Modeling of SARS-CoV-2 spread in Hunan, China showed that a minority of people infected with COVID-19 transmitted most infections. More than half of infections were spread before infected people developed symptoms. The findings could help inform better policies to control the spread of COVID-19 while balancing economic impact.
A comprehensive study shows wearing masks significantly reduces the number of infections, far more than other measures such as social distancing. It shows that airborne transmission is highly virulent and dominates the spread of COVID-19. It reveals that the difference with and without masks represents the determinant in shaping the trends of the pandemic.
Link to article: https://www.pnas.org/content/early/2020/06/10/2009637117
Paper published in Science looks at how travel and quarantine influence the dynamics of the spread of COVID-19. It concludes that the travel quarantine introduced in Wuhan on 23 January 2020 only delayed epidemic progression by 3 to 5 days within China, but international travel restrictions did help to slow spread elsewhere in the world until mid-February. The results suggest that early detection, hand washing, self-isolation, and household quarantine will likely be more effective than travel restrictions at mitigating this pandemic.
Link to paper: https://science.sciencemag.org/content/368/6489/395.full
This study mapped the coronavirus epidemic curve for 25 countries and modeled how the spread of the virus has changed in response to the various lockdown measures. It classifies each country’s public health response using New Zealand’s four alert system. Levels 1 and 2 represent relatively relaxed controls, whereas levels 3 and 4 are stricter. By mapping the change in the effective reproduction number (Reff, an indicator of the actual spread of the virus in the community) against response measures, the research shows countries that implemented level 3 and 4 restrictions sooner had greater success in pushing Reff to below 1.
The new coronavirus is likely to keep spreading for at least another 18 months to two years—until 60% to 70% of the population has been infected, says a new report. The primary focus of these scenarios is on the Northern Hemisphere, but similar patterns could occur in the Global South, as well. The lack of robust healthcare infrastructure and comorbidities such as other infections, malnutrition, and chronic respiratory disease in certain areas of the Global South could result in the pandemic being even more severe in those areas, as was noted during the 1918-19 pandemic.
Link to PDF: CIDRAP report COVID-19 to spread up to 2 years
MIT has developed a model to determine the efficacy of quarantine measures and better predict the spread of the virus. The model found that in places where strong measures were implemented quickly, the quarantine effort could effectively curb the spread of the virus. In places where the quarantine efforts were rolled out slowly, the effort to slow the spread has been less effective. The model predicts when the coronavirus ‘plateau’ will take place, finding that the cases aren’t likely to start stagnating until some time between April 15 and April 20. It says that restrictions on quarantine can only be made when multiple conditions are met, including when the transmission is controlled, hospitals have capacities to meet all the needs of the public, workplaces have effective preventative measures in place, and more.