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Reye Syndrome Surveillance -- United States, 1989

Reye syndrome (RS) is an acute illness that occurs almost exclusively in children; it is characterized clinically by profuse vomiting and neurologic dysfunction, sometimes progressing to delirium, coma, and death.* Continuous national surveillance for RS was established in December 1976 (1). This report summarizes RS cases for the 1989 surveillance year (December 1, 1988-November 20, 1989).

For the 1989 surveillance year--a period characterized by widespread influenza B activity--25 cases of RS were reported by state health departments to CDC's National Reye Syndrome Surveillance System (NRSSS). This equals the lowest number of cases reported since continuous national surveillance began and is 25% of the lowest number previously reported during a year with extensive influenza B activity (Table 1).

Nineteen (76%) of the patients had a reported antecedent illness within 3 weeks before onset of vomiting or neurologic symptoms; 13 had respiratory illnesses; three had varicella, and three had diarrhea without respiratory symptoms. Eighteen (72%) cases occurred in January, February, and March--the peak months for respiratory viral infections, including influenza types B and A(H1N1).

Of the 25 reported RS patients, 14 (56%) were female; 23 (92%) were white, one was black, and for one, race was unknown. Nineteen patients were greater than or equal to 5 years of age, and six were less than 5 years of age, representing declines of 72% and 82%, respectively, since 1986, the most recent prior year in which influenza B was the predominant influenza strain.

Approximately 70% of patients were admitted to hospitals in precomatose stages of RS (stages 0, 1, or 2). The largest number (seven) of patients were identified with stage 2 on admission, followed by stage 1 (six) and stages 0, 3, 4, and 5 (three each). The most severe phases of illness after hospitalization were stage 1 (two), stage 2 (seven), stage 3 (two), stage 4 (three), and stage 5 (six). One patient received treatment that precluded classification (i.e., she had received anesthetic or paralyzing agents in her treatment); the most severe stage was not reported for four.

Of the 24 patients for whom short-term outcomes were reported, 10 died (case-fatality rate: 42%). Reported by: Local and state health departments. Epidemiology Activity, Div of Viral and Rickettsial Diseases, Center for Infectious Diseases, CDC.

Editorial Note

Editorial Note: The annual number of cases reported to the NRSSS has decreased sharply since 1980 (Table 1), coinciding with increased public awareness of the association between the ingestion of aspirin during antecedent varicella or influenza-like illness and subsequent development of RS (2-7). In addition, the use of aspirin-containing medication to treat children with these viral illnesses has decreased (1,8,9).

The total number of reported RS cases in 1989 is lower than would be expected in a year with substantial influenza B activity. Before recognition of the association between aspirin use and risk for RS, periods of increased influenza B activity were characterized by substantial increases in the number of RS cases (10). In 1989, the number of reported cases was the same as in 1988; however, when compared with 1986, the last year with predominant influenza B activity, RS cases markedly decreased.

For 1985, 1986, and 1987, the percentage of patients less than 5 years of age were 53%, 38%, and 53%, respectively. These percentages were higher than in past years (1978-1984) and raised concerns that, as the overall number of reported cases decreased, a greater proportion would occur in the less than 5-year age group--a group for whom the diagnosis of RS may be complicated by metabolic disorders with manifestations similar to RS (11,12). For 1988 and 1989, the percentage of cases reported in this age group decreased to previous levels, suggesting that physicians may be more likely to rule out these metabolic disorders before diagnosing RS.

Preliminary results from 1990 surveillance indicate a continuing decline in the number of RS cases in the United States. As RS becomes increasingly rare, interest in reporting may also wane. Health-care personnel and public health agencies are urged to continue reporting to the NRSSS to assure adequate monitoring of the changing epidemiology of this illness.


  1. Barrett MJ, Hurwitz ES, Schonberger LB, Rogers MF. Changing

epidemiology of Reye syndrome in the United States. Pediatrics 1986;77:598-602.

2. Hurwitz ES, Barrett MJ, Bregman D, et al. Public Health Service study on Reye's syndrome and medications: report of the pilot phase. N Engl J Med 1985;313:849-57.

3. Hurwitz ES, Barrett MJ, Bregman D, et al. Public Health Service study of Reye's syndrome and medications: report of the main study. JAMA 1987;257:1905-11.

4. Pinsky PF, Hurwitz ES, Schonberger LB, Gunn WJ. Reye's syndrome and aspirin: evidence for a dose-response effect. JAMA 1988;260:657-61.

5. Starko KM, Ray CG, Dominguez LB, Stromberg WL, Woodall DF. Reye's syndrome and salicylate use. Pediatrics 1980;66:859-64.

6. Waldman RJ, Hall WN, McGee H, Van Amburg G. Aspirin as a risk factor in Reye's syndrome. JAMA 1982;247:3089-94.

7. Halpin TJ, Holtzhauer FJ, Campbell RJ, et al. Reye's syndrome and medication use. JAMA 1982;248:687-91.

8. Remington PL, Rowley D, McGee H, Hall WN, Monto AS. Decreasing trends in Reye syndrome and aspirin use in Michigan, 1979 to 1984. Pediatrics 1986;77:93-8.

9. Arrowsmith JB, Kennedy DL, Kuritsky JN, Faich GA. National patterns of aspirin use and Reye syndrome reporting, United States, 1980 to 1985. Pediatrics 1987;79:858-63.

10. Corey L, Rubin RJ, Hattwick MAW, Noble GR, Cassidy E. A nationwide outbreak of Reye's syndrome: its epidemiologic relationship to influenza B. Am J Med 1976;61:615-25.

11. Hurwitz ES. The changing epidemiology of Reye's syndrome in the United States: further evidence for a public health success (Editorial). JAMA 1988;260:3178-80.

12. Rowe PC, Valle D, Brusilow SW. Inborn errors of metabolism in children referred with Reye's syndrome: a changing pattern. JAMA 1988;260:3167-70.

*According to CDC's case definition, the following conditions must be met for consideration as a RS case: 1) acute, noninflammatory encephalopathy documented a) by alteration in the level of consciousness and, if available, a record of cerebrospinal fluid containing less than or equal to 8 leukocytes per mm3 or b) by histologic specimen demonstrating cerebral edema without perivascular or meningeal inflammation; 2) hepatopathy documented either by a liver biopsy or autopsy considered to be diagnostic of RS or by a threefold or greater rise in the levels of either serum aspartate aminotransferase, serum alanine aminotransferase, or serum ammonia; and 3) no more reasonable explanation for the cerebral and hepatic abnormalities.

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