Dr. MJ Bazos MD, Patient Handout
Hemolytic Uremic Syndrome
Hemolytic Uremic Syndrome (HUS), commonly referred to as "Hamburger Disease", is a disease that affects the kidneys and other organs. It poses a substantial threat to Canadian children as one of the leading causes of both acute and chronic kidney failure. HUS is more commonly seen in the warmer months of the year, following a gastrointestinal illness caused primarily by a particular strain of bacteria known as E.coli 0157:H7. While other types of E.coli are commonly found in the gastrointestinal tract of healthy humans, this particular strain (0157:H7) is not usually present except in diarrheal illnesses. This bacteria (E.coli 0157:H7) is known to produce toxins, which are the main cause of the symptoms related to the gastrointestinal illness. The most common symptoms of E.coli 0157:H7 Gastroenteritis are the following:
People of all age groups are at risk for E.coli 0157:H7 gastroenteritis; however, young children and the elderly are at greater risk for more severe symptoms. This infection is highly contagious. Thousands of Canadians are identified with this infection each year and many epidemics have been reported in Canada (the most recent being Walkerton), the United States, and Europe.
E.coli 0157:H7 bacteria originates in the intestines of animals and is carried typically in their feces which can contaminate meat during and after slaughter. This bacteria has been associated with consumption of undercooked ground beef (hence, "Hamburger Disease"), unpasteurized milk and cheese, cold cuts, hot dogs, chicken, pork, lamb, and contaminated water sources. Recent studies conducted by the Canadian Pediatric Kidney Disease Research Centre (CPKDRC), have also reported a strong association of this infection with person-to-person spread through the fecal-oral route. In addition, poor hand washing and improper food handling are high-risk factors for the spread of this bacteria.
Approximately one in every ten children who have E.coli 0157:H7 gastroenteritis will go on to develop Hemolytic Uremic Syndrome. HUS is caused by the effect of toxins (produced by the E.coli bacteria) on the body's circulation, affecting red blood cells, the kidneys, and in some cases, the brain. HUS is usually diagnosed between the eighth and twelfth day of the diarrheal illness, although many children have developed HUS earlier on.
A very small number of children will develop the disease beyond two weeks of their diarrheal illness. HUS has been reported in the adult population; however, it is more commonly seen in children, most often affecting those less than five years of age.
Symptoms of HUS include extreme irritability and fatigue, paleness of the skin, and a decrease in urine output.
Children must be watched very carefully for signs of HUS following an E.coli 0157:H7 gastrointestinal illness. Usually associated with a lengthy hospital stay, at least 80% of children who develop HUS will require multiple blood transfusions, and approximately 50% will need dialysis. Recent Canadian studies have shown evidence of permanent kidney damage in some patients following an acute episode. In more recent years, approximately 3-5% of children die due to complications of HUS.
The following are recommended prevention measures: