Measles, 2007

One case of measles was reported during 2007. The case was confirmed by a positive measles IgM antibody test. The case-patient was a 16 month-old child residing in the metropolitan area. The child had returned from an extended stay in Japan 2 days prior to rash onset and was therefore considered an international importation. The child had a history of vaccination for measles at exactly 1 year of age. The child’s mother was born in Japan and had measles at 2 years of age and subsequently received measles-containing vaccine in 2002. Maternal measles antibodies have been shown to persist longer in infants born to mothers with disease-induced immunity than mothers with vaccine-induced immunity. It is possible that circulating maternal antibody neutralized the vaccine virus, inhibiting a protective immune response in the case-patient.

No secondary cases were identified despite numerous exposures just prior to and during the child’s measles prodrome. Exposure notification and follow-up were conducted for the child’s primary care clinic and assistance with follow-up for passengers on three airplane flights was provided by the CDC.

This was the second consecutive year with a reported case of measles in Minnesota. In 2006, a case was reported in a 7-month-old infant adopted from Africa. The child had arrived in the United States 9 days prior to rash onset and was therefore considered an international importation.
Suspect measles cases should be reported to MDH immediately. Blood specimens for IgM serologic testing should be drawn at least 72 hours after rash onset. Testing for measles IgM antibody provides timely results; however, the positive predictive value is suboptimal when disease incidence is low (as it is currently). Multiple tests (including acute and convalescent measles IgG antibody and viral culture) are therefore strongly recommended. Testing for both measles and rubella is routinely recommended for individuals presenting with acute generalized rash and fever. Blood specimens for acute and convalescent IgG serology should be drawn within 4 days of rash onset and again 3 to 5 weeks later, and tested as paired sera. Specimens for viral culture (throat swabs, urine, or nasopharyngeal swabs) should be collected as soon as possible within 10 days of rash onset.

• For up to date information see>> Measles
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2007