Transmissibility of coronavirus disease 2019 in Chinese cities with different dynamics of imported cases

Background Monitoring the reproduction number (Rt) of the disease could help determine whether there is sustained transmission in a population, but areas with similar epidemic trends could have different transmission dynamics given the risk from imported cases varied across regions. In this study, we examined the Rt of coronavirus disease 2019 (COVID-19) by taking different dynamics of imported cases into account and compared the transmissibility of COVID-19 at different intervention periods in Hangzhou and Shenzhen. Methods We obtained the daily aggregated counts of laboratory-confirmed imported and local cases of COVID-19 infections in Hangzhou and Shenzhen from January 1 to March 13, 2020. Daily Rt and piecewise Rt before and after Wuhan lockdown were estimated, accounting for imported cases. Results Since the epidemic of COVID-19 in Shenzhen was dominated by imported cases, Rt was around 0.1 to 0.7 before the Wuhan lockdown. After the lockdown of Wuhan and the initialization of measures in response to the outbreak, local transmission was well-controlled as indicated by a low estimated value of piecewise Rt, 0.15 (95% CI [0.09–0.21]). On the contrary, Rt obtained for Hangzhou ranged from 1.2 to 4.9 with a piecewise Rt of 2.55 (95% CI [2.13–2.97]) before the lockdown of Wuhan due to the surge in local cases. Because of the Wuhan lockdown and other outbreak response measures, Rt dropped below unity in mid-February. Conclusions Even though Shenzhen had more cases than Hangzhou, local transmission did not sustain probably due to limited transmission from imported cases owing to the reduction in local susceptibles as residents left the city during Chunyun. The lockdown measures and local outbreak responses helped reduce the local transmissibility.

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Transmissibility of coronavirus disease 2019 (COVID-19) in Chinese cities with different transmission dynamics of imported cases

10.1101/2020.03.15.20036541 ◽

2020 ◽

Author(s):

Ka Chun Chong ◽

Wei Cheng ◽

Shi Zhao ◽

Feng Ling ◽

Kirran N. Mohammad ◽

...

Keyword(s):

Reproduction Number ◽

Likelihood Function ◽

Transmission Dynamics ◽

Time Varying ◽

Outbreak Response ◽

Chinese Cities ◽

Imported Cases ◽

Response Measures ◽

Local Transmission

AbstractBackgroundMonitoring the time-varying reproduction number (Rt) of the disease is useful in determining whether there is sustained transmission in a population. In this study, we examined Rt of COVID-19 and compared its transmissibility between different intervention periods in Hangzhou and Shenzhen.MethodsDaily aggregated counts of confirmed imported and local cases between January 1, 2020 and March 13, 2020 were analysed. A likelihood function was constructed to estimate Rt, accounting for imported cases.ResultsAlthough Hangzhou had fewer number of cases than Shenzhen, Shenzhen had higher proportion of imported cases than Hangzhou (83% vs 29%). Since the epidemic of COVID-19 in Shenzhen was dominated by imported cases, Rt was kept below unity through time. On the contrary, Rt was greater than unity in Hangzhou from 16 January to 7 February due to the surge in local cases. Credits to the Wuhan lockdown and outbreak response measures following the local lockdown, Rt decreased steadily and dropped below unity in mid-February.ConclusionThe lockdown measures and local outbreak responses helped reduce the potential of local transmission in Hangzhou and Shenzhen. Meanwhile, cities with similar epidemic trend could have different transmission dynamics given the variation in imported cases.

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Tracking progress towards malaria elimination in China: estimates of reproduction numbers and their spatiotemporal variation

10.1101/628842 ◽

2019 ◽

Author(s):

Isobel Routledge ◽

Shengjie Lai ◽

Katherine E Battle ◽

Azra C Ghani ◽

Manuel Gomez-Rodriguez ◽

...

