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Mobile apps for travel medicine and ethical considerations: A systematic review. Travel Med Infect Dis 2021; 43:102143. [PMID: 34256131 DOI: 10.1016/j.tmaid.2021.102143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/30/2021] [Accepted: 07/02/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND The advent of mobile applications for health and medicine will revolutionize travel medicine. Despite their many benefits, such as access to real-time data, mobile apps for travel medicine are accompanied by many ethical issues, including questions about security and privacy. METHODS A systematic literature review as conducted following PRISMA guidelines. Database screening yielded 1795 results and seven papers satisfied the criteria for inclusion. Through a mix of inductive and deductive data extraction, this systematic review examined both the benefits and challenges, as well as ethical considerations, of mobile apps for travel medicine. RESULTS Ethical considerations were discussed with varying depth across the included articles, with privacy and data protection mentioned most frequently, highlighting concerns over sensitive information and a lack of guidelines in the digital sphere. Additionally, technical concerns about data quality and bias were predominant issues for researchers and developers alike. Some ethical issues were not discussed at all, including equity, and user involvement. CONCLUSION This paper highlights the scarcity of discussion around ethical issues. Both researchers and developers need to better integrate ethical reflection at each step of the development and use of health apps. More effective oversight mechanisms and clearer ethical guidance are needed to guide the stakeholders in this endeavour.
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Buchwald AG, Grover E, Van Dyke J, Kechris K, Lu D, Liu Y, Zhong B, Carlton EJ. Human Mobility Associated With Risk of Schistosoma japonicum Infection in Sichuan, China. Am J Epidemiol 2021; 190:1243-1252. [PMID: 33438003 DOI: 10.1093/aje/kwaa292] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 12/15/2020] [Accepted: 12/29/2020] [Indexed: 11/12/2022] Open
Abstract
Urbanization increases human mobility in ways that can alter the transmission of classically rural, vector-borne diseases like schistosomiasis. The impact of human mobility on individual-level Schistosoma risk is poorly characterized. Travel outside endemic areas may protect against infection by reducing exposure opportunities, whereas travel to other endemic regions may increase risk. Using detailed monthly travel- and water-contact surveys from 27 rural communities in Sichuan, China, in 2008, we aimed to describe human mobility and to identify mobility-related predictors of S. japonicum infection. Candidate predictors included timing, frequency, distance, duration, and purpose of recent travel as well as water-contact measures. Random forests machine learning was used to detect key predictors of individual infection status. Logistic regression was used to assess the strength and direction of associations. Key mobility-related predictors include frequent travel and travel during July-both associated with decreased probability of infection and less time engaged in risky water-contact behavior, suggesting travel may remove opportunities for schistosome exposure. The importance of July travel and July water contact suggests a high-risk window for cercarial exposure. The frequency and timing of human movement out of endemic areas should be considered when assessing potential drivers of rural infectious diseases.
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Thongsripong P, Hyman JM, Kapan DD, Bennett SN. Human-Mosquito Contact: A Missing Link in Our Understanding of Mosquito-Borne Disease Transmission Dynamics. ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA 2021; 114:397-414. [PMID: 34249219 PMCID: PMC8266639 DOI: 10.1093/aesa/saab011] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Indexed: 05/26/2023]
Abstract
Despite the critical role that contact between hosts and vectors, through vector bites, plays in driving vector-borne disease (VBD) transmission, transmission risk is primarily studied through the lens of vector density and overlooks host-vector contact dynamics. This review article synthesizes current knowledge of host-vector contact with an emphasis on mosquito bites. It provides a framework including biological and mathematical definitions of host-mosquito contact rate, blood-feeding rate, and per capita biting rates. We describe how contact rates vary and how this variation is influenced by mosquito and vertebrate factors. Our framework challenges a classic assumption that mosquitoes bite at a fixed rate determined by the duration of their gonotrophic cycle. We explore alternative ecological assumptions based on the functional response, blood index, forage ratio, and ideal free distribution within a mechanistic host-vector contact model. We highlight that host-vector contact is a critical parameter that integrates many factors driving disease transmission. A renewed focus on contact dynamics between hosts and vectors will contribute new insights into the mechanisms behind VBD spread and emergence that are sorely lacking. Given the framework for including contact rates as an explicit component of mathematical models of VBD, as well as different methods to study contact rates empirically to move the field forward, researchers should explicitly test contact rate models with empirical studies. Such integrative studies promise to enhance understanding of extrinsic and intrinsic factors affecting host-vector contact rates and thus are critical to understand both the mechanisms driving VBD emergence and guiding their prevention and control.
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Affiliation(s)
- Panpim Thongsripong
- Department of Microbiology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA
| | - James M Hyman
- Department of Mathematics, Tulane University, 6823 St. Charles Avenue, New Orleans, LA 70118, USA
| | - Durrell D Kapan
- Department of Entomology and Center for Comparative Genomics, Institute of Biodiversity Sciences and Sustainability, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA
- Center for Conservation and Research Training, Pacific Biosciences Research Center, University of Hawai’i at Manoa, 3050 Maile Way, Honolulu, HI 96822
| | - Shannon N Bennett
- Department of Microbiology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA
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Tam G, Cowling BJ, Maude RJ. Analysing human population movement data for malaria control and elimination. Malar J 2021; 20:294. [PMID: 34193167 PMCID: PMC8247220 DOI: 10.1186/s12936-021-03828-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/22/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Human population movement poses a major obstacle to malaria control and elimination. With recent technological advances, a wide variety of data sources and analytical methods have been used to quantify human population movement (HPM) relevant to control and elimination of malaria. METHODS The relevant literature and selected studies that had policy implications that could help to design or target malaria control and elimination interventions were reviewed. These studies were categorized according to spatiotemporal scales of human mobility and the main method of analysis. RESULTS Evidence gaps exist for tracking routine cross-border HPM and HPM at a regional scale. Few studies accounted for seasonality. Out of twenty included studies, two studies which tracked daily neighbourhood HPM used descriptive analyses as the main method, while the remaining studies used statistical analyses or mathematical modelling. CONCLUSION Although studies quantified varying types of human population movement covering different spatial and temporal scales, methodological gaps remain that warrant further studies related to malaria control and elimination.
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Affiliation(s)
- Greta Tam
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Benjamin J Cowling
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Richard J Maude
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7LG, UK. .,The Open University, Milton Keynes, MK7 6AA, UK. .,Harvard TH Chan School of Public Health, Harvard University, Boston, MA, 02115, USA.
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Tun STT, Min MC, Aguas R, Fornace K, Htoo GN, White LJ, Parker DM. Human movement patterns of farmers and forest workers from the Thailand-Myanmar border. Wellcome Open Res 2021. [DOI: 10.12688/wellcomeopenres.16784.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Human travel patterns play an important role in infectious disease epidemiology and ecology. Movement into geographic spaces with high transmission can lead to increased risk of acquiring infections. Pathogens can also be distributed across the landscape via human travel. Most fine scale studies of human travel patterns have been done in urban settings in wealthy nations. Research into human travel patterns in rural areas of low- and middle-income nations are useful for understanding the human components of epidemiological systems for malaria or other diseases of the rural poor. The goal of this research was to assess the feasibility of using GPS loggers to empirically measure human travel patterns in this setting, as well as to quantify differing travel patterns by age, gender, and seasonality. Methods: In this pilot study we recruited 50 rural villagers from along the Myanmar-Thailand border to carry GPS loggers for the duration of a year. The GPS loggers were programmed to take a time-stamped reading every 30 minutes. We calculated daily movement ranges and multi-day trips by age and gender. We incorporated remote sensing data to assess patterns of days and nights spent in forested or farm areas, also by age and gender. Results: Our study showed that it is feasible to use GPS devices to measure travel patterns, though we had difficulty recruiting women and management of the project was relatively intensive. We found that older adults traveled farther distances than younger adults and adult males spent more nights in farms or forests. Conclusion: The results of this study suggest that further work along these lines would be feasible in this region. Furthermore, the results from this study are useful for individual-based models of disease transmission and land use.
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Temperature, traveling, slums, and housing drive dengue transmission in a non-endemic metropolis. PLoS Negl Trop Dis 2021; 15:e0009465. [PMID: 34115753 PMCID: PMC8221794 DOI: 10.1371/journal.pntd.0009465] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 06/23/2021] [Accepted: 05/10/2021] [Indexed: 11/24/2022] Open
Abstract
Dengue is steadily increasing worldwide and expanding into higher latitudes. Current non-endemic areas are prone to become endemic soon. To improve understanding of dengue transmission in these settings, we assessed the spatiotemporal dynamics of the hitherto largest outbreak in the non-endemic metropolis of Buenos Aires, Argentina, based on detailed information on the 5,104 georeferenced cases registered during summer-autumn of 2016. The highly seasonal dengue transmission in Buenos Aires was modulated by temperature and triggered by imported cases coming from regions with ongoing outbreaks. However, local transmission was made possible and consolidated heterogeneously in the city due to housing and socioeconomic characteristics of the population, with 32.8% of autochthonous cases occurring in slums, which held only 6.4% of the city population. A hierarchical spatiotemporal model accounting for imperfect detection of cases showed that, outside slums, less-affluent neighborhoods of houses (vs. apartments) favored transmission. Global and local spatiotemporal point-pattern analyses demonstrated that most transmission occurred at or close to home. Additionally, based on these results, a point-pattern analysis was assessed for early identification of transmission foci during the outbreak while accounting for population spatial distribution. Altogether, our results reveal how social, physical, and biological processes shape dengue transmission in Buenos Aires and, likely, other non-endemic cities, and suggest multiple opportunities for control interventions. Dengue fever is mainly transmitted by a mosquito species that is highly urbanized, and lays eggs and develops mostly in artificial water containers. Dengue transmission is sustained year-round in most tropical regions of the world, but in many subtropical/temperate regions it occurs only in the warmest months. To improve understanding of dengue transmission in these regions, we analyzed one of the largest outbreaks in Buenos Aires city, a subtropical metropolis. Based on information on 5,104 georeferenced cases during summer-autumn 2016, we found that most transmission occurred in or near home, that slums had the highest risk of transmission, and that, outside slums, less-affluent neighborhoods of houses (vs. apartments) favored transmission. We showed that the cumulative effects of temperature over the previous few weeks set the temporal limits for transmission to occur, and that the outbreak was sparked by infected people arriving from regions with ongoing outbreaks. Additionally, we implemented a statistical method to identify transmission foci in real-time that improves targeting control interventions. Our results deepen the understanding of dengue transmission as a result of social, physical, and biological processes, and pose multiple opportunities for improving control of dengue and other mosquito-borne viruses such as Zika, chikungunya, and yellow fever.
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Liyanage P, Rocklöv J, Tissera HA. The impact of COVID-19 lockdown on dengue transmission in Sri Lanka; A natural experiment for understanding the influence of human mobility. PLoS Negl Trop Dis 2021; 15:e0009420. [PMID: 34111117 PMCID: PMC8192006 DOI: 10.1371/journal.pntd.0009420] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 04/28/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Dengue is one of the major public health problems in Sri Lanka. Its outbreak pattern depends on a multitude of drivers, including human mobility. Here we evaluate the impact of COVID-19 related mobility restriction (lockdown) on the risk of dengue in Sri Lanka. METHODOLOGY Two-stage hierarchical models were fitted using an interrupted time-series design based on the notified dengue cases, January 2015 to July 2020. In the first stage model, the district level impact was estimated using quasi-Poisson regression models while accounting for temporal trends. Estimates were pooled at zonal and national levels in the second stage model using meta-analysis. The influence of the extended period of school closure on dengue in children in the western province was compared to adults. FINDINGS Statistically significant and homogeneous reduction of dengue risk was observed at all levels during the lockdown. Overall an 88% reduction in risk (RR 0.12; 95% CI from 0.08 to 0.17) was observed at the national level. The highest impact was observed among children aged less than 19 years showing a 92% reduction (RR 0.8; 95% CI from 0.03 to 0.25). We observed higher impact in the dry zone having 91% reduction (RR 0.09; 95% CI from 0.05 to 0.15) compared to wet zone showing 83% reduction (RR 0.17; 95% CI from 0.09 to 0.30). There was no indication that the overall health-seeking behaviour for dengue had a substantial influence on these estimates. SIGNIFICANCE This study offers a broad understanding of the change in risk of dengue during the COVID-19 pandemic and associated mobility restrictions in Sri Lanka. The analysis using the mobility restrictions as a natural experiment suggests mobility patterns to be a very important driver of dengue transmission.
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Affiliation(s)
- Prasad Liyanage
- Department of Epidemiology and Global Health, Umeå University, Umeå, Sweden
- Ministry of Health, Colombo, 01000, Sri Lanka
| | - Joacim Rocklöv
- Department of Public Health and Clinical Medicine, Section of Sustainable Health, Umeå University, Umeå, Sweden
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Lee SA, Jarvis CI, Edmunds WJ, Economou T, Lowe R. Spatial connectivity in mosquito-borne disease models: a systematic review of methods and assumptions. J R Soc Interface 2021; 18:20210096. [PMID: 34034534 PMCID: PMC8150046 DOI: 10.1098/rsif.2021.0096] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/26/2021] [Indexed: 12/14/2022] Open
Abstract
Spatial connectivity plays an important role in mosquito-borne disease transmission. Connectivity can arise for many reasons, including shared environments, vector ecology and human movement. This systematic review synthesizes the spatial methods used to model mosquito-borne diseases, their spatial connectivity assumptions and the data used to inform spatial model components. We identified 248 papers eligible for inclusion. Most used statistical models (84.2%), although mechanistic are increasingly used. We identified 17 spatial models which used one of four methods (spatial covariates, local regression, random effects/fields and movement matrices). Over 80% of studies assumed that connectivity was distance-based despite this approach ignoring distant connections and potentially oversimplifying the process of transmission. Studies were more likely to assume connectivity was driven by human movement if the disease was transmitted by an Aedes mosquito. Connectivity arising from human movement was more commonly assumed in studies using a mechanistic model, likely influenced by a lack of statistical models able to account for these connections. Although models have been increasing in complexity, it is important to select the most appropriate, parsimonious model available based on the research question, disease transmission process, the spatial scale and availability of data, and the way spatial connectivity is assumed to occur.
