May 2022 Board of Health Meeting - COVID-19 Surveillance and Epidemiology – April, 2022 Information Report

Meeting Document Type
Information Report
COVID-19 Surveillance and Epidemiology – April, 2022


Epidemiology and Evaluation Department


May 4, 2022


COVID-19 Surveillance and Epidemiology – April, 2022



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.

Due to the recent surge in Omicron cases and changes in eligibility for testing, testing capacity is limited and case, contact, and outbreak management has been modified to focus on high-risk settings. As a result, case counts in the report are an underestimate of the true number of individuals with COVID-19 in Windsor-Essex County and may impact data completeness. Please interpret these data accordingly. Due to these changes, data from before December 31, 2021 should not be compared to data after the testing changes.


In the month of April, the health unit reported 3,131 confirmed high-risk cases of COVID-19. As the weeks progressed in April, the weekly high-risk incidence rate decreased from 187.6 cases per 100,000 population (Week 14) to 112.0 cases per 100,000 population (Week 17).  

In-Patient and ICU Admissions

In April, in-patient COVID-19 hospitalizations remained relatively stable in Windsor-Essex County although there was an increase at the beginning of the month. A total of 266 new COVID-19 related patients were admitted to local hospitals.

Percent Positivity

Locally, Windsor-Essex County continued to experience an incremental increase in percent positivity for the first three weeks in April, followed by a decrease during the last week. This is in contrast to week-to-week increase observed in March. The local percent positivity rate for COVID-19 declined to approximately 13.8% in the last week of the month. It is also important to note that these were for high-risk individuals that were eligible for testing.

Wastewater Surveillance

For the month of April, viral signal for COVID-19 in wastewater saw a significant increase for the first two weeks, followed by a decline during the last two weeks. Current levels are beginning to reach levels observed during the onset of the Omicron wave in December 2021.  


In the month of April, 40 outbreaks were declared in high-risk settings compared to the 21 outbreaks in March. This includes 21 outbreaks in long-term care and retirement homes, 9 in hospital settings, and 10 in other congregate settings. As of April 30th, there were 29 active outbreaks in the Windsor-Essex County region.


For the month of April 2022, 17 deaths were reported that were attributed to COVID-19. This is similar to the number of deaths reported in March.


With the changes in testing eligibility, and guidance with case, contact, and outbreak management, the health unit has modified its public reporting to better understand the burden of illness locally. New indicators, such as wastewater data, have been included as a proxy indicator for COVID-19 case counts, which are underestimated. 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.