Pediatric Hemolytic Uremic Syndrome in France

Hemolytic uremic syndrome (HUS) resulting from infection with Shiga toxin-producing Escherichia coli (STEC) primarily affects young children. This rare but serious complication mainly affects the kidneys and occurs in 5 to 8% of cases.

Before progressing to HUS, these infections cause abdominal pain accompanied by bloody, mucus-containing diarrhea or, more rarely, simple diarrhea.

The main objectives of this surveillance are to describe the spatial and temporal trends of pediatric HUS, to detect outbreaks in order to guide control measures, and to communicate about prevention measures.

Transmission of HUS is primarily foodborne

Shiga toxin-producing Escherichia coli, the bacteria responsible for hemolytic uremic syndrome, are present in the intestines of ruminants (primarily cows and calves, but also goats, sheep, deer, etc.). These bacteria are excreted in feces and can contaminate the environment (water, manure, soil) and food. They are highly resistant to cold (surviving for several days in a refrigerator), but are destroyed by cooking.

Contamination can occur:

• By ingesting contaminated food consumed raw or undercooked: beef (especially ground beef), unpasteurized milk or dairy products, apple juice, raw vegetables, or contaminated drinking water;

• By touching the mouth with dirty hands after touching animals carrying the bacteria or their contaminated environment;

• Through contact with a sick person who has diarrhea and excretes the bacteria in their stool.

Preventing HUS through hygiene and avoiding certain high-risk foods

The E. coli bacteria responsible for HUS are present in the intestines of many ruminant animals (cows, calves, goats, sheep, etc.) and are excreted in feces, which can then contaminate the environment (water, manure, soil) and food. These bacteria tolerate cold well (they survive in a refrigerator or freezer) but are destroyed when cooked thoroughly.

A few simple tips to reduce the risk of transmission:

In the kitchen:

• Always wash your hands before preparing meals;

• Meat, especially ground beef, as well as dishes made with ground meat, must be cooked thoroughly to reach 70°C (not pink or rare);

• Raw milk, cheeses made from raw milk, and dairy products made from raw milk should not be consumed by children under 5 years of age (opt for hard, cooked cheeses [such as Emmental, Comté, Gruyère, Beaufort], processed cheese spreads, and cheeses made from pasteurized milk);

• flour-based preparations (pizza/cookie dough/cake/pie/crepes, etc.) should not be eaten raw or undercooked;

• Vegetables, lettuce, fruits, and herbs, especially those to be eaten raw, must be thoroughly washed before consumption, after peeling if necessary;

• Raw foods must be stored separately from cooked or ready-to-eat foods;

• Cooked dishes and leftovers must be promptly refrigerated and thoroughly reheated before consumption;

• Kitchen utensils (especially if they have previously come into contact with raw foods such as meat or cheese), as well as countertops, must be thoroughly washed to prevent cross-contamination.

During activities and leisure time:

• Children should not drink untreated water (well water, river water, stream water, etc.) and should avoid swallowing it while swimming (in lakes, rivers, ponds, etc.).

• Very young children (under 5 years old) should avoid contact with cows, calves, sheep, goats, etc., and their environments; if contact with these animals occurs, handwashing (with soap and water) must be done systematically before the child puts their fingers in their mouth.

A serious illness with a high risk of long-term complications

HUS secondary to infection with Shiga toxin-producing Escherichia coli occurs at both ends of the age spectrum, particularly in young children. It is the leading cause of acute kidney failure in children under three years of age in France. Other organs may also be affected, notably the brain and heart, and the risk of long-term complications is significant. The reported mortality rate is less than 5% in the scientific literature; in France, it is less than 1% according to surveillance data.

Symptomatic treatment

HUS secondary to infection with Shiga toxin-producing Escherichia coli requires hospitalization, with management focused primarily on treating symptoms. Severe cases may require dialysis and/or blood transfusion in an intensive care unit.