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Affiliation(s)
- Sophie A. Lee
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Centre on Climate Change and Planetary Health, London School of Hygiene & Tropical Medicine, London, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Christopher I. Jarvis
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - W. John Edmunds
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | | | - Rachel Lowe
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Centre on Climate Change and Planetary Health, London School of Hygiene & Tropical Medicine, London, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
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Bhatia S, Lassmann B, Cohn E, Desai AN, Carrion M, Kraemer MUG, Herringer M, Brownstein J, Madoff L, Cori A, Nouvellet P. Using digital surveillance tools for near real-time mapping of the risk of infectious disease spread. NPJ Digit Med 2021; 4:73. [PMID: 33864009 PMCID: PMC8052406 DOI: 10.1038/s41746-021-00442-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 03/16/2021] [Indexed: 02/02/2023] Open
Abstract
Data from digital disease surveillance tools such as ProMED and HealthMap can complement the field surveillance during ongoing outbreaks. Our aim was to investigate the use of data collected through ProMED and HealthMap in real-time outbreak analysis. We developed a flexible statistical model to quantify spatial heterogeneity in the risk of spread of an outbreak and to forecast short term incidence trends. The model was applied retrospectively to data collected by ProMED and HealthMap during the 2013-2016 West African Ebola epidemic and for comparison, to WHO data. Using ProMED and HealthMap data, the model was able to robustly quantify the risk of disease spread 1-4 weeks in advance and for countries at risk of case importations, quantify where this risk comes from. Our study highlights that ProMED and HealthMap data could be used in real-time to quantify the spatial heterogeneity in risk of spread of an outbreak.
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Affiliation(s)
- Sangeeta Bhatia
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, Faculty of Medicine, London, UK.
| | - Britta Lassmann
- ProMED, International Society for Infectious Diseases, Brookline, MA, USA
| | - Emily Cohn
- Computational Epidemiology Group, Division of Emergency Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Angel N Desai
- ProMED, International Society for Infectious Diseases, Brookline, MA, USA
| | - Malwina Carrion
- ProMED, International Society for Infectious Diseases, Brookline, MA, USA
- Department of Health Science, Sargent College, Boston University, Boston, MA, USA
| | - Moritz U G Kraemer
- Computational Epidemiology Group, Division of Emergency Medicine, Boston Children's Hospital, Boston, MA, USA
- Department of Zoology, Tinbergen Building, Oxford University, Oxford, UK
- Department of Pediatrics, Harvard Medical School, Boston, USA
| | | | - John Brownstein
- Computational Epidemiology Group, Division of Emergency Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Larry Madoff
- ProMED, International Society for Infectious Diseases, Brookline, MA, USA
| | - Anne Cori
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, Faculty of Medicine, London, UK
| | - Pierre Nouvellet
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, Faculty of Medicine, London, UK
- School of Life Sciences, University of Sussex, Brighton, UK
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Liu L, Wu T, Liu B, Nelly RMJ, Fu Y, Kang X, Chen C, Huang Z, Wu B, Wang J, Zhu Z, Ma J, Liu M, Zhang Y, Bao C, Lin F, Chen W, Xia Q. The Origin and Molecular Epidemiology of Dengue Fever in Hainan Province, China, 2019. Front Microbiol 2021; 12:657966. [PMID: 33841385 PMCID: PMC8025777 DOI: 10.3389/fmicb.2021.657966] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 03/02/2021] [Indexed: 01/20/2023] Open
Abstract
There was an outbreak of Dengue fever on September 5, 2019, in Hainan Province, which has not been endemic for 28 years. We aim to describe the clinical and epidemiological features of the 2019 outbreak in Hainan Province and identify the cause. All type 1 Dengue fever cases that occurred in this outbreak of Hainan exhibited mild clinical symptoms. The epidemiological investigations indicate that the outbreak might originate from workers in the Xiuying area, Haikou City, form a concentrated outbreak, and then spread out. Bayesian phylogenies results and epidemiological data were used to infer a likely series of events for the dengue virus's potential spread and trace the possible sources. The strains' sequences were close to a sequence from the nearby Guangdong province, supporting the hypothesis that the dengue virus was imported from Guangdong province and then spread across Hainan province. Furthermore, it is interesting that two other strains didn't group with this cluster, suggesting that additional introduction pathways might exist. The study indicated that the dengue fever epidemic presented two important modes in Hainan. Firstly, epidemics prevalence was caused by imported cases, and then endogenous epidemics broke out in the natural epidemic focus.
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Affiliation(s)
- Lin Liu
- NHC Key Laboratory of Control of Tropical Diseases, Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, China
| | - Tao Wu
- Department of Infectious Diseases, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Biao Liu
- NHC Key Laboratory of Control of Tropical Diseases, Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, China
| | - Rajaofera Mamy Jayne Nelly
- NHC Key Laboratory of Control of Tropical Diseases, Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, China
| | - Yumei Fu
- NHC Key Laboratory of Control of Tropical Diseases, Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, China
| | - Xun Kang
- NHC Key Laboratory of Control of Tropical Diseases, Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, China
| | - Chuizhe Chen
- NHC Key Laboratory of Control of Tropical Diseases, Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, China
| | - Zenyan Huang
- NHC Key Laboratory of Control of Tropical Diseases, Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, China
| | - Biao Wu
- Department of Infectious Diseases, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Jiao Wang
- Department of Infectious Diseases, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Zhongyi Zhu
- BGI PathoGenesis Pharmaceutical Technology, BGI-Shenzhen, Shenzhen, China.,BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Jinmin Ma
- BGI PathoGenesis Pharmaceutical Technology, BGI-Shenzhen, Shenzhen, China
| | - Ming Liu
- Department of Infectious Diseases, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Yanru Zhang
- Department of Infectious Diseases, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Chuanyu Bao
- Department of Emergency Surgery, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Feng Lin
- Department of Infectious Diseases, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Weijun Chen
- BGI PathoGenesis Pharmaceutical Technology, BGI-Shenzhen, Shenzhen, China.,BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Qianfeng Xia
- NHC Key Laboratory of Control of Tropical Diseases, Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, China
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Zheng J, Shi B, Xia S, Yang G, Zhou XN. Spatial patterns of <em>Plasmodium vivax</em> transmission explored by multivariate auto-regressive state-space modelling - A case study in Baoshan Prefecture in southern China. GEOSPATIAL HEALTH 2021; 16. [PMID: 33733649 DOI: 10.4081/gh.2021.879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/21/2020] [Indexed: 06/12/2023]
Abstract
The transition from the control phase to elimination of malaria in China through the national malaria elimination programme has focussed attention on the need for improvement of the surveillance- response systems. It is now understood that routine passive surveillance is inadequate in the parasite elimination phase that requires supplementation by active surveillance in foci where cluster cases have occurred. This study aims to explore the spatial clusters and temporal trends of malaria cases by the multivariate auto-regressive state-space model (MARSS) along the border to Myanmar in southern China. Data for indigenous cases spanning the period from 2007 to 2010 were extracted from the China's Infectious Diseases Information Reporting Management System (IDIRMS). The best MARSS model indicated that malaria transmission in the study area during 36 months could be grouped into three clusters. The estimation of malaria transmission patterns showed a downward trend across all clusters. The proposed methodology used in this study offers a simple and rapid, yet effective way to categorize patterns of foci which provide assistance for active monitoring of malaria in the elimination phase.
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Affiliation(s)
- Jinxin Zheng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai, China; National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China; Chinese Center for Tropical Diseases Research, Shanghai.
| | - Benyun Shi
- School of Computer Science and Technology, Nanjing Tech University, Nanjing, Jiangsu.
| | - Shang Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai, China; National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China; Chinese Center for Tropical Diseases Research, Shanghai.
| | - Guojing Yang
- Hainan Medical University, Laboratory of Tropical Environment and Health, Haikou, Hainan, China; Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute; University of Basel, Basel.
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai, China; National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China; Chinese Center for Tropical Diseases Research, Shanghai.
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Jones RT, Pretorius E, Ant TH, Bradley J, Last A, Logan JG. The use of islands and cluster-randomized trials to investigate vector control interventions: a case study on the Bijagós archipelago, Guinea-Bissau. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190807. [PMID: 33357055 PMCID: PMC7776941 DOI: 10.1098/rstb.2019.0807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2020] [Indexed: 12/30/2022] Open
Abstract
Vector-borne diseases threaten the health of populations around the world. While key interventions continue to provide protection from vectors, there remains a need to develop and test new vector control tools. Cluster-randomized trials, in which the intervention or control is randomly allocated to clusters, are commonly selected for such evaluations, but their design must carefully consider cluster size and cluster separation, as well as the movement of people and vectors, to ensure sufficient statistical power and avoid contamination of results. Island settings present an opportunity to conduct these studies. Here, we explore the benefits and challenges of conducting intervention studies on islands and introduce the Bijagós archipelago of Guinea-Bissau as a potential study site for interventions intended to control vector-borne diseases. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.
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Affiliation(s)
- Robert T. Jones
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
- ARCTEC, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - Elizabeth Pretorius
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - Thomas H. Ant
- Centre for Virus Research, Bearsden Road, Bearsden, Glasgow G61 1QH, UK
| | - John Bradley
- MRC International Statistics and Epidemiology Group, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - Anna Last
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - James G. Logan
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
- ARCTEC, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
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Lim JT, Chew LZX, Choo ELW, Dickens BSL, Ong J, Aik J, Ng LC, Cook AR. Increased Dengue Transmissions in Singapore Attributable to SARS-CoV-2 Social Distancing Measures. J Infect Dis 2021; 223:399-402. [PMID: 33000172 PMCID: PMC7543616 DOI: 10.1093/infdis/jiaa619] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/28/2020] [Indexed: 12/02/2022] Open
Abstract
Social distancing (SD) measures aimed at curbing the spread of SARS-CoV-2 remain an important public health intervention. Little is known about the collateral impact of reduced mobility on the risk of other communicable diseases. We used differences in dengue case counts pre- and post implementation of SD measures and exploited heterogeneity in SD treatment effects among different age groups in Singapore to identify the spillover effects of SD measures. SD policy caused an increase of over 37.2% in dengue cases from baseline. Additional measures to preemptively mitigate the risk of other communicable diseases must be considered before the implementation/reimplementation of SARS-CoV-2 SD measures.
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Affiliation(s)
- Jue Tao Lim
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Lawrence Zheng Xiong Chew
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
- Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore, Singapore, Singapore
| | - Esther Li Wen Choo
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Borame Sue Lee Dickens
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Janet Ong
- Environmental Health Institute, National Environmental Agency, Singapore, Singapore
| | - Joel Aik
- Environmental Health Institute, National Environmental Agency, Singapore, Singapore
| | - Lee Ching Ng
- Environmental Health Institute, National Environmental Agency, Singapore, Singapore
| | - Alex R Cook
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
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Telle O, Nikolay B, Kumar V, Benkimoun S, Pal R, Nagpal BN, Paul RE. Social and environmental risk factors for dengue in Delhi city: A retrospective study. PLoS Negl Trop Dis 2021; 15:e0009024. [PMID: 33571202 PMCID: PMC7877620 DOI: 10.1371/journal.pntd.0009024] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 12/01/2020] [Indexed: 12/16/2022] Open
Abstract
Global urbanization is leading to an inexorable spread of several major diseases that need to be stemmed. Dengue is one of these major diseases spreading in cities today, with its principal mosquito vector superbly adapted to the urban environment. Current mosquito control strategies are proving inadequate, especially in the face of such urbanisation and novel, evidence-based targeted approaches are needed. Through combined epidemiological and entomological approaches, we aimed to identify a novel sanitation strategy to alleviate the burden of dengue through how the dengue virus spreads through the community. We combined surveillance case mapping, prospective serological studies, year-round mosquito surveys, socio-economic and Knowledge Attitudes and Practices surveys across Delhi. We identified lack of access to tap water (≤98%) as an important risk factor for dengue virus IgG sero-positivity (adjusted Odds Ratio 4.69, 95% C.I. 2.06–10.67) and not poverty per se. Wealthier districts had a higher dengue burden despite lower mosquito densities than the Intermediary income communities (adjusted Odds Ratio 2.92, 95% C.I. 1.26–6.72). This probably reflects dengue being introduced by people travelling from poorer areas to work in wealthier houses. These poorer, high density areas, where temperatures are also warmer, also had dengue cases during the winter. Control strategies based on improved access to a reliable supply of tap water plus focal intervention in intra-urban heat islands prior to the dengue season could not only lead to a reduction in mosquito abundance but also eliminate the reservoir of dengue virus clearly circulating at low levels in winter in socio-economically disadvantaged areas. Identifying disease hotspots and individual risk factors for dengue can enable targeted intervention strategies. We conducted combined serological, entomological and socio-economic surveys across 18 areas within Delhi, taken from the total 1280 colonies (i.e. the administrative units of reference in Delhi) for which we classified their socio-economic typology. We additionally performed a Knowledge, Attitudes, Practices survey at a household level within the most socially disadvantaged sub-districts. Finally, we mapped all the winter dengue cases to 250 m x 250 m units along with their winter mean temperatures. We found that access to tap water was an important risk factor for exposure to dengue virus (DENV) and this was confirmed even within the socially disadvantaged sub-districts. The Wealthy colonies had a high burden of DENV infection despite low mosquito densities, likely linked to their connectedness through daily human mobility. The winter burden of dengue occurred majoritarily in the socio-economically disadvantaged colonies, which also have higher mean temperatures and urban heat islands. Improved access to tap water could lead to a reduction in dengue, not only for those directly affected but for the general population. Targeted intervention through mosquito control in winter in the socially disadvantaged areas could offer a rational strategy for optimising control efforts.
