Viral gastroenteritis

Abstract

Enteric viruses, particularly rotaviruses and noroviruses, are a leading cause of gastroenteritis worldwide. Rotaviruses primarily affect young children, accounting for almost 40% of hospital admissions for diarrhoea and 200 000 deaths worldwide, with the majority of deaths occurring in developing countries. Two vaccines against rotavirus were licensed in 2006 and have been implemented in 95 countries as of April, 2018. Data from eight high-income and middle-income countries showed a 49-89% decline in rotavirus-associated hospital admissions and a 17-55% decline in all-cause gastroenteritis-associated hospital admissions among children younger than 5 years, within 2 years of vaccine introduction. Noroviruses affect people of all ages, and are a leading cause of foodborne disease and outbreaks of gastroenteritis worldwide. Prevention of norovirus infection relies on frequent hand hygiene, limiting contact with people who are infected with the virus, and disinfection of contaminated environmental surfaces. Norovirus vaccine candidates are in clinical trials; whether vaccines will provide durable protection against the range of genetically and antigenically diverse norovirus strains remains unknown. Treatment of viral gastroenteritis is based primarily on replacement of fluid and electrolytes.

Figure 1:. Estimates of the annual burden and individual lifetime risks for norovirus disease across all age groups in the USA

Ranges represent point estimates from different studies, not uncertainty bounds. Reproduced from Hall and colleagues.

Figure 2:. Current rotavirus vaccine introduction map

As of April, 2018, 95 countries have introduced rotavirus vaccines; this includes 88 national introductions, three ongoing phased introductions (Pakistan, India, and Philippines), and four pilot or sub-national introductions (Canada, Italy, Sweden, and Thailand). Data are from the ROTA council.

Figure 3:. Percentage of rotavirus tests with positive results for the different weeks of the year starting in July and finishing in June, USA, 2000–15

The maximum and minimum percentage of rotavirus-positive tests for 2000–06 could have occurred during any of these six baseline seasons. Since the introduction of a rotavirus vaccine in the USA, epidemics have occurred every other year (ie, 2008–09, 2010–11, 2012–13, and 2014–15). Data were obtained from the US Centers for Disease Control and Prevention National Respiratory and Enteric Virus Surveillance System.