Keyword(s):

Yunnan Province ◽

Reproduction Number ◽

Individual Level ◽

Reproduction Numbers ◽

Imported Cases ◽

Geostatistical Models ◽

Sources Of Infection ◽

Spatio Temporal ◽

The Relationship ◽

Local Transmission

AbstractChina reported zero locally-acquired malaria cases in 2017 and 2018. Understanding the spatio-temporal pattern underlying this decline, especially the relationship between locally-acquired and imported cases, can inform efforts to maintain elimination and prevent re-emergence. This is particularly pertinent in Yunnan province, where the potential for local transmission is highest. Using a geo-located individual-level dataset of cases recorded in Yunnan province between 2011 and 2016, we jointly estimate the case reproduction number, Rc, and the number of unobserved sources of infection. We use these estimates within spatio-temporal geostatistical models to map how transmission varied over time and space, estimate the timeline to elimination and the risk of resurgence. Our estimates suggest that, maintaining current intervention efforts, Yunnan is unlikely to experience sustained local transmission up to 2020. However, even with a mean Rc of 0.005 projected for the year 2019, locally-acquired cases are possible due to high levels of importation.

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Scaled deployment of Wolbachia to protect the community from Aedes transmitted arboviruses

Gates Open Research ◽

10.12688/gatesopenres.12844.1 ◽

2018 ◽

Vol 2 ◽

pp. 36 ◽

Cited By ~ 16

Author(s):

Scott L. O'Neill ◽

Peter A. Ryan ◽

Andrew P. Turley ◽

Geoff Wilson ◽

Kate Retzki ◽

...

Keyword(s):

New Technologies ◽

Communicable Disease ◽

Community Support ◽

Dengue Case ◽

Queensland Health ◽

Dengue Transmission ◽

Before And After ◽

Imported Cases ◽

The City ◽

Mosquito Monitoring

Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville. Methods: The wMel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results: Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km2 in four stages over 28 months with full community support. A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion: Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km2 quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission

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Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses

Gates Open Research ◽

10.12688/gatesopenres.12844.3 ◽

2019 ◽

Vol 2 ◽

pp. 36 ◽

Cited By ~ 65

Author(s):

Scott L. O'Neill ◽

Peter A. Ryan ◽

Andrew P. Turley ◽

Geoff Wilson ◽

Kate Retzki ◽

...

Keyword(s):

New Technologies ◽

Communicable Disease ◽

Community Support ◽

Dengue Case ◽

Queensland Health ◽

Dengue Transmission ◽

Before And After ◽

Imported Cases ◽

The City ◽

Mosquito Monitoring

Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville. Methods: The wMel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results: Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km2 in four stages over 28 months with full community support. A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion: Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km2 quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission

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Accounting for imported cases in estimating the time-varying reproductive number of COVID-19

10.1101/2021.02.09.21251416 ◽

2021 ◽

Author(s):

Tim K. Tsang ◽

Peng Wu ◽

Eric H. Y. Lau ◽

Benjamin J. Cowling

Keyword(s):

Public Health ◽

Control Measures ◽

Transmission Dynamics ◽

Reproductive Number ◽

Considerable Proportion ◽

Time Varying ◽

Health Measures ◽

Imported Cases ◽

The Impact ◽

Local Transmission

ABSTRACTBackgroundEstimating the time-varying reproductive number, Rt, is critical for monitoring transmissibility of an emerging infectious disease during outbreaks. When local transmission is effectively suppressed, imported cases could substantially impact transmission dynamics.MethodsWe developed methodology to estimate separately the Rt for local cases and imported cases, since certain public health measures aim only to reduce onwards transmission from imported cases. We applied the framework to data on COVID-19 outbreaks in Hong Kong.ResultsWe estimated that the Rt for local cases decreased from above one in the early phase of outbreak to below one after tightening of public health measures. Assuming the same infectiousness of local and imported cases underestimated Rt for local cases due to control measures targeting travelers.ConclusionsWhen a considerable proportion of all cases are imported, the impact of imported cases in estimating Rt is critical. The methodology described here can allow for differential infectiousness of local imported cases.

