Strep A and toxic shock syndrome: what’s the link?

Toxic shock syndrome (TSS) is a rare, life-threatening condition caused by bacterial toxins entering the blood stream.¹

When caught early, patients with TSS may present with fever and chills, muscles aches, nausea and vomiting. However, the disease can quickly progress, and within 24 to 48 hours, patients may develop hypotension, tachycardia, tachypnoea and organ failure.²

TSS is a medical emergency that requires immediate medical attention. Patients presenting with early signs of TSS should be immediately hospitalised for standard treatment of shock and organ failure.³

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What causes toxic shock syndrome?

TSS is caused by either group A streptococcus bacteria (known as streptococcal TSS) or staphylococcus aureus bacteria (known as non-streptococcal TSS).⁴

These bacteria are common and harmless when on the outside of the body, and for those who have the antibodies, the bacteria can live in the body without causing symptoms or making them feel unwell.

However, if the bacteria get into the blood stream through a compromised barrier, tissue damage can occur and organs may stop working, which can be fatal.

This could be through a skin injury (such as a cut, burn or surgical wound) or through a mucus membrane such as inside the nose, throat or the vagina. In around half of cases, the bacteria’s route of entry remains unknown.³

Do tampons cause toxic shock syndrome?

It is a myth that tampons cause TSS. While TSS is associated with tampon use, only around half of TSS infections are related to menstruation.⁵

TSS is caused by bacteria, so while some develop the condition while using tampons, pads or menstrual cups (particularly if you use them for too long), TSS can also be caused by insect bites, skin infections or surgery.

Higher absorbency tampons increase the risk of TSS, so it is better to use a lower absorbency tampon and ensure you are changing your tampon regularly. The same rule applies from menstrual cups, pads and other period protection methods.⁵

Symptoms of toxic shock syndrome

As well as symptoms such as fever, chills, muscles aches, nausea and vomiting, patients with TSS may present with a sore throat, diarrhoea, dizziness and confusion.⁶

In some patients, the lips, tongue and the whites of the eyes turn a bright red. Some patients will also have a sunburn-like rash; however, this is typically caused by non-streptococcal TSS and is only occasionally seen in streptococcal TSS.⁴

Since many of these symptoms are common in other conditions and diseases, the differential diagnosis of patients in the early stages of STSS is broad, and misdiagnosis is common.³

Prevalence and at-risk groups

The incidence of TSS ranges is estimated to be around 0.03 to 0.50 cases per 100,000 people, with overall mortality around 8%.⁷

In the UK, the latest data suggests there are around 40 cases per year, although this is thought to have declined in recent years after tampon manufacturers stopped selling super-absorbent tampons.⁷

TSS can occur in anyone, but it is more common in adults 65 years of age or older and children, as they may not yet have the necessary antibodies to fight off the infection.⁸

People with diabetes, a weak immune system, chronic lung disease or heart disease are also at increased risk, as well as those who have surgical wounds, a local infection in the skin or deep tissue, or have recently given birth, had a miscarriage or an abortion.⁸

Treating toxic shock syndrome

Early diagnosis and rapid intervention are the key to reduce or prevent the inflammation which leads to rapid deterioration.⁶

TSS is typically treated in hospital or in an intensive care unit in advanced cases. Intravenous antibiotics and fluids are often used to treat shock and prevent organ damage, while dialysis may be required for patients with kidney failure.⁷

Medication to treat low blood pressure and pooled immunoglobulin may also be administered to help the body fight off the infection.⁶

The site of infection will need to undergo a deep surgical clean and any dead tissue may need to be removed. In severe cases, amputations of fingers, toes, or limbs may be necessary, although this is rare.⁶

Streptococcus A (strep A) infections

Group A Streptococcus (GAS), also known as Strep A, is what causes streptococcal TSS. However, not all strep A infections will progress onto TSS.

Most of the time, strep A will cause mild diseases such as a sore throat (strep throat), tonsillitis and impetigo, but in rare cases, it can cause TSS, necrotising fasciitis (known as the “flesh-eating disease”) and necrotising pneumonia.⁹

Strep A infections only become serious when they are ‘invasive’ (iGAS). This is a very rare form of infection, but the current incidence of iGAS is relatively high compared to previous periods, particularly in children. However, as in previous seasons, the majority of iGAS cases are among those aged over 45 years, particularly in those aged over 75 years.

The latest statistics from the UK Health Security Agency (UKHSA) show that there have been 2,965 iGAS cases across all age groups between 12 September 2022 and 16 April 2023, compared to 2,898 across the whole of the last comparably high season in 2017 to 2018.¹⁰

Cases are significantly higher in children compared to previous periods, with 701 iGAS cases in those aged 18 years and under between September 2022 and April 2023, compared to 205 cases in the 2017 to 2018 season.

During this period, there have been 401 deaths (from any cause recorded within seven days of an iGAS infection diagnosis) across all age groups in England. This figure includes 47 children aged under 18 years in England. In the September 2017 to September 2018 season, there were 354 deaths in total across the season, including 27 deaths among children aged under 18 years.

Increases in other countries such as France, Ireland, the Netherlands and Sweden have also been reported, particularly in children under the age of 10 years old.¹¹

The World Health Organization says it is “likely” that the increase in cases of iGAS disease in children is associated with the recent increased circulation of respiratory viruses, including seasonal influenza and respiratory syncytial virus, as coinfection of viruses with GAS may increase the risk of iGAS disease.¹¹

The WHO is therefore encouraging public health authorities to raise awareness of iGAS among clinicians and the general public.

Preventing, diagnosing and treating GAS infections

Healthcare professionals should ensure they are promptly testing and treating GAS infections according to national guidelines.

GAS infections should be included in the differential diagnosis of children who present with severe respiratory syndromes and those with preceding viral infection (including chickenpox), as well as those who have been in close contact with scarlet fever patient, according to the WHO.

The public health body also encourages schools and other educational facilities to ensure good hand and respiratory hygiene practices, as well as good indoor ventilation, for the rest of the Spring, which usually sees higher levels of GAS infections.

Toys and other frequently touched surfaces should also be regularly cleaned and disinfected to minimise the chances of transmission.

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