Issue 138 Item 6 Type 1 Epidemic in Philadelphia Possibly Triggered by Measles

An epidemic of type 1 diabetes in Philadelphia, Pennsylvania, in 1993 may have been triggered by a measles epidemic. >Researchers at the University of Pennsylvania and the Children’s Hospital of Philadelphia identified a total of 209 cases from 1990 to 1994, with an overall age-adjusted rate in Philadelphia of 13.3 cases of type 1 diabetes per 100,000 children per year. The overall incidence of type 1 in Philadelphia is about the same as that in other diabetes registries in the United States, the researchers note.

A jump in the incidence of type 1 (32 cases) occurred between January and June 1993, approxi­mately two years after a measles epidemic in 1991. The study con­tends that the cases of type 1 may have developed when the measles virus triggered an autoimmune attack on the insulin-producing beta cells of ill children.

The highest rate of type I by race was in the Hispanic population-in Philadelphia, primarily Puerto Ricans-with an incidence rate of 15.5 per 100,000 children. There also was a marked increase in type 1 diabetes among African-American children, which the researchers spec­ulate might have partly resulted from misclassification of cases that actu­ally involve type 2. Diabetes Care, November 2002