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Affiliation(s)
- Olivier Telle
- Géographie-cités, Université Paris-1 Panthéon-Sorbonne, Paris, France
- Centre for Policy Research, Dharam Marg, Delhi, India
- * E-mail:
| | - Birgit Nikolay
- Mathematical Modelling of Infectious Diseases, Institut Pasteur, Centre National de la Recherche Scientifique, Paris, France
| | - Vikram Kumar
- National Institute of Malaria Research, Sector 8, Dwarka, Delhi, India
| | - Samuel Benkimoun
- Géographie-cités, Université Paris-1 Panthéon-Sorbonne, Paris, France
- Centre de Sciences Humaines, UMIFRE 20 CNRS-MAE,Delhi, India
| | - Rupali Pal
- Centre de Sciences Humaines, UMIFRE 20 CNRS-MAE,Delhi, India
| | - BN Nagpal
- National Institute of Malaria Research, Sector 8, Dwarka, Delhi, India
| | - Richard E. Paul
- Institut Pasteur, Functional Genetics of Infectious Diseases Unit, Paris, France
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Mahmud AS, Kabir MI, Engø-Monsen K, Tahmina S, Riaz BK, Hossain MA, Khanom F, Rahman MM, Rahman MK, Sharmin M, Hossain DM, Yasmin S, Ahmed MM, Lusha MAF, Buckee CO. Megacities as drivers of national outbreaks: The 2017 chikungunya outbreak in Dhaka, Bangladesh. PLoS Negl Trop Dis 2021; 15:e0009106. [PMID: 33529229 PMCID: PMC7880496 DOI: 10.1371/journal.pntd.0009106] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 02/12/2021] [Accepted: 01/04/2021] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Several large outbreaks of chikungunya have been reported in the Indian Ocean region in the last decade. In 2017, an outbreak occurred in Dhaka, Bangladesh, one of the largest and densest megacities in the world. Population mobility and fluctuations in population density are important drivers of epidemics. Measuring population mobility during outbreaks is challenging but is a particularly important goal in the context of rapidly growing and highly connected cities in low- and middle-income countries, which can act to amplify and spread local epidemics nationally and internationally. METHODS We first describe the epidemiology of the 2017 chikungunya outbreak in Dhaka and estimate incidence using a mechanistic model of chikungunya transmission parametrized with epidemiological data from a household survey. We combine the modeled dynamics of chikungunya in Dhaka, with mobility estimates derived from mobile phone data for over 4 million subscribers, to understand the role of population mobility on the spatial spread of chikungunya within and outside Dhaka during the 2017 outbreak. RESULTS We estimate a much higher incidence of chikungunya in Dhaka than suggested by official case counts. Vector abundance, local demographics, and population mobility were associated with spatial heterogeneities in incidence in Dhaka. The peak of the outbreak in Dhaka coincided with the annual Eid holidays, during which large numbers of people traveled from Dhaka to other parts of the country. We show that travel during Eid likely resulted in the spread of the infection to the rest of the country. CONCLUSIONS Our results highlight the impact of large-scale population movements, for example during holidays, on the spread of infectious diseases. These dynamics are difficult to capture using traditional approaches, and we compare our results to a standard diffusion model, to highlight the value of real-time data from mobile phones for outbreak analysis, forecasting, and surveillance.
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Affiliation(s)
- Ayesha S. Mahmud
- Department of Demography, University of California, Berkeley, Berkeley, California, United States of America
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Md. Iqbal Kabir
- National Institute of Preventive and Social Medicine, Dhaka, Bangladesh
- Directorate General of Health Services, Dhaka, Bangladesh
| | | | - Sania Tahmina
- Directorate General of Health Services, Dhaka, Bangladesh
| | | | - Md. Akram Hossain
- National Institute of Preventive and Social Medicine, Dhaka, Bangladesh
| | - Fahmida Khanom
- National Institute of Preventive and Social Medicine, Dhaka, Bangladesh
| | | | | | | | | | | | | | | | - Caroline O. Buckee
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
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Schaber KL, Perkins TA, Lloyd AL, Waller LA, Kitron U, Paz-Soldan VA, Elder JP, Rothman AL, Civitello DJ, Elson WH, Morrison AC, Scott TW, Vazquez-Prokopec GM. Disease-driven reduction in human mobility influences human-mosquito contacts and dengue transmission dynamics. PLoS Comput Biol 2021; 17:e1008627. [PMID: 33465065 PMCID: PMC7845972 DOI: 10.1371/journal.pcbi.1008627] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 01/29/2021] [Accepted: 12/11/2020] [Indexed: 02/01/2023] Open
Abstract
Heterogeneous exposure to mosquitoes determines an individual’s contribution to vector-borne pathogen transmission. Particularly for dengue virus (DENV), there is a major difficulty in quantifying human-vector contacts due to the unknown coupled effect of key heterogeneities. To test the hypothesis that the reduction of human out-of-home mobility due to dengue illness will significantly influence population-level dynamics and the structure of DENV transmission chains, we extended an existing modeling framework to include social structure, disease-driven mobility reductions, and heterogeneous transmissibility from different infectious groups. Compared to a baseline model, naïve to human pre-symptomatic infectiousness and disease-driven mobility changes, a model including both parameters predicted an increase of 37% in the probability of a DENV outbreak occurring; a model including mobility change alone predicted a 15.5% increase compared to the baseline model. At the individual level, models including mobility change led to a reduction of the importance of out-of-home onward transmission (R, the fraction of secondary cases predicted to be generated by an individual) by symptomatic individuals (up to -62%) at the expense of an increase in the relevance of their home (up to +40%). An individual’s positive contribution to R could be predicted by a GAM including a non-linear interaction between an individual’s biting suitability and the number of mosquitoes in their home (>10 mosquitoes and 0.6 individual attractiveness significantly increased R). We conclude that the complex fabric of social relationships and differential behavioral response to dengue illness cause the fraction of symptomatic DENV infections to concentrate transmission in specific locations, whereas asymptomatic carriers (including individuals in their pre-symptomatic period) move the virus throughout the landscape. Our findings point to the difficulty of focusing vector control interventions reactively on the home of symptomatic individuals, as this approach will fail to contain virus propagation by visitors to their house and asymptomatic carriers. Human mobility patterns can play an integral role in vector-borne disease dynamics by characterizing an individual’s potential contacts with disease-transmitting vectors. Dengue virus is transmitted by a sedentary vector, but human mobility allows individuals to have contact with mosquitoes at their home and other houses they frequent (their activity space). When accounting for the decreased mobility of symptomatic dengue cases in an agent-based simulation model, however, we found a severely diminished role of the activity space in onward transmission. Those who received the majority of their mosquito contacts outside their home experienced decreases in expected bites and onward transmission when mobility changes were accounted for. Onward transmission was driven by a synergistic relationship between the number of mosquitoes in an individual’s home and their biting suitability, where even those with the highest biting suitability would have limited contribution to transmission given a low number of household mosquitoes. Reactive vector control, which often targets symptomatic cases, could be effective for slowing onward transmission from these cases, but will fail to control virus transmission due to the disproportionate contribution of asymptomatic infections.
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Affiliation(s)
- Kathryn L. Schaber
- Program of Population Biology, Ecology and Evolution, Emory University, Atlanta, Georgia, United States of America
| | - T. Alex Perkins
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Alun L. Lloyd
- Biomathematics Graduate Program and Department of Mathematics, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Lance A. Waller
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Uriel Kitron
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
| | - Valerie A. Paz-Soldan
- Department of Global Community Health and Behavioral Sciences, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
| | - John P. Elder
- Graduate School of Public Health, San Diego State University, San Diego, California, United States of America
| | - Alan L. Rothman
- Institute for Immunology and Informatics and Department of Cell and Molecular Biology, University of Rhode Island, Providence, Rhode Island, United States of America
| | - David J. Civitello
- Department of Biology, Emory University, Atlanta, Georgia, United States of America
| | - William H. Elson
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
| | - Amy C. Morrison
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Thomas W. Scott
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
| | - Gonzalo M. Vazquez-Prokopec
- Program of Population Biology, Ecology and Evolution, Emory University, Atlanta, Georgia, United States of America
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
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67
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Effect of daily human movement on some characteristics of dengue dynamics. Math Biosci 2021; 332:108531. [PMID: 33460675 DOI: 10.1016/j.mbs.2020.108531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 11/21/2022]
Abstract
Human movement is a key factor in infectious diseases spread such as dengue. Here, we explore a mathematical modeling approach based on a system of ordinary differential equations to study the effect of human movement on characteristics of dengue dynamics such as the existence of endemic equilibria, and the start, duration, and amplitude of the outbreak. The model considers that every day is divided into two periods: high-activity and low-activity. Periodic human movement between patches occurs in discrete times. Based on numerical simulations, we show unexpected scenarios such as the disease extinction in regions where the local basic reproductive number is greater than 1. In the same way, we obtain scenarios where outbreaks appear despite the fact that the local basic reproductive numbers in these regions are less than 1 and the outbreak size depends on the length of high-activity and low-activity periods.
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68
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Shi B, Zheng J, Xia S, Lin S, Wang X, Liu Y, Zhou XN, Liu J. Accessing the syndemic of COVID-19 and malaria intervention in Africa. Infect Dis Poverty 2021; 10:5. [PMID: 33413680 PMCID: PMC7788178 DOI: 10.1186/s40249-020-00788-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/16/2020] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND The pandemic of the coronavirus disease 2019 (COVID-19) has caused substantial disruptions to health services in the low and middle-income countries with a high burden of other diseases, such as malaria in sub-Saharan Africa. The aim of this study is to assess the impact of COVID-19 pandemic on malaria transmission potential in malaria-endemic countries in Africa. METHODS We present a data-driven method to quantify the extent to which the COVID-19 pandemic, as well as various non-pharmaceutical interventions (NPIs), could lead to the change of malaria transmission potential in 2020. First, we adopt a particle Markov Chain Monte Carlo method to estimate epidemiological parameters in each country by fitting the time series of the cumulative number of reported COVID-19 cases. Then, we simulate the epidemic dynamics of COVID-19 under two groups of NPIs: (1) contact restriction and social distancing, and (2) early identification and isolation of cases. Based on the simulated epidemic curves, we quantify the impact of COVID-19 epidemic and NPIs on the distribution of insecticide-treated nets (ITNs). Finally, by treating the total number of ITNs available in each country in 2020, we evaluate the negative effects of COVID-19 pandemic on malaria transmission potential based on the notion of vectorial capacity. RESULTS We conduct case studies in four malaria-endemic countries, Ethiopia, Nigeria, Tanzania, and Zambia, in Africa. The epidemiological parameters (i.e., the basic reproduction number [Formula: see text] and the duration of infection [Formula: see text]) of COVID-19 in each country are estimated as follows: Ethiopia ([Formula: see text], [Formula: see text]), Nigeria ([Formula: see text], [Formula: see text]), Tanzania ([Formula: see text], [Formula: see text]), and Zambia ([Formula: see text], [Formula: see text]). Based on the estimated epidemiological parameters, the epidemic curves simulated under various NPIs indicated that the earlier the interventions are implemented, the better the epidemic is controlled. Moreover, the effect of combined NPIs is better than contact restriction and social distancing only. By treating the total number of ITNs available in each country in 2020 as a baseline, our results show that even with stringent NPIs, malaria transmission potential will remain higher than expected in the second half of 2020. CONCLUSIONS By quantifying the impact of various NPI response to the COVID-19 pandemic on malaria transmission potential, this study provides a way to jointly address the syndemic between COVID-19 and malaria in malaria-endemic countries in Africa. The results suggest that the early intervention of COVID-19 can effectively reduce the scale of the epidemic and mitigate its impact on malaria transmission potential.
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Affiliation(s)
- Benyun Shi
- School of Computer Science and Technology, Nanjing Tech University, Nanjing, 211800 Jiangsu China
| | - Jinxin Zheng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025 China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
- Chinese Center for Tropical Diseases Research, Shanghai, 200025 China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, 200025 China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Shang Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025 China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
- Chinese Center for Tropical Diseases Research, Shanghai, 200025 China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, 200025 China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Shan Lin
- College of Information Engineering, Nanjing University of Finance & Economics, Nanjing, 210003 Jiangsu China
| | - Xinyi Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025 China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
- Chinese Center for Tropical Diseases Research, Shanghai, 200025 China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, 200025 China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Yang Liu
- Department of Computer Science, Hong Kong Baptist University, Hong Kong, China
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025 China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
- Chinese Center for Tropical Diseases Research, Shanghai, 200025 China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025 China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, 200025 China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Jiming Liu
- Department of Computer Science, Hong Kong Baptist University, Hong Kong, China
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Wojtusiak J, Bagchi P, Durbha SSKRTN, Mobahi H, Mogharab Nia R, Roess A. COVID-19 Symptom Monitoring and Social Distancing in a University Population. JOURNAL OF HEALTHCARE INFORMATICS RESEARCH 2021; 5:114-131. [PMID: 33437913 PMCID: PMC7790352 DOI: 10.1007/s41666-020-00089-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 11/20/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022]
Abstract
This paper reports on our efforts to collect daily COVID-19-related symptoms for a large public university population, as well as study relationship between reported symptoms and individual movements. We developed a set of tools to collect and integrate individual-level data. COVID-19-related symptoms are collected using a self-reporting tool initially implemented in Qualtrics survey system and consequently moved to .NET framework. Individual movement data are collected using off-the-shelf tracking apps available for iPhone and Android phones. Data integration and analysis are done in PostgreSQL, Python, and R. As of September 2020, we collected about 184,000 daily symptom responses for 20,000 individuals, as well as over 15,000 days of GPS movement data for 175 individuals. The analysis of the data indicates that headache is the most frequently reported symptom, present almost always when any other symptoms are reported as indicated by derived association rules. It is followed by cough, sore throat, and aches. The study participants traveled on average 223.61 km every week with a large standard deviation of 254.53 and visited on average 5.77 ± 4.75 locations each week for at least 10 min. However, there is no evidence that reported symptoms or prior COVID-19 contact affects movements (p > 0.3 in most models). The evidence suggests that although some individuals limit their movements during pandemics, the overall study population do not change their movements as suggested by guidelines.
