Ongoing outbreak of hepatitis A in Italy: preliminary report as of 31 May 2013.

Since January 2013, an unusual increase in hepatitis A cases has been detected in northern Italy. A total number of 352 cases were reported to the integrated surveillance system between January and the end of May 2013 and this represents a 70% increase compared to the same period of the previous year. The outbreak is ongoing and the public health authorities are continuing their investigations to establish the transmission vehicle and to control the outbreak. a total of 352 cases of hepatitis A were reported to the Italian national surveillance system, corresponding to a 70%, 54%, and 34% increase in HAV notifications compared to the same period in 2012, 2011 and 2010, respectively. Here we describe the epidemiological features of the cases and the investigation of the outbreak. Hepatitis A is a notifiable disease in Italy. According to the national legislation, laboratory-confirmed cases of hepatitis A virus (HAV) infection are reported by clini-cians to the local health units (LHUs) which are responsible for the epidemiological investigation. From the LHUs, notifications are sent to the regional health authorities (RHAs) and from here to the Ministry of Health. However, the routine notification system does not collect information on risk groups and risk factors associated with hepatitis A and there is an important delay in the transmission of the data [1]. For this reason , in 1984, a specific sentinel surveillance system for acute viral hepatitis (SEIEVA-Sistema Epidemiologico Integrato Epatiti Virali Acute) was set up in parallel with the official notification system in Italy [2]. Data included in the SEIEVA system provide insight into the risk factors associated with the disease. Data collected by SEIEVA are provided by LHUs, which participate on a voluntary basis. A case is defined as a person with an acute illness including symptoms clinically compatible with hepatitis A, such as fever, fatigue, nausea, vomiting, abdominal pain, dark urine and jaundice, and positive for IgM anti-HAV. Cases are interviewed using a standardised online questionnaire collecting socio-demographic, clinical and laboratory information , and information on possible risk factors (shellfish consumption, contact with a jaundice case, travel to an endemic area, child attending daycare in the household , intravenous drug use in the last six months). After the alert issued by the northern European countries about a possible association between the hepatitis A cases and frozen berries [3], the consumption of mixed frozen berries was included as another possible risk factor …