scholarly journals Backcalculating the Incidence of Infection with COVID-19 on the Diamond Princess

2020 ◽  
Vol 9 (3) ◽  
pp. 657 ◽  
Author(s):  
Hiroshi Nishiura
Keyword(s):  
Close Contact ◽  
Peak Time ◽  
Risk Of Infection ◽  
Movement Restriction ◽  
Illness Onset ◽  
Epidemic Curve ◽  
Time Period ◽  
Restriction Policy ◽  
Time Of Infection ◽  
Novel Coronavirus

To understand the time-dependent risk of infection on a cruise ship, the Diamond Princess, I estimated the incidence of infection with novel coronavirus (COVID-19). The epidemic curve of a total of 199 confirmed cases was drawn, classifying individuals into passengers with and without close contact and crew members. A backcalculation method was employed to estimate the incidence of infection. The peak time of infection was seen for the time period from 2 to 4 February 2020, and the incidence has abruptly declined afterwards. The estimated number of new infections among passengers without close contact was very small from 5 February on which a movement restriction policy was imposed. Without the intervention from 5 February, it was predicted that the cumulative incidence with and without close contact would have been as large as 1373 (95% CI: 570, 2176) and 766 (95% CI: 587, 946) cases, respectively, while these were kept to be 102 and 47 cases, respectively. Based on an analysis of illness onset data on board, the risk of infection among passengers without close contact was considered to be very limited. Movement restriction greatly reduced the number of infections from 5 February onwards.

scholarly journals Prediction of peak and termination of novel coronavirus COVID-19 epidemic in Iran

2020 ◽  
Vol 31 (11) ◽  
pp. 2050152
Author(s):  
Sepehr Rafieenasab ◽  
Amir-Pouyan Zahiri ◽  
Ehsan Roohi
Keyword(s):  
Statistical Data ◽  
Sir Model ◽  
Model Parameters ◽  
Peak Time ◽  
Infected People ◽  
Epidemic Curve ◽  
Immunization Rates ◽  
Long Time ◽  
Novel Coronavirus ◽  
Official Data

The growth and development of COVID-19 transmission have significantly attracted the attention of many societies, particularly Iran, that have been struggling with this contagious, infectious disease since late February 2020. In this study, the known “Susceptible-Infectious-Recovered (SIR)” and some other mathematical approaches were used to investigate the dynamics of the COVID-19 epidemic to provide a suitable assessment of the COVID-19 virus epidemic in Iran. The epidemic curve and SIR model parameters were obtained with the use of Iran’s official data. The recovered people were considered alongside the official number of confirmed victims as the reliable long-time statistical data. The results offer important predictions of the COVID-19 virus epidemic such as the realistic number of victims, infection rate, peak time and other characteristics. Besides, the effectiveness of infection and immunization rates to the number of infected people and epidemic end time are reported. Finally, different suggestions for decreasing victims are offered.

scholarly journals Prediction of Peak and Termination of Novel Coronavirus Covid-19 Epidemic in Iran

2020 ◽  
Author(s):  
Amir-Pouyan Zahiri ◽  
Sepehr RafieeNasab ◽  
Ehsan Roohi
Keyword(s):  
Infectious Disease ◽  
Infection Rate ◽  
Growth And Development ◽  
Statistical Data ◽  
Sir Model ◽  
Model Parameters ◽  
Peak Time ◽  
Epidemic Curve ◽  
Long Time ◽  
Novel Coronavirus

AbstractThe growth and development of Covid-19 transmission have significantly cut the attention of many societies, particularly Iran that has been struggling with this contagious, infectious disease since late February 2020. In the present study, the known SIR model was used for the dynamics of an epidemic to provide a suitable assessment of the COVID-19 virus epidemic in Iran. The epidemic curve and SIR model parameters were obtained with the use of Iran statistical data. The recovered people were considered alongside the official number of confirmed victims as the reliable long-time statistical data of Iran. The results offered many important predictions of the COVID-19 virus epidemic such as realistic number of victims, infection rate, peak time, and other characteristics.

