Your child will need some tests to diagnose (or identify) STEC-HUS and find out the best treatment. Your child will need an examination, blood test, urine test and stool test.


Your doctor will examine your child, and talk to you or your child about the symptoms and any medicines that your child takes. 

Your child’s blood pressure will be measured, using a special instrument. This is because HUS may cause high blood pressure, or hypertension.

Blood test

A small amount of blood will be taken from a vein, with a needle and syringe, for a blood test. The sample will be sent to a laboratory for testing. The blood test will look for:

  • information about blood cells
  • signs of a recent infection by E. coli or another germ
  • how well your child’s kidneys are working
  • the amounts of important chemicals in your child’s blood.

Read more about blood tests for HUS

Information about blood cells and haemoglobin

A full blood count measures the numbers of different types of blood cells. Children with HUS normally have a low number of platelets, blood cells that form clots to help the body heal. They may also have a low amount of haemoglobin, the substance on red blood cells that carries oxygen round the body. 

In a blood film, a thin layer of blood is examined under a microscope. In HUS, this may show broken red blood cells (these are called fragments). 


A blood test can check if there are any antibodies, proteins that are made by the immune system to find and kill specific germs. This gives information about whether there has been an infection caused by E. coli, or STEC.

How well the kidneys are working

Urea and creatinine are chemicals that are made in the body. They are waste products and normally removed by the kidneys into urine. In severe cases of HUS, these may build up and there are higher amounts of these in the blood than usual.

The blood test can also find out how well the kidneys are working (kidney function), by measuring the amount of creatinine in the blood. This can be used to estimate the glomerular filtration rate (GFR), which is the amount of fluid (liquid) the kidneys filter each minute. 

Other chemicals

Electrolytes are chemicals in the body – we need the right balance of these to stay healthy. Some important electrolytes include the following:

  • sodium helps balance the amount of water in the body
  • potassium is needed for the muscles, including the heart muscle, to work properly
  • bicarbonate balances the amount of acid in our body, or the pH balance (also called the acid–base balance)
  • phosphate is important for bones, teeth and muscles
  • calcium is important for bones and teeth, helps blood to clot and also helps the muscles, including the heart muscle, to work.

Urine test

You or a nurse may need to collect some of your child’s urine in a small, clean container for a urine test. A dipstick will be dipped into the urine – this is a strip with chemical pads that change colour depending on what substances are in the urine. The sample may also be sent to a laboratory for more accurate tests.

Children with HUS may have blood cells and/or protein in their urine.

Stool test

Your child will need a stool test, which is normally done at the hospital. A nurse will collect a stool (poo) sample from your child. 

Children with HUS may be found to have STEC in their stool.

Telling the local health protection unit

If your doctor finds that your child has a STEC infection – even if he or she does not develop HUS – your clinic or hospital will inform your local health protection unit. A public health officer may speak with you to find out how your child might have been infected. This will help prevent the infection from spreading.