Risk factors for SARS-CoV-2 transmission in student residences: a case-ascertained study

Abstract

Background We aimed to investigate the overall secondary attack rates (SAR) of COVID-19 in student residences and to identify risk factors for higher transmission. Methods We retrospectively analysed the SAR in living units of student residences which were screened in Leuven (Belgium) following the detection of a COVID-19 case. Students were followed up in the framework of a routine testing and tracing follow-up system. We considered residence outbreaks followed up between October 30th 2020 and May 25th 2021. We used generalized estimating equations (GEE) to evaluate the impact of delay to follow-up, shared kitchen or sanitary facilities, the presence of a known external infection source and the recent occurrence of a social gathering. We used a generalized linear mixed model (GLMM) for validation. Results We included 165 student residences, representing 200 residence units (N screened residents = 2324). Secondary transmission occurred in 68 units which corresponded to 176 secondary cases. The overall observed SAR was 8.2%. In the GEE model, shared sanitary facilities (p = 0.04) and the recent occurrence of a social gathering (p = 0.003) were associated with a significant increase in SAR in a living unit, which was estimated at 3% (95%CI 1.5-5.2) in the absence of any risk factor and 13% (95%CI 11.4-15.8) in the presence of both. The GLMM confirmed these findings. Conclusions Shared sanitary facilities and the occurrence of social gatherings increase the risk of COVID-19 transmission and should be considered when screening and implementing preventive measures.

Keeping university open did not increase the risk of SARS-CoV-2 acquisition: A test negative case-control study among students

“…Visiting discos or clubs was associated with an increased risk of SARS-CoV-2 infection, consistent with a large body of evidence on the role of parties in the youth population [5,8,12,18,20,50] and the fact that in discos or clubs the recommended controls and preventive measures are more likely to be sidelined [51]. Conversely, social activities often considered highrisk, such as frequenting restaurants, bars or pubs, did not have an impact on the risk of infection in our sample, contrary to evidence in the published literature [5,[7][8][9]12].…”

“…In this context, the identification of risk factors for the transmission of SARS-CoV-2 infection is crucial to guide health policy decisions aimed at limiting virus transmission and, at the same time, preserving the normal activities of everyday life as far as possible [2,3]. However, few analytical epidemiological studies have been conducted worldwide to investigate the risk factors for SARS-CoV-2 acquisition [4][5][6][7][8][9][10][11][12][13], particularly in healthy individuals attending community settings and areas posing unique challenges for transmission control, such as schools [14][15][16] and higher education institutions (HEIs) [17][18][19][20].…”

Unravelling the effect of winter holiday celebrations on SARS-CoV-2 transmission

“…Christmas and New Year celebrations were essentially limited to private gatherings in residential locations, although no limit was imposed on the number of attendees. Despite these measures, a surge in COVID-19 cases was detected after New Year's Eve 2022 (NYE) by our targeted test and trace program for higher education students in the city of Leuven 13 .…”