreased the larval indices in the intervention group. Students from the same group with high scores in knowledge and self-reported practices were less likely to exhibit Aedes larval positivity in their residential areas. Conclusion This study demonstrated the impact of the dengue training programme on the KAP of students and short-term family larval control practices, which influenced household larval indices.
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Affiliation(s)
- Soe Htet Aung
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Suparat Phuanukoonnon
- Department of Social and Environmental Science, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Aye Mon Mon Kyaw
- Central Epidemiology Unit, Department of Public Health, Ministry of Health, Myanmar
| | - Saranath Lawpoolsri
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Patchara Sriwichai
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Thailand
| | | | - Podjanee Jittamala
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Thailand
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Liu Y, Wang X, Tang S, Cheke RA. The relative importance of key meteorological factors affecting numbers of mosquito vectors of dengue fever. PLoS Negl Trop Dis 2023; 17:e0011247. [PMID: 37053307 PMCID: PMC10128945 DOI: 10.1371/journal.pntd.0011247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 04/25/2023] [Accepted: 03/15/2023] [Indexed: 04/15/2023] Open
Abstract
Although single factors such as rainfall are known to affect the population dynamics of Aedes albopictus, the main vector of dengue fever in Eurasia, the synergistic effects of different meteorological factors are not fully understood. To address this topic, we used meteorological data and mosquito-vector association data including Breteau and ovitrap indices in key areas of dengue outbreaks in Guangdong Province, China, to formulate a five-stage mathematical model for Aedes albopictus population dynamics by integrating multiple meteorological factors. Unknown parameters were estimated using a genetic algorithm, and the results were analyzed by k-Shape clustering, random forest and grey correlation analysis. In addition, the population density of mosquitoes in 2022 was predicted and used for evaluating the effectiveness of the model. We found that there is spatiotemporal heterogeneity in the effects of temperature and rainfall and their distribution characteristics on the diapause period, the numbers of peaks in mosquito densities in summer and the annual total numbers of adult mosquitoes. Moreover, we identified the key meteorological indicators of the mosquito quantity at each stage and that rainfall (seasonal rainfall and annual total rainfall) was more important than the temperature distribution (seasonal average temperature and temperature index) and the uniformity of rainfall annual distribution (coefficient of variation) for most of the areas studied. The peak rainfall during the summer is the best indicator of mosquito population development. The results provide important theoretical support for the future design of mosquito vector control strategies and early warnings of mosquito-borne diseases.
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Affiliation(s)
- Yan Liu
- School of Mathematics and Statistics, Shaanxi Normal University, Xi'an, Shaanxi, China
| | - Xia Wang
- School of Mathematics and Statistics, Shaanxi Normal University, Xi'an, Shaanxi, China
| | - Sanyi Tang
- School of Mathematics and Statistics, Shaanxi Normal University, Xi'an, Shaanxi, China
| | - Robert A Cheke
- Natural Resources Institute, University of Greenwich at Medway, Chatham Maritime, Chatham, United Kingdom
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Huynh TTT, Minakawa N. A comparative study of dengue virus vectors in major parks and adjacent residential areas in Ho Chi Minh City, Vietnam. PLoS Negl Trop Dis 2022; 16:e0010119. [PMID: 35020732 PMCID: PMC8789112 DOI: 10.1371/journal.pntd.0010119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 01/25/2022] [Accepted: 12/21/2021] [Indexed: 11/23/2022] Open
Abstract
The primary dengue virus vectors, Aedes aegypti and Aedes albopictus, are primarily daytime biting mosquitoes. The risk of infection is suspected to be considerable in urban parks due to visitor traffic. Despite the importance of vector control for reducing dengue transmission, little information is available on vector populations in urban parks. The present study characterized mosquito habitats and estimated vector densities in the major urban parks in Ho Chi Minh City, Vietnam and compared them with those in adjacent residential areas. The prevalences of habitats where Aedes larvae were found were 43% and 9% for the parks and residential areas, respectively. The difference was statistically significant (prevalence ratio [PR]: 5.00, 95% CI: 3.85–6.49). The prevalences of positive larval habitats were significantly greater in the parks for both species than the residential areas (PR: 1.52, 95% CI: 1.04–2.22 for A. aegypti, PR: 10.10, 95% CI: 7.23–14.12 for A. albopictus). Larvae of both species were positively associated with discarded containers and planters. Aedes albopictus larvae were negatively associated with indoor habitats, but positively associated with vegetation shade. The adult density of A. aegypti was significantly less in the parks compared with the residential areas (rate ratio [RR]; 0.09, 95% CI: 0.05–0.16), while the density of A. albopictus was significantly higher in the parks (RR: 9.99, 95% CI: 6.85–14.59). When the species were combined, the density was significantly higher in the parks (RR: 2.50, 95% CI: 1.92–3.25). The urban parks provide suitable environment for Aedes mosquitoes, and A. albopictus in particular. Virus vectors are abundant in the urban parks, and the current vector control programs need to have greater consideration of urban parks. The primary dengue virus vectors, Aedes aegypti and Aedes albopictus, are primarily daytime biting mosquitoes and therefore the risk of infection may be considerable in urban parks due to human foot traffic. Prior to the present study little information was available on vector populations in urban parks. Here we describe that larvae of both species were positively associated with discarded containers and planters. Aedes albopictus larvae were negatively associated with indoor habitats, but positively associated with vegetation shade. Aedes albopictus was predominant in the urban parks while A. aegypti was predominant in adjacent residential areas. When the species were combined the density of vectors was greater in the urban parks. The current vector control programs need to take into consideration vector intensity within urban parks.