Embedding Isolation, Contact Tracing, and Quarantine in Transmission Dynamics of the Coronavirus Epidemic—A Case Study of COVID-19 in Wuhan

2021 ◽  
Author(s):  
Miao Yu ◽  
Zhongsheng Hua
Keyword(s):  
Close Contact ◽  
Transmission Dynamics ◽  
Contact Tracing ◽  
Social Distancing ◽  
Infected People ◽  
Epidemic Curve ◽  
Specific Effects ◽  
Lag Effect ◽  
Novel Coronavirus

Coronaviruses have caused multiple global pandemics. As an emerging epidemic, the coronavirus disease relies on nonpharmacological interventions to control its spread. However, the specific effects of these interventions are unknown. To evaluate their effects, we extend the susceptible–latent–infectious–recovered model to include suspected cases, confirmed cases, and their contacts and to embed isolation, close contact tracing, and quarantine into transmission dynamics. The model simplifies the population into two parts: the undiscovered part (where the virus spreads freely—the extent of freedom is determined by the strength of social distancing policy) and the discovered part (where the cases are incompletely isolated or quarantined). Through the isolation of the index case (suspected or confirmed case) and the subsequent tracing and quarantine of its close contacts, the infections flow from the undiscovered part to the discovered part. In our case study, multisource data of the novel coronavirus SARS-CoV-2 (COVID-19) in Wuhan were collected to validate the model, the parameters were calibrated based on the prediction of the actual number of infections, and then the time-varying effective reproduction number was obtained to measure the transmissibility of COVID-19 in Wuhan, revealing the timeliness and lag effect of the nonpharmacological interventions adopted there. Finally, we simulated the situation in the absence of a strict social distancing policy. Results show that the current efforts of isolation, close contact tracing, and quarantine can take the epidemic curve to the turning point, but the epidemic could be far from over; there were still 4,035 infected people, and 1,584 latent people in the undiscovered part on March 11, 2020, when the epidemic was actually over with a strict social distancing policy.

SARS-COV2 virus and Coronavirus disease (COVID-19)

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 977-982
Author(s):  
Mohamed J. Saadh ◽  
Bashar Haj Rashid M ◽  
Roa’a Matar ◽  
Sajeda Riyad Aldibs ◽  
Hala Sbaih ◽  
...  
Keyword(s):  
Close Contact ◽  
Antiviral Agents ◽  
Health Concern ◽  
The Novel ◽  
Global Public Health ◽  
Fatal Disease ◽  
Mild Disease ◽  
Life Threatening ◽  
Novel Coronavirus

SARS-COV2 virus causes Coronavirus disease (COVID-19) and represents the causative agent of a potentially fatal disease that is of great global public health concern. The novel coronavirus (2019) was discovered in 2019 in Wuhan, the market of the wet animal, China with viral pneumonia cases and is life-threatening. Today, WHO announces COVID-19 outbreak as a pandemic. COVID-19 is likely to be zoonotic. It is transmitted from bats as intermediary animals to human. Also, the virus is transmitted from human to human who is in close contact with others. The computerized tomographic chest scan is usually abnormal even in those with no symptoms or mild disease. Treatment is nearly supportive; the role of antiviral agents is yet to be established. The SARS-COV2 virus spreads faster than its two ancestors, the SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), but has lower fatality. In this article, we aimed to summarize the transmission, symptoms, pathogenesis, diagnosis, treatment, and vaccine to control the spread of this fatal disease.

scholarly journals Visitor Restriction Policy on Pediatric Wards During Novel Coronavirus (COVID-19) Outbreak: A Survey Study Across North America

2020 ◽  
Author(s):  
Taito Kitano ◽  
Pierre-Philippe Piché-Renaud ◽  
Helen E Groves ◽  
Laurie Streitenberger ◽  
Renee Freeman ◽  
...  
Keyword(s):  
North America ◽  
Personal Protective Equipment ◽  
Survey Study ◽  
Protective Equipment ◽  
The Novel ◽  
Restriction Policy ◽  
Novel Coronavirus