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Affiliation(s)
- Janusz Wojtusiak
- Health Informatics Program, Department of Health Administration and Policy, George Mason University, Fairfax, VA USA
| | - Pramita Bagchi
- Department of Statistics, George Mason University, Fairfax, VA USA
| | | | - Hedyeh Mobahi
- Health Informatics Program, Department of Health Administration and Policy, George Mason University, Fairfax, VA USA
| | - Reyhaneh Mogharab Nia
- Health Informatics Program, Department of Health Administration and Policy, George Mason University, Fairfax, VA USA
| | - Amira Roess
- Department of Global and Community Health, George Mason University, Fairfax, VA USA
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Origin and Spread of the Dengue Virus Type 1, Genotype V in Senegal, 2015-2019. Viruses 2021; 13:v13010057. [PMID: 33406660 PMCID: PMC7824722 DOI: 10.3390/v13010057] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 01/20/2023] Open
Abstract
Dengue virus (DENV) is the most widespread arthropod-borne virus, with the number and severity of outbreaks increasing worldwide in recent decades. Dengue is caused by genetically distinct serotypes, DENV-1–4. Here, we present data on DENV-1, isolated from patients with dengue fever during an outbreak in Senegal and Mali (Western Africa) in 2015–2019, that were analyzed by sequencing the envelope (E) gene. The emergence and the dynamics of DENV-1 in Western Africa were inferred by using maximum likelihood and Bayesian methods. The DENV-1 grouped into a monophyletic cluster that was closely related to those from Southeast Asia. The virus appears to have been introduced directly into Medina Gounass (Suburb of Dakar), Senegal (location probability = 0.301, posterior = 0.76). The introduction of the virus in Senegal occurred around 2014 (95% HPD = 2012.88–2014.84), and subsequently, the virus moved to regions within Senegal (e.g., Louga and Fatick), causing intense outbreaks in the subsequent years. The virus appears to have been introduced in Mali (a neighboring country) after its introduction in Senegal. In conclusion, we present evidence that the outbreak caused by DENV-1 in urban environments in Senegal and Mali after 2015 was caused by a single viral introduction from Asia.
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Parhizgari N, Piazak N, Mostafavi E. Vector-borne diseases in Iran: epidemiology and key challenges. Future Microbiol 2021; 16:51-69. [PMID: 33438476 DOI: 10.2217/fmb-2019-0306] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Vector-borne diseases have become a global health concern in recent decades as a result of global warming, globalization, growth in international trade and travel, use of insecticide and drug resistance. This review study addressed the key vector-borne diseases and their current status in Iran to emphasize the requirements for further research on vector-borne diseases. The dispersion patterns of these diseases differ in various regions. Some of them such as Crimean-Congo hemorrhagic fever, and Q fever are distributed all across Iran, whereas some others such as plague, leishmaniasis, tularemia, and malaria are restricted to specific areas. The high prevalence of vectors throughout the country necessitates enhancing the monitoring and surveillance of emerging and reemerging vector-borne diseases and their potential vectors.
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Affiliation(s)
- Najmeh Parhizgari
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.,Department of Epidemiology and Biostatistics, Research Centre for Emerging & Reemerging infectious diseases, Pasteur Institute of Iran, Tehran, Iran
| | - Norair Piazak
- Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Ehsan Mostafavi
- Department of Epidemiology and Biostatistics, Research Centre for Emerging & Reemerging infectious diseases, Pasteur Institute of Iran, Tehran, Iran.,National Reference Laboratory for Plague, Tularemia & Q fever, Research Centre for Emerging & Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran
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Núñez-López M, Alarcón Ramos L, Velasco-Hernández JX. Migration rate estimation in an epidemic network. APPLIED MATHEMATICAL MODELLING 2021; 89:1949-1964. [PMID: 32952269 PMCID: PMC7486824 DOI: 10.1016/j.apm.2020.08.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 07/31/2020] [Accepted: 08/06/2020] [Indexed: 05/07/2023]
Abstract
Most of the recent epidemic outbreaks in the world have as a trigger, a strong migratory component as has been evident in the recent Covid-19 pandemic. In this work we address the problem of migration of human populations and its effect on pathogen reinfections in the case of Dengue, using a Markov-chain susceptible-infected-susceptible (SIS) metapopulation model over a network. Our model postulates a general contact rate that represents a local measure of several factors: the population size of infected hosts that arrive at a given location as a function of total population size, the current incidence at neighboring locations, and the connectivity of the network where the disease spreads. This parameter can be interpreted as an indicator of outbreak risk at a given location. This parameter is tied to the fraction of individuals that move across boundaries (migration). To illustrate our model capabilities, we estimate from epidemic Dengue data in Mexico the dynamics of migration at a regional scale incorporating climate variability represented by an index based on precipitation data.
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Affiliation(s)
- M Núñez-López
- Department of Mathematics, ITAM Río Hondo 1, Ciudad de México 01080, México
| | - L Alarcón Ramos
- Departamento de Matemáticas Aplicadas y Sistemas, Universidad Autónoma Metropolitana, Cuajimalpa, Av. Vasco de Quiroga 4871, Cuajimalpa de Morelos, 05300, México
| | - J X Velasco-Hernández
- Instituto de Matemáticas, Universidad Nacional Autónoma de México, Boulevard Juriquilla No. 3001, Juriquilla, 76230, México
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Chaves LF, Valerín Cordero JA, Delgado G, Aguilar-Avendaño C, Maynes E, Gutiérrez Alvarado JM, Ramírez Rojas M, Romero LM, Marín Rodríguez R. Modeling the association between Aedes aegypti ovitrap egg counts, multi-scale remotely sensed environmental data and arboviral cases at Puntarenas, Costa Rica (2017–2018). CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2021; 1:100014. [PMID: 35284867 PMCID: PMC8906134 DOI: 10.1016/j.crpvbd.2021.100014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/20/2021] [Accepted: 01/26/2021] [Indexed: 11/29/2022]
Abstract
Problems with vector surveillance are a major barrier for the effective control of vector-borne disease transmission through Latin America. Here, we present results from a 80-week longitudinal study where Aedes aegypti (L.) (Diptera: Culicidae) ovitraps were monitored weekly at 92 locations in Puntarenas, a coastal city in Costa Rica with syndemic Zika, chikungunya and dengue transmission. We used separate models to investigate the association of either Ae. aegypti-borne arboviral cases or Ae. aegypti egg counts with remotely sensed environmental variables. We also evaluated whether Ae. aegypti-borne arboviral cases were associated with Ae. aegypti egg counts. Using cross-correlation and time series modeling, we found that arboviral cases were not significantly associated with Ae. aegypti egg counts. Through model selection we found that cases had a non-linear response to multi-scale (1-km and 30-m resolution) measurements of temperature standard deviation (SD) with a lag of up to 4 weeks, while simultaneously increasing with finely-grained NDVI (30-m resolution). Meanwhile, median ovitrap Ae. aegypti egg counts increased, and respectively decreased, with temperature SD (1-km resolution) and EVI (30-m resolution) with a lag of 6 weeks. A synchrony analysis showed that egg counts had a travelling wave pattern, with synchrony showing cyclic changes with distance, a pattern not observed in remotely sensed data with 30-m and 10-m resolution. Spatially, using generalized additive models, we found that eggs were more abundant at locations with higher temperatures and where EVI was leptokurtic during the study period. Our results suggest that, in Puntarenas, remotely sensed environmental variables are associated with both Ae. aegypti-borne arbovirus transmission and Ae. aegypti egg counts from ovitraps. We sampled Ae. aegypti eggs using ovitraps for 80 weeks in Puntarenas, Costa Rica. We were able to correlate Ae. aegypti egg-counts and arboviral cases with remotely sensed data. Egg counts and arboviral cases were correlated with temperature and vegetation indices. Arboviral cases were not associated with egg counts.
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74
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Balingit JC, Carvajal TM, Saito-Obata M, Gamboa M, Nicolasora AD, Sy AK, Oshitani H, Watanabe K. Surveillance of dengue virus in individual Aedes aegypti mosquitoes collected concurrently with suspected human cases in Tarlac City, Philippines. Parasit Vectors 2020; 13:594. [PMID: 33239063 PMCID: PMC7687837 DOI: 10.1186/s13071-020-04470-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 11/05/2020] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Vector control measures are critical for the prevention and reduction of dengue virus (DENV) transmission. Effective vector control is reliant not only on knowledge of mosquito abundance, but also on the timely and accurate detection of mosquito-borne infection. Mosquito-based virus surveillance programs typically rely on pool-based mosquito testing, although whether individual-based mosquito testing is a feasible alternative to this has not been widely studied. Applying an individual-based mosquito testing approach, we conducted a 1-month surveillance study of DENV in adult Aedes aegypti mosquitoes in homes of suspected dengue patients during the 2015 peak dengue season in Tarlac City, Philippines to more accurately assess the mosquito infection rate and identify the DENV serotypes and genotypes concurrently co-circulating in mosquitoes and patients there. METHODS We performed a one-step multiplex real-time reverse transcription-polymerase chain reaction (RT-PCR) assay for the simultaneous detection and serotyping of DENV in patients and individual female Ae. aegypti mosquitoes. Additionally, we performed sequencing and phylogenetic analyses to further characterize the detected DENV serotypes in mosquitoes and patients at the genotype level. RESULTS We collected a total of 583 adult Ae. aegypti mosquitoes, of which we individually tested 359 female mosquitoes for the presence of DENV. Ten (2.8%) of the 359 female mosquitoes were positive for the presence of DENV. We detected DENV-1, DENV-2, and DENV-4 in the field-collected mosquitoes, which was consistent with the serotypes concurrently found in infected patients. Sequencing and phylogenetic analyses of the detected DENV serotypes based on the partial sequence of the evelope (E) gene revealed three genotypes concurrently present in the sampled mosquitoes and patients during the study period, namely DENV-1 genotype IV, DENV-2 Cosmopolitan genotype, and DENV-4 genotype II. CONCLUSIONS We demonstrated the utility of a one-step multiplex real-time RT-PCR assay for the individual-based DENV surveillance of mosquitoes. Our findings reinforce the importance of detecting and monitoring virus activity in local mosquito populations, which are critical for dengue prevention and control.
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Affiliation(s)
- Jean Claude Balingit
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime Japan
| | - Thaddeus M. Carvajal
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime Japan
- Biological Control Research Unit, Center for Natural Science and Environmental Research, De La Salle University, Taft Avenue, Manila, Philippines
| | - Mariko Saito-Obata
- Department of Virology, Tohoku University Graduate School of Medicine, Sendai, Miyagi Japan
- Tohoku-RITM Collaborative Research Center on Emerging and Reemerging Infectious Diseases, Muntinlupa, Metro Manila Philippines
| | - Maribet Gamboa
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime Japan
| | - Amalea Dulcene Nicolasora
- Molecular Biology Laboratory, Research Institute for Tropical Medicine, Muntinlupa, Metro Manila Philippines
| | - Ava Kristy Sy
- Virology Department, Research Institute for Tropical Medicine, Muntinlupa, Metro Manila Philippines
| | - Hitoshi Oshitani
- Department of Virology, Tohoku University Graduate School of Medicine, Sendai, Miyagi Japan
| | - Kozo Watanabe
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime Japan
- Biological Control Research Unit, Center for Natural Science and Environmental Research, De La Salle University, Taft Avenue, Manila, Philippines
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75
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Leach CB, Hoeting JA, Pepin KM, Eiras AE, Hooten MB, Webb CT. Linking mosquito surveillance to dengue fever through Bayesian mechanistic modeling. PLoS Negl Trop Dis 2020; 14:e0008868. [PMID: 33226987 PMCID: PMC7721181 DOI: 10.1371/journal.pntd.0008868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 12/07/2020] [Accepted: 10/08/2020] [Indexed: 12/12/2022] Open
Abstract
Our ability to effectively prevent the transmission of the dengue virus through targeted control of its vector, Aedes aegypti, depends critically on our understanding of the link between mosquito abundance and human disease risk. Mosquito and clinical surveillance data are widely collected, but linking them requires a modeling framework that accounts for the complex non-linear mechanisms involved in transmission. Most critical are the bottleneck in transmission imposed by mosquito lifespan relative to the virus' extrinsic incubation period, and the dynamics of human immunity. We developed a differential equation model of dengue transmission and embedded it in a Bayesian hierarchical framework that allowed us to estimate latent time series of mosquito demographic rates from mosquito trap counts and dengue case reports from the city of Vitória, Brazil. We used the fitted model to explore how the timing of a pulse of adult mosquito control influences its effect on the human disease burden in the following year. We found that control was generally more effective when implemented in periods of relatively low mosquito mortality (when mosquito abundance was also generally low). In particular, control implemented in early September (week 34 of the year) produced the largest reduction in predicted human case reports over the following year. This highlights the potential long-term utility of broad, off-peak-season mosquito control in addition to existing, locally targeted within-season efforts. Further, uncertainty in the effectiveness of control interventions was driven largely by posterior variation in the average mosquito mortality rate (closely tied to total mosquito abundance) with lower mosquito mortality generating systems more vulnerable to control. Broadly, these correlations suggest that mosquito control is most effective in situations in which transmission is already limited by mosquito abundance.
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Affiliation(s)
- Clinton B. Leach
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, United States of America
- Department of Statistics, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jennifer A. Hoeting
- Department of Statistics, Colorado State University, Fort Collins, Colorado, United States of America
| | - Kim M. Pepin
- National Wildlife Research Center, United States Department of Agriculture, Wildlife Services, Fort Collins, Colorado, United States of America
| | - Alvaro E. Eiras
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Mevin B. Hooten
- Department of Statistics, Colorado State University, Fort Collins, Colorado, United States of America
- U.S. Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit, Fort Collins, Colorado, United States of America
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Colleen T. Webb
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, United States of America
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76
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Chin WCB, Bouffanais R. Spatial super-spreaders and super-susceptibles in human movement networks. Sci Rep 2020; 10:18642. [PMID: 33122721 PMCID: PMC7596054 DOI: 10.1038/s41598-020-75697-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 10/14/2020] [Indexed: 12/03/2022] Open
Abstract
As lockdowns and stay-at-home orders start to be lifted across the globe, governments are struggling to establish effective and practical guidelines to reopen their economies. In dense urban environments with people returning to work and public transportation resuming full capacity, enforcing strict social distancing measures will be extremely challenging, if not practically impossible. Governments are thus paying close attention to particular locations that may become the next cluster of disease spreading. Indeed, certain places, like some people, can be “super-spreaders”. Is a bustling train station in a central business district more or less susceptible and vulnerable as compared to teeming bus interchanges in the suburbs? Here, we propose a quantitative and systematic framework to identify spatial super-spreaders and the novel concept of super-susceptibles, i.e. respectively, places most likely to contribute to disease spread or to people contracting it. Our proposed data-analytic framework is based on the daily-aggregated ridership data of public transport in Singapore. By constructing the directed and weighted human movement networks and integrating human flow intensity with two neighborhood diversity metrics, we are able to pinpoint super-spreader and super-susceptible locations. Our results reveal that most super-spreaders are also super-susceptibles and that counterintuitively, busy peripheral bus interchanges are riskier places than crowded central train stations. Our analysis is based on data from Singapore, but can be readily adapted and extended for any other major urban center. It therefore serves as a useful framework for devising targeted and cost-effective preventive measures for urban planning and epidemiological preparedness.
