Rotavirus infection overview

# Overview
Rotavirus infection is the most common cause of severe diarrhea in the children. It is one of the causes of the gastroenteritis disease. Children vaccination against the rotavirus is very important to prevent any upcoming infection by the virus. Other care measures have been held in order to prevent the occasion of the rotavirus infection. These measures include: access to clean safe drinking water, washing hands regularly and personal and food hygiene. The infection can be transmitted feco-orally and it occurs through multiple viral replication. Rotavirus infections should be differentiated from other organisms which cause watery diarrhea like the adenovirus, e. coli bacteria and taenia spp. Children are in a high risk for getting infected by rotavirus especially the children who are left in a child care center and the unvaccinated children. Patients present with diarrhea, vomiting and low grade fever. They may appear pale and signs of dehydration like sunken eye and may be observed in severe cases. Prevention of dehydration and following the rehydration measures is the first line of management of rotavirus infection.

# Historical perspective
Rotavirus discovery goes back to the last century after the infection of several children with gastroenteritis of unknown reason. Studies have been held for long time through the years from 1940 till 1973. In 1973, Dr. Ruth Bishop was able to identify the pathogen causing the disease as Rotavirus.

# Classification
There is no known classification for the rotavirus infection but it can be classified according to the age into adult rotavirus infection and child rotavirus infection.

# Pathophysiology
Rotavirus is transmitted by the feco-oral route. It is transmitted from the infected children to other individuals before and after the occurance of the diarrhea. It can also spread through infected hands, food and objects like toys. Pathogenesis of the rotavirus takes place in the intestine where virus replication takes place and severe watery diarrhea takes place. Rotavirus protein number 4 plays an important role in causing the diarrhea and the rotavirus clinical manifestations. The infection destroys number of the intestinal digestive enzymes and malabsorption takes place leading to diarrhea. Rotavirus infection is not limited to the intestine only. It can affects the central nervous system causing meningitis.

# Causes
Rotaviruses are a genus of viruses belonging to the Reoviridae family. Seven major groups have been identified, three of which (groups A, B, and C) infect humans, with group A being the most common and widespread one. They cause vomiting and diarrhea and are the most common cause of severe diarrhea in children, killing about 600,000 children every year in developing countries (as of 2005).

# Differentiating rotavirus infection from other diseases
Rotavirus must be differentiated from other diseases and pathogens that cause watery diarrhea. In the below table it is differentiated from the other viruses that can cause the diarrhea like adenovirus, bacteria like the E. coli, and parasites like the taenia spp.

# Epidemiology and Demographics
Rotavirus infection is the leading cause of severe diarrhea among the infants and children. It affects approximately, 120 million individuals annually causing death of 600,000-650,000 world-wide. It occurs more in the winter. It affects children more than adults. It is more common in developing countries. There is no racial predilection.

# Risk factors
Children are in a high risk for getting infected by rotavirus especially the children who are left in a child care center and the unvaccinated children. However, adults can be in the risk as well. The immunocompromised patients and adults who are in contact with infected children are in risk for rotavirus infection.

# Natural History, Complications and Prognosis
Rotavirus infection is a self-limited disease. It may lead to dehydration, occasionally. Dehydration is one of the most important complications that may occur following the infection. Seizures are also a complication of the rotavirus infection. The disease prognosis is good.

# Diagnosis

## History and symptoms
Rotavirus clinical manifestations usually start to develop two days after the infection. It is more severe in children more than adults. Its severity depends on whether it is the first infection or recurrent. The first infection is more severe. It may be asymptomatic or causes watery diarrhea and in very severe cases it may cause severe dehydration. The children infected by the rotavirus present with high grade fever as well as vomiting.

## Physical examination
Patients infected with rotavirus infection may appear lethargic and pale in severe cases. They also have low blood pressure and fever due to infection. Signs of dehydration are more noticed in the infants as they could have sunken eye and depressed fontanelle. Convulsions also may be noticed in severe cases.

## Lab diagnosis
Diagnosis of Rotavirus infection is feasible through several diagnostic techniques. These techniques include electron microscopy, reverse transcriptase polymerase chain reaction and RNA electrophoresis. Stool examination for the virus is important to detect the extracted viruses. Also, ELISA and immunochromatographic assays can be used for antigen detection.

## X Ray
There are no x-ray findings associated with rotavirus infection.

## CT Scan
There are no CT scan findings associated with rotavirus infection. However, it may be used to exclude other neurological diseases in case the rotavirus affects the nervous system.

## Echocardiography or Ultrasound
There are no ultrasound findings associated with rotavirus infection.

## Other Imaging Findings
There are no other imaging findings associated with rotavirus infection.

# Treatment

## Medical therapy
The most important aspect of treating viral gastroenteritis in children and adults is to prevent dehydration. This treatment should begin at home. A physician may give specific instructions about what kinds of fluid to give. CDC recommends that families with infants and young children keep a supply of oral rehydration solution (ORS) at home at all times and use the solution when diarrhea first occurs in the child. Medications, including antibiotics (which have no effect on viruses) and other treatments, should be avoided unless specifically recommended by a physician.

## Surgery
Surgical intervention is not recommended for the management of rotavirus infection.

## Prevention
Rotavirus infection prevention relies completely on children vaccination against the infection.  New vaccines have been shown to be safe and effective in 2006. These two rotavirus vaccines are the Rotarix and Rotateq.