Norwalk virus

General or Other | - Others | Norwalk virus (Disease)


Norwalk virus was officially renamed norovirus by the International Committee on Taxonomy of Viruses in 2002. The virions contain a single-stranded RNA molecule in round to hexagonal capsids that are 35-39 nm in diameter, with icosahedral symmetry. The surface structure of the capsid is a regular pattern with distinctive features and 32 cup-shaped depressions.

Norovirus was first recognized as a cause of gastroenteritis in 1972, when it was detected in stool samples collected from infected elementary school students and contacts during an outbreak in Norwalk, Ohio, in 1968. It was declared a member of the Caliciviridae family of viruses in 1993. It is now considered the most common cause of epidemic nonbacterial gastroenteritis in the world.

Causes and Risk factors

Norwalk virus, the strain of which is also referred to as caliciviruses, can enter the body through food or water contaminated with the stool of an infected person. This food borne disease is also spread through other media like contaminated eggs, seafood (especially shellfish harvested in contaminated water like sewage), ice, ready to eat foods and salad ingredients etc. Eating half cooked food also increases the chances of Norwalk virus infestation.

Diagnosis and Treatment

Unfortunately, there is no specific treatment for Norwalk virus that causes gastroenteritis, as of now. The only treatment is complete rest, plenty of fluids and practicing hygiene. This disorder may resolve itself after a period of four to five days. Recovery may also depend on the health of the immune system of an individual. However during this period, the infected person must take proper care so as not to spread the infection. Diagnosis, before treatment, is mainly a series of tests conducted by the medical practitioner to detect the severity of the condition. The doctor may observe the symptoms exhibited by the affected person and also test stool samples to detect the presence of this virus. Once the diagnostic tests are carried out, the doctor may administer treatment, which help reduce the severity of this disorder.