Public Health Notice: Outbreak of Salmonella infections linked to snakes and rodents

On this page

• Why you should take note
• Investigation summary
• Who is most at risk
• What you should do to protect your health
• Symptoms
• What the Government of Canada is doing
• Epidemiological information
• Additional information
• Media contact
• Public inquiries
• Investigation History

Why should you take note

The Public Health Agency of Canada collaborated with provincial public health partners to investigate an outbreak of Salmonella infections that occurred in seven provinces. The outbreak appears to be over and the investigation is winding down.

Investigation findings identified exposure to both snakes and rodents as a likely source of the outbreak. Many of the individuals who became sick reported having direct or indirect contact with snakes, pet rats and feeder rodents (used as reptile food) before their illnesses occurred. The Salmonella strain that made people sick was also found in snake habitats from the homes of ill individuals and in a rodent breeding facility.

Although this outbreak appears to be over, it is possible that people could still get sick because snakes and rodents can carry Salmonella bacteria even though they appear to be healthy and clean and show no sign of illness. Even having indirect contact by touching their environments can put you at risk for developing a Salmonella infection.

Canadians are advised to always practise good hand hygiene, frequent handwashing and safe handling of snakes and rodents, their food and their environments.

Investigation summary

In total, 106 confirmed cases of Salmonella Typhimurium illness were reported in the following provinces: British Columbia (5), Manitoba (1), Ontario (19), Quebec (61), New Brunswick (9), Nova Scotia (5) and Newfoundland and Labrador (6). Individuals became sick between April 2017 and November 2020. Seven individuals were hospitalized. No deaths were reported. Individuals who became ill were between 3 months and 88 years of age. One-third of the reported illnesses occurred in children 10 years of age and younger. The majority of cases (54%) were female.

The collaborative outbreak investigation was initiated because of an increase in reports of Salmonella Typhimurium illnesses in multiple jurisdictions across Canada. Through the use of a laboratory method called whole genome sequencing, some Salmonella Typhimurium illnesses dating back to 2017 were identified to have the same genetic strain as the illnesses that occurred in 2020. Salmonella Typhimurium with this genetic strain was also found in snake habitats from the homes of ill individuals and in a rodent breeder’s environment.In Canada, Salmonella Typhimurium is a common strain with an average of 750 cases reported per year to the Public Health Agency of Canada. There have been past outbreaks of Salmonella illnesses linked to snakes and rodents, and the findings from these investigations have highlighted the important role snake and rodent owners can play in preventing new illnesses linked to these types of pets.

Who is most at risk

Anyone can become sick with a Salmonella infection, but children aged 5 years and under, older adults, pregnant women or people with weakened immune systems are at higher risk for contracting serious illness.

Most people who become ill from a Salmonella infection will recover fully after a few days. It is possible for some people to be infected with the bacteria and to not get sick or show any symptoms, but to still be able to spread the infection to others.

What should you do to protect your health

Snakes and rodents can carry Salmonella. To prevent direct or indirect spread of Salmonella to others, follow these simple steps to help reduce your risk of becoming ill from contact with reptiles (including snakes), rodents and their environments.

• Always wash your hands immediately after touching a reptile or rodent, and anything they eat, or after being in the area where they live, play or touch.
• Regularly clean any surfaces or objects your reptile or rodent touches with soapy water followed by a household sanitizer.
• Never kiss a pet rodent or reptile.
• Do not keep reptiles or rodents in homes, daycare centres, schools or other facilities with children aged 5 years and under.
• Always supervise children when they touch or play with reptiles or rodents. Do not let them put reptiles and rodents or their supplies near their face or share their food or drinks with pets. Make sure they thoroughly wash their hands after touching reptiles or rodents.
• Do not clean or bathe reptiles and rodents in the kitchen sink or in bathroom sinks or bathtubs.
• Do not keep food used for reptiles or rodents in the kitchen or any room where people eat or drink.
• Keep reptiles and rodents and all their food, containers and toys away from the kitchen and other places where food is made or eaten.
• Do not keep frozen rodents in the same fridge or freezer as human food. Freezing rodents does not kill Salmonella.
• Always defrost and prepare frozen rodents outside the kitchen, using dedicated utensils and containers.
• Be aware of the specific needs of your reptile. Stress for a reptile can increase shedding of Salmonella.
• Always keep reptiles and live rodents in habitats specifically designed for them.
• If you choose to have a reptile or rodent in your home, talk to your health care provider or veterinarian about the right reptile or rodent for your family, especially if your family includes children, pregnant women, immunocompromised individuals, or adults 65 years of age and over.

Symptoms

Symptoms of a Salmonella infection, called salmonellosis, typically start 6 to 72 hours after exposure to Salmonella bacteria from an infected animal, person, or contaminated product.

