Incubation period of COVID-19: a rapid systematic review and meta-analysis of observational research

Abstract

ObjectivesThe aim of this study was to conduct a rapid systematic review and meta-analysis of estimates of the incubation period of COVID-19.DesignRapid systematic review and meta-analysis of observational research.SettingInternational studies on incubation period of COVID-19.ParticipantsSearches were carried out in PubMed, Google Scholar, Embase, Cochrane Library as well as the preprint servers MedRxiv and BioRxiv. Studies were selected for meta-analysis if they reported either the parameters and CIs of the distributions fit to the data, or sufficient information to facilitate calculation of those values. After initial eligibility screening, 24 studies were selected for initial review, nine of these were shortlisted for meta-analysis. Final estimates are from meta-analysis of eight studies.Primary outcome measuresParameters of a lognormal distribution of incubation periods.ResultsThe incubation period distribution may be modelled with a lognormal distribution with pooled mu and sigma parameters (95% CIs) of 1.63 (95% CI 1.51 to 1.75) and 0.50 (95% CI 0.46 to 0.55), respectively. The corresponding mean (95% CIs) was 5.8 (95% CI 5.0 to 6.7) days. It should be noted that uncertainty increases towards the tail of the distribution: the pooled parameter estimates (95% CIs) resulted in a median incubation period of 5.1 (95% CI 4.5 to 5.8) days, whereas the 95th percentile was 11.7 (95% CI 9.7 to 14.2) days.ConclusionsThe choice of which parameter values are adopted will depend on how the information is used, the associated risks and the perceived consequences of decisions to be taken. These recommendations will need to be revisited once further relevant information becomes available. Accordingly, we present an R Shiny app that facilitates updating these estimates as new data become available.

Quarantine and testing strategies in contact tracing for SARS-CoV-2: a modelling study

“…The timing of the peak Ct was sampled from the incubation period (time from exposure to onset of symptoms) using the pooled log-normal distribution from a published meta-analysis. 10 The peak Ct value is normally distributed with mean 22·3 and SD of 4·2 9 and the time of cessation of viral shedding, a return to baseline, is parameterised as normally distributed with mean 17 days after exposure and SD of 0·94 days for symptomatic individuals, 11 with asymptomatic individuals having a duration that is 40% shorter. 10 The peak and end times are drawn, for each individual, in such a way that each individual is at the same quantile, q, in the cumulative densities of each distribution; this guarantees that the ordering of peak and end is maintained and that there are no rapid returns to baseline Ct after a slow transition to peak Ct. We then fit a cubic Hermite spline 12 to the generated exposure, peak, and end values for each individual, constraining the slope of the curve to be zero at each of them, to simulate viral load kinetics (in Ct) over the course of infection.…”

Playing Non-Professional Football in COVID-19 Time: A Narrative Review of Recommendations, Considerations, and Best Practices

“…Immediately after confinement, players should receive medical assessments, with body temperature assessment, respiratory/cardiovascular screening, blood analysis, and PCR, which, due to approximately five days of median incubation period for COVID-19 [ 3 , 35 ], the PCR should be repeated some days after. However, independently of the reason of the isolation training period, once the team training is started, players should be continuously enrolled in those training scenarios, demanding decision-making, cognitive, and physical skills (coordinative), and dynamic ever-changing space–time interactions between teammates and opponents in relation to the ball [ 36 ].…”

Characterizing COVID-19 and Influenza Illnesses in the Real World via Person-Generated Health Data

“…Analyses focused on two different periods: an ILI-event period, conservatively defined as days −10 through +20 relative to self-reported symptom onset (day 0), and a baseline period—all other days before and after the ILI-event period. Given the sparse and often conflicting literature regarding the incubation period and illness duration for COVID-19 that was available at the time analysis was conducted, 61 , 62 , 63 , 64 the ILI-event period was intentionally wide to capture potential asymptomatic days during the incubation period of the virus (days [−10, −1]) and a potentially long recovery (days [0, 20]). Valid days were defined as those with 10 or more hours of sensor wear time or at least one main sleep period.…”