Epidemic and sporadic gastroenteritis is an important public health problem in both high income and low-income countries. In the last 30 years, several viruses have been identified as etiological agents of gastroenteritis in humans.

Outbreaks of gastroenteritis may be caused by rotaviruses, astroviruses, adenoviruses and the human caliciviruses. The human caliciviruses are assigned to two genera, the Norovirus and Sapovirus. The Norovirus cause illness in people of all age groups, whereas the Sapovirus predominantly cause illness in children. Epidemic viral gastroenteritis or “winter vomiting disease” was described as early as 1929 but it took over 40 years to the discovery of the Norwalk virus using immune electron microscopy in faecal samples in 1972. These specimens were collected during an outbreak of acute gastroenteritis which occurred in 1968 in an elementary school in Norwalk, Ohio, USA.

Europe: Increase in reported number of Norovirus outbreaks
Since the summer 2006, several EU countries have faced an increase in reported number of Norovirus outbreaks or confirmed cases. In many countries, the outbreaks have hit severely in hospitals and other public settings. Two novel virus strains of GII.4 seem to circulate across Europe. (ECDC, European Centre for Disease Prevention and Control). Emerging diseases have a significant impact on morbidity and mortality (Robert-Koch- Institut, Berlin: 48 reported deaths in 2007 caused by Norovirus).

Unites States: More than 1,000 acute gastroenteritis outbreaks
Noroviruses are enterically transmitted and are a frequent cause of acute gastroenteritis, affecting 23 million people annually in the United States. CDC solicited information from the health departments all over the United States. They reported a total of 1,316 acute gastroenteritis outbreaks with onset during October-December 2006; a median of 50 % occurred in long-term-care facilities. (CDC, Centers for Disease Control and Prevention)

Outbreak cost analysis
Recent studies on the socio-economic burden have analyzed the cost in health care settings. A study described a Norovirus outbreak and its control in a tertiary care hospital in the U.S. This study determined outbreak costs, including the estimated lost revenue associated with unit closures, sick leave, and cleaning expenses. The total estimate of economic impact of this outbreak on this hospital was $ 657,644 (Johnston et al 2007).

Outbreak cost analysis
The most useful measures are early diagnosis followed by the appropriate hygiene interventions.
For instance, diagnosis within three days instead of four days of the first case reduces outbreak duration by seven days (Lopman et al. 2004).

The fundamental question remains – Are Noroviruses emerging? Before we can answer to this question, what does emerging disease mean? According to World Health Organization (WHO): “An emerging disease is one that has appeared in a population for the first time, or that may have existed previously but is rapidly increasing in incidence or geographic range.” Both incidence and geographic range increased in the last couple of years. The increased detection of Norovirus is a result of better application of improved diagnostics. Thus, this is leading to higher numbers of Norovirus cases. However, as described new circulating Norovirus strains are emerged worldwide. So, we can answer this question very clear. Yes, Noroviruses are emerging!

Second, a timely clinical testing as close as possible to the patient helps tremendously to reduce the amount of affected people and therefore also the overall expenses on the health care system.

In summary, don’t waste time – Rapid diagnostics for Gastroenteritis