Outbreaks and Increased Absenteeism in Schools

Respiratory outbreaks

A respiratory outbreak is an increase in respiratory illness among a group of people at the same time and place. Respiratory illnesses can be caused by bacteria or viruses that affect the respiratory system (e.g., nose, throat, and lungs).​​

Symptoms of a respiratory illness include fever, cough, runny nose, congestion, sneezing, sore throat, and difficulty swallowing. Other symptoms may include headache, sore muscles, fatigue, poor appetite, and irritability. COVID-19, influenza and respiratory syncytial virus (RSV) are examples of viruses that cause respiratory illness​es. Respiratory illnesses can spread:​

  • From person to person through contact with droplets of someone who has a respiratory illness. This can be spread from coughing, sneezing, and talking. ​
  • Indirectly through contact with contaminated objects/surfaces​.

Enteric illness and outbreaks

Gastrointestinal Illness

Enteric outbreaks (or gastroenteritis outbreaks) is a sudden onset of gastrointestinal illness and may occur in schools throughout the year. Gastrointestinal illness (GI) is caused by bacteria, viruses, or parasites leading to symptoms such as nausea, vomiting and diarrhea.

GI illnesses can spread:​​

  • From person-person through contact with bodily fluids​​
  • Through consumption of contaminated food/water​​
  • Indirectly through contact with contaminated object/surfaces

How to collect stool specimens

Collecting stool samples will tell us which organism or germ is making people sick. This will help ensure the right measures are put in place to stop and prevent more people from getting sick. Only ill students or staff may be asked to collect a stool sample. Kits are not for parents or other household members.  

Gastrointestinal (GI) symptoms like vomiting, diarrhea, and nausea can be symptoms of COVID-19, which continues to circulate in the community. It is highly recommended that individuals who are experiencing symptoms complete both a Rapid Antigen Test and a stool sample.   


How to Collect a Stool Sample

Step 1: Get the kit

Get a stool sample kit from the school if you have had GI symptoms within the last 48 hours.  The kit should include two sterile containers. The container with the WHITE cap is empty and will test for viruses. The container with the GREEN cap has a red liquid called transport medium and will test for bacteria. DO NOT drink the red liquid! You will put a stool sample into both containers using the individual lids of the containers that have a scoop on the inside. 

  • Check the expiration date on the sterile containers. DO NOT use expired kits. Contact the school for another kit.

Step 2: Label the sample containers and fill in the requisition form. ***This step is very important.

If the label and/or form are missing information, or is illegible, or filled out incorrectly, the lab will not test the sample.  

  1. Label the sample containers with the individual’s name, health card number (ID number on the label), and the date/time the stool sample is collected.     
  2. Complete all the required sections of the “General Test Requisition” form provided
  • Patient information section
  • Public health unit outbreak number – This number can be found on the Increased Illness Letter or by calling the school
  • Date stool sample collected
  • Date of symptom onset (the day symptoms started)

Step 3: Collect the stool sample  

Do not allow the stool to come in contact with the toilet water. If the stool touches the toilet water, it is no longer an acceptable sample. 

If blood or mucus is present in the stool, always take a sample from this part of the stool 

1. Adults and toilet trained children can defecate into a clean container (i.e. a disposable plate). TIP: Urinate first if needed. Children who are not toilet trained, the stool sample can be taken from the soiled diaper or directly from the child's training "potty."

2. Using the individual "scoop" attached to lid of each container, transfer stool into the corresponding sterile container. Fill the white cap container first.  

  • Fill to the line indicated on the container. Do not overfill.   
  • Tighten the caps. Do not use extra force to tighten the caps as the containers may crack and leak.  
  • Place the containers in the inner pocket of the plastic biohazard bag and seal the zip-lock bag.  

3. Place the General Test Requisition form in the small outer pocket of the plastic biohazard bag. DO NOT place the form in the inner pocket where the sample containers are. Place the biohazard bag into the brown paper bag and refrigerate the sample(s) immediately after collection. 

4. Stool samples should be placed on the bottom shelf of a fridge that does NOT contain food. 

  • A cooler with ice or an ice pack can be used if a separate fridge is not available.
  • DO NOT freeze the sample.

5. Perform hand hygiene. If hands are visibly soiled, use soap and water.

6. Call your school for stool sample pick-up and delivery to the Public Health Laboratory located in Ottawa. The deadline for same-day pick up is Monday to Friday before 3 pm.

  • Please ensure you provide verbal consent to the school so they may provide your name and address to OPH for stool sample pick up. 

Infection prevention and control measures during outbreaks

Infection prevention and control measures during outbreaks

Schools follow infection control measures as part of their daily operations. During an outbreak, some measures may need to be adjusted or enhanced. These may include: 

1.      Exclusion of Ill Students and/or Staff

Students and/or staff should stay at home when they have:

  • Symptoms of an enteric illness, including vomiting and/or diarrhea, and until their symptoms have been resolved for at least 48 hours
  • Symptoms of a respiratory illness, including fever, cough, sore throat, congestion, runny nose, or sneezing until they are fever-free and feeling better without the use of medication for 24 hours.

During an outbreak, staff should be watchful in monitoring students for symptoms of illness.  Students and staff are encouraged to self-screen for symptoms of illness before attending school. Students can return to school after they have completed their period of exclusion/isolation and should continue to follow public health measures when planning to resume regular activities.

2.      Cohorting of Ill Students

If possible, ill students should be kept in a separate, supervised area that can be easily cleaned and disinfected, until a parent or guardian takes them home.

3.      Cleaning and Disinfection

Routine cleaning and disinfection are essential to prevent the spread of germs. During outbreaks, you may need to take additional measures, including, but not limited to, the following:

4.      Hand Hygiene

Hand hygiene is essential for all staff and students to prevent the spread of germs. Young children should be supervised when performing hand hygiene to ensure it is done properly. Hand hygiene includes both hand washing and hand sanitizing and should be done more frequently during outbreaks.

You must ensure that:

  • Hands are washed with liquid soap and running water for at least 15 seconds if visibly soiled
  • Hands should be rubbed with 60-90% alcohol-based hand sanitizers for at least 15 seconds if not visibly soiled.

More information on how to perform hand hygiene for children and infants can be found on parentinginottawa.ca.

Printable hand hygiene resources by OPH are available below under “hand hygiene resources”.

Hand hygiene resources



IPAC Checklist for schools

This infection prevention and control (IPAC) checklist outlines the recommended safety measures to prevent the spread of illness. Some of the recommendations are for consideration and may not be applicable or appropriate for all schools. The recommendations that are from the Ministry of Education's health and safety measures for 2022-2023 are marked with an asterisk (*) and must be implemented.


IPAC Checklist for Schools 2022-2023 (PDF - 192 KB)

Environmental cleaning and disinfection in child care centres and schools

Shared items and high touch surfaces can be sources for spread of infection, especially in child care centres and schools. Such surfaces may include door knobs, taps, handrails, phones, computer keyboards, elevator buttons, countertops, as well as shared sports equipment or toys. These surfaces and items can easily become contaminated by viruses or bacteria which can spread from one person to another. Developing policies and procedures for cleaning and disinfection is important to prevent the spread of infections in your centre or school.


Cleaning is the physical action of removing debris from a surface. Cleaning with soap or detergent, and water, will remove organic material such as food, body fluids, fecal matter, or soil from surfaces. Residue from the soap or detergent must be rinsed off prior to disinfection to prevent neutralization of some disinfectants.


Disinfection must occur after cleaning. Disinfection inactivates or kills microorganisms (germs) that may be present on surfaces and that cleaning does not remove. A number of disinfectant products can be used in a child care facility on a regular basis. A different disinfectant may be required in outbreak situations. This may be discussed with your product supplier or with Ottawa Public Health as needed.

All-in-one cleaning/disinfecting products must contain a drug identification number (DIN) from Health Canada. The disinfectant contact time, which is the time that a surface must remain wet for a disinfectant to be effective, varies between products. Follow manufacturers' instructions for disinfectant contact times, dilution and handling of products, including for pre-saturated disinfectant wipes. If gloves are indicated for handling a product, ensure they are single use and discarded between tasks.

Flip-top bottles are preferred to apply cleaning solution. If using a spray bottle, saturate the cloth first then wipe the surface. Avoid the use of aerosol cans as this can propel the germs and cleaning solution into the air.

