Infection control for norovirus

Abstract

Norovirus infections are notoriously difficult to prevent and control, owing to their low infectious dose, high shedding titre, and environmental stability. The virus can spread through multiple transmission routes, of which person-to-person and foodborne are the most important. Recent advances in molecular diagnostics have helped to establish norovirus as the most common cause of sporadic gastroenteritis and the most common cause of outbreaks of acute gastroenteritis across all ages. In this article, we review the epidemiology and virology of noroviruses, and prevention and control guidelines, with a focus on the principles of disinfection and decontamination. Outbreak management relies on sound infection control principles, including hand hygiene, limiting exposure to infectious individuals, and thorough environmental decontamination. Ideally, all infection control recommendations would rely on empirical evidence, but a number of challenges, including the inability to culture noroviruses in the laboratory and the challenges of outbreak management in complex environments, has made it difficult to garner clear evidence of efficacy in certain areas of infection control. New experimental data on cultivable surrogates for human norovirus and on environmental survivability and relative resistance to commonly used disinfectants are providing new insights for further refinining disinfection practices. Finally, clinical trials are underway to evaluate the efficacy of vaccines, which may shift the current infection control principles to more targeted interventions.

Keywords: Disinfection; epidemiology; infection control; norovirus; nosocomial.

FIG. 1

Setting of (a) norovirus outbreaks reported in five European countries with broad-based surveillance, 2002, n = 1115, and (b) the USA, 2009–2013, n = 2895. Long Term Care Facility (LTCF). Adapted from Lopman et al. [15] and Vega et al. [13].

FIG. 2

Distribution of norovirus genotype (GI, GII.4, GII non-4) by mode of transmission (a) and by outbreak setting (b), as well as mode of transmission by outbreak setting (c), from 2895 norovirus outbreaks reported to CaliciNet, 2009–2013. Adapted from Vega et al. [13].