Italy has reported the highest annual total of Hemolytic Uremic Syndrome (HUS) cases since records began.

From January to December 2022, 91 cases were recorded. This is the most observed in a single year since the start of surveillance in 1988. HUS is a severe complication associated with E. coli infection that causes kidney failure and can result in lifelong, serious health problems and death.

The number is still lower than in France, which recorded 128 HUS cases in 2021. This was the lowest figure since 2017 and was down from 167 in 2020. Data for 2022 is not yet available but a rise is expected due to an outbreak linked to Nestlé Buitoni Fraîch’Up brand frozen pizzas.

The Italian Haemolytic Uremic Syndrome Registry is operated by the Italian Society of Pediatric Nephrology and the Italian National Institute of Health (ISS). 

The rise was particularly marked in summer from June to August during which more than half of HUS patients were reported. There was a peak in June with 16 reports. A cluster of cases associated with STEC O26 infection in Emilia-Romagna between June and July contributed to this increase.

Details on affected people and type of E. coli
Overall, 89 patients were under the age of 15. The median age for cases in 2022 was 42 months old.

Incidence rates varied by region but the majority of cases were recorded in Emilia-Romagna with 12 infections and Campania with 11.

Patients came from 16 regions. In three cases the disease was linked to foreign travel while in one instance, HUS was registered in a foreign citizen staying in Italy.

Regions in which the reporting rate of HUS cases was higher than the national average included Abruzzo, Campania, Emilia-Romagna, Liguria, Marche, Piedmont, Puglia, and Tuscany.

In 72 cases with samples tested, an infection with Shiga toxin-producing E. coli (STEC) was found. In 64 cases it was possible to identify information on the serogroup.

The so-called top-5 serogroups – O26, O157, O111, O145, and O103 – dominated results. A total of 38 samples were O26. E. coli O157 was the second highest. The high rate of O26 in HUS cases reflects a longer-term trend and is in line with other European countries, said Italian health officials.

In 2021 in Europe, 365 HUS cases were reported and four children died. The majority were in the youngest age groups from 0 to 4 and 5 to 14 years old. Serogroup O26 was most common followed by O157.