Small bowel (small intestine)
Infectious disorders
Rotavirus

Author: Elliot Weisenberg, M.D. (see Authors page)

Revised: 2 May 2017, last major update April 2017

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: Rotavirus
Cite this page: Rotavirus. PathologyOutlines.com website. http://pathologyoutlines.com/topic/smallbowelrotavirus.html. Accessed November 22nd, 2017.
Definition / general
  • Primarily diarrheal illness caused by infection with Rotavirus
Essential features
  • Rotavirus is a segmented, non enveloped double stranded RNA virus
  • It is ubiquitous and infection is essentially universal first occurring in early childhood
  • Transmission is fecal-oral either via direct contact with stool or via fomites
  • In the developed world, the vast majority of infections cause self limited diarrheal illness or, in subsequent infections and vaccinated populations, are asymptomatic
  • Most cases in the developing world are similar; however, the World Health Organization estimates that in 2013 approximately 215,000 children under 5 years old died from rotavirus infection (WHO - Rotavirus)
  • Live attenuated vaccines are available and their use has resulted in a dramatic worldwide decrease of severe disease
  • Intestinal intussusception is a rare but well recognized potential complication of vaccination
Terminology
  • Rotavirus is a genus of the Reoviridae family
ICD-10 coding
  • A08.0
Epidemiology
  • Rotavirus is ubiquitous and infection is essentially universal in childhood in all socioeconomic groups
  • Transmission is fecal-oral either via direct contact with stool or via fomites
  • Infection generally first occurs around 6 months of age as the gastrointestinal tract matures and passive immunity from breast milk wanes
  • Infection may occur earlier in infants fed formula and in parts of India, Asia and sub-Saharan Africa where protection from maternal antibodies appears to be less effective
  • Reinfection occurs throughout life and in most children older than 2 years and adults infection is minimally symptomatic or asymptomatic due to immunity either from prior infections or vaccination
  • In the developed world, disease was more common in winter and spring; however, whether this pattern is still valid with widespread vaccination is unclear
  • Transmission in the daycare and hospital setting is common
  • Viral particles are hardy and resistant to chlorinated drinking water although they are vulnerable to alcohol based hand sanitizer and spray disinfectants
  • The World Health Organization estimates that in 2013 approximately 215,000 children under 5 years old died from rotavirus infection, overwhelmingly in the developing world compared to 528,000 in 2000 (WHO - Estimated rotavirus deaths for children)
  • According to the CDC in the United States rotavirus causes over 400,000 doctor visits, 200,000 emergency room visits, 55,000 to 70,000 hospitalizations and from 20 to 60 deaths each year (CDC - Rotavirus in the U.S.)
  • Serologically rotavirus is classified into serogroups, subgroups and G and P serotypes
  • Genotypically, it is classified into electropherotypes, genogroups and G and P genotypes
  • There is a substantial geographic and temporal variation in strain distribution and antigenic drift as well as introduction and reassortment with animal viruses which increases genetic diversity
  • Epidemiologically nucleic acid testing is increasingly replacing serologic testing
  • Further information is available from the Rotavirus Classification Working Group's database (RotaC v2.0 - Classification Tool for Rotavirusses)
Sites
  • Infection occurs in the small intestine
Pathophysiology
  • The pathophysiology is complex and not fully understood
  • Enterocytes at villous tips are initially infected; the virus binds surface carbohydrates and penetrates the cell membrane leading to transcription of viral RNA
  • Damage to the mucosa leads to malabsorption
  • The activity of disaccharidases and peptidases in the brush border is decreased and osmosis from unabsorbed nutrients contributes to the diarrhea
  • Glucose cotransport of electrolytes is decreased but oral rehydration solutions are still affective (see Treatment below)
  • Mature enterocytes are lost and initially replaced by immature secretory cells
  • There is net secretion of water in part mediated by the enteric nervous system
  • Clearance of infection is complex and involves overlapping elements of innate, cellular and humoral immunity
  • Virus is usually shed for 6 to 10 days after patients become symptomatic
Clinical features
  • There is an incubation period of 1 - 3 days
  • Illness in infants and young children usually starts with vomiting and fever lasting 2 - 3 days, progressing to 4 - 5 days of profuse watery diarrhea
  • In symptomatic older children and adults there is 1 - 4 days of diarrhea with anorexia, crampy abdominal pain and low grade fever
  • Chronic infections may occur in immunosuppressed patients excepting HIV; isotonic dehydration and metabolic acidosis occur in severe cases
  • Viremia is uncommon; extraintestinal manifestations are rare and described in the liver and kidney
  • Intestinal intussusception is a rare but well recognized potential complication of vaccination
  • Prior intussusception is a contraindication to vaccination
  • Patient deaths are due to dehydration and electrolyte abnormalities that lead to cardiac failure or less commonly seizures or aspiration pneumonia
Diagnosis
  • Enzyme immunoassay and PCR are the mainstays
  • Latex agglutination is often used in resource poor areas
  • Viral culture and electron microscopy are largely of historical interest
  • Microbiologic diagnosis is rarely required
Laboratory
  • Severe disease may cause metabolic acidosis and high urine specific gravity
  • Mild elevation of transaminases and uric acid may occur
  • Leukocytosis is rare and stool is usually negative for white blood cells and blood
Prognostic factors
  • Disease is most severe in infants and young children
  • Immunosuppressed patients often suffer from more severe disease and cannot receive the live attenuated vaccine although patients infected with HIV do not suffer more severe disease and should be vaccinated
  • Infection in the developing world is more likely to lead to severe illness or death; this is related to less access to health care, malnutrition, the presence of other infections and possibly larger inoculums
Case reports
Treatment
  • Mild to moderate disease: oral rehydration
  • Severe disease: intravenous lactated ringers or normal saline until oral rehydration can be tolerated
  • Infants: return to breast feeding or formula as soon as it can be tolerated
  • In the developing world, zinc supplementation and some probiotics in children older than 6 months may reduce disease duration
  • Diosmectite, a type of aluminum magnesium clay silica, is available in parts of Europe and controls gastroenteritis
  • Oral immunoglobulins have a possible role in chronic disease and for high risk patients where vaccination is unlikely to be effective (premature infants) or is contraindicated
  • Antibiotics are not indicated
  • Vaccination is recommended to commence at 2 months of age
Microscopic (histologic) description
  • Biopsy is rarely performed
  • The findings are nonspecific; villi are shortened, blunted and lined by cuboidal cells
  • There is crypt hyperplasia and increased mononuclear cells within the lamina propria
  • Apoptotic epithelial cells may be present
  • Disease may be patchy in distribution
  • Viral inclusions are not present
Electron microscopy images

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Missing Image

Multiple rotavirus particles
Differential diagnosis
  • Other causes of infectious gastroenteritis and enterocolitis
Board review question #1
    What is true regarding Rotavirus?

  1. Most death occur in the elderly
  2. Characteristic viral inclusions are diagnostic
  3. The incidence has increased
  4. Intussusception is a rare but recognized complication associated with vaccination
  5. Infection typically affects the sigmoid colon and rectum
Board review answer #1
D. Intussusception is a rare but recognized complication associated with vaccination; however, there is broad agreement that the benefits of vaccination greatly exceed the risk