Abstract Visitor restriction policies in pediatric wards during the novel coronavirus (COVID-19) outbreak are variable. Among 36 hospitals that responded to our survey, 97% allowed at least 1 visitor, with 67% restricting to 1 caregiver. Sixty-nine percent required the visitor to wear personal protective equipment and only 19% allowed non-household visitors.

scholarly journals Understanding potential implications for non-trophic parasite transmission based on vertebrate behavior at mesocarnivore carcass sites

2021 ◽  
Author(s):  
Moisés Gonzálvez ◽  
Carlos Martínez-Carrasco ◽  
Marcos Moleón
Keyword(s):  
Red Fox ◽  
Close Contact ◽  
Infection Risk ◽  
Camera Traps ◽  
Emerging Pathogens ◽  
Domestic Species ◽  
Time Period ◽  
Wild Canids ◽  
Rubbing Behavior ◽  
Trophically Transmitted Parasites

AbstractHigh infection risk is often associated with aggregations of animals around attractive resources. Here, we explore the behavior of potential hosts of non-trophically transmitted parasites at mesocarnivore carcass sites. We used videos recorded by camera traps at 56 red fox (Vulpes vulpes) carcasses and 10 carcasses of other wild carnivore species in three areas of southeastern Spain. Scavenging species, especially wild canids, mustelids and viverrids, showed more frequent rubbing behavior at carcass sites than non-scavenging and domestic species, suggesting that they could be exposed to a higher potential infection risk. The red fox was the species that most frequently contacted carcasses and marked and rubbed carcass sites. Foxes contacted heterospecific carcasses more frequently and earlier than conspecific ones and, when close contact occurred, it was more likely to be observed at heterospecific carcasses. This suggests that foxes avoid contact with the type of carcass and time period that have the greatest risk as a source of parasites. Overall, non-trophic behaviors of higher infection risk were mainly associated with visitor-carcass contact and visitor contact with feces and urine, rather than direct contact between visitors. Moreover, contact events between scavengers and carnivore carcasses were far more frequent than consumption events, which suggests that scavenger behavior is more constrained by the risk of acquiring meat-borne parasites than non-trophically transmitted parasites. This study contributes to filling key gaps in understanding the role of carrion in the landscape of disgust, which may be especially relevant in the current global context of emerging and re-emerging pathogens. Graphical abstract

scholarly journals Assessing Interventions against Coronavirus Disease 2019 (COVID-19) in Osaka, Japan: A Modeling Study

2021 ◽  
Vol 10 (6) ◽  
pp. 1256
Author(s):  
Ko Nakajo ◽  
Hiroshi Nishiura
Keyword(s):  
Model Comparison ◽  
Reproduction Number ◽  
State Of Emergency ◽  
Illness Onset ◽  
Epidemic Dynamics ◽  
Osaka Prefecture ◽  
Time Of Infection ◽  
Single Intervention ◽  
Second Wave ◽  
Combined Interventions

Estimation of the effective reproduction number, R(t), of coronavirus disease (COVID-19) in real-time is a continuing challenge. R(t) reflects the epidemic dynamics based on readily available illness onset data, and is useful for the planning and implementation of public health and social measures. In the present study, we proposed a method for computing the R(t) of COVID-19, and applied this method to the epidemic in Osaka prefecture from February to September 2020. We estimated R(t) as a function of the time of infection using the date of illness onset. The epidemic in Osaka came under control around 2 April during the first wave, and 26 July during the second wave. R(t) did not decline drastically following any single intervention. However, when multiple interventions were combined, the relative reductions in R(t) during the first and second waves were 70% and 51%, respectively. Although the second wave was brought under control without declaring a state of emergency, our model comparison indicated that relying on a single intervention would not be sufficient to reduce R(t) < 1. The outcome of the COVID-19 pandemic continues to rely on political leadership to swiftly design and implement combined interventions capable of broadly and appropriately reducing contacts.

