P-09 Heterogeneity of SARS-CoV-2 Transmission within Departments at a Tertiary Educational Institution, Grenada, and its implications for control
Author(s):
N Cudjoe, PJ Fields , V Matthew-Belmar , B Sharma , E Chitan , TP Noel , K Yearwood, CNL Macpherson
Year of Presentation:
2023
Objective: Non-pharmaceutical (physical distancing, masks, hand washing, ventilation, physical barriers, testing with isolation and quarantine for infected individuals and contact tracing, etc.) were coupled with a vaccination mandate to limit transmission of SARS-CoV-2. The aim to limit transmission and maintain low infection rates were important drivers of policy which aimed to limit severe outcomes of SARS-CoV-2 infection.
Methods: This retrospective longitudinal study examine transmission patterns within and between departments at a tertiary education institution in Grenada which enforced a vaccination entry requirement to a closed campus from June 2021 to date. PCR and rapid tests were freely available to all individuals who were allowed access to the campus facility. The null hypothesis assumed that the rate of infection would be the same in all departments adjusted for size. Data from all 48 departments were collected and assessed from August 2020 – December 2022.
Results: A total of 233 (10.7%) out of 2181 individuals tested positive. Adjusting for differences in the sizes of departments, six departments were found to have proportions significantly higher than expected (p < 0.001) and accounted for 40% of all positives. In contrast, four departments experienced zero positive test results, which was much lower than the 14 to 15 that would have been expected.
Conclusion: The concentration of positive cases in a few departments, whilst others experienced no cases, reflects inter and intra exposure rate differences related to human behavior and reflects departmental responsibilities. Reduction of transmission necessitates additional preventative measures for high-risk groups.