Recorded presentation

Lorraine Yeung, MD, MPH¹, Perrianne Lurie, MD, MPH, FACPM², Gustavo Dayan, MD³, Edward Eduardo, MPH³, Robert Levy⁴, Phyllis Britz, RN⁵, and Mark Papania, MD, MPH³. (1) National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, MS E-86, Atlanta, GA 30333, (2) Division of Infectious Disease Epidemiology, Pennsylvania Department of Health, P.O. Box 90, Room 933, Harrisburg, PA 17110, 717-787-3350, plurie@state.pa.us, (3) National Immunization Program, Division of Viral Vaccine Preventable Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, MS E-61, Atlanta, GA 30333, (4) Department of Emergency Medicine, Morristown Memorial Hospital, 100 Madison Ave., Morristown, NJ 07960, (5) Bureau of Community Health Systems, Southeast District Office, Pennsylvania Department of Health, 625 