scholarly journals Thoracic Surgery during Coronavirus Disease 2019 (COVID-19): The Experience of a Level 1 Trauma Center

2020 ◽  
Author(s):  
Jeremy Smelt ◽  
Gowthanan Santhirakumaran ◽  
Paul Vaughan ◽  
Ian Hunt ◽  
Carol Tan
Keyword(s):  
Thoracic Surgery ◽  
Trauma Center ◽  
Time Frame ◽  
World Health ◽  
Global Pandemic ◽  
Trauma Service ◽  
Time Period ◽  
Novel Coronavirus ◽  
Health Organization ◽  
Level 1 Trauma Center

Abstract Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus primarily affecting the respiratory system, was initially diagnosed in Wuhan, China, in late 2019. Identified as coronavirus disease 2019 (COVID-19) by the World Health Organization, the virus rapidly became a global pandemic. The effects on health care worldwide were unprecedented as countries adapted services to treat masses of critically ill patients.The aim of this study is to analyze the effect that the COVID-19 pandemic had on thoracic surgery at a major trauma center during peak prevalence. Methods Prospective unit data were collected for all patients who underwent thoracic surgery during March 2020 until May 2020 inclusive. Retrospective data were collected from an earlier comparable time period as a comparison. Results In the aforementioned time frame, 117 thoracic surgical operations were performed under the care of four thoracic surgeons. Six operations were performed on three patients who were being treated for SARS-CoV-2. One operation was performed on a patient who had recovered from SARS-CoV-2. There were no deaths due to SARS-CoV-2 in any patient undergoing thoracic surgery. Conclusion This study demonstrates that during the first surge of SARS-CoV-2, it was possible to adapt a thoracic oncology and trauma service without increase in mortality due to COVID-19. This was only possible due to a significant reduction in trauma referrals, cessation of benign and elective work, and the more stringent reprioritization of cancer surgery. This information is vital to learn from our experience and prepare for the predicted second surge and any similar future pandemics we might face.

Sick on the Frontlines:A Cross Sectional Study on COVID-19 Infection, Symptom Severity Amongst Emergency Medicine Residents and Fellows in Urban Academic Hospital Settings (Preprint)

2021 ◽  
Author(s):  
Stacey Frisch ◽  
Sarah Jones ◽  
James Willis ◽  
Richard Sinert
Keyword(s):  
New York ◽  
Emergency Medicine ◽  
Cross Sectional Study ◽  
The Novel ◽  
Academic Hospital ◽  
Cross Sectional ◽  
Time Period ◽  
High Infection ◽  
Novel Coronavirus ◽  
Specific Symptoms

BACKGROUND COVID-19, an illness caused by the novel coronavirus SARS-CoV-2, affected many aspects of healthcare worldwide in 2020. From March to May of 2020, New York City (NYC) experienced a large surge of cases. OBJECTIVE The authors aimed to characterize the amount of illness experienced by residents and fellows in 2 NYC hospitals during this time period. METHODS This was a cross-sectional observational study. An IRB-exempt survey was distributed to emergency medicine housestaff in May 2020 and submissions were accepted through August 2020. RESULTS 64 residents and fellows responded to our survey (a 62% response rate). 42% of responders tested positive for SARS-CoV-2 antibodies. Most residents experienced symptoms that could be consistent with COVID-19 however few received PCR testing. Fevers and/or chills along with loss of smell and/or taste were the most specific symptoms for COVID-19, with p-values <0.05. All 13 housestaff who reported no symptoms during the study period tested negative for SARS-CoV-2 antibodies. CONCLUSIONS Our study demonstrated that the rate of COVID-19 illness among emergency department housestaff is much higher than previously reported. Further studies are needed to characterize illness among medical staff in emergency departments across the nation. The high infection rate among emergency medicine trainees stresses the importance of supplying adequate PPE for healthcare professionals.

Sign in / Sign up

Export Citation Format

Share Document