ATLANTA - Rotavirus infections are the most common cause of severe gastroenteritis among infants and young children worldwide. In the United States each year, rotavirus infections account for an estimated 3.5 million cases of diarrhea, 500,000 physician visits, 50,000 hospitalizations and 20 deaths among children younger than 5 years of age.
In addition, rotavirus accounts for almost half of U.S. hospitalizations for diarrhea among children younger than 5 years, including approximately 50% of hospitalizations for diarrhea during annual seasonal peaks. It is also an important cause of nosocomial gastroenteritis.
Rotavirus activity in the United States is monitored by the National Respiratory and Enteric Virus Surveillance System (NREVSS), a voluntary, laboratory-based system.
According to the NREVSS, from July 1996 through June 1997, a total of 69 laboratories in 42 states participated and reported weekly to the Centers for Disease Control and Prevention (CDC) the number of stool specimens tested for rotavirus by antigen-detection and electron microscopy methods and the number of positive results.
Of the 23,199 fecal specimens examined, 6,183 were positive for rotavirus. Timing of rotavirus activity varied by geographic location; peak activity occurred first in the Southwestern U.S. in November 1996 and last in the Northeastern half of the country in April and May of 1997.
The reasons for the sequential pattern in rotavirus activity across the United States are still unknown.
The NREVSS system uses an automated telephone reporting system to transmit reports from participating laboratories to the CDC and allows timely analysis of rotavirus trends. Limitations of the system are:
The large disease burden and high cost associated with rotavirus infections in the United States have been the impetus for development of rotavirus vaccines. Two human animal reassortant vaccines seem safe and effective and one vaccine was recommended for licensure for use among American children; both the Advisory Committee of Immunization Practices and the Committee on Infectious Diseases of the American Academy of Pediatrics are considering recommendations for the use of the vaccine in children.
CDC scientists said the prospect of a program for childhood vaccination against rotavirus in this country highlights the need for continued surveillance. Laboratory-based surveillance has helped characterize the trends of rotavirus infections and provided a baseline for monitoring changes in the epidemiology of these infections following vaccine introduction.
Efforts to enhance rotavirus surveillance should include surveillance for rotavirus-associated diarrheal outcomes, particularly hospitalizations, and for rotavirus strains. These measures also will help access vaccine implementation and the potential emergence of novel or unusual rotaviruses.
For more information:
- Laboratory-based surveillance for rotavirus - United States. MMWR. 1997:46;1092-4.
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