P2 domain profiles and shedding dynamics in prospectively monitored norovirus outbreaks.

Background: Norovirus P2 domain is commonly used to extrapolate transmission within an outbreak (OB) setting. The current definition is that transmission among cases is considered to be proven when no sequence variation is found.

Objectives: Previous studies have shown a high mutation rate and errors during replication of the norovirus genome, therefore the validity of this criterion must be evaluated.

Unrecognized norovirus infections in health care institutions and their clinical impact.

Noroviruses (NoVs) have emerged as the leading cause of acute viral gastroenteritis (GE) in humans. Although diagnostic facilities have greatly improved, significant underdiagnosis of NoV in hospitals may still occur, thereby increasing clinical burden and nosocomial spread. We evaluated the underdiagnosis of sporadic NoV infections in a tertiary care hospital and estimated its clinical impact.

Nosocomial transmission of norovirus is mainly caused by symptomatic cases.

Background: Nosocomial norovirus (NoV) infection is common and may increase the burden of disease in healthcare settings, particularly in vulnerable hospitalized patients. Implementing effective infection control during and after admission may limit further spread, but evidence-based measures are lacking.

Methods: In this study, we performed a systematic evaluation of sources and modes of transmission during NoV outbreaks within 2 types of healthcare facilities.

Using molecular epidemiology to trace transmission of nosocomial norovirus infection.

Nosocomial norovirus (NoV) infection is common and may lead to complications in vulnerable hospitalized patients. Understanding sources and modes of transmission of noroviruses within health care settings will support the design of evidence-based strategies for reducing introduction and further spread. We sequenced a highly variable segment of the genome to identify possible clusters in patients with and without acute gastroenteritis who were hospitalized in the period 2002-2007.