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Epidemiologic Notes and Reports Update: Eosinophilia-Myalgia Syndrome Associated with Ingestion of L-Tryptophan -- United States, as of January 9,1990

As of January 9, 1046 eosinophilia-myalgia syndrome (EMS) cases have been reported to CDC from 49 states, the District of Columbia, and Puerto Rico (Figure 1) (1-3). Only Alaska has reported no cases (Figure 1). Seven deaths have been reported in patients who met the surveillance case definition and who used L-tryptophan (LT).

As of January 9, CDC has received completed report forms from 38 states and Puerto Rico with information about 429 cases fitting the case definition. Ages of these patients ranged from 11 years to 84 years (median: 48 years); 96% of patients were non-Hispanic white, 2% were Hispanic, and 1% were black. Three hundred sixty (84%) were female. Four hundred nineteen (98%) had histories of LT ingestion preceding onset of symptoms; dosage ranged from 26 mg to 15,000 mg per day (median: 1500 mg per day). Three hundred seventy-two (87%) reported onset of symptoms during or after July 1989 (Figure 2). Of the EMS patients reported thus far, 139 (32%) have required hospitalization.

Physicians report suspected cases to state and local health departments, and information is recorded on a standardized case-report form. Total numbers of EMS cases are telephoned weekly to CDC by health departments, and case-report forms mailed when completed; this results in a timely accumulation of total numbers but a lag in availability of detailed data. Reported by: State and territorial health departments. Div of Environmental Hazards and Health Effects, Center for Environmental Health and Injury Control, CDC.


  1. CDC. Eosinophilia-myalgia syndrome--New Mexico. MMWR 1989;38:765-7.

  2. CDC. Eosinophilia-myalgia syndrome and L-tryptophan-containing products--New Mexico, Minnesota, Oregon, and New York, 1989. MMWR 1989;38:785-8.

  3. CDC. Update: eosinophilia-myalgia syndrome associated with ingestion of L-tryptophan--United States. MMWR 1989;38:842-3.

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