Respiratory Virus Activity in Durham Region

A COVID-19 death reported on the Data Tracker is a death resulting from a clinically compatible illness in a confirmed COVID-19 case. The number of deaths includes those for which COVID-19 is the underlying cause of death, COVID-19 contributed to but was not the underlying cause of death, and those with type of death listed as unknown or missing. It excludes deaths where the cause of death is unrelated to COVID-19 (e.g., trauma).

An institutional outbreak is one that occurs in a long-term care home (LTCH), retirement home (RH) or hospital. Outbreaks in congregate living settings such as group homes and shelters are not counted as institutional outbreaks.

For LTCHs and RHs, a confirmed COVID-19 outbreak is currently defined as: two or more residents with a common epidemiological link (e.g., same unit, floor, etc.), each with a positive molecular or rapid antigen test, within a 7-day period, where both cases have reasonably acquired their infection in the home.

Epidemiological link is defined as reasonable evidence of transmission between residents/staff/visitors and there is a risk of transmission of COVID-19 to residents within the home.

For hospitals, a confirmed COVID-19 outbreak is defined as two or more patients with a common epidemiological link (e.g., within a specified area/unit/floor/ward), both with positive results from a polymerase chain reaction (PCR) test OR rapid molecular test OR rapid antigen test within a 7-day period where both cases have reasonably acquired their infection in the acute care facility.

COVID-19 outbreak definitions have changed throughout the pandemic. Prior to April 8, 2021, only one case of COVID-19 occurring in a resident or staff was needed for an outbreak to be declared in a LTCH or RH.

A confirmed respiratory infection outbreak (other than COVID-19) is defined as two cases of acute respiratory infections (ARI) within 48 hours with any common epidemiological link (e.g., unit, floor), at least one of which must be laboratory-confirmed, or three cases of ARI (laboratory confirmation not necessary) occurring within 48 hours with any common epidemiological link (e.g., unit, floor).

Any outbreak where influenza was identified is reported under the appropriate influenza category (Influenza A or Influenza B) regardless of what other virus is also identified in the outbreak. Examples of respiratory infections include rhinovirus, metapneumovirus and parainfluenza virus.

Note that the definitions above are for surveillance purposes only. Public health units have the discretion to declare an outbreak when investigating suspected cases and conditions in institutions, including when the above definitions are not completely met, based on Ministry of Health COVID-19 guidance for public health units on LTCHs, RHs and on the congregate living settings on acute care settings, and on other respiratory infection outbreaks in long-term care homes.

Health statistics including infectious disease case counts, COVID-19 positive tests, hospitalizations, deaths, and institutional outbreaks from the provincial systems are dynamic and always changing. The day that the data are extracted can make a big difference because data are continually being processed.

COVID-19 wastewater data is no longer available due to the wind down of the provincial Wastewater Surveillance Initiative. We would like to thank all our partners that supported this initiative including the Ontario Ministry of the Environment, Conservation and Parks (MECP), Ontario Tech University, Toronto Metropolitan University, and the Durham Region Works Department, including the Corbett Water Pollution Control Plant (WPCP) and the Darlington WPCP. Durham Region Health Department continues to monitor respiratory virus activity using the best available data. This includes COVID-19 test positivity data to monitor COVID-19 activity in the community.