Outbreak report: measles cluster in south-eastern Sydney with transmission in a general practice waiting room

Abstract

South Eastern Sydney Public Health Unit recently investigated a cluster of 5 cases of measles with onset in December 2000. The index case was a 31-year-old male who presented to his doctor with a rash and fever. The diagnosis was confirmed by a positive measles IgM assay at a private pathology laboratory. The illness was thought to have been acquired through occupational exposure in another health area. The second and third cases were siblings aged 18 months and 3 years who were thought to have become infected after a few minutes' contact with the index case in the waiting room of a local general practice. Measles was subsequently transmitted to 2 other children, aged 5 and 4 years, who were childcare contacts of the second case. All 4 affected children had documentation of one MMR vaccination at 1 year of age whilst the 5-year-old had documentation of a second MMR vaccine dose at 4 to 5 years of age. In addition to the index case, laboratory confirmation was obtained for 3 of the 4 subsequent cases by the Serology and Virology Laboratories, SEALS Randwick. In 2 cases, measles IgM was detected, and in 2 cases measles antigen was detected in throat swabs by direct immunofluorescence.