Almost 80 hemolytic uremic syndrome (HUS) cases were registered between July 2019 and June 2020 in Italy.

The 77 patients came from 17 regions in the country while one person contracted HUS while abroad. Notification rates varied by region but were highest in Aosta Valley and higher than 1 case per 100,000 in Basilicata, Calabria, Liguria, Lombardy, Marche, Trento, and Bolzano.

Seventy of those affected were under 15 years of age. The median age of patients at the clinical onset of the disease was 2 years and 7 months for the past 12 months and the past decade.

HUS is a serious condition that can lead to kidney failure, permanent health problems, and even death. It is most often triggered by Shiga toxin-producing E. coli (STEC) infection, according to the Centers for Disease Control and Prevention.

Early symptoms include decreased urine output, diarrhea, and feeling slow and tired. HUS usually develops one to two weeks after initial symptoms of E. coli infection.

The sharp rise in STEC O80; lockdown impact
In 49 of the 75 HUS cases examined for STEC between July 2019 and June 2020, it was possible to confirm the diagnosis of STEC infection. Among these, the so-called top-5 STEC serogroups of O26, O157, O111, O145, and O103 dominate, representing 89 percent of STEC identified in HUS cases with the main one being O26.

In the past 12 months, the frequency of diagnosis for STEC O80 infection has tripled compared to the previous 10 years. Although the number of cases is limited, STEC O80 is considered an emerging serogroup in Europe.

Over the period studied, the majority of HUS cases were in the second half of 2019 with more than 70 percent of the total. There was a similar seasonal trend compared to the previous 10 years, although the overall number of patients is higher and there was a delayed seasonal peak compared to the summer jump of previous years.

In the early months of 2020, there were more infections than the seasonal forecast followed by a marked decline in the March to May quarter, coinciding with the lockdown due to the COVID-19 pandemic. The overall number of cases compared to what was expected halved, passing from an average of 11 to five. In June, the number of patients appeared to be in line with the seasonal forecast.