Rotavirus

Rotaviruses are double stranded RNA viruses which are most frequently noted as causing gastroenteritis in children.

• rotaviruses are ribonucleic acid (RNA) viruses that are contained within a protein capsule
  • rotavirus strains are classified based on the outer layer proteins VP7 (G type) and VP4 (P type). Although there are at least 15 G types and 28 P types, only 10 G and 11 P types have been identified in humans
    
    
  • rotavirus is highly contagious
    • transmission by the faecal-oral route is most frequent, although respiratory transmission may also occur
      • 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
        
        
    • rotavirus infections in humans cause 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
        
        
    • rotavirus infection in the UK is seasonal, occurring mostly in winter and early spring (January to March). 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
      • infections in adults are rarely reported, although they are not uncommon in individuals caring for, or in contact with, children who have rotavirus gastroenteritis. Older children and adults can also develop asymptomatic infection, which may be important in maintaining rotavirus infection in the community

There is an oral vaccine for rotavirus available in the UK.

• first dose at two months (approximately eight weeks) of age.
• second dose at least four weeks after the first dose
• preferable that the full course of two doses of Rotarix® be completed before 16 weeks of age, allowing at least four weeks between the first and second dose. This is to provide protection before the main burden of disease and avoid temporal association between vaccination and intussusception
• rotavirus vaccine can be given at the same time as the other vaccines administered as part of the routine childhood immunisation programme, (including BCG vaccine), and so should ideally be given at the scheduled two month and three month vaccination visits
• vaccine is over 85% effective at protecting against severe rotavirus gastroenteritis in the first two years of life
• although the vaccine is a live attenuated virus, with the exception of severe combined immune-deficiency (SCID), the benefit from vaccination may exceed any risk in other forms of immunosuppression (1)
  • therefore, there are very few infants who cannot receive rotavirus vaccine
  • breast feeding and medications for gastro-oesophageal reflux are not contraindications for rotavirus vaccination. The rotavirus vaccine can also be administered before, at the same time as, or after administration of any blood product, including those containing antibody/immunoglobulin
  • where there is doubt, appropriate advice should be sought from an immunisation coordinator or consultant in health protection rather than withholding vaccination (1)

Reference:

• (1) Immunisation Against Infectious Disease (April 2019) - "The Green Book".Chapter 27b Rotavirus.