Factors influencing SARS-CoV-2 transmission and outbreak control measures in densely populated settings

Abstract

Starting with a handful of SARS-CoV-2 infections in dormitory residents in late March 2020, rapid transmission in their dense living environments ensued and by October 2020, more than 50,000 acute infections were identified across various dormitories in Singapore. The aim of the study is to identify combination of factors facilitating SARS-CoV-2 transmission and the impact of control measures in a dormitory through extensive epidemiological, serological and phylogenetic investigations, supported by simulation models. Our findings showed that asymptomatic cases and symptomatic cases who did not seek medical attention were major drivers of the outbreak. Furthermore, each resident had about 30 close contacts and each infected resident spread to 4.4 (IQR 3.5–5.3) others at the start of the outbreak. The final attack rate of the current outbreak was 76.2% (IQR 70.6–98.0%) and could be reduced by further 10% under a modified dormitory housing condition. These findings are important when designing living environments in a post COVID-19 future to reduce disease spread and facilitate rapid implementation of outbreak control measures.

Clinical predictors of late SARS‐CoV‐2 positivity in Italian internal medicine wards

“…The aim of the study was then to identify whether ED length of stay may have a role as predictor of late positivity to SARS‐CoV‐2 infection independently of other clinical variables, as emerging in literature. 7 , 8 They were selected among those significantly different at descriptive analyses: contact with suspected cases, fever and dyspnoea. Alongside, the same criteria were used to identify potential biochemical biomarkers: pCO2, fibrinogen, LDH, ferritin and CRP.…”

“…Conversely, even a slightly longer stay at ED was significantly associated with late SARS-CoV-2 positivity (3 vs. 2 days, p = 0.012). Since patients with late SARS-CoV-2 positivity were immediately transferred to dedicated units, the median length of stay in internal medicine wards, not SARS-CoV-2-dedicated, was lower in this group of patients (7 days 3-13 vs. 10 days, [6][7][8][9][10][11][12][13][14][15][16][17] p < 0.001), without significant differences in the overall hospitalization time (Table S1).…”

“…Clinical and management variables were investigated, aiming at identifying potential predictors of late SARS‐CoV‐2 positivity and their impact on patient outcome. 6 , 7 Alongside, potential value of common laboratory test at hospital admission was explored.…”

“…By focussing on this critical point, we here retrospectively analyzed cases of late SARS‐CoV‐2 positivity occurring within internal medicine wards, formally not SARS‐CoV‐2‐dedicated. Clinical and management variables were investigated, aiming at identifying potential predictors of late SARS‐CoV‐2 positivity and their impact on patient outcome 6,7 . Alongside, potential value of common laboratory test at hospital admission was explored.…”

Data-driven multiscale modelling and analysis of COVID-19 spatiotemporal evolution using explainable AI

“…have shifted from broad interventions such as widespread lockdowns and closures, to risk-based and targeted strategies (e.g., contact tracing, public gathering rules, etc.) which may best tailor to the socioeconomic characteristics of a specific country ( Ministry of Health, 2020b ; Pung et al, 2021 ; Services & Department, 2021 ), hence resulting in varying government stringency indexes ( Ma et al, 2021 ) being implemented globally. At the same time, COVID-19 vaccinations have now been incorporated into humanity's defence mechanism despite the continual debate over the effectiveness of the different vaccines and their long-term impacts on human health ( Mbbs et al, 2020 ; Pilishvili et al, 2021 ; Thompson et al, 2021 ).…”