Diarrea emorragica acuta, infezione da Escherichia coli produttori di Shiga tossine e sindrome emolitica uremica

Hemolytic uremic syndrome (HUS) associated with Shiga toxin-producing Escherichia coli (STEC) infection is a major individual and public health challenge and it is the leading cause of acute kidney injury in children. In Western countries, HUS complicates about 15% of STEC infections, which usually present with acute bloody diarrhea (ABD). At least 6-7% of cases of ABD in children (rising to 15-20% during summer) are caused by STEC. The widespread use of molecular microbiology techniques enables the diagnosis of STEC infection before HUS onset in an increasing number of patients generating a window of preventive and/or therapeutic opportunities. Given the rapid progression of the disease, all children with ABD should be tested as early as possible for Shiga toxin (Stx) encoding genes. Stx-positive patients should then be closely monitored for HUS development by urine dipstick for the development of hemoglobinuria. This proactive diagnostic approach allows the application of measures aimed at preventing or mitigating the severity of HUS among which stands the early and generous fluid administration. Moreover, although antibiotics are not recommended in STEC infections, recent data suggest a promising potential preventive role for bacteriostatic agents (e.g. azithromycin) if given early during the infection. The aim of the present contribution is to share the approach to ABD and STEC infection as endorsed by the scientific societies actively engaged in this area (AMCLI, SIGENP, SIMEUP, SIN, SIP, SIPPS, SITIP). The goal is to promote the early diagnosis of STEC infection by molecular microbiology of ABDs nationwide, thereby improving our understanding of the mechanisms of disease spreading, and hopefully reducing the incidence of HUS and its case fatality rate as well as improving both short- and long-term outcomes.