Rotavirus

Rotavirus is the most common cause of severe diarrhea in children and infants worldwide. Before a vaccine was introduced in the United States, the disease caused more than 400,000 doctor visits and 200,000 emergency room visits each year, resulting in as many as 60 deaths annually in children younger than five. Globally, rotavirus kills about 450,000 children under age 5 each year, with most deaths occurring in developing countries.

Symptoms and Causative Agent

Rotavirus is a double-stranded RNA virus of the reovirus family. Viewed under an electron microscope, the virus is shaped like a wheel, hence its name (rota being Latin for “wheel”). Several species and subtypes of rotavirus cause disease in humans.

The most common symptom of rotavirus infection is watery diarrhea. It may also cause fever, abdominal pain, and vomiting. Complications from rotavirus infection are described below.

Transmission

Rotavirus spreads via the fecal-oral route: from the waste of an infected person to the mouth of another individual. This can occur via contamination of hands or objects, such as toys. The virus spreads easily among children and can also be passed from children to those with whom they are in close contact.

A person’s first infection with rotavirus usually causes acute illness, but later infections produce milder symptoms and are often asymptomatic (meaning they cause no visible symptoms). Asymptomatic infections in adults, however, may lead to the virus transmitted to close contacts.

Treatment and Care

No specific treatments exist for rotavirus infections. Rather, they are treated with supportive care, such as oral rehydration, rest, and fever relief.

Complications

In about 1 in 50 cases of rotavirus illness, children develop severe dehydration from diarrhea and vomiting. Hospitalization is usually necessary in these cases, and children are rehydrated via liquids delivered via a nasogastric tube or intravenously. Prompt rehydration therapy usually leads to a positive outcome, but deaths from rotavirus still occur in developed countries and, more commonly, in developing countries. Worldwide, the World Health Organization estimates that about 450,000 deaths from rotavirus illness occurred in 2008 (the latest year for which data are available).

Available Vaccines and Vaccination Campaigns

The first vaccine for rotavirus, RotaShield, was licensed and recommended for routine childhood immunization in 1998. Wyeth Pharmaceuticals, however, withdrew the vaccine in 1999 due to safety concerns. Scientists associated the vaccine with a rare intestinal problem called intussusception, a potentially fatal telescoping of part of the bowel.

No rotavirus vaccine was available until 2006, when the Advisory Committee on Immunization Practices recommended routine infant immunization with three doses of the recently licensed RotaTeq vaccine, developed by H. Fred Clark, PhD, Stanley A. Plotkin, MD, and Paul A. Offit, MD. The Food and Drug Administration licensed another rotavirus vaccine, Rotarix, for use in the United States in 2008. Rotarix is given to infants in two doses. Both vaccines are given orally as drops.

CDC has carefully monitored the incidence of rotavirus disease in the United States since 2000. Their studies show that the number of positive test results for rotavirus was substantially lower than the median observed during 2000-2006. Additionally, it appears that hospitalization rates for acute gastroenteritis dropped by 16% in 2007 and by 45% in 2008 compared with the earlier period. Researchers have estimated that rotavirus vaccination prevented about 55,000 hospitalizations in 2008.

Worldwide, rotavirus continues to take a toll. About 450,000 children under age 5 die each year from rotavirus illness. Efforts are being made to make the rotavirus vaccine available in the developing world, where deaths from rotavirus illness are more common. Mexico was one of the first countries to receive the rotavirus vaccine in 2006. By the 2009 rotavirus season, deaths from diarrheal disease had dropped in both the target population for vaccination (children younger than 11 months old, where the mortality rate dropped by 40%) and among children between one and two years of age (the mortality rate dropped by almost 30%). The fact that death dropped even in a part of the population not targeted by the vaccine suggests that herd immunity benefited the unvaccinated individuals: with fewer infections, the disease circulated less in the population, leaving less opportunity for exposure.

Sources

• Centers for Disease Control and Prevention. . Epidemiology and Prevention of Vaccine-Preventable Diseases. Atkinson, W., Wolfe, S., Hamborsky, J. eds. 13th ed. Washington DC: Public Health Foundation, 2015. (562 KB). Accessed 01/25/2018.
• Feigin, R.D., Cherry, J.D., Demmler, G.J., Kaplan, S.L. Texbook of Pediatric Infectious Diseases, 5th ed., vol 2. Philadelphia: Saunders, 2004.
• Plotkin, S.A., Orenstein, W.A., Offit, P.A. Vaccines, 5th ed. Philadelphia: Saunders, 2008.
• Richardson, V., Hernandez-Pichardo, J., Quintanar-Solares, M., Esparza-Aguilar, M., Johnson, B., Gomez-Altamirano, C.M., Parashar, U., Patel, M. . N Engl J Med 2010; 362:299-305. Accessed 01/25/2018.
• World Health Organization. . Accessed 01/25/2018.