Shana Lucas

CRA

Disease

Rotavirus

Causative Agents

Rotaviruses are non-enveloped, double stranded RNA that are a part of the Reovirdae family. There are seven species of Rotavirus, known as A, B, C, D, E, F, and G. The most common type is A. These virons (def) can go up to 76.5 nanometers (def) in size.

Epidemiology

Rotaviruses are endemic, especially among children, infecting most by age three. Different serotypes (def) of the virus can affect the same person and after time this causes them to acquire immunity to rotavirus. Young children have not had the time to build up this immunity, so those between the ages of 6-24 months have a higher risk of rotavirus turning into a serious disease. When adults are infected it is usually mild and due to having an infected baby.

Rotaviruses infect the bowels, causing severe diarrhea. This virus accounts for an estimated 55,000 children being hospitalized, 200,000 emergency room visits and 400,000 doctor visits per year in the US alone.  Worldwide approximately 600,000 children die from the virus annually.

Outbreaks of rotavirus in the US begin in the South in the fall and spread to the Northeast by spring. The outbreaks are most prevalent during these months but still can occur at any time of the year.

The largest epidemic of rotavirus A that has been recorded happened in Nicaragua in 2005. Rotavirus B which is adult diarrhea or ADRV caused a major epidemic in China, a result of drinking water that had been contaminated by sewage.

Transmission

There are seven serotypes of Rotavirus, A-G. Types A-C affects humans, with type A being most common. Types A-G can affect animals.  The virus is most commonly transmitted by the fecal – oral route, infecting the cells that line the small intestine, but can also be transferred by contact with contaminated surfaces, hands or objects and to a lesser degree, the respiratory route.

Signs and Symptoms

There is a 2 day incubation period for the rotavirus disease.  One of the first symptoms to appear is vomiting, accompanied by fever and followed by profuse diarrhea.  Due to the diarrhea, dehydration is of serious concern and is the leading cause of death related to rotavirus infection.

The first infection usually presents the most symptoms and the infections that follow are less harsh or asymptomatic, since the immune system has built immunity and provide protection. Subsequent infections that present with symptoms are often due to a different rotavirus A serotype.

Prevention and Treatment

There isn’t a specific treatment for rotavirus. The infection usually clears up on its own in three to nine days. The vomiting and diarrhea that accompanies the virus needs to be treated so that dehydration doesn’t occur. This includes constant replacement of fluids and electrolytes lost during the infection.  This can be done with water, water plus salts or water plus salt and sugar.

Prevention of rotavirus is difficult, due to the virus being so widespread. Hand washing after using the restroom or changing a diaper can help. The virus is resistant to common disinfectants, but is inactivated by chlorine. When a patient is hospitalized with the virus, they are put in isolation on Contact Precautions (def).

In 1998 a rotavirus vaccine was approved, but was pulled from the market after only a year due to an increased risk of intussusceptions (def).  February 2006, a new vaccine was approved by the FDA.  The name is RotaTeq, a live oral vaccine that is given in three doses to children at ages 2, 4, 6 months of age.  Another vaccine, Rotarix, was approved in 2008 and is given in two doses at ages 2 and 4 months.  Both vaccines are given orally.  Primary studies show the vaccine prevents between 74%-84% of infections and about 98% of severe infections.

Bibliography

Wikipedia, “Rotavirus”. April 5, 2010 (http://en.wikipedia.org/wiki/Rotavirus)

CDC,  “About Rotavirus”. April 5, 2010 (www.cdc.gov/rotavirus/about_rotavirus.htm)

Medicinenet ,”Rotavirus Infection”. April 5, 2010  (www.medicinenet.com/script/main/art.asp?articlekey=11920)