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Affiliation(s)
- Wei Chien Benny Chin
- Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| | - Roland Bouffanais
- Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore.
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Lim JT, Dickens BSL, Chew LZX, Choo ELW, Koo JR, Aik J, Ng LC, Cook AR. Impact of sars-cov-2 interventions on dengue transmission. PLoS Negl Trop Dis 2020; 14:e0008719. [PMID: 33119609 PMCID: PMC7595279 DOI: 10.1371/journal.pntd.0008719] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/16/2020] [Indexed: 12/23/2022] Open
Abstract
An estimated 105 million dengue infections occur per year across 120 countries, where traditional vector control is the primary control strategy to reduce contact between mosquito vectors and people. The ongoing sars-cov-2 pandemic has resulted in dramatic reductions in human mobility due to social distancing measures; the effects on vector-borne illnesses are not known. Here we examine the pre and post differences of dengue case counts in Malaysia, Singapore and Thailand, and estimate the effects of social distancing as a treatment effect whilst adjusting for temporal confounders. We found that social distancing is expected to lead to 4.32 additional cases per 100,000 individuals in Thailand per month, which equates to 170 more cases per month in the Bangkok province (95% CI: 100-242) and 2008 cases in the country as a whole (95% CI: 1170-2846). Social distancing policy estimates for Thailand were also found to be robust to model misspecification, and variable addition and omission. Conversely, no significant impact on dengue transmission was found in Singapore or Malaysia. Across country disparities in social distancing policy effects on reported dengue cases are reasoned to be driven by differences in workplace-residence structure, with an increase in transmission risk of arboviruses from social distancing primarily through heightened exposure to vectors in elevated time spent at residences, demonstrating the need to understand the effects of location on dengue transmission risk under novel population mixing conditions such as those under social distancing policies.
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Affiliation(s)
- Jue Tao Lim
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Borame Sue Lee Dickens
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Lawrence Zheng Xiong Chew
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore, Singapore
| | - Esther Li Wen Choo
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Joel Ruihan Koo
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Joel Aik
- Environmental Health Institute, National Environmental Agency, Singapore
| | - Lee Ching Ng
- Environmental Health Institute, National Environmental Agency, Singapore
| | - Alex R. Cook
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
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78
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Zhang Y, Riera J, Ostrow K, Siddiqui S, de Silva H, Sarkar S, Fernando L, Gardner L. Modeling the relative role of human mobility, land-use and climate factors on dengue outbreak emergence in Sri Lanka. BMC Infect Dis 2020; 20:649. [PMID: 32883213 PMCID: PMC7469426 DOI: 10.1186/s12879-020-05369-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 08/25/2020] [Indexed: 12/24/2022] Open
Abstract
Background More than 80,000 dengue cases including 215 deaths were reported nationally in less than 7 months between 2016 and 2017, a fourfold increase in the number of reported cases compared to the average number over 2010–2016. The region of Negombo, located in the Western province, experienced the greatest number of dengue cases in the country and is the focus area of our study, where we aim to capture the spatial-temporal dynamics of dengue transmission. Methods We present a statistical modeling framework to evaluate the spatial-temporal dynamics of the 2016–2017 dengue outbreak in the Negombo region of Sri Lanka as a function of human mobility, land-use, and climate patterns. The analysis was conducted at a 1 km × 1 km spatial resolution and a weekly temporal resolution. Results Our results indicate human mobility to be a stronger indicator for local outbreak clusters than land-use or climate variables. The minimum daily temperature was identified as the most influential climate variable on dengue cases in the region; while among the set of land-use patterns considered, urban areas were found to be most prone to dengue outbreak, followed by areas with stagnant water and then coastal areas. The results are shown to be robust across spatial resolutions. Conclusions Our study highlights the potential value of using travel data to target vector control within a region. In addition to illustrating the relative relationship between various potential risk factors for dengue outbreaks, the results of our study can be used to inform where and when new cases of dengue are likely to occur within a region, and thus help more effectively and innovatively, plan for disease surveillance and vector control.
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Affiliation(s)
- Ying Zhang
- Department of Civil and Systems Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.,Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Jefferson Riera
- Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Kayla Ostrow
- Department of Civil and Systems Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Sauleh Siddiqui
- Department of Environmental Science, American University, Washington, DC, 20016, USA
| | - Harendra de Silva
- Department of Pediatrics, University of Colombo, Colombo, 00900, Sri Lanka
| | - Sahotra Sarkar
- Department of Philosophy, Department of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
| | - Lakkumar Fernando
- Centre for Clinical Management of Dengue and Dengue Haemorrhagic Fever, Negombo, 11500, Sri Lanka
| | - Lauren Gardner
- Department of Civil and Systems Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.
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Vyhmeister E, Provan G, Doyle B, Bourke B. Multi-cluster and environmental dependant vector born disease models. Heliyon 2020; 6:e04090. [PMID: 32939408 PMCID: PMC7479329 DOI: 10.1016/j.heliyon.2020.e04090] [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: 03/20/2020] [Revised: 04/26/2020] [Accepted: 05/26/2020] [Indexed: 12/09/2022] Open
Abstract
Vector-born disease models are extensively used for surveillance and control processes. The most simple and generally use model (SEIR-SEI model) cannot explain a variety of phenomena involved in these diseases spread and development. In order to obtain a wider insight of the vector-born disease models (and the dynamics involved in them), this work focuses into analyse the classical model, a modified versions of it, and 8 their parameters. The modified version includes host mobility, 9 environmental, re-susceptibility, and mosquito life cycle considerations. As results it is observed that there are a limiting number of parameters that play the most important roles in the dynamics (those related to mortality rates, recovery rate from infectious, and pathogen transmission probabilities). Therefore, parameters determination should focus primarily into estimate these values. Stronger effects of the environmental variables are observed and expected by using different parameters and/or the use of multiple environmental variable at the same time.
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Affiliation(s)
| | - Gregory Provan
- Insight Research Centre, University Collage Cork, Cork, Ireland
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80
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Nacher M, Douine M, Gaillet M, Flamand C, Rousset D, Rousseau C, Mahdaoui C, Carroll S, Valdes A, Passard N, Carles G, Djossou F, Demar M, Epelboin L. Simultaneous dengue and COVID-19 epidemics: Difficult days ahead? PLoS Negl Trop Dis 2020; 14:e0008426. [PMID: 32797035 PMCID: PMC7428060 DOI: 10.1371/journal.pntd.0008426] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Mathieu Nacher
- Centre d’Investigation Clinique Antilles Guyane, CIC INSERM 1424, Centre Hospitalier Andrée Rosemon, Cayenne, French Guiana
- DFR Santé, Université de Guyane, Cayenne, French Guiana
- * E-mail:
| | - Maylis Douine
- Centre d’Investigation Clinique Antilles Guyane, CIC INSERM 1424, Centre Hospitalier Andrée Rosemon, Cayenne, French Guiana
| | - Mélanie Gaillet
- Centres Délocalisés de Prévention et de Soins, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | - Claude Flamand
- Unité d’épidémiologie, Institut Pasteur de la Guyane, Cayenne, French Guiana
| | - Dominique Rousset
- Centre National de Référence Arbovirus et virus respiratoires, Institut Pasteur de la Guyane, Cayenne, French Guiana
| | - Cyril Rousseau
- Santé Publique France, CIRE Antilles Guyane, Cayenne, French Guiana
| | - Chedli Mahdaoui
- Maison de Garde, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | | | - Audrey Valdes
- Hygiène, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | | | - Gabriel Carles
- Service d’obstétrique, centre hospitalier de l’Ouest Guyanais, French Guiana
| | - Félix Djossou
- Service des Maladies Infectieuses et Tropicales, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | - Magalie Demar
- DFR Santé, Université de Guyane, Cayenne, French Guiana
- Laboratoire, Centre Hospitalier de Cayenne, Cayenne, French Guiana
- TBIP, Université de Guyane, Cayenne, French Guiana
| | - Loïc Epelboin
- Service des Maladies Infectieuses et Tropicales, Centre Hospitalier de Cayenne, Cayenne, French Guiana
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81
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Association of genotype III of dengue virus serotype 3 with disease outbreak in Eastern Sudan, 2019. Virol J 2020; 17:118. [PMID: 32731875 PMCID: PMC7392696 DOI: 10.1186/s12985-020-01389-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 07/24/2020] [Indexed: 12/15/2022] Open
Abstract
Background Dengue fever (DF) is an arthropod-borne disease caused by dengue virus (DENV). DENV is a member of the genus Flavivirus in the family Flaviviridae. Recently, DENV has been reported as an important emerging infectious viral pathogen in Sudan. Multiple outbreaks and sporadic cases of DF have been frequently reported in the eastern region of Sudan. The present study was conducted to confirm DENV outbreak in Kassala State, eastern Sudan, 2019, and to provide some information on the molecular characterization of the DENV isolate associated with the disease outbreak. Methods A hundred serum samples were collected during the outbreak from residents of Kassala State, Sudan, 2019. ELISA was used to detect DENV non structural protein NS1 (DENV-NS1) in acute phase sera sampled during the disease outbreak. RT-PCR assays were used to amplify a fragment of the capsid/pre-membrane region (CprM) of the viral polyprotein gene. The PCR products of the amplified CprM region of the viral polyprotein gene were purified and partial sequences were generated and used to confirm the specificity of DENV sequences and to identify the virus serotype. Phylogenetic tree was constructed to determine the genotype of DENV associated with the outbreak. Results Using DENV-NS1 ELISA assay, DENV infection was confirmed in 23% sampled sera. The detection of DENV RNA was made possible using group-specific RT-PCR assay. The virus was serotyped as DENV serotype 3 (DENV-3) using DENV serotype-specific RT-PCR assay. Phylogenetic analysis of the partial CprM sequences of the viral polyprotein gene indicates that the virus belonged to genotype III of DENV-3. Conclusion The scientific data presented in this investigation confirmed that genotype III of DENV-3 was associated with the disease outbreak in eastern Sudan, 2019. The study represents the first report on molecular characterization of DENV-3 in Sudan.
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82
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Muñoz ÁG, Chourio X, Rivière-Cinnamond A, Diuk-Wasser MA, Kache PA, Mordecai EA, Harrington L, Thomson MC. AeDES: a next-generation monitoring and forecasting system for environmental suitability of Aedes-borne disease transmission. Sci Rep 2020; 10:12640. [PMID: 32724218 PMCID: PMC7387552 DOI: 10.1038/s41598-020-69625-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 07/16/2020] [Indexed: 11/29/2022] Open
Abstract
Aedes-borne diseases, such as dengue and chikungunya, are responsible for more than 50 million infections worldwide every year, with an overall increase of 30-fold in the last 50 years, mainly due to city population growth, more frequent travels and ecological changes. In the United States of America, the vast majority of Aedes-borne infections are imported from endemic regions by travelers, who can become new sources of mosquito infection upon their return home if the exposed population is susceptible to the disease, and if suitable environmental conditions for the mosquitoes and the virus are present. Since the susceptibility of the human population can be determined via periodic monitoring campaigns, the environmental suitability for the presence of mosquitoes and viruses becomes one of the most important pieces of information for decision makers in the health sector. We present a next-generation monitoring and forecasting system for [Formula: see text]-borne diseases' environmental suitability (AeDES) of transmission in the conterminous United States and transboundary regions, using calibrated ento-epidemiological models, climate models and temperature observations. After analyzing the seasonal predictive skill of AeDES, we briefly consider the recent Zika epidemic, and the compound effects of the current Central American dengue outbreak happening during the SARS-CoV-2 pandemic, to illustrate how a combination of tailored deterministic and probabilistic forecasts can inform key prevention and control strategies .