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Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses

Gates Open Research ◽

10.12688/gatesopenres.12844.2 ◽

2018 ◽

Vol 2 ◽

pp. 36 ◽

Cited By ~ 16

Author(s):

Scott L. O'Neill ◽

Peter A. Ryan ◽

Andrew P. Turley ◽

Geoff Wilson ◽

Kate Retzki ◽

...

Keyword(s):

New Technologies ◽

Communicable Disease ◽

Community Support ◽

Dengue Case ◽

Queensland Health ◽

Dengue Transmission ◽

Before And After ◽

Imported Cases ◽

The City ◽

Mosquito Monitoring

Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville. Methods: The wMel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results: Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km2 in four stages over 28 months with full community support. A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion: Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km2 quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission

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EVALUATION OF THE EFFECTIVENESS OF NECK SHOULDER PAIN TREAMENT BY ACUPUNCTURE, MASSAGE AND TRADITIONAL MEDICINE REMEDY

Journal of Medicine and Pharmacy ◽

10.34071/jmp.2013.2.15 ◽

2013 ◽

pp. 110-117

Author(s):

Thi Tan Nguyen

Keyword(s):

Traditional Medicine ◽

Shoulder Pain ◽

Research Methodology ◽

Pain Treatment ◽

Central Hospital ◽

Treatment Results ◽

Good Account ◽

Before And After ◽

The City ◽

Pain Patients

Objectives: To assess the effectiveness neck shoulder pain treatment by acupuncture, massage and traditional medicine remedy. Materials and Methods: 42 patients included in the inpatient and outpatient at the Department of Traditional Medicine, Hue Central Hospital and Traditional Medicine Hospital of Thua Thien Hue, was diagnosed as neck shoulder pain. Patients were treated with acupuncture, massage and medicine, according to the research methodology, assessing the results before and after treatment. Results: The age accounted for the highest proportion of 31-45 (42.49%), the second is between the ages of 46-60 (26.18%) and> 60 (26.18%). Incidence in the city (66.67%) than rural (33.33%) (p <0:05). Patients presented with neck shoulder pain (100%), together with the head pain, pain in the shoulder, arm numbness, movement restrictions tilted head bowed. Conclusion: good variety and accounted for 71.42% of which are quite good account of 14.28%, only 2.38% is poor. Results of good, high aged 31-45 (35.72%) and in patients with a course of treatment (66.66%). Key words: neck shoulder pain, acupuncture, massage, traditional medicine remedy.

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Car Sharing as a Strategy to Address GHG Emissions in the Transport System: Evaluation of Effects of Car Sharing in Amsterdam

Sustainability ◽

10.3390/su13042418 ◽

2021 ◽

Vol 13 (4) ◽

pp. 2418

Author(s):

Ana María Arbeláez Vélez ◽

Andrius Plepys

Keyword(s):

Ghg Emissions ◽

Transport Systems ◽

Car Ownership ◽

Low Carbon ◽

Car Sharing ◽

Shared Mobility ◽

Before And After ◽

Business To Consumer ◽

The City ◽

Carbon Transport

Shared mobility options, such as car sharing, are often claimed to be more sustainable, although evidence at an individual or city level may contradict these claims. This study aims to improve understanding of the effects of car sharing on transport-related emissions at an individual and city level. This is done by quantifying the greenhouse gas (GHG) emissions of the travel habits of individuals before and after engaging with car sharing. The analysis uses a well-to-wheel (WTW) approach, including both business-to-consumer (B2C) and peer-to-peer (P2P) car-sharing fleets. Changes in GHG emissions after engaging in car sharing vary among individuals. Transport-related GHG emissions caused by car-free individuals tend to increase after they engage in car sharing, while emissions caused by previous car owners tend to fall. At the city level, GHG emissions savings can be achieved by using more efficient cars in sharing systems and by implementing greener mobility policies. Changes in travel habits might help to reduce GHG emissions, providing individuals migrate to low-carbon transport modes. The findings can be used to support the development and implementation of transport policies that deter car ownership and support shared mobility solutions that are integrated in city transport systems.

