rotavirus gastroenteritis

Last edited 02/2020

Rotavirus gastroenteritis is an important cause of diarrhoea and vomiting in children, affecting boys more often than girls. It is the most common cause of gastroenteritis in children, but is not a notifiable illness and therefore not recorded as frequently as bacterial gastroenteritis (1)

• gastroenteritis that usually lasts from three to eight days
  • rotavirus gastroenteritis is characterised by mild fever with severe diarrhoea, vomiting, stomach cramps, and can lead to dehydration. Nearly all children will have at least one episode of rotavirus gastroenteritis before reaching five years of age

There are winter and spring peaks, which fall off in the summer. Usually the patient is less than one year old; rotavirus is only seen in the under fives and in the elderly.

Cause:

• Rotavirus - 3 serogroups (A, B and C) with A being the most common

Reservoir:

• Humans
• Animal reservoirs exist but animal-to-human transmission does not occur

Epidemiology:

• main cause of viral gastroenteritis in children in developed and developing countries
• most cases occur in children aged 6 months -2 years
• most cases in the UK occur in winter and spring, with a peak in March
• outbreaks in settings such as nurseries are common, though with the implementation of a vaccination programme in the UK from 2014, the incidence has decreased, and the epidemiological picture may change

Transmission:

• person-to-person spread via faecal-oral route is most common
• transmission by the faecal-oral route is most frequent, although respiratory transmission may also occur (1)
  • although good hygiene measures can help prevent spread of the disease, the robustness of rotavirus and the low infectious dose (10-100 virus particles), makes standard sanitary measures to halt transmission of the virus relatively ineffective
    
• people of any age can be infected by rotavirus but most infections occur in children between one month and four years of age
  • infection in newborns is common but tends to be either mild or asymptomatic, probably because of protection by circulating maternal antibodies
  • infections are often recurrent, and, by three years of age, many children will have experienced infection on more than one occasion
    • once someone has had a rotavirus infection they usually develop immunity, although it may be short lived
      • second and subsequent infections with a strain previously encountered are often asymptomatic; symptomatic second infections are usually associated with a different genotype
• transmission may also occur via contact with contaminated environmental surfaces. The virus is resistant to many disinfectants (inactivated by chlorine)

Incubation period:

• 1 - 4 days

Common clinical features:

• watery diarrhoea and vomiting with/without fever, abdominal pain and dehydration
• vomiting usually resolves within 1-3 days and diarrhoea within 5-7 days but it can take up to 2 weeks

Infectivity:

• infectious from 2 days before symptom onset to 10 days after symptoms resolve. May be longer in immunocompromised individuals

Diagnosis is made from examination of faecal suspensions or faecal fluids. Treatment is with oral rehydration therapy.

Notes:

• rotaviruses are ribonucleic acid (RNA) viruses that are contained within a protein capsule
  • rotavirus is highly contagious
  • oral Rotavirus vaccine at 2 and 3 months is now part of the routine childhood vaccination schedule in the UK. Those involved in nappy changing of recently vaccinated babies should observe good personal hygiene as traces of the vaccine virus may be excreted in faeces and may enable onward transmission, particularly to persons with weakened immune systems
  • if a child is tested for Rotavirus near the date of immunisation, the vaccine virus may be detected in stool and where the child presents with symptomatic gastroenteritis, testing for other infectious aetiologies should be considered (2)

Reference:

• (1) Immunisation Against Infectious Disease (April 2019) - "The Green Book".Chapter 27b Rotavirus
• (2) PHE (2019). Recommendations for the Public Health Management of Gastrointestinal Infections