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Affiliation(s)
- Trang Thi Thuy Huynh
- Department of Medical Entomology and Zoonotics, Pasteur Institute in Ho Chi Minh City, Ho Chi Minh City, Vietnam
- Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
- Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Noboru Minakawa
- Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
- * E-mail:
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Cui G, Zhong S, Zheng T, Li Z, Zhang X, Li C, Hemming-Schroeder E, Zhou G, Li Y. Aedes albopictus life table: environment, food, and age dependence survivorship and reproduction in a tropical area. Parasit Vectors 2021; 14:568. [PMID: 34743753 PMCID: PMC8573987 DOI: 10.1186/s13071-021-05081-x] [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: 06/12/2021] [Accepted: 10/26/2021] [Indexed: 11/29/2022] Open
Abstract
Background Environmental conditions affect the biology of mosquito vectors. Aedes albopictus is a major vector of many important diseases including dengue, Zika, and chikungunya in China. Understanding the development, fecundity, and survivorship of Ae. albopictus mosquitoes in different environmental conditions is beneficial for the implementation of effective vector control measures. Methods Aedes albopictus larval and adult life-table experiments were conducted under natural conditions in indoor, half-shaded, and fully shaded settings, simulating the three major habitat types in Hainan Province, a tropical island in the South China Sea. Temperature, humidity, and light intensity were recorded daily. Larval rearing used habitat water and tap water, with and without additional artificial food. Development time, survivorship, pupation rate, and adult emergence rates were monitored. Adult mosquito survivorship and fecundity were monitored daily and reproductive rates were determined, and age-dependent survivorship and reproduction were analyzed. Results The pupation time and male and female emergence times were significantly shorter in indoor conditions than in shaded and half-shaded conditions for both tap water with added food and habitat water with added food groups. For habitat water with added food, the shaded environment had the lowest pupation rate among the settings. For tap water with added food group, the shaded environment had the lowest pupation rate. The mean survival time of females was 27.3 ± 0.8 days in the indoor condition, which was significantly longer than that in the half-shaded (18.4 ± 0.6 days) and shaded (13.8 ± 1.2 days) conditions. Adult mortality was age-dependent, and the rate of change in mortality with age was not significantly different among different environmental conditions. The mean net replacement rate (R0) of female mosquitoes showed no significant difference among the three conditions, whereas the per capita intrinsic growth rate (r) in the shaded condition was 42.0% and 20.4% higher than that in the indoor and half-shaded conditions, respectively. Female daily egg mass was also age-dependent in all the settings, decaying exponentially with age. Conclusions Our results imply that half-shaded conditions are likely the best natural condition for adult emergence and female reproduction, and food supply is crucial for larval development and pupation. The results provide new avenues for integrated mosquito management in indoor and outdoor areas, especially in half-shaded areas. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-05081-x.
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Affiliation(s)
- Guzhen Cui
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, 571199, China.,Key Laboratory of Medical Microbiology and Parasitology of Education Department of Guizhou, School of Basic Medical Science, Guizhou Medical University, Guiyang, 550025, China
| | - Saifeng Zhong
- Department of Pathogen Biology, Hainan Medical University, Haikou, 571199, China
| | - Tuquan Zheng
- Department of Pathogen Biology, Hainan Medical University, Haikou, 571199, China
| | - Zhangrui Li
- Department of Pathogen Biology, Hainan Medical University, Haikou, 571199, China
| | - Xu Zhang
- Department of Pathogen Biology, Hainan Medical University, Haikou, 571199, China
| | - Chuang Li
- Department of Pathogen Biology, Hainan Medical University, Haikou, 571199, China
| | - Elizabeth Hemming-Schroeder
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92617, USA
| | - Guofa Zhou
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92617, USA.
| | - Yiji Li
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, 571199, China. .,Department of Pathogen Biology, Hainan Medical University, Haikou, 571199, China. .,Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Haikou, 571199, China.