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Epidemiological Analysis of the 2019 Dengue Epidemic in Bhutan

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18010354 ◽

2021 ◽

Vol 18 (1) ◽

pp. 354

Author(s):

Tsheten Tsheten ◽

Angus Mclure ◽

Archie C. A. Clements ◽

Darren J. Gray ◽

Tenzin Wangdi ◽

...

Keyword(s):

Reproduction Number ◽

Monsoon Season ◽

Outbreak Response ◽

Spatial And Temporal Patterns ◽

Epidemiological Analysis ◽

Preparedness Plan ◽

Epidemic Period ◽

Timely Response ◽

National Preparedness ◽

Dengue Epidemic

Bhutan experienced its largest and first nation-wide dengue epidemic in 2019. The cases in 2019 were greater than the total number of cases in all the previous years. This study aimed to characterize the spatiotemporal patterns and effective reproduction number of this explosive epidemic. Weekly notified dengue cases were extracted from the National Early Warning, Alert, Response and Surveillance (NEWARS) database to describe the spatial and temporal patterns of the epidemic. The time-varying, temperature-adjusted cohort effective reproduction number was estimated over the course of the epidemic. The dengue epidemic occurred between 29 April and 8 December 2019 over 32 weeks, and included 5935 cases. During the epidemic, dengue expanded from six to 44 subdistricts. The effective reproduction number was <3 for most of the epidemic period, except for a ≈1 month period of explosive growth, coinciding with the monsoon season and school vacations, when the effective reproduction number peaked >30 and after which the effective reproduction number declined steadily. Interventions were only initiated 6 weeks after the end of the period of explosive growth. This finding highlights the need to reinforce the national preparedness plan for outbreak response, and to enable the early detection of cases and timely response.

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The effect of COVID19 pandemic restrictions on an urban rodent population

Scientific Reports ◽

10.1038/s41598-021-92301-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Miguel A. Bedoya-Pérez ◽

Michael P. Ward ◽

Max Loomes ◽

Iain S. McGregor ◽

Mathew S. Crowther

Keyword(s):

Binary Data ◽

Sampling Interval ◽

Resource Scarcity ◽

Health Authorities ◽

Before And After ◽

Directional Change ◽

Public Health Authorities ◽

Bait Stations ◽

Rodent Populations ◽

The City

AbstractShortly after the enactment of restrictions aimed at limiting the spread of COVID-19, various local government and public health authorities around the world reported an increased sighting of rats. Such reports have yet to be empirically validated. Here we combined data from multi-catch rodent stations (providing data on rodent captures), rodent bait stations (providing data on rodent activity) and residents’ complaints to explore the effects of a six week lockdown period on rodent populations within the City of Sydney, Australia. The sampling interval encompassed October 2019 to July 2020 with lockdown defined as the interval from April 1st to May 15th, 2020. Rodent captures and activity (visits to bait stations) were stable prior to lockdown. Captures showed a rapid increase and then decline during the lockdown, while rodent visits to bait stations declined throughout this period. There were no changes in the frequency of complaints during lockdown relative to before and after lockdown. There was a non-directional change in the geographical distribution of indices of rodent abundance suggesting that rodents redistributed in response to resource scarcity. We hypothesize that lockdown measures initially resulted in increased rodent captures due to sudden shortage of human-derived food resources. Rodent visits to bait stations might not show this pattern due to the nature of the binary data collected, namely the presence or absence of a visit. Relocation of bait stations driven by pest management goals may also have affected the detection of any directional spatial effect. We conclude that the onset of COVID-19 may have disrupted commensal rodent populations, with possible implications for the future management of these ubiquitous urban indicator species.

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