Hemolytic uremic syndrome (HUS) is a primarily renal complication of infections caused by Shiga toxin-producing Escherichia coli (STEC), which can be transmitted through food, a contaminated environment, or person-to-person contact. Although rare, it is a serious condition that primarily affects young children. Before progressing to HUS, these infections cause abdominal pain accompanied by bloody, mucus-containing diarrhea or, more rarely, simple diarrhea. Each year, between 100 and 160 cases of pediatric HUS are reported to Santé publique France. The Agency has coordinated the surveillance of pediatric hemolytic uremic syndrome in France since 1996 in collaboration with the National Reference Center for E. coli, Shigella, and Salmonella (Institut Pasteur, Paris) and its associated National Reference Center (AP-HP, Robert Debré University Hospital, Microbiology Department, Paris).

Pediatric HUS: Key Figures for 2021

• 128 reported cases of pediatric HUS

• The incidence observed in 2021 is the lowest since 2017: 1.12 cases per 100,000 children under 15

• Higher incidence among children under 3 years of age (4.30 cases per 100,000 children)

• Highest incidence rates observed in Bourgogne-Franche-Comté and Auvergne-Rhône-Alpes

• Serogroup 026 remains the most common in France, accounting for 35.1% of confirmed cases.

• Outbreak of a foodborne illness (FBI) in a school setting caused by STEC O157 and linked to the consumption of raw cucumbers in a salad. In total, 35 cases of infection, including eight confirmed cases of STEC O157 (two HUS), were linked to this foodborne illness outbreak. This is the first outbreak in France linked to the consumption of vegetables where contamination in the suspected food item has been documented.

Preventive measures to avoid transmission of the E. coli bacteria responsible for HUS

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 their feces, which can then contaminate the environment (water, manure, soil) and food. These bacteria tolerate cold temperatures 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 ground meat products, must be thoroughly cooked to an internal temperature of 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-pressed cheeses [such as Emmental, Comté, Gruyère, Beaufort], spreadable processed cheeses, 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;

• Prepared meals and leftovers must be refrigerated promptly and reheated thoroughly 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

• Children should not drink untreated water (from wells, rivers, streams, 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.