Haemolytic uraemic syndrome (HUS): causes, symptoms and treatment

Kidney Care UK explains the name: haemolytic refers to the breakdown of blood cells, uraemic to the kidneys not removing waste as well as they should, and syndrome to the fact that different parts of the body are affected. STEC HUS, also called typical HUS or diarrhoea-associated HUS, damages the small blood vessels inside the kidneys and so affects how well they work.

TravelHealthPro notes that HUS can be caused by some medicines and other infections, but STEC is the most common cause. A different condition, atypical HUS (aHUS), is a different condition, and Kidney Care UK describes STEC HUS as different from aHUS.

The UK Kidney Association describes a UK research group for Shiga toxin-associated HUS, led by a consultant paediatric nephrologist, collecting national data to understand the condition better, which reflects how rare it is.

HUS happens in a few people after they get gastroenteritis. Kidney Care UK says most people recover from gastroenteritis without problems but around 1 in 10 of those with STEC infection will develop STEC HUS. The E. coli bacteria produce a poison called Shiga toxin, which damages the cells of the blood vessels in the kidneys; it is not yet clear why some people develop HUS after infection.

The infection can come from eating undercooked meat, fruit and vegetables that have not been washed properly, drinking contaminated water, not washing hands after touching infected animals or areas where they were, such as farms, petting zoos or campsites, being close to other people with the illness, and swimming or playing in infected water. TravelHealthPro adds that it is extremely contagious because only a small number of bacteria are needed to cause illness, and that infection can occur in holiday settings including all-inclusive resorts.

The first symptoms are those of gastroenteritis. Kidney Care UK lists stomach pain, feeling or being sick, diarrhoea lasting several days, passing less urine than normal or none, and a high temperature, often with sweating and shivers. Blood may appear in the poo after a few days. Excessive tiredness and anaemia can develop after about a week, and some children develop pinhead-sized red or purple spots on the skin.

TravelHealthPro lists symptoms of HUS progressing as passing less urine than normal or none at all, swelling of the feet, ankles and legs, extreme tiredness, pale skin, fainting and bruising easily. It advises getting medical advice urgently if you or your child have bloody diarrhoea, show signs of dehydration such as passing less urine than usual or drowsiness, or develop any of these symptoms. Some people, especially young children, can become dehydrated quickly.

The NHS advice on diarrhoea and vomiting also says to call 111 if there is bloody diarrhoea or bleeding from the bottom, and to call 999 or go to A&E for blue, grey, pale or blotchy skin, severe difficulty breathing, or confusion.

Kidney Care UK says STEC HUS is usually diagnosed by blood, urine and stool (poo) tests, and blood pressure is checked because HUS can cause high blood pressure. HUS can also affect the central nervous system, which may temporarily affect vision, thought processes and movement, and an MRI scan may be recommended to check the extent of this. Around 3 in 100 people with STEC HUS develop insulin-dependent diabetes as the condition can affect the pancreas.

STEC HUS is a notifiable disease, so your doctor will tell the public health authorities so that they can identify the cause and minimise further infection. Kidney Care UK says the bacteria are infectious and can be passed from person to person, so doctors may ask you to stay off work or keep your child home from school or nursery.

Kidney Care UK says there is currently no direct treatment for STEC HUS. Care focuses on protecting the kidneys and keeping the body healthy until the illness resolves, which usually happens within one or two weeks, as with ordinary gastroenteritis.

• Around seven in ten people with STEC HUS recover completely and do not need follow-up treatment, according to Kidney Care UK, though annual reviews may be recommended.

• All children with STEC HUS are followed up for signs of high blood pressure or protein in the urine as adults.

• In some adults the kidney damage is more severe and long-term dialysis or transplant may be needed.

Because of how easily STEC spreads, hygiene is the main defence. Kidney Care UK advises hand washing with soap and water (not gel or wipes) before eating and after going to the toilet, high-temperature washing of clothes, bedding and towels at 60 degrees or above, not sharing plates or glasses with someone who is infected, and avoiding contact with farm animals if you are infected.

TravelHealthPro lists safe food and water practices, including avoiding under-cooked burgers and unpasteurised dairy products and not drinking or swimming in contaminated water. The NHS says that for diarrhoea and vomiting people should stay off school or work until they have not been sick or had diarrhoea for at least 2 days, and do not use a swimming pool until at least 48 hours after symptoms stop.

HUS is dealt with in NHS hospitals, with children usually cared for by paediatric nephrology teams and adults by renal services. Admission, dialysis and follow-up are free at the point of use. Because it is notifiable, public health teams are involved in tracing the source.

Kidney Care UK says it is not aware of any UK-based support groups for STEC HUS, and the UK Kidney Association mentions Haemolytic Uraemic Syndrome Help (HUSH) as a UK support group that offers support to people affected and their families.