Household bleach diluted in water is an inexpensive and effective disinfectant and can be used for most surfaces. It should be prepared daily. Ensure that surfaces are cleaned with a detergent or cleaning agent before the household bleach mixture is used as a disinfectant.

Follow instructions

It might be tempting to mix cleaning products to make sure your facility is germ-free -- but don’t. Mixing some cleaners and disinfectants (like chlorine bleach and ammonia) can be harmful, even deadly. Others can irritate your eyes, nose, or throat and cause breathing problems.

The following table can be used as a reference for preparing household bleach solutions:




Contact time

100 parts per million (ppm)

To sanitize items such as combs, brushes and floors

To sanitize kitchen utensils in a commercial dishwasher

2 mL of bleach with 1 litre of water

OR ½ teaspoon (tsp) of bleach with 4 cups of water

1 minute

200 ppm

To sanitize dishes and utensils in place when they are too large to be washed in a dishwasher or submerged in a sink

To sanitize kitchen surfaces such as counter tops and cutting boards

4 mL of bleach with 1 litre of water


¾ tsp of bleach with 4 cups of water

1 minute

500 ppm

To sanitize child care surfaces, diapering stations, toys, play areas, pet cages and high touch surfaces

10 mL of bleach with 1 litre of water


2 tsp of bleach with 4 cups of water

2 minutes

1000 ppm

During the COVID-19 pandemic, to sanitize child care surfaces, diapering stations, toys, play areas, pet cages and high touch hard surfaces.

20 mL of bleach with 1 litre of water


4 tsp of bleach with 4 cups of water

1 minute

5000 ppm

To disinfect surfaces or items that have been in contact with blood or body fluids, including blood spills, vomit or fecal (stool) contamination

To sanitize surfaces or items during outbreaks of illnesses in child care or school settings

100 mL of bleach with 1 litre of water


½ cup of bleach with 4 cups of water

≥10 minutes

*Note: The contact time, also known as the wet time, is the time that the disinfectant needs to stay wet on a surface to make sure it can kill all the germs. It is the length of time you leave the solution on the surface before wiping it down.

Cleaning and disinfection checklist

Commonly touched surfaces and items should be cleaned and disinfected frequently (e.g. at least once a day) to limit the potential spread of germs. When the facility is experiencing an outbreak, cleaning and disinfection of these surfaces and items is required more often. Develop a checklist specific to your facility, using this checklist as a guide. Remember to always work from clean areas to dirty areas. If using household bleach solutions, please see the household bleach solution table as a reference on how to prepare bleach solutions for sanitizing or disinfection of specific surfaces and items .

General areas:

  • Door knobs/frames/handles/other frequently touched areas on the door
  • Locker doors/cubby holes/storage bins for children
  • Desks/tables/chairs/counter tops
  • Hand railings
  • Light switches
  • Water fountains
  • Elevator buttons
  • Shared equipment (such as toys, sports equipment and musical instruments after each use, computer keyboards and mice, etc.)
  • Telephones/faxes/photocopiers/intercoms
  • Play areas and toy storage areas
  • Floors (especially where children play on them)

Kitchen/staff room:

  • Food preparation areas and equipment
  • Counter tops
  • Fridge handles
  • Microwaves
  • Coffee pots/kettles
  • Tables/chairs

Child and staff washrooms:

  • Stall door edges and locks
  • Coat hooks
  • Sanitary napkin dispensers
  • Paper towel dispensers
  • Soap dispensers
  • Taps/faucets
  • Flush handles
  • Toilet seats
  • Toilet bowls and urinals

Important points to remember:

  • Use single use cloths or disposable paper towels to clean sinks and toilets/urinals
  • Ensure an adequate supply of paper towels and soap
  • Do not top up partially empty dispensers; once empty, containers should be cleaned, disinfected, dried, and then refilled
  • Soap/detergent must be rinsed off prior to disinfection
  • Follow instructions. It might be tempting to mix cleaning products to make sure your facility is germ-free -- but don’t. Mixing some cleaners and disinfectants (like chlorine bleach and ammonia) can be harmful, even deadly. Others can irritate your eyes, nose, or throat and cause breathing problems.

