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 looks at certain genetic
variations in people that are associated with susceptibility to infection and
the diverse clinical presentation of coronavirus disease (COVID-19) – including
asymptomatic cases and severe forms of the disease in younger patients.
Link to study: https://www.medrxiv.org/content/10.1101/2020.05.01.20088054v1
New paper shows that
when exposed to the MERS Coronavirus (CoV) bat cells adapt—not by producing
inflammation-causing proteins but rather by maintaining a natural antiviral
response. Simultaneously, the MERS virus also adapts to the bat host cells by
very rapidly mutating one specific gene. Operating together, these adaptations
result in the virus remaining long-term in the bat but being rendered harmless.
Instead of killing bat cells as the virus does with human cells, the MERS
coronavirus enters a long-term relationship with the host, maintained by the
bat’s unique ‘super’ immune system. SARS-CoV-2 is thought to operate in the
same way. The work suggests that stresses on bats—such as wet markets, other
diseases, and possibly habitat loss—may have a role in coronavirus spilling
over to other species.
Link to paper: https://www.nature.com/articles/s41598-020-64264-1
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.
This article in Scientific American points out that three-quarters of the emerging pathogens that infect humans leaped from animals, many of the creatures in the forest habitats that we are slashing and burning to create land for crops, including biofuel plants, and for mining and housing. The more we clear, the more we come into contact with wildlife that carries microbes well suited to kill us—and the more we concentrate those animals in smaller areas where they can swap infectious microbes, raising the chances of novel strains.
Link to article: https://www.scientificamerican.com/article/stopping-deforestation-can-prevent-pandemics/
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