What is rotavirus

Rotavirus is a double-stranded RNA virus, responsible for causing severe gastroenteritis, primarily in infants and newborns. Ten different species of rotavirus have been identified (A to J), among which Rotavirus A most commonly affects humans.¹

A brief history

Rotavirus was first observed and reported by Bishop et. al. using electron micrography, from intestinal tissue of children suffering from acute non-bacterial gastroenteritis. The virus was not observed after the children recovered, leading to the conclusion that it had an association with the occurrence of acute gastroenteritis.² The term “rotavirus” was used to describe this virus due to its morphological similarity to a wheel.³

Population at risk

Gastroenteritis due to rotavirus is primarily believed to be a condition affecting infants and children - almost all children are predicted to be infected by rotavirus by age 3 (before the vaccine was publicly available).⁴ Various studies have concluded that the main population at risk ranges from 6 to 24 months old.⁵ Infants younger than 3 months of age also demonstrate relatively lower rates of rotavirus infection, likely due to passive immunity via maternal antibodies, supplied through breastfeeding.⁴

Other than infants, the following populations may also be at risk of rotavirus infections:⁶

1. Elder patients - adults over 65 years
2. Adults in close proximity to infants suffering from rotavirus infections (hospital workers, family members)
3. Immunocompromised individuals

Mechanism of action/pathogenesis

Transmission of rotavirus primarily occurs via the faecal-oral route. The main reservoir of the virus is the human small intestine, where it replicates and infects enterocytes of small intestinal villi, resulting in structural and functional changes in the intestinal epithelium. Diarrhoea occurs due to multiple factors, including destruction of enterocytes, which results in malabsorption. Villi, which are primarily absorptive, get disproportionately destroyed, which results in decreased absorption from the intestine, and more secretion.⁴

Symptoms

Rotavirus infections may occur at all stages of life; however, they are usually asymptomatic due to a person’s immune response. The incubation period for the virus is approximately 1 to 3 days, and symptoms usually last for 3 to 7 days. The following symptoms are most commonly observed:^4,6

• Low-grade fever
• Vomiting
• Diarrhoea
• Stomach ache
• Symptoms of dehydration, such as less frequent urination, cool, dry skin, dizziness, and dry mouth, ay present, especially in infants

Dehydration is the most common complication of rotavirus infections. Infants and newborns are particularly at risk of dehydration - the condition could become life-threatening if care is not taken immediately.⁶

Diagnosis

Due to its nature, diagnosis can usually be performed based on medical history and physical examination. Stools infected by rotavirus have a distinctive odour, which aids in diagnosis. For a confirmatory test, a stool sample may be collected for lab testing.⁶

Management

There is no definite cure for rotavirus infections. The infection usually resolves after approximately a week, thus, treatment mostly involves management of symptoms, primarily dehydration. Oral rehydration and maintaining electrolyte balance are the key strategies of management. In more severe cases, fluids may be provided via IV, with constant monitoring of vitals. The prognosis of a well-managed child is excellent.⁷

A medical professional should be immediately contacted in the following situations:⁸ 

• Severe diarrhoea for more than 24 hours
• Symptoms of dehydration are observed (dry mouth, crying without tears, cold, dry skin)
• Prolonged, high fever

Prevention

Although breastfeeding has not been clinically proven to prevent rotavirus infections, it is associated with a milder onset in affected infants; hence, breastfeeding should be encouraged. Proper personal hygiene and sanitation should be practised to minimise transmission. Contaminated objects should be treated with care to prevent further spread.⁴

Vaccines have been reported to be effective in preventing rotavirus infections or attenuating symptoms even if infection occurs.6 The Centres for Disease Control recommends routine vaccination of all infants eligible for vaccination (without contraindications). Vaccine availability and schedule vary for different countries, hence, local medical professionals should be consulted. Vaccination may be started as early as 6 weeks.³ In the United Kingdom, two doses of rotavirus vaccines are given at 8 and 12 weeks. Further information and contraindications are available on the NHS website.

Conclusion

Rotavirus infections are usually non-serious, self-resolving infections which primarily affect infants, elderly adults, and immunocompromised individuals. Management is focused towards treating symptoms, and vaccines should be administered for prevention. Patients should be kept under observation until symptoms resolve, and medical professionals should be contacted immediately in case of severe, prolonged symptoms.