What is haemolytic uraemic syndrome (STEC HUS)?
Haemolytic uraemic syndrome (HUS) is a rare condition that damages the small blood vessels inside the kidneys.
Haemolytic – it involves the blood
Uraemic – it involves the kidneys
Syndrome – there are several different things going on at the same time
STEC HUS is different to aHUS (atypical haemolytic uraemic syndrome).
STEC HUS can occur after a stomach infection caused by the bacteria Shiga toxin-producing Escherichia coli (STEC), a type of E.coli.
STEC HUS affects around 1 in 100,000 people in the UK. There are about 100 new cases a year. It usually affects children under the age of ten. Men and women are affected equally.
STEC HUS is also sometimes known as typical HUS or diarrhoea-associated (D+) haemolytic uremic syndrome.
What are the signs and symptoms of STEC HUS?
The first symptoms of STEC HUS are linked to gastroenteritis (commonly called a stomach bug) and include:
- diarrhoea that lasts for several days
- urinating less than normal or not at all
- feeling and/or being sick
- stomach pain
- high temperature (over 30˚), often with excessive sweating and/or shivers
Blood may appear in the poo after a few days of diarrhoea.
Excessive tiredness and anaemia can develop after about a week.
Some children develop pinhead-sized red or purple spots on the skin.
The bacteria that causes STEC HUS is infectious. Children may be advised to stay home from school and family members should take care to keep things clean to avoid the infection spreading.
What causes STEC HUS?
STEC HUS can occur when infected by a particular type of the E.coli bacteria. Infection may come from:
- contact with farm animals such as cows
- drinking unpasteurised milk
- swimming in contaminated water
- eating undercooked meat or contaminated produce such as lettuce, spinach and bean sprouts
The bacteria can also be passed from person to person.
Not everyone who is infected with the bacteria will develop STEC HUS. Localised outbreaks may occur but in general, one in ten people infected by the bacteria will go on to develop STEC HUS.
It is not yet clear why some people develop STEC HUS after infection. Age appears to be a factor, as STEC HUS is more likely to develop in children under the age of five and adults over 65. There may also be a genetic susceptibility, although this is still being investigated.
When STEC HUS does develop, the E.coli bacteria produces a poison called Shiga toxin which damages the cells of the blood vessels in the kidneys. This affects how well the kidneys can work and can cause permanent damage if it is not treated.
How is STEC HUS diagnosed?
STEC HUS is usually diagnosed in children by a clinical examination, blood, urine and stool tests.
In rare cases, a kidney biopsy may also be performed if the diagnosis is unclear.
Does STEC HUS affect other parts of the body?
Around 3 in 100 people with STEC HUS develop insulin-dependent diabetes as it can affect the functioning of the pancreas.
In very rare cases, STEC HUS can affect the brain and cause seizures.
Does STEC HUS run in families?
STEC HUS does not have a genetic cause so it cannot be inherited. However, the bacteria that causes STEC HUS is infectious so it can spread to other members of the same household. It is therefore very important to follow good hygiene practices including:
- high temperature washing of clothes, bedding and towels
- washing hands with soap and water (not gel or wipes) before eating and after going to the toilet
- not sharing plates or glasses with someone who is infected
- avoiding contact with farm animals
How is STEC HUS treated?
There is currently no direct treatment for STEC HUS so care focuses on protecting the kidneys and keeping the body healthy until the illness resolves itself. This usually happens within one or two weeks, as with normal stomach infections.
Young children may be admitted to hospital so that their fluid levels can be monitored and nutritional supplements prescribed to help their bodies fight the infection. Young babies may need a feeding tube for a short time.
In some cases, a short-term course of dialysis is needed in order to temporarily take over the work of the kidneys to give them time to recover.
Antibiotics are not recommended as a form of treatment for STEC HUS. They are not needed for this type of infection and may actually increase the release of toxins in the intestines.
Around seven in ten people with STEC HUS recover completely and do not need any follow up treatment. Annual reviews may be recommended to check that everything remains stable.
In some adults, the kidney damage is more severe and long-term dialysis or transplant may be needed.
STEC HUS is classed as a notifiable disease so the local public health authority will be told in order to identify the cause of the outbreak and minimise further infection. Cases of STEC HUS in children should also be reported to the British Paediatric Surveillance Unit.
Where can I get more information or support about STEC HUS?
For more information on STEC HUS including its diagnosis, symptoms and treatment, visit Haemolytic Uraemic Syndrome Help (HUSH).
Publication date: 11/2023
Review date: 11/2026
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