NOROVIRUS

Norovirus (NoV), causing the winter vomiting disease, is today recognized as the most important agent of acute human gastroenteritis
The etiology of diarrheas can involve several agents, such as viruses, bacteria, and parasites. Bacterial agents are relatively more important in developing countries, whereas viral agents are more relevant in industrialized countries. The importance of these agents is related to hygiene and sanitation conditions for the population1. In 1972, a 27-nm viral particle was discovered in  an infectious filtrate of human fecal samples over a gastroenteritis outbreak in Norwalk, Ohio3. Since then, the number of viral agents associated with gastroenteritis has progressively increased, with rotaviruses4, astroviruses5, and Norwalk-like viruses6 being identified.
Noroviruses constitute a genus within the family Caliciviridae. The human pathogens within this genus cause at least 95% of nonbacterial gastroenteritis outbreaks, and 50% of all gastroenteritis outbreaks, throughout the world. It is estimated that there are approximately 23 million Norovirus infections per year in the United States alone,  causing  50,000  hospitalizations and 300 deaths. International evidence suggests that between one and three percent of people can expect to become infected with Norovirus each year.

TABLE OF CONTENTS
CHAPTER 1 : INTRODUCTION 
CHAPTER 2:  EPIDEMIOLOGY 
CHAPTER 3.1:  MODE OF                TRANSMISSION 
                   3.2 PATHOGENESIS 
CHAPTER 4.1: SIGNS AND SYMPTOMS 
                   4.2: DURATION OF ILLNESS 
CHAPTER 5.1: TREATMENT 
                   5.2: PREVENTION AND CONTROL 
CHAPTER 6: CONCLUSION 

REFERENCES 
Ahmed, SM., Hall, AJ., Robinson, AE., et al (August 2014). “Global prevalence of Norovirus in cases of gastroenteritis: a systematic review and meta-analysis”. Lancet infect DIS 14 (8):725-30. 
Atmar, RL., Opekun, AR., Culger, MA., Estes, MK., Crowford, SE., Neill, FH. and  Graham, DY. (October 2008). “Norwalk virus shedding after experimental human infection’’.
Centre for disease control and prevention, (CDC), (April 16, 2016). Vessel sanitation program balmoral.
Goodgame, R., (2006). “Norovirus gastroenteritis”. Curr Gastroenterol Rep. 8(5).
Heijne, JC., Teunis, .P., Morroy, .G., Idijkmans, .G., Oostueens, Duizer, .E., Kretzschmar, .M., and Wallinga, .J. (2009). “Enhanced Hygiene measure and Norovirus transmission during an outbreak”.
Moore, MD., Goulter, RM. and Jaykus, .L. (April 2015). “Human Norovirus as a foodborne 
                Pathogen challenges and development”.                                                                   
Morrillo, SG., Timenetsky, MDO C. (2011). “Norovirus: an overview”. Revista Da associacao 
               scientists.2007-12-09. Retrieved 2014-02-09.