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Affiliation(s)
- Á G Muñoz
- International Research Institute for Climate and Society (IRI), The Earth Institute at Columbia University, Palisades, New York, NY, 10964, USA.
| | - X Chourio
- International Research Institute for Climate and Society (IRI), The Earth Institute at Columbia University, Palisades, New York, NY, 10964, USA
| | - Ana Rivière-Cinnamond
- Pan-American Health Organization (PAHO), World Health Organization (WHO), Washington, DC, USA
| | - M A Diuk-Wasser
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, 10027, USA
| | - P A Kache
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, 10027, USA
| | - E A Mordecai
- Biology Department, Stanford University, Stanford, CA, 94305, USA
| | - L Harrington
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - M C Thomson
- International Research Institute for Climate and Society (IRI), The Earth Institute at Columbia University, Palisades, New York, NY, 10964, USA
- Wellcome Trust, London, NW1 2BE, UK
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Prevalence and control implications of bovine trypanosomes in endemic areas of northern Uganda. Trop Anim Health Prod 2020; 52:3259-3264. [PMID: 32699961 DOI: 10.1007/s11250-020-02353-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 07/13/2020] [Indexed: 10/23/2022]
Abstract
African animal trypanosomiasis (AAT), a disease complex caused by tsetse fly-transmitted Trypanosoma brucei brucei, T. congolense savannah ITS, and T. vivax, continues to inflict heavy losses to the animal industry in terms of decreased livestock production and productivity. Live bait technology and chemotherapy have been used as a control strategy in northern Uganda since 2006 with minimal success. Here, we report the results of a cross-sectional study carried out in Lango subregion, Uganda, to assess the species prevalence of bovine trypanosome in cattle using the internal transcribed spacer (ITS) of trypanosome ribosomal DNA (rDNA). Blood samples were collected from 1090 cattle by ear vein puncture and screened using a single pair of primers designed to amplify ITS ribosomal DNA (rDNA). Our results indicate an overall prevalence of 40.18% (438/1090, 95% CI 30.82-54.51). T. vivax constituted 32.66% (356/1090), T. congolense 2.39% (26/1090), T. brucei 1.28% (14/1090), T. godfreyi 0.09%(1/1090), T. brucei and T. congolense 0.36% (4/1090), T. brucei and T. vivax 1.47% (16/1090), T. vivax and T. congolense 1.65% (18/1090), T. vivax and T. simiae 0.18% (2/1090), and T. vivax and T. godfreyi 0.09% (1/1090) of infections. Over 91.7% of infections involved single species, while 9.5% were mixed infections. Over 90.2% (37/41) of the mixed infections involved T. vivax as one of the species, while 53.7% (22/41) involved T. congolense. The high prevalence of AAT and the continued presence of T. brucei raise public health concerns because of the zoonotic implications. An integrated approach that involves mass treatment of cattle, vector, and animal movement control should be adopted to reduce the risk of both AAT and HAT.
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84
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Shi B, Lin S, Tan Q, Cao J, Zhou X, Xia S, Zhou XN, Liu J. Inference and prediction of malaria transmission dynamics using time series data. Infect Dis Poverty 2020; 9:95. [PMID: 32678025 PMCID: PMC7367373 DOI: 10.1186/s40249-020-00696-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 06/11/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Disease surveillance systems are essential for effective disease intervention and control by monitoring disease prevalence as time series. To evaluate the severity of an epidemic, statistical methods are widely used to forecast the trend, seasonality, and the possible number of infections of a disease. However, most statistical methods are limited in revealing the underlying dynamics of disease transmission, which may be affected by various impact factors, such as environmental, meteorological, and physiological factors. In this study, we focus on investigating malaria transmission dynamics based on time series data. METHODS A data-driven nonlinear stochastic model is proposed to infer and predict the dynamics of malaria transmission based on the time series of prevalence data. Specifically, the dynamics of malaria transmission is modeled based on the notion of vectorial capacity (VCAP) and entomological inoculation rate (EIR). A particle Markov chain Monte Carlo (PMCMC) method is employed to estimate the model parameters. Accordingly, a one-step-ahead prediction method is proposed to project the number of future malaria infections. Finally, two case studies are carried out on the inference and prediction of Plasmodium vivax transmission in Tengchong and Longling, Yunnan province, China. RESULTS The results show that the trained data-driven stochastic model can well fit the historical time series of P. vivax prevalence data in both counties from 2007 to 2010. Moreover, with well-trained model parameters, the proposed one-step-ahead prediction method can achieve better performances than that of the seasonal autoregressive integrated moving average model with respect to predicting the number of future malaria infections. CONCLUSIONS By involving dynamically changing impact factors, the proposed data-driven model together with the PMCMC method can successfully (i) depict the dynamics of malaria transmission, and (ii) achieve accurate one-step-ahead prediction about malaria infections. Such a data-driven method has the potential to investigate malaria transmission dynamics in other malaria-endemic countries/regions.
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Affiliation(s)
- Benyun Shi
- School of Computer Science and Technology, Nanjing Tech University, Nanjing, 211800 Jiangsu China
| | - Shan Lin
- College of Information Engineering, Nanjing University of Finance & Economics, NanjingJiangsu, 210003 China
| | - Qi Tan
- Department of Computer Science, Hong Kong Baptist University, Kowloon, Hong Kong
| | - Jie Cao
- College of Information Engineering, Nanjing University of Finance & Economics, NanjingJiangsu, 210003 China
| | - Xiaohong Zhou
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, 510515 Guangdong China
| | - Shang Xia
- National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention, Shanghai, 200025 China
- Key Laboratory of Parasite and Vector Biology, National Health Commission of the People Republic of China, Shanghai, 200025 China
- Chinese Center for Tropical Disease Research, Shanghai, 200025 China
- Shanghai, 200025 China
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention, Shanghai, 200025 China
- Key Laboratory of Parasite and Vector Biology, National Health Commission of the People Republic of China, Shanghai, 200025 China
- Chinese Center for Tropical Disease Research, Shanghai, 200025 China
- Shanghai, 200025 China
| | - Jiming Liu
- Department of Computer Science, Hong Kong Baptist University, Kowloon, Hong Kong
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85
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Pollard EJM, MacLaren D, Russell TL, Burkot TR. Protecting the peri-domestic environment: the challenge for eliminating residual malaria. Sci Rep 2020; 10:7018. [PMID: 32341476 PMCID: PMC7184721 DOI: 10.1038/s41598-020-63994-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 04/07/2020] [Indexed: 11/09/2022] Open
Abstract
Malaria transmission after universal access and use of malaria preventive services is known as residual malaria transmission. The concurrent spatial-temporal distributions of people and biting mosquitoes in malaria endemic villages determines where and when residual malaria transmission occurs. Understanding human and vector population behaviors and movements is a critical first step to prevent mosquito bites to eliminate residual malaria transmission. This study identified where people in the Solomon Islands are over 24-hour periods. Participants (59%) were predominantly around the house but not in their house when most biting by Anopheles farauti, the dominant malaria vector, occurs. While 84% of people slept under a long-lasting insecticide-treated bed net (LLIN), on average only 7% were under an LLIN during the 18:00 to 21:00 h peak mosquito biting period. On average, 34% of participants spend at least one night away from their homes each fortnight. Despite high LLIN use while sleeping, most human biting by An. farauti occurs early in the evening before people go to sleep when people are in peri-domestic areas (predominantly on verandas or in kitchen areas). Novel vector control tools that protect individuals from mosquito bites between sundown and when people sleep are needed for peri-domestic areas.
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Affiliation(s)
- Edgar J M Pollard
- James Cook University, Australian Institute of Tropical Health and Medicine, Cairns, QLD 4870, Australia.
| | - David MacLaren
- James Cook University, Australian Institute of Tropical Health and Medicine, Cairns, QLD 4870, Australia
| | - Tanya L Russell
- James Cook University, Australian Institute of Tropical Health and Medicine, Cairns, QLD 4870, Australia
| | - Thomas R Burkot
- James Cook University, Australian Institute of Tropical Health and Medicine, Cairns, QLD 4870, Australia.
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Squarre D, Hayashida K, Gaithuma A, Chambaro H, Kawai N, Moonga L, Namangala B, Sugimoto C, Yamagishi J. Diversity of trypanosomes in wildlife of the Kafue ecosystem, Zambia. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2020; 12:34-41. [PMID: 32420023 PMCID: PMC7215119 DOI: 10.1016/j.ijppaw.2020.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/11/2020] [Accepted: 04/11/2020] [Indexed: 11/07/2022]
Abstract
The Kafue ecosystem is a vast conservation protected area comprising the Kafue National Park (KNP) and the Game Management Areas (GMA) that act as a buffer around the national park. The KNP has been neglected as a potential foci for rhodesiense sleeping sickness despite the widespread presence of the tsetse vector and abundant wildlife reservoirs. The aim of this study was to generate information on circulating trypanosomes and their eminent threat/risk to public health and livestock production of a steadily growing human and livestock population surrounding the park. We detected various trypanosomes circulating in different mammalian wildlife species in KNP in Zambia by applying a high throughput ITS1-polymerase chain reaction (PCR)/nanopore sequencing method in combination with serum resistant associated-PCR/Sanger sequencing method. The prevalence rates of trypanosomes in hartebeest, sable antelope, buffalo, warthog, impala and lechwe were 6.4%, 37.2%, 13.2%, 11.8%, 2.8% and 11.1%, respectively. A total of six trypanosomes species or subspecies were detected in the wildlife examined, including Trypanosoma brucei brucei, T. godfreyi, T. congolense, T. simiae and T. theileri. Importantly we detected human infective T. b. rhodesiense in buffalo and sable antelope with a prevalence of 9.4% and 12.5%, respectively. In addition, T. b. rhodesiense was found in the only vervet monkey analyzed. The study thus reaffirmed that the Kafue ecosystem is a genuine neglected and re-emerging foci for human African trypanosomiasis. This is the first assessment of the trypanosome diversity circulating in free-ranging wildlife of the KNP. Detected six African trypanosomes in wildlife species of Kafue National Park using ITS1-PCR and Nanopore sequencing method. Confirmed presence of Trypanosoma brucei rhodesiense using SRA PCR. Identified unique divergence of SRA sequence of Trypanosoma brucei rhodesiense from buffalo, sable and vervet monkey.
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Affiliation(s)
- David Squarre
- Research Center for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan.,Wildlife Veterinary Unit, Department of National Parks and Wildlife, P/Bag 1, Chilanga, Zambia.,The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, EH25 9RG, UK, United Kingdom
| | - Kyoko Hayashida
- Research Center for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Alex Gaithuma
- Research Center for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Herman Chambaro
- Research Center for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan.,Central Veterinary Research Institute, P.O Box, 33980, Chilanga, Zambia
| | - Naoko Kawai
- Research Center for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Ladslav Moonga
- Department of Paraclinical Studies, University of Zambia, P.O. Box 32379, Lusaka, 10101, Zambia
| | - Boniface Namangala
- Department of Paraclinical Studies, University of Zambia, P.O. Box 32379, Lusaka, 10101, Zambia
| | - Chihiro Sugimoto
- Research Center for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan.,Global Station for Zoonosis Control, GI-CoRE, Hokkaido University, Kita-ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Junya Yamagishi
- Research Center for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan.,Global Station for Zoonosis Control, GI-CoRE, Hokkaido University, Kita-ku, Sapporo, Hokkaido, 001-0020, Japan
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Recent transmission of dengue virus and associated risk Facors among residents of Kassala state, eastern Sudan. BMC Public Health 2020; 20:530. [PMID: 32306941 PMCID: PMC7168835 DOI: 10.1186/s12889-020-08656-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 04/05/2020] [Indexed: 12/26/2022] Open
Abstract
Background Acute arboviral infections are distributed worldwide including Sudan, and dengue fever (DENV) is not an exception. The virus activity has recently been frequently reported in Kassala State, eastern Sudan. However, an appropriate epidemiological study would be necessary to provide accurate and precise estimates of the magnitude of recent DENV transmission in this area of endemicity. Methods In the present investigation, a cross sectional study was conducted to advance beyond the current knowledge of the epidemiology of the disease in Kassala State. The prevalence of the disease was estimated and associated risk factors were determined. Sampled sera were collected and screened for recent dengue transmissionas as determined by DENV-IgM enzyme-linked immunosorbent assay (ELISA). The collection of data for risk assessment was supported by a well designed structured questionnaire. Results The prevalence of recent DENV infection was estimated to be (11.42%). Potential risk factors to DENV seropsitivity include, age (OR = 3.24, CI = 1.81–5.77,p-value = 0.001); low income (OR = 3.75, CI = 1.57–8.93, p-value = 0.027); mosquito control (OR = 4.18, CI = 2.33–7.51, p-value = 0.004); and localities. Conclusion The present study showed a high rate of circulating DENV IgM antibodies among the participants of the study (11.42%), suggesting recent transmission of DENV in Kassala State, eastern Sudan. The frequent occurrence of DENV infections necessitates the need for improved surveillance programs and prevention measures to combat this important arboviral disease in Sudan.
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Bajwala VR, John D, Rajasekar D, Eapen A, Murhekar MV. Burden of Dengue with Related Entomological and Climatic Characteristics in Surat City, Gujarat, India, 2011-2016: An Analysis of Surveillance Data. Am J Trop Med Hyg 2020; 103:142-148. [PMID: 32314687 DOI: 10.4269/ajtmh.19-0967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We estimated the incidence of laboratory-confirmed dengue patients for Surat city, India, using surveillance data from 2011 to 2016 and described the related entomological indices and climatic factors. There was a rise in incidence from 1.5 to 17.6 per 100,000 population, as the numbers of notified cases have increased because of better surveillance system. The case notification was 1.3 times higher for the public sector than the private sector. The larval indices were below the transmission level (House index, Breteau index < 1%). The median age of dengue patients was 20 years (IQR: 14-28), with a male to female ratio of 1.6:1. Five peripheral vector control units contributed to 1,013 (41.4%) confirmed cases with rising incidence in other units also. The number of dengue patients peaked during post-monsoon. Spearman's correlation of vector density with humidity (r s = 0.556), rainfall (r s = 0.644), and number of cases (r s = 0.708) suggested climate favorable for vector breeding. There is a good system of public-private coordination for dengue surveillance. However, there is a need to reassess the vector indices threshold for transmission in the city.
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Affiliation(s)
- Viral R Bajwala
- Department of Health and Hospital, Surat Municipal Corporation, Surat City, India
| | - Denny John
- ICMR-National Institute of Medical Statistics, New Delhi, India.,Campbell South Asia, New Delhi, India
| | - Daniel Rajasekar
- National Institute of Epidemiology, Indian Council of Medical Research, Chennai, India
| | - Alex Eapen
- ICMR - National Institute of Malaria Research, Chennai, India
| | - Manoj V Murhekar
- National Institute of Epidemiology, Indian Council of Medical Research, Chennai, India
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89
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Lenhart A, Morrison AC, Paz-Soldan VA, Forshey BM, Cordova-Lopez JJ, Astete H, Elder JP, Sihuincha M, Gotlieb EE, Halsey ES, Kochel TJ, Scott TW, Alexander N, McCall PJ. The impact of insecticide treated curtains on dengue virus transmission: A cluster randomized trial in Iquitos, Peru. PLoS Negl Trop Dis 2020; 14:e0008097. [PMID: 32275653 PMCID: PMC7176142 DOI: 10.1371/journal.pntd.0008097] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 04/22/2020] [Accepted: 01/28/2020] [Indexed: 11/18/2022] Open
Abstract
Dengue is one of the most important vector-borne diseases, resulting in an estimated hundreds of millions of infections annually throughout the tropics. Control of dengue is heavily dependent upon control of its primary mosquito vector, Aedes aegypti. Innovative interventions that are effective at targeting the adult stage of the mosquito are needed to increase the options for effective control. The use of insecticide-treated curtains (ITCs) has previously been shown to significantly reduce the abundance of Ae. aegypti in and around homes, but the impact of ITCs on dengue virus (DENV) transmission has not been rigorously quantified. A parallel arm cluster-randomized controlled trial was conducted in Iquitos, Peru to quantify the impact of ITCs on DENV seroconversion as measured through plaque-reduction neutralization tests. Seroconversion data showed that individuals living in the clusters that received ITCs were at greater risk to seroconverting to DENV, with an average seroconversion rate of 50.6 per 100 person-years (PY) (CI: 29.9–71.9), while those in the control arm had an average seroconversion rate of 37.4 per 100 PY (CI: 15.2–51.7). ITCs lost their insecticidal efficacy within 6 months of deployment, necessitating re-treatment with insecticide. Entomological indicators did not show statistically significant differences between ITC and non-ITC clusters. It’s unclear how the lack of protective efficacy reported here is attributable to simple failure of the intervention to protect against Ae. aegypti bites, or the presence of a faulty intervention during much of the follow-up period. The higher risk of dengue seroconversion that was detected in the ITC clusters may have arisen due to a false sense of security that inadvertently led to less routine protective behaviors on the part of households that received the ITCs. Our study provides important lessons learned for conducting cluster randomized trials for vector control interventions against Aedes-transmitted virus infections. Dengue is one of the most important mosquito-borne diseases affecting humans, resulting in an estimated hundreds of millions of infections annually throughout the tropics. To control dengue, most public health programs use a variety of methods to kill the primary mosquito vector, Aedes aegypti. Water holding containers that harbor larvae (and other immature stages) are treated or eliminated. During emergencies, large insecticide spray campaigns are deployed to kill infected adult mosquitoes. Innovative interventions that are effective at targeting adult mosquitoes in sustainable ways are needed to increase the options for control of dengue and other Aedes borne virus diseases. The use of insecticide-treated curtains (ITCs) has previously been shown to significantly reduce Ae. aegypti numbers in and around homes, but the impact of ITCs on dengue virus (DENV) transmission has not previously been quantified. Using a rigorous study design in which 10 clusters (~90 houses per cluster) were provided multiple ITCs to place in their homes was compared to 10 clusters of homes without ITCs. Assignment of which clusters received ITCs was randomized. Blood samples were obtained at 9-month intervals from residents living in all the clusters, so that people with serological evidence of a DENV infection could be identified by comparing paired samples. Seroconversion data showed that individuals living in the clusters that received ITCs were at greater risk to DENV seroconverting, with an average seroconversion rate of 50.6 per 100 person-years (PY) (CI: 29.9–71.9). Conversely, those in the control arm had an average seroconversion rate of 37.4 per 100 PY (CI: 15.2–51.7). ITCs lost their insecticidal efficacy within 6 months of deployment, necessitating re-treatment with insecticide. Ae. aegypti populations did not show statistically significant differences between ITC and non-ITC clusters. The reason for higher transmission in the ITC treated clusters could be attributable to failure of the curtains (loss of efficacy) and/or that the curtains were not sufficiently effective at protecting against mosquito bites. The higher risk of DENV seroconversion in ITC clusters may be due to a false sense of security that inadvertently led to less routine protective behaviors on the part of households that received the ITC.
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Affiliation(s)
- Audrey Lenhart
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Amy C. Morrison
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
- * E-mail:
| | - Valerie A. Paz-Soldan
- Department of Global Community Health and Behavioral Sciences, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
- Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Brett M. Forshey
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - Jhonny J. Cordova-Lopez
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Helvio Astete
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - John P. Elder
- San Diego State University, San Diego, California, United States of America
| | - Moises Sihuincha
- Director, Department of Internal Medicine, Hospital de Apoyo Iquitos, Peru
| | - Esther E. Gotlieb
- Department of Global Community Health and Behavioral Sciences, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
| | - Eric S. Halsey
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - Tadeusz J. Kochel
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - Thomas W. Scott
- Department of Entomology and Nematology, University of California, Davis, California, United States of America
| | - Neal Alexander
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Philip J. McCall
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Quintero J, Ronderos Pulido N, Logan J, Ant T, Bruce J, Carrasquilla G. Effectiveness of an intervention for Aedes aegypti control scaled-up under an inter-sectoral approach in a Colombian city hyper-endemic for dengue virus. PLoS One 2020; 15:e0230486. [PMID: 32236142 PMCID: PMC7112230 DOI: 10.1371/journal.pone.0230486] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 03/03/2020] [Indexed: 11/18/2022] Open
Abstract
Aedes aegypti transmitted arboviral diseases are of significant importance in Colombia, particularly since the 2014/2015 introduction of chikungunya and Zika in the Americas and the increasing spread of dengue. In response, the Colombian government initiated the scaling-up of a community-based intervention under inter and multi-sector partnerships in two out of four sectors in Girardot, one of the most hyper-endemic dengue cities in the country. Using a quasi-experimental research design a scaled-up community-led Aedes control intervention was assessed for its capacity to reduce dengue from January 2010 to August 2017 in Girardot, Colombia. Reported dengue cases, and associated factors were analysed from available data sets from the Colombian disease surveillance systems. We estimated the reduction in dengue cases before and after the intervention using, Propensity Score Matching and an Autoregressive Moving Average model for robustness. In addition, the differences in dengue incidence among scaling-up phases (pre-implementation vs sustainability) and between treatment groups (intervention and control areas) were modelled. Evidence was found in favour of the intervention, although to maximise impact the scaling-up of the intervention should continue until it covers the remaining sectors. It is expected that a greater impact of the intervention can be documented in the next outbreak of dengue in Girardot.
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Affiliation(s)
- Juliana Quintero
- Eje de Salud Poblacional, Fundación Santa Fe de Bogotá, Bogotá, Colombia
- Universidad Santo Tomas, Bogotá, Colombia
| | | | - James Logan
- Eje de Salud Poblacional, Fundación Santa Fe de Bogotá, Bogotá, Colombia
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Thomas Ant
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jane Bruce
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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91
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The time series seasonal patterns of dengue fever and associated weather variables in Bangkok (2003-2017). BMC Infect Dis 2020; 20:208. [PMID: 32164548 PMCID: PMC7068876 DOI: 10.1186/s12879-020-4902-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/18/2020] [Indexed: 12/21/2022] Open
Abstract
Background In Thailand, dengue fever is one of the most well-known public health problems. The objective of this study was to examine the epidemiology of dengue and determine the seasonal pattern of dengue and its associate to climate factors in Bangkok, Thailand, from 2003 to 2017. Methods The dengue cases in Bangkok were collected monthly during the study period. The time-series data were extracted into the trend, seasonal, and random components using the seasonal decomposition procedure based on loess. The Spearman correlation analysis and artificial neuron network (ANN) were used to determine the association between climate variables (humidity, temperature, and rainfall) and dengue cases in Bangkok. Results The seasonal-decomposition procedure showed that the seasonal component was weaker than the trend component for dengue cases during the study period. The Spearman correlation analysis showed that rainfall and humidity played a role in dengue transmission with correlation efficiency equal to 0.396 and 0.388, respectively. ANN showed that precipitation was the most crucial factor. The time series multivariate Poisson regression model revealed that increasing 1% of rainfall corresponded to an increase of 3.3% in the dengue cases in Bangkok. There were three models employed to forecast the dengue case, multivariate Poisson regression, ANN, and ARIMA. Each model displayed different accuracy, and multivariate Poisson regression was the most accurate approach in this study. Conclusion This work demonstrates the significance of weather in dengue transmission in Bangkok and compares the accuracy of the different mathematical approaches to predict the dengue case. A single model may insufficient to forecast precisely a dengue outbreak, and climate factor may not only indicator of dengue transmissibility.
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Teissier Y, Paul R, Aubry M, Rodo X, Dommar C, Salje H, Sakuntabhai A, Cazelles B, Cao-Lormeau VM. Long-term persistence of monotypic dengue transmission in small size isolated populations, French Polynesia, 1978-2014. PLoS Negl Trop Dis 2020; 14:e0008110. [PMID: 32142511 PMCID: PMC7080275 DOI: 10.1371/journal.pntd.0008110] [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: 10/11/2019] [Revised: 03/18/2020] [Accepted: 02/02/2020] [Indexed: 01/18/2023] Open
Abstract
Understanding the transition of epidemic to endemic dengue transmission remains a challenge in regions where serotypes co-circulate and there is extensive human mobility. French Polynesia, an isolated group of 117 islands of which 72 are inhabited, distributed among five geographically separated subdivisions, has recorded mono-serotype epidemics since 1944, with long inter-epidemic periods of circulation. Laboratory confirmed cases have been recorded since 1978, enabling exploration of dengue epidemiology under monotypic conditions in an isolated, spatially structured geographical location. A database was constructed of confirmed dengue cases, geolocated to island for a 35-year period. Statistical analyses of viral establishment, persistence and fade-out as well as synchrony among subdivisions were performed. Seven monotypic and one heterotypic dengue epidemic occurred, followed by low-level viral circulation with a recrudescent epidemic occurring on one occasion. Incidence was asynchronous among the subdivisions. Complete viral die-out occurred on several occasions with invasion of a new serotype. Competitive serotype replacement has been observed previously and seems to be characteristic of the South Pacific. Island population size had a strong impact on the establishment, persistence and fade-out of dengue cases and endemicity was estimated achievable only at a population size in excess of 175 000. Despite island remoteness and low population size, dengue cases were observed somewhere in French Polynesia almost constantly, in part due to the spatial structuration generating asynchrony among subdivisions. Long-term persistence of dengue virus in this group of island populations may be enabled by island hopping, although could equally be explained by a reservoir of sub-clinical infections on the most populated island, Tahiti. Dengue virus is the most significant arthropod-borne virus infecting man. Understanding how long dengue virus can persist in populations of varying size is key to understanding its epidemiology. This is, however, impossible to achieve in settings where dengue is endemic, because of continued human movement and is further complexified by the occurrence of several co-circulating serotypes. By contrast, French Polynesia, an isolated group of 72 inhabited islands in the South Pacific, has had intermittent majoritarily monotypic dengue epidemics since the 1940s and offers a unique opportunity to address questions of viral persistence, turnover and the importance of spatial sub-structure in determining dengue epidemiology. Collating and analyzing a database of laboratory-confirmed dengue cases from across French Polynesia over a 35 year period we were able to show that dengue virus die-out can occur with or without replacement by a new serotype, monotypic transmission of dengue viruses fails to be maintained within small island populations but can persist for years among isolated islands connected via air and sea links. This remarkable long-term persistence of dengue virus in French Polynesia could be maintained by asynchronous viral transmission among connected islands and/or by repeated seeding from a reservoir of sub-clinical infections in the most populated island, Tahiti.
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Affiliation(s)
- Yoann Teissier
- Laboratoire de recherche sur les maladies infectieuses à transmission vectorielle, Institut Louis Malardé, Papeete, Tahiti, French Polynesia
- Université Paris Descartes, PSL University, Paris, France
| | - Richard Paul
- Institut Pasteur, Unité de Génétique Fonctionnelle des Maladies Infectieuses, UMR 2000 CNRS, Paris, France
- Pasteur Kyoto International Joint Research Unit for Integrative Vaccinomics, Kyoto, Japan
- * E-mail: (RP); (VMCL)
| | - Maite Aubry
- Laboratoire de recherche sur les maladies infectieuses à transmission vectorielle, Institut Louis Malardé, Papeete, Tahiti, French Polynesia
| | - Xavier Rodo
- ICREA, Barcelona, Spain
- CLIMA (Climate and Health) Program, ISGlobal, Barcelona, Spain
| | - Carlos Dommar
- CLIMA (Climate and Health) Program, ISGlobal, Barcelona, Spain
| | - Henrik Salje
- Institut Pasteur, Mathematical Modelling of Infectious Diseases Unit, UMR 2000, Centre National de la Recherche Scientifique, Paris, France
| | - Anavaj Sakuntabhai
- Institut Pasteur, Unité de Génétique Fonctionnelle des Maladies Infectieuses, UMR 2000 CNRS, Paris, France
- Pasteur Kyoto International Joint Research Unit for Integrative Vaccinomics, Kyoto, Japan
| | - Bernard Cazelles
- International Center for Mathematical and Computational Modeling of Complex Systems (UMMISCO), UMI 209, Sorbonne Université - IRD, Bondy cedex, France
- iGLOBE, UMI CNRS 3157, University of Arizona, Tucson, Arizona, United States of America
- IBENS, UMR 8197 CNRS-ENS Ecole Normale Supérieure, Paris, France
| | - Van-Mai Cao-Lormeau
- Laboratoire de recherche sur les maladies infectieuses à transmission vectorielle, Institut Louis Malardé, Papeete, Tahiti, French Polynesia
- * E-mail: (RP); (VMCL)
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93
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Swei A, Couper LI, Coffey LL, Kapan D, Bennett S. Patterns, Drivers, and Challenges of Vector-Borne Disease Emergence. Vector Borne Zoonotic Dis 2020; 20:159-170. [PMID: 31800374 PMCID: PMC7640753 DOI: 10.1089/vbz.2018.2432] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Vector-borne diseases are emerging at an increasing rate and comprise a disproportionate share of all emerging infectious diseases. Yet, the key ecological and evolutionary dimensions of vector-borne disease that facilitate their emergence have not been thoroughly explored. This study reviews and synthesizes the existing literature to explore global patterns of emerging vector-borne zoonotic diseases (VBZDs) under changing global conditions. We find that the vast majority of emerging VBZDs are transmitted by ticks (Ixodidae) and mosquitoes (Culicidae) and the pathogens transmitted are dominated by Rickettsiaceae bacteria and RNA viruses (Flaviviridae, Bunyaviridae, and Togaviridae). The most common potential driver of these emerging zoonoses is land use change, but for many diseases, the driver is unknown, revealing a critical research gap. While most reported VBZDs are emerging in the northern latitudes, after correcting for sampling bias, Africa is clearly a region with the greatest share of emerging VBZD. We highlight critical gaps in our understanding of VBZD emergence and emphasize the importance of interdisciplinary research and consideration of deeper evolutionary processes to improve our capacity for anticipating where and how such diseases have and will continue to emerge.
