Group A streptococcus (GAS)

""Group A streptococcus (GAS) is a bacteria that is often found in the throat and on the skin. In some cases, the presence of GAS does not cause any problems or symptoms. In other cases, it can be responsible for a broad spectrum of diseases. These diseases include simple and uncomplicated sore throats and skin infections such as strep throat and impetigo. These can also include rare cases of invasive (serious) illnesses such as necrotizing fasciitis (flesh eating disease) and toxic shock syndrome (TSS).

Image Content Provider: S. Lowry - University of Ulster

January 2024 Update

Similar to other provinces, Manitoba has seen an increase in reported cases of invasive GAS (iGAS) post-pandemic. Only invasive infections are reportable to public health.

Confirmed cases of iGAS for the period of January 1 to December 31.

Year Confirmed Cases Deaths
(% of cases with a fatal outcome)
2023 271
(18.7 cases per 100,000 population)
2022 167
(11.7 cases per 100,000 population)
2021 116
(8.3 cases per 100,000 population)
2020 152
(11.0 cases per 100,000 population)
2019 161
(11.7 cases per 100,000 population)

Data updated January 31, 2024. Data will be updated quarterly.

Note: Fluctuations in case numbers are expected as cases are investigated and information is updated.


Symptoms of GAS infections will vary based on the disease the infection causes. Symptoms can range from no symptoms at all to very severe symptoms, including death.

Strep throat: Symptoms may include a swollen red sore throat and tonsil, high fever, headache, and swollen lymph nodes in the neck.

In rare cases, strep throat can lead to rheumatic fever. Here, the infection damages the heart's valves and can cause congestive heart failure or swelling of the lining of the heart.

Scarlet fever: Infected individuals may experience a quickly spreading red rash that feels like sandpaper on the body. They may also have red swollen lips and red spots on the tongue.

Impetigo: Symptoms may include a red skin rash that looks like a group of small blisters or red bumps. When the blisters burst and fluid seeps out, the fluid dries and the blisters become coated with a yellow or grey crust.

Toxic shock syndrome: Streptococcal TSS results in a rapid drop in blood pressure and organ failure. Symptoms may include fever, redness of the skin, dizziness, influenza-like symptoms, confusion, shock, diarrhoea, vomiting and severe muscle pain.

Streptococcal TSS is not the same as the "toxic shock syndrome" due to the bacteria Staphylococcus aureus associated with tampon usage.

Necrotizing Fasciitis (sometimes called "the flesh-eating bacteria"): This destroys muscles, fat, and skin tissue. Symptoms may include fever and intense pain, redness and swelling in the affected area. Often the pain is disproportionate to (much worse than) the appearance of the infection.


GAS is normally spread through close person-to-person contact. This includes kissing and sharing of personal items such as drinking cups, forks, spoons and cigarettes.

People with strep throat or a skin infection are more likely to spread the bacteria. Those who have no symptoms are less contagious.

Although rare, invasive illnesses caused by GAS occur when the germs get into parts of the body where germs are usually not found. These include blood, muscle or lungs.


Treatment will vary based on the disease a person has. Some diseases, such as strep throat, can heal on their own. Others, such as impetigo, may require the use of antibiotics to heal.

For invasive GAS infections, antibiotics, hospitalization and surgery may be required. Surgery is almost always required for necrotising fasciitis.


GAS infections can be prevented by practicing good hand hygiene. Do not share personal items that may have saliva on it. Keep all wounds clean and watch for redness and swelling at the wound site.

If you have had close contact with a person with invasive GAS disease, contact your local public health office for assistance. Public health will follow up with close contacts of cases and recommend antibiotics for some people.

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