The number of children who suffered a potentially fatal complication of E. coli infection in France declined in 2021.

Hemolytic uremic syndrome (HUS) is a type of kidney failure that can result in lifelong, serious health problems and death.

Santé publique France surveillance data on HUS only cover children younger than 15 years old in the country.

The 128 HUS cases in 2021 are the lowest recorded since 2017 and are down from 167 in 2020.

There was a high incidence in children under the age of 3 and for patients in the Bourgogne-Franche-Comté and Auvergne-Rhône-Alpes regions.

Details about HUS infections
E. coli O26 remains the most frequent, representing more than a third of confirmed cases. The second was O80 and O157 was the third. After several years of decline in the share of cases due to the O157 serotype, a slight increase was observed in 2021.

In 2021, 55 percent of reported cases were female and two-thirds were children younger than the age of 3. The youngest was 10 days old. The usual seasonal peak was observed, especially in the month of August.

The median length of hospitalization was nine days but this ranged from 3 to 38 days for the 37 cases with such information available.

Cases of sporadic HUS notified to Santé publique France are not subject to systematic investigation to identify the source of contamination because of the multiple possible sources.

Eleven epidemiological investigations were initiated in 2021 around grouped cases of HUS or Shiga toxin-producing E. coli (STEC) infections versus 17 in 2020. More detail was given on three incidents.

One was linked to a nursery and was due to person-to-person transmission and another involved a leisure center but the origin remained unknown.

The third sickened 35 people, with eight confirmed O157 cases and was linked to cucumbers from Belgium. Ten people were hospitalized.

Identified cases were children in different schools, the parent of a pupil and elderly adults who received meals through a local delivery program. The median age of patients was 8 with a range of 4 to 89 years old and almost two-thirds were female.

Italian figures
In Italy, between August 2021 and July 2022, 78 cases of HUS were recorded. From the start of September 2020 to the end of August 2021 there were 49 cases. 

The most recent data shows patients came from 15 regions. In one case, illness was found after a trip abroad and another case was a foreign national staying in Italy. Overall, 76 patients were under the age of 15 and slightly more females than males were affected.

From May to July 2022, the number of HUS cases reported was higher than expected with a particular rise in June. From September to December 2021, the rate was lower than in previous years.

In 58 of 61 positive cases for STEC, the serogroup could be identified. Among these, the so-called top 5: O26, O157, O111, O145 and O103 dominated with O26 behind the most cases.