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Affiliation(s)
- Andrea Swei
- Department of Biology, San Francisco State University, San Francisco, California
| | - Lisa I. Couper
- Department of Biology, Stanford University, Palo Alto, California
| | - Lark L. Coffey
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California
| | - Durrell Kapan
- Institute for Biodiversity Science and Sustainability, California Academy of Sciences, San Francisco, California
| | - Shannon Bennett
- Institute for Biodiversity Science and Sustainability, California Academy of Sciences, San Francisco, California
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94
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Arinaitwe E, Dorsey G, Nankabirwa JI, Kigozi SP, Katureebe A, Kakande E, Rek J, Rosenthal PJ, Drakeley C, Kamya MR, Staedke SG. Association Between Recent Overnight Travel and Risk of Malaria: A Prospective Cohort Study at 3 Sites in Uganda. Clin Infect Dis 2020; 68:313-320. [PMID: 29868722 DOI: 10.1093/cid/ciy478] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 05/31/2018] [Indexed: 11/14/2022] Open
Abstract
Background Human movement can undermine malaria control efforts. However, understanding of the association between travel and malaria infection in Africa is limited. We evaluated the association between recent overnight travel and malaria incidence in Uganda. Methods All children aged 0.5-10 years and 1 adult living in 266 randomly selected households within 3 different regions of Uganda were followed up prospectively. Information on overnight travel was collected in 2015-2016. Malaria, defined as fever with parasites detected by microscopy, was measured using passive surveillance. Results At least 1 overnight trip was reported by 64 of 275 (23.3%) participants in Walukuba, 37 of 317 (11.7%) in Nagongera, and 19 of 314 (6.1%) in Kihihi. Among individuals who traveled, the incidence of malaria was higher in the first 60 days after traveling, compared with periods without recent travel at all 3 sites (overall, 1.15 vs 0.33 episodes per person-year; incidence rate ratio, 3.53; 95% confidence interval, 1.85-6.73; P < .001). Risk factors for malaria within 60 days after overnight travel included young age (19.5% in children vs 4.9% in adults; odds ratio, 5.29; 95% confidence interval, 1.34-21.0; P = .02) and not using an insecticide-treated net during travel (18.0% for no use vs 4.1% for any use; 5.10; 1.07-24.5; P = .04). Conclusions Recent overnight travel was associated with a higher incidence of malaria. Individuals who travel may represent a high-risk group that could be targeted for malaria control interventions, particularly use of insecticide-treated nets.
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Affiliation(s)
- Emmanuel Arinaitwe
- London School of Hygiene and Tropical Medicine, United Kingdom.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, University of California, San Francisco
| | | | - Simon P Kigozi
- London School of Hygiene and Tropical Medicine, United Kingdom.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Elijah Kakande
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, United Kingdom
| | - Moses R Kamya
- School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Sarah G Staedke
- London School of Hygiene and Tropical Medicine, United Kingdom
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95
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Xu Z, Bambrick H, Pongsumpun P, Ming Tang I, Yakob L, Devine G, Frentiu FD, Williams G, Hu W. Does Bangkok have a central role in the dengue dynamics of Thailand? Parasit Vectors 2020; 13:22. [PMID: 31931886 PMCID: PMC6958813 DOI: 10.1186/s13071-020-3892-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 01/07/2020] [Indexed: 01/28/2023] Open
Abstract
Background Bangkok plays a central role in the commerce of Thailand. This study aimed to characterize the district-level spatial-temporal patterns of dengue in Thailand and explore if a dengue peak in Bangkok led the peaks of dengue in other Thai provinces. Methods Monthly dengue data at district level in Thailand from January 2004 to December 2017 were obtained and used to assess the spatial and seasonal patterns of dengue in Thailand. As our seasonal decomposition and cross-correlation analyses showed that dengue in Bangkok peaked in November, which was a few months after the dengue peak in most other provinces, we used a time-series generalized linear model to explore if there was another province in which the dengue case number was most predictive of dengue case numbers in other Thai provinces. Results The highest district-level annual dengue incidence rates (per 10,000) in the three time periods (i.e. 2004–2008, 2009–2013 and 2014–2017) were 58.08 (Samphanthawong), 85.93 (Mueang Krabi), and 66.60 (Mae Sariang), respectively. Dengue incidence rates in the western part of Northern Thailand, southern part of Central Thailand, southern part of Eastern Thailand, and Southern Thailand were higher than in other regions. Dengue in most districts of Thailand peaked in June, July or August, but dengue peaks in all districts of Bangkok occurred in November. The number of dengue cases in Nakhon Ratchasima was most predictive of the number of dengue cases in other provinces in Thailand by a one-month lag. Conclusions Our results suggest that the dengue peak in Bangkok did not lead the peaks of dengue in other Thai provinces. Future research exploring how changes in socio-ecological factors (e.g. road network and climate factors) in Nakhon Ratchasima have affected the transmission of dengue in Thailand might shed some new light on the prevention and control of dengue.
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Affiliation(s)
- Zhiwei Xu
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, 4059, Australia.,Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, 4059, Australia.,School of Public Health, Faculty of Medicine, University of Queensland, Brisbane, 4006, Australia
| | - Hilary Bambrick
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, 4059, Australia.,Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, 4059, Australia
| | - Puntani Pongsumpun
- Department of Mathematics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok, 10520, Thailand
| | - I Ming Tang
- Computational & Applied Science for Smart Innovation Cluster (CLASSIC), Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand
| | - Laith Yakob
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, WC1H 9SH, UK
| | - Gregor Devine
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia
| | - Francesca D Frentiu
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, 4059, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, 4059, Australia
| | - Gail Williams
- School of Public Health, Faculty of Medicine, University of Queensland, Brisbane, 4006, Australia
| | - Wenbiao Hu
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, 4059, Australia. .,Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, 4059, Australia.
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96
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Rocklöv J, Tozan Y, Ramadona A, Sewe MO, Sudre B, Garrido J, de Saint Lary CB, Lohr W, Semenza JC. Using Big Data to Monitor the Introduction and Spread of Chikungunya, Europe, 2017. Emerg Infect Dis 2019; 25:1041-1049. [PMID: 31107221 PMCID: PMC6537727 DOI: 10.3201/eid2506.180138] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
With regard to fully harvesting the potential of big data, public health lags behind other fields. To determine this potential, we applied big data (air passenger volume from international areas with active chikungunya transmission, Twitter data, and vectorial capacity estimates of Aedes albopictus mosquitoes) to the 2017 chikungunya outbreaks in Europe to assess the risks for virus transmission, virus importation, and short-range dispersion from the outbreak foci. We found that indicators based on voluminous and velocious data can help identify virus dispersion from outbreak foci and that vector abundance and vectorial capacity estimates can provide information on local climate suitability for mosquitoborne outbreaks. In contrast, more established indicators based on Wikipedia and Google Trends search strings were less timely. We found that a combination of novel and disparate datasets can be used in real time to prevent and control emerging and reemerging infectious diseases.
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97
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Guerra CA, Citron DT, García GA, Smith DL. Characterising malaria connectivity using malaria indicator survey data. Malar J 2019; 18:440. [PMID: 31870353 PMCID: PMC6929427 DOI: 10.1186/s12936-019-3078-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 12/14/2019] [Indexed: 12/13/2022] Open
Abstract
Malaria connectivity describes the flow of parasites among transmission sources and sinks within a given landscape. Because of the spatial and temporal scales at which parasites are transported by their hosts, malaria sub-populations are largely defined by mosquito movement and malaria connectivity among them is largely driven by human movement. Characterising malaria connectivity thus requires characterising human travel between areas with differing levels of exposure to malaria. Whilst understanding malaria connectivity is fundamental for optimising interventions, particularly in areas seeking or sustaining elimination, there is a dearth of human movement data required to achieve this goal. Malaria indicator surveys (MIS) are a generally under utilised but potentially rich source of travel data that provide a unique opportunity to study simple associations between malaria infection and human travel in large population samples. This paper shares the experience working with MIS data from Bioko Island that revealed programmatically useful information regarding malaria importation through human travel. Simple additions to MIS questionnaires greatly augmented the level of detail of the travel data, which can be used to characterise human travel patterns and malaria connectivity to assist targeting interventions. It is argued that MIS potentially represent very important and timely sources of travel data that need to be further exploited.
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Affiliation(s)
- Carlos A Guerra
- Medical Care Development International, 8401 Colesville Road, Suite 425, Silver Spring, MD, 20910, USA.
| | - Daniel T Citron
- Institute for Health Metrics and Evaluation, University of Washington, 2301 Fifth Avenue, Seattle, 98121, USA
| | - Guillermo A García
- Medical Care Development International, 8401 Colesville Road, Suite 425, Silver Spring, MD, 20910, USA
| | - David L Smith
- Institute for Health Metrics and Evaluation, University of Washington, 2301 Fifth Avenue, Seattle, 98121, USA
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98
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Spatially Adjusted Time-varying Reproductive Numbers: Understanding the Geographical Expansion of Urban Dengue Outbreaks. Sci Rep 2019; 9:19172. [PMID: 31844099 PMCID: PMC6914775 DOI: 10.1038/s41598-019-55574-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 11/26/2019] [Indexed: 12/25/2022] Open
Abstract
The basic reproductive number (R0) is a fundamental measure used to quantify the transmission potential of an epidemic in public health practice. However, R0 cannot reflect the time-varying nature of an epidemic. A time-varying effective reproductive number Rt can provide more information because it tracks the subsequent evolution of transmission. However, since it neglects individual-level geographical variations in exposure risk, Rt may smooth out interpersonal heterogeneous transmission potential, obscure high-risk spreaders, and hence hamper the effectiveness of control measures in spatial dimension. Therefore, this study proposes a new method for quantifying spatially adjusted (time-varying) reproductive numbers that reflects spatial heterogeneity in transmission potential among individuals. This new method estimates individual-level effective reproductive numbers (Rj) and a summarized indicator for population-level time-varying reproductive number (Rt). Data from the five most severe dengue outbreaks in southern Taiwan from 1998-2015 were used to demonstrate the ability of the method to highlight early spreaders contributing to the geographic expansion of dengue transmission. Our results show spatial heterogeneity in the transmission potential of dengue among individuals and identify the spreaders with the highest Rj during the epidemic period. The results also reveal that super-spreaders are usually early spreaders that locate at the edges of the epidemic foci, which means that these cases could be the drivers of the expansion of the outbreak. Therefore, our proposed method depicts a more detailed spatial-temporal dengue transmission process and identifies the significant role of the edges of the epidemic foci, which could be weak spots in disease control and prevention.
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99
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Zhou S, Zhou S, Liu L, Zhang M, Kang M, Xiao J, Song T. Examining the Effect of the Environment and Commuting Flow from/to Epidemic Areas on the Spread of Dengue Fever. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16245013. [PMID: 31835451 PMCID: PMC6950619 DOI: 10.3390/ijerph16245013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 12/25/2022]
Abstract
Environment and human mobility have been considered as two important factors that drive the outbreak and transmission of dengue fever (DF). Most studies focus on the local environment while neglecting environment of the places, especially epidemic areas that people came from or traveled to. Commuting is a major form of interactions between places. Therefore, this research generates commuting flows from mobile phone tracked data. Geographically weighted Poisson regression (GWPR) and analysis of variance (ANOVA) are used to examine the effect of commuting flows, especially those from/to epidemic areas, on DF in 2014 at the Jiedao level in Guangzhou. The results suggest that (1) commuting flows from/to epidemic areas affect the transmission of DF; (2) such effects vary in space; and (3) the spatial variation of the effects can be explained by the environment of the epidemic areas that commuters commuted from/to. These findings have important policy implications for making effective intervention strategies, especially when resources are limited.
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Affiliation(s)
- Shuli Zhou
- School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China;
- Guangdong Provincial Engineering Research Center for Public Security and Disaster, Guangzhou 510275, China
| | - Suhong Zhou
- School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China;
- Guangdong Provincial Engineering Research Center for Public Security and Disaster, Guangzhou 510275, China
- Correspondence: (S.Z.); (T.S.)
| | - Lin Liu
- Center of Geo-Informatics for Public Security, School of Geographical Sciences, Guangzhou University, Guangzhou 510006, China;
- Department of Geography, University of Cincinnati, Cincinnati, OH 45221-0131, USA
| | - Meng Zhang
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; (M.Z.); (M.K.)
| | - Min Kang
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; (M.Z.); (M.K.)
| | - Jianpeng Xiao
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China;
| | - Tie Song
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; (M.Z.); (M.K.)
- Correspondence: (S.Z.); (T.S.)
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100
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Assessing the interplay between human mobility and mosquito borne diseases in urban environments. Sci Rep 2019; 9:16911. [PMID: 31729435 PMCID: PMC6858332 DOI: 10.1038/s41598-019-53127-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 10/17/2019] [Indexed: 12/21/2022] Open
Abstract
Urbanization drives the epidemiology of infectious diseases to many threats and new challenges. In this research, we study the interplay between human mobility and dengue outbreaks in the complex urban environment of the city-state of Singapore. We integrate both stylized and mobile phone data-driven mobility patterns in an agent-based transmission model in which humans and mosquitoes are represented as agents that go through the epidemic states of dengue. We monitor with numerical simulations the system-level response to the epidemic by comparing our results with the observed cases reported during the 2013 and 2014 outbreaks. Our results show that human mobility is a major factor in the spread of vector-borne diseases such as dengue even on the short scale corresponding to intra-city distances. We finally discuss the advantages and the limits of mobile phone data and potential alternatives for assessing valuable mobility patterns for modeling vector-borne diseases outbreaks in cities.
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