Respiratory Infection Outbreaks in Institutions and Public Hospitals

Reporting Obligations

Suspected outbreaks must be reported immediately by phone to the Thunder Bay District Health Unit at 625-8318 or toll-free 1-888-294-6630, ext. 8318 (Monday-Friday, 8:30am to 4:30pm). After hours and on weekends/holidays call Thunder Bay Answering Service at (807) 624-1280.

Use the following line list documents:



Aetiologic Agent:

Outbreaks of respiratory infections in institutions are caused by a variety of respiratory viruses such as influenza A and B, respiratory syncytial virus (RSV), parain- uenza, rhinovirus, human metapneumovirus, coronaviruses and adenovirus. Bacteria that occasionally cause respiratory outbreaks in institutions are Chlamydophila pneumoniae, Legionella spp. and Mycoplasma pneumoniae (Atypical Pneumonia).

Clinical Presentation:

These viruses often cause similar acute respiratory symptoms: common cold, pharyngitis, runny nose or sneezing, congestion, sore throat, hoarseness or difficulty swallowing, dry cough, swollen or tender glands in the neck, fever/abnormal temperature, malaise, myalgia, loss of appetite, headache and chills.

Modes of transmission:

Person to person, droplet transmission as well as contact with fomites may also occur.

Incubation Period:

Varies depending on the causative agent

Period of Communicability:

Varies depending on the causative agent


Risk Factors/Susceptibility

All persons are susceptible, however susceptibility is greater in the very young and the institutionalized elderly. Residents, caregivers, and health care workers who have not received current influenza vaccination are more susceptible to influenza.


Diagnosis & Laboratory Testing

Whenever there are two cases of acute respiratory infections (ARI) within 48 hours on one unit, an outbreak should be suspected and tests should be done to determine the causative organism. Early recognition of cases signaling suspected outbreaks and swift action are essential for effective management. Timely specimen collection, communication and the implementation of appropriate control measures have the potential to make a significant impact in the course of the outbreak that will benefit both residents and staff.

An outbreak can be declared at any time by the Medical Officer of Health (or their designate), the Medical Director of the LTCH or the Director of Nursing and Personal Care of the LTCH. Laboratory confirmation of an organism is not required to declare an outbreak. There should be discussion between the Medical Officer of Health or designate and the LTCH regarding whether to declare a facility-wide outbreak or unit specific outbreak when the cases are on one unit/floor and can be confined to that unit.

Testing Information & Requisition


Treatment & Case Management

Treatment of individual cases is under the direction of the attending health care provider.. Cases are managed as part of the outbreak by staff at the facility using A Guide to the Control of Respiratory Infection Outbreaks in Long-Term Care Homes, 2018 (or as current). A case definition is the criteria that will be used throughout the outbreak to consider a resident or staff member as an outbreak-associated case.

Staff from the Thunder Bay District Health Unit will collaborate with the facility and provide guidance and support to the infection control practitioner.



1. Ministry of Health and Long Term Care, Infectious Diseases Protocol - Appendix 1 (2022) Respiratory Infection Outbreaks in Institutions and Public Hospitals.

2. MOHLTC, A Guide to the Control of Respiratory Infection Outbreaks in Long-Term Care Homes, March 2018

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