Symptoms include:

• fever
• chills
• diarrhea
• abdominal cramps
• headache
• nausea
• vomiting

These symptoms usually last for 4 to 7 days. In healthy people, salmonellosis often clears up without treatment. In some cases, severe illness and hospitalization may occur. In some cases, antibiotics may be required. People who are infected with Salmonella bacteria can be infectious from several days to several weeks. People who experience symptoms, or who have underlying medical conditions, should contact their health care provider if they suspect they have a Salmonella infection.

What is the Government of Canada doing

The Government of Canada is committed to protecting the health of Canadians from enteric disease outbreaks. The Public Health Agency of Canada leads the human health investigation into an outbreak and is in regular contact with its federal, provincial and territorial partners to monitor the situation and to collaborate on steps to address an outbreak.

The Government of Canada will continue to update Canadians if new information related to these investigations becomes available.

Epidemiological information

Figure 1 is an epidemiological curve for this outbreak, which shows the numbers of new cases by month. Outbreak investigators use this information to show when illnesses begin, when they peak and when they trail off. It can take several weeks from the time a person becomes ill to when the illness is reported and testing confirms a link to the outbreak. Data are available for 106 cases.

Figure 1 - Text Equivalent

Table 1 – Number of people confirmed to be infected with Salmonella Typhimurium by month of illness onset or specimen collection

Month of symptom onset or specimen collection	Number of cases
April 2017	1
May 2017	5
June 2017	3
July 2017	8
August 2017	2
September 2017	5
October 2017	1
November 2017	4
December 2017	0
January 2018	7
February 2018	2
March 2018	3
April 2018	3
May 2018	1
June 2018	2
July 2018	3
August 2018	3
September 2018	0
October 2018	2
November 2018	0
December 2018	3
January 2019	3
February 2019	2
March 2019	3
April 2019	4
May 2019	4
June 2019	4
July 2019	5
August 2019	5
September 2019	2
October 2019	2
November 2019	1
December 2019	1
January 2020	0
February 2020	1
March 2020	2
April 2020	1
May 2020	2
June 2020	0
July 2020	1
August 20200	1
September 2020	1
October 2020	1
November 2020	1

Additional information

• Salmonellosis (Salmonella)
• Pets: Healthy animals, healthy people

Media contact

Public Health Agency of Canada
Media Relations
613-957-2983

Public inquiries

Call toll-free: 1-866-225-0709
Email: info@hc-sc.gc.ca

Investigation History

Public Health Notice: December 10, 2019

Why should you take note

The Public Health Agency of Canada is collaborating with provincial public health partners to investigate an outbreak of Salmonella infections occurring in six provinces. The outbreak is ongoing, as recent illnesses continue to be reported to the Public Health Agency of Canada.

Based on the investigation findings to date, exposure to both snakes and rodents has been identified as a likely source of the outbreak. Many of the individuals who became sick reported having direct or indirect contact with snakes, pet rats and feeder rodents (used as reptile food) before their illnesses occurred. The investigation is ongoing, and it is possible that other sources could be identified.

In an effort to prevent further illnesses, Canadians are advised to practise good hand hygiene, frequent handwashing and safe handling of snakes and rodents, their food and their environments.

This public health notice will be updated as the investigation evolves.

Investigation summary

As of December 10, 2019, there are 92 confirmed cases of Salmonella Typhimurium illness in the following provinces: British Columbia (4), Ontario (16), Quebec (52), New Brunswick (9), Nova Scotia (5) and Newfoundland and Labrador (6). Individuals became sick between April 2017 and October 2019. Six individuals have been hospitalized. No deaths have been reported. Individuals who became ill are between 0 and 88 years of age. The majority of cases (57%) are female.

The collaborative outbreak investigation was initiated this fall because of an increase in reports of Salmonella Typhimurium illnesses in multiple jurisdictions across Canada. Cases have continued to be reported since the investigation was initiated. Through the use of a laboratory method called whole genome sequencing, some Salmonella Typhimurium illnesses dating back to 2017 and 2018 were identified to have the same genetic strain as the illnesses that occurred in 2019.

It is possible that more recent illnesses may be reported in the outbreak because there is a period of time between when a person becomes ill and when the illness is reported to public health officials. For this outbreak, the illness reporting period is between 4 and 5 weeks.

In Canada, Salmonella Typhimurium is a common strain with an average of 750 cases reported per year to the Public Health Agency of Canada. There have been past outbreaks of Salmonella illnesses linked to snakes and rodents, and the findings from these investigations have highlighted the important role snake and rodent owners can play in preventing new illnesses linked to these types of pets.