Epidemiology
· Internet search patterns reveal clinical course of COVID-19 disease progression and pandemic spread across 32 countries. Authors from the Predictive Medicine Group at Boston Children's Hospital analyzed internet search patterns in over 32 countries, revealing important epidemiological data that could be used to identify patterns of COVID-19 transmission. Internet search histories were temporally correlated with documented COVID-19 cases and deaths, revealing increased internet searches for COVID-19 symptoms an average of 18 days prior to the documented rise in COVID-19 test positivity. The data also demonstrated a "clear temporal association" between internet searches and the clinical course of disease, with progression of searches on initial symptoms occurring 5.2 days before a rise in searches for shortness of breath, and 22 days before a rise in reported COVID-19 deaths. These results highlight how real-time analysis of internet search data can be a useful tool in identifying COVID-19 transmission during the critical initial days of an outbreak; however, this approach may raise ethical debates on internet privacy and data collection.
Transmission & Prevention
· Social distancing can positively alter the clinical course of COVID-19 in young adults. Physicians from the Swiss Armed Forces assessed the spread of COVID-19 illness among three companies of soldiers at a Swiss military base (n=508); company 1 had their own barracks while companies 2 and 3 shared barracks. A soldier in company 3 developed COVID-19 on March 11, 2020. On day 35 of the outbreak, authors tested 363 asymptomatic soldiers from all 3 groups and found evidence of past or current infection in 15% (13/88) of those from company 1, 64% in company 2, and 59% in company 3. Symptomatic infections were documented in 0% of company 1, 27% of company 2, and 31 % of company 3. Authors suggest the relative lack of COVID-19 illness in company 1 compared to 2 and 3 supports the effectiveness of social distancing and hygiene measures both in preventing disease spread and mitigating disease severity.
R&D: Diagnosis & Treatments
· Can culturable SARS-CoV-2 in hospitalized patients with COVID-19 be helpful in determining illness progression? Researchers from multiple South Korean institutions describe a case series investigating viral shedding by analyzing serial respiratory cultures in 21 hospitalized patients with mild-to-moderate COVID-19. Findings include a median time from symptom onset to viral clearance of 7 days in culture (95% CI, 5-10 days) and 34 days on real-time PCR (95% CI lower boundary 24 days), with viable virus identified until 3 days after fever resolution. Viral load and cycle-threshold values below 28.4 were positively correlated, and the incidence of culture positivity decreased with greater time from onset of symptoms. These findings can be used to guide isolation periods and risk estimation of secondary transmission in COVID-19 patients, but further research with a larger and more diverse patient population can allow for better extrapolation.
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