SUBMITTED BY

Epidemiology and Evaluation Department

DATE

November, 2021

SUBJECT

COVID-19 Surveillance and Epidemiology – October, 2021

BACKGROUND

Overview

The Epidemiology & Evaluation department conducts on-going population health assessment and surveillance. The data and surveillance for COVID-19 plays an integral role in understanding and managing the pandemic locally. The evidence provides information on how the pandemic has and is evolving, assessing the risk and severity, and assists in the development of timely interventions to limit further spread in the community.

Trends

In the month of October (2021), the health unit reported 808 confirmed cases of COVID-19. This is a 47.6% decrease in case counts compared to the previous month of September (2021). Similarly, the monthly case rate for October was 186.95 cases per 100,000 population, which is lower compared to the monthly rate in September (356.8 cases per 100,000 population). In Ontario, during the month of October, the case rate was 91.5 cases per 100,000 population. This is approximately 2.0 times lower compared to the rate of Windsor-Essex County.

Age and Gender

Approximately 51% (413) of the cases were among males and 49% among females. A disproportionately (28.6%) higher number of cases, in October 2021,  were reported among those 0 to 18 years of age, followed by 15.6% among those 30 to 39 years of age, and 15.3% in the 19 to 29 year age group. Comparatively, from the onset of the pandemic locally (March 1, 2020 to October 31, 2021), approximately 15% of our cases were in the 0 to 19 age group.

Municipal Distribution

The Town of Leamington had the highest case rates (403.1 cases per 100,000 population), followed by Essex (349.8 cases per 100,000 population), Tecumseh (199.5 cases per 100,000 population), and the city of Windsor (17.1 cases per 100,000 population). However, looking at the distribution of cases, 49% of cases were from the City of Windsor, 15% from Leamington, and 9% from Essex.

Risk Factors

For the month of October 2021, the top five risk factors reported were being an elementary or secondary student (19.1%), being a resident of congregate living setting (5.0%), being a health care worker (2.4%), being a farm worker (2.1%), and being an educational staff member (1.9%).

Variants of Concern (VOCs)

Of the 1,542 cases reported in the month of October, genomic sequencing results were available for 718 cases (89% of cases). Overall, 69% of cases reported were due to the Delta variant (B.1.617.2), 7% of cases reported results without a variant, and 24% were not sequenced to identify a mutation or a VOC.

Source of Acquisition

Approximately, 38% of cases in October 2021 acquired COVID-19 from their household contact, 20% from a close contact outside of their household, 5% due to being related to an outbreak, and 4% from travel-related outside of the province (e.g., to another province and/or outside of Canada).

Outcome Status

Of the 808 cases reported in October 2021, 72% (582) had their infection resolved, 194 cases (24%) were active and being followed by the health unit, and 2.6% (21) of cases were lost to follow-up. Six deaths were reported in October (2021) due to COVID-19.

Vaccination Status

21,889 doses were administered to Windsor-Essex County residents in the month of October compared to over 34,500 doses in the month of September. This represents a 36% decrease for the month of October (2021). Approximately 62% of the doses administered were second doses to complete a vaccination series, 32% were first doses to individuals who were previously unvaccinated, and 6% were among those in the highest risk priority groups (e.g., residents of long-term care and retirement homes).

Among the 808 cases reported in October 2021, 63% were unvaccinated (or not eligible to receive a vaccine), 29% were fully vaccinated, 6% were partially protected with one dose, and 2% were not yet protected after receiving the first dose. Among the 356 unvaccinated cases, approximately 58% were among those 0 to 18 years of age which includes children who were ineligible to receive the vaccine.

CURRENT INITIATIVES

The health unit will continue to monitor and provide epidemiological expertise on COVID-19 to internal leadership, community partners, and residents to support evidence-informed decision-making. This includes daily epidemiological updates, weekly epidemiological presentations to the community and supporting policy decisions through data driven approaches