Importance of molecular typing in confirmation of the source of a national hepatitis A virus outbreak in Norway and the detection of a related cluster in Germany.

In March 2014, after an increase of notifications of domestically acquired hepatitis A virus infections, an outbreak investigation was launched in Norway. Sequenced-based typing results showed that these cases were associated with a strain that was identical to one causing an ongoing multinational outbreak in Europe linked to frozen mixed berries. Thirty-three confirmed cases with the outbreak strain were notified in Norway from November 2013 to June 2014. Epidemiological evidence and trace-back investigations linked the outbreak to the consumption of a berry mix cake. Identification of the hepatitis A virus outbreak strain in berries from one of the implicated cakes confirmed the cake to be the source. Subsequently, a cluster in Germany linked to the cake was also identified.

Rotavirus outbreak among adults in a university hospital in Germany.

BACKGROUND: Rotaviruses are the main cause of acute viral gastroenteritis in children under five years of age. Adults seem to be less frequently affected by rotaviruses most likely due to partial immunity resulting from prior infections. OBJECTIVES: To describe a hospital-associated outbreak of rotavirus infections among adults. STUDY DESIGN: Routine diagnostics and contact screening of symptomatic patients hospitalized at the university hospital of Freiburg. For rotavirus-positive patients, we performed rotavirus genotyping of all rotavirus RT-PCR positive samples and phylogenetic analysis. RESULTS: Between December 2016 and April 2017 routine diagnostics showed an unexpectedly high number of rotavirus infections among adults with the exception of one pediatric case. In total, 32 temporal-associated cases were identified. Among these, two asymptomatic cases were detected. Genotyping showed that all isolates belonged to rotavirus G2P[4]. Phylogenetic analysis confirmed an outbreak. Infection prevention and control successfully contained further spread. CONCLUSIONS: Infections with rotavirus are rare among adults but may spread between patients making timely recognition of rotavirus infections important for infection control. Rapid phylogenetic analysis is crucial for proactive infection control.