What Causes Hemolytic Uremic Syndrome?
The immune system attacks the blood cells in HUS. Consequently, the red blood cell level decreases, the platelet level drops, and the kidneys are injured.(5)
HUS in Children
In children, Escherichia coli (E. coli) is the main underlying cause of HUS. E. coli comes in many forms, and most are not harmful. The E coli bacteria are normally found in the intestines of healthy individuals and animals. In some cases, however, specific strains of E. coli that are spread through food can cause infections that could lead to HUS. E. coli can also be found in water contaminated with feces.
In children younger than five, HUS is most commonly caused by infection with E. coli bacteria. Humans and animals who are healthy normally have a type of bacteria called E. coli in their intestines. E. coli can take many different forms, most of which are harmless. There are some strains, however, that cause diarrhea.
A toxin called Shiga toxin is produced by some strains of E.coli that cause diarrhea. Shiga toxin-producing E. coli is known as STEC. Infection with a strain of STEC can cause the Shiga toxin to enter your bloodstream and damage blood vessels, which can lead to HUS. However, even those who contract the most dangerous strains of E coli generally don’t develop HUS.
Among the other causes of HUS in children are:
- A pneumococcal infection, a human immunodeficiency virus infection or influenza infection
- The use of certain medications, especially those used in the treatment of cancer and those used to suppress the immune system of recipients of organ transplants.
Atypical HUS – a rare type of HUS – can be passed on genetically to children. This form of HUS does not necessarily affect people who inherit the mutated gene. An infection, certain medications or chronic health conditions may trigger the activation of the mutated gene and can cause HUS.