For more information, call Ottawa Public Health at 613-580-6744

Cleaning and disinfection of toys

Infants and young children share toys and often place them in their mouths. This increases the risk of spreading infections. To reduce this risk, play areas and storage spaces should be cleaned and disinfected on a regular basis. Ensure that the disinfectant is safe and suitable for use on toys. Consult the manufacturer's recommendations for dilution and contact times for these disinfectants.

Cleaning and disinfecting hard plastic toys

  • Remove toys from the play area after use and place them in a collection box for cleaning and disinfection
  • Clean and disinfect the collection box at the same time that toys are being cleaned and disinfected
  • Clean toys in hot soapy water prior to using a disinfectant
  • Use a brush to clean crevices or hard to reach areas
  • Rinse toys well under running water as soap may neutralize the disinfectant
  • Soak toys in an appropriate disinfectant for required amount of time (contact time)
  • Use a solution of 10 ml (2 tsp) sodium hypochlorite (household bleach) per 1 liter (4 cups) of water as a disinfectant. This solution requires a contact time of 2 minutes. Only mix bleach with water and never with other disinfectants or cleaners
  • In the context of the COVID-19 pandemic, it would be reasonable to instead use a mixture of 20 mL of bleach with 1 litre of water (or 4 tsp of bleach with 4 cups of water) to disinfect hard surfaces with 1 minute of contact time. It is important to remember to make a fresh bleach solution each time you disinfect, or at least everyday. *Note: The contact time, also known as the wet time, is the time that the disinfectant needs to stay wet on a surface to make sure it can kill all the germs. It is the length of time you leave the solution on the surface before wiping it down.
  • Rinse toys with clean water to remove any disinfectant solution, if indicated on the label; bleach does not require rinsing
  • Clean and disinfect dishwasher-safe, hard plastic toys in a commercial dishwasher with a sanitizer or a hot rinse cycle
  • Completely air dry toys before they are returned to use
  • Keep a record of when toys were cleaned and disinfected

Cleaning and disinfecting soft, porous toys or dress up clothes

  • Launder fabrics or plush toys in a washing machine with hot water, and dry in a clothes dryer on a hot cycle
  • Avoid using disinfectant products on porous surfaces

Cleaning other items

  • Clean and disinfect other items (e.g., scissors, puzzles, storage bins, etc.) when they are visibly dirty
  • Items such as books and some craft equipment may be difficult to clean, so consider discarding them once they are soiled
  • Avoid sensory play during an outbreak, such as activities using play dough, sand or water
  • Clean and disinfect computer keyboards, mice and other electronics between uses

Follow instructions

It might be tempting to mix cleaning products to make sure your facility is germ-free -- but don’t. Mixing some cleaners and disinfectants (like chlorine bleach and ammonia) can be harmful, even deadly. Others can irritate your eyes, nose, or throat and cause breathing problems.

For more information, call Ottawa Public Health at 613-580-6744.

Reporting outbreaks to Ottawa Public Health

Reporting outbreaks to Ottawa Public Health

When the absenteeism rate increases above what the school would typically experience and the absences are not perceived to be linked to other factors such as holidays, the school principal should notify OPH. Schools can also contact OPH for any health-related concerns or increase in absenteeism.

Report to OPH

If an increase in absenteeism is noted, notify OPH at 613-580-6744, ext 26325, Monday to Friday from 8:30 am to 4:30 pm or 3-1-1 after hours.

Chain of infection

Download PDF [429 kb]

Diagram showing the chain of infection for germs

Germs (agent)

  • Bacteria
  • Viruses
  • Parasites

Where germs live (reservoir)

  • People
  • Animals/Pets (dogs, cats, reptiles)
  • Wild animals
  • Food
  • Soil
  • Water

How germs get out (portal of exit)

  • Mouth (vomit, saliva)
  • Cuts in the skin (blood)
  • During diapering and toileting stool

Germs get around (mode of transmission)

  • Contact (hands, toys, sand)
  • Droplets (when you speak, sneeze or cough)

How germs get in (portal of entry)

  • Mouth
  • Cuts in the skin
  • Eyes

Next sick person (susceptible host)

  • Babies
  • Children
  • Elderly
  • People with a weakened immune system
  • Unimmunized people
  • Anyone

Cycle repeats

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