Epidemiology for public health
Istituto Superiore di Sanità
Epidemiology for public health - ISS

Italian Haemolytic Uraemic Syndrome Registry

The Italian Haemolytic Uraemic Syndrome (HUS) Registry collects information on cases of this condition reported across the country. Data are recorded systematically and continuously. The registry is operated by the Italian Society of Paediatric Nephrology (Società Italiana di Nefrologia Pediatrica - SiNePe), in collaboration with the Istituto Superiore di Sanità (ISS). Cases of the disease are mainly reported by the paediatric and adult nephrology centres participating in the surveillance, through the HUS Registry information system (ISSEU).

Report / 1 March 2020 - 28 February 2021

HUS is considered a rare condition. In Italy, 54 cases were recorded between 1 March 2020 and 28 February 2021. Patients were from 15 different regions (this information was unavailable in 1 case), and only 1 was diagnosed with HUS after returning from abroad. Of the 54 cases, 51 (94%) were recorded in the paediatric population (<15 years of age). Over the last 12 months, the average notification rate for this age group has been 0.61 cases per 100,000 residents, with marked regional variations. The highest rate was observed in Valle d’Aosta (5.8 cases per 100,000 population), while in 6 other Regions or Autonomous Provinces (Umbria, Liguria, Veneto, Lombardy, Calabria and Autonomous Province of Bolzano) the notification rate was higher than the national average.

The number of HUS cases reported to the Italian registry in the six months between September 2020 and February 2021 was considerably lower than expected, declining from an average of 24.4 cases for the same period in the previous 10 years to 14 cases. This corresponds to a relative decrease of 42.6%, despite figures for October and December 2020 being in line with expectations. By contrast, the number of HUS cases reported in June-August 2020 was broadly comparable with the expected total for that three-month period, and an excess of cases was actually observed in August 2020 (+7.4 cases, +75% compared with the average for the month in the previous 10 years). It is plausible to assume that measures to control the COVID-19 pandemic may have significantly contributed to reducing HUS incidence in the paediatric population. The total number of cases reported in March-May 2020 was also lower than expected, declining from an average of 11 cases in the previous years to 5.

HUS is known to predominantly affect the paediatric population (<15 years of age), and is often developed in the earliest years of life. The median age of clinical onset among the cases reported in the last 12 months was 2.5 years, compared to 2 in the previous 10 years. Cases aged over 15, recorded between 1 March 2020 and 28 February 2021, accounted for 6% (N=3) of the total. Distribution by sex showed no significant differences between males and females.

Of the 43 HUS cases tested for Shiga toxin-producing E. coli (STEC) between 1 March 2020 and 28 February 2021, 37 (86%) had STEC infection confirmed by at least one laboratory test performed on biological samples (faeces and/or serum). Tests were carried out at the ISS National Reference Laboratory for E. coli or other laboratories approved by the Italian HUS Registry (1). For 35 of the 37 positive cases, the STEC serogroup was also identified: in 89% (N=33) of the HUS cases for which this information was available, one of the top-5 STEC serogroups (O26, O157, O111, O145, O103) was detected, while in two cases, co-infection with STEC strains belonging to two different serogroups (O26/O157 and O145/O177) was reported. It should also be noted that infections with STEC 080 have been diagnosed more frequently in the last 12 months, compared to the previous 10 years. This is an important finding because, despite the small number of affected cases, STEC 080 is considered an emerging serogroup in Europe. In the remaining two cases, STEC infection was diagnosed using techniques that did not allow serogroup identification.


Risorse utili
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Note 1: HUS (Molecular Epidemiology and Public Health Laboratory, University of Bari; Microbiology Laboratory of the Ca’ Granda Ospedale Maggiore General Hospital, Milan)


Publication date: 25 March 2021

Authors: Gaia Scavia, Arnold Knijn, Eleonora Ventola, Stefano Morabito – Istituto Superiore di Sanità, Registro Italiano Sindrome Emolitico Uremica (SEU); Licia Peruzzi, Società Italiana Nefrologia Pediatrica (SiNePe)