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Leonard MP, Oliver JD. Mosquito Guttersnipe: A New Sampling Tool for Roof Gutters, Tree Holes, and Other Elevated Mosquito Habitats. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2021; 37:109-112. [PMID: 34184048 DOI: 10.2987/20-6988.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mosquitoes pose health risks to human populations by serving as vectors of diseases. Mosquito control organizations are responsible for inspecting and controlling vector populations to reduce the risk of infection of these diseases. Current sampling methods are effective for numerous types of mosquito habitat, but not conducive for sampling small overhead habitat such as roof gutters or tree holes. We have developed and tested a tool called the Mosquito GutterSnipe to sample these overhead habitats. Volumetric and larval capacity testing of the tool prototype demonstrated comparable sampling integrity to standard mosquito dipping methods. The GutterSnipe can be employed as a reliable way to sample previously overlooked mosquito habitat. Its current model is cost effective and easy to produce for mosquito control organizations and easy to use for inspectors.
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Affiliation(s)
- Mark P Leonard
- University of Minnesota, Division of Environmental Health Sciences, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Jonathan D Oliver
- University of Minnesota, Division of Environmental Health Sciences, 420 Delaware Street SE, Minneapolis, MN 55455
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Ong J, Chong CS, Yap G, Lee C, Abdul Razak MA, Chiang S, Ng LC. Gravitrap deployment for adult Aedes aegypti surveillance and its impact on dengue cases. PLoS Negl Trop Dis 2020; 14:e0008528. [PMID: 32764763 PMCID: PMC7439811 DOI: 10.1371/journal.pntd.0008528] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 08/19/2020] [Accepted: 06/26/2020] [Indexed: 01/13/2023] Open
Abstract
House Index, Container Index, and Breteau Index are the most commonly used indices for dengue vector surveillance. However, these larval indices are a poor proxy for measuring the adult population—which is responsible for disease transmission. Information on the adult distribution and density are important for assessing transmission risk as well as for developing effective control strategies. This study introduces a new entomological index, Gravitrap aegypti index (GAI), which estimates the adult female Aedes aegypti population in the community and presents its association with dengue cases. Gravitraps were deployed across 34 treatment sites in Singapore from September 2013 to September 2016. The GAI, derived from the Gravitrap surveillance data, was analysed to investigate the spatio-temporal patterns of the Ae. aegypti population in Singapore. The index was further categorised into low, moderate, and high-risk groups and its association with dengue cases were examined. A Before-After Control Impact analysis was performed to evaluate the epidemiology impact of Gravitrap system on dengue transmission. The Ae. aegypti population exhibits a seasonal pattern, and spatial heterogeneity in Ae. aegypti abundance was observed among treatment sites. The Ae. aegypti population was also found to be unevenly distributed among floors of an apartment block, with low floors (floors 1–4) having a higher abundance of mosquitoes trapped than mid (floors 5–8) and high (floors ≥9) floors. Areas with high GAI were shown to have higher dengue case count. Gravitrap has also demonstrated to be a good dengue control tool. The contribution of cases by treatment sites to the national numbers was lower after Gravitraps deployment. The GAI, which is of better relevance to dengue transmission risk, could be recommended as an indicator for decision making in vector control efforts, and to monitor the spatio-temporal variability of the adult Aedes population in the country. In addition, findings from this study indicate that Gravitraps can be used as a dengue control tool to reduce dengue transmission. In the absence of an effective vaccine: vector surveillance and control remain the key strategy for dengue prevention and control. The collection of the adult female Aedes mosquito is thus important to understand disease transmission dynamics. Information on its distribution and density are also essential for assessing transmission risk as well as for devising an effective control strategy. Here, we described a new approach to dengue vector surveillance based on adult female Aedes trapping using Gravitraps. Using the Gravitrap surveillance data, we derived a new entomological index, Gravitrap aegypti index (GAI), which estimates the adult female Ae. aegypti population in the community and presents its association with dengue cases. When analysed, the index can provide useful information on the spatio-temporal distribution of the Ae. aegypti population in the country and hence, assist planning of vector control. The GAI, which is of better relevance to dengue transmission risk, could be used as an indicator for decision making in vector control efforts, and to monitor the spatio-temporal variability of the adult Aedes population. In addition, findings from this study indicate that Gravitraps can be used as a dengue control tool to reduce dengue transmission.
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Affiliation(s)
- Janet Ong
- Environmental Health Institute, National Environment Agency, Singapore
| | - Chee-Seng Chong
- Environmental Health Institute, National Environment Agency, Singapore
| | - Grace Yap
- Environmental Public Health Operations, National Environment Agency, Singapore
| | - Caleb Lee
- Environmental Health Institute, National Environment Agency, Singapore
| | | | - Suzanna Chiang
- Environmental Health Institute, National Environment Agency, Singapore
| | - Lee-Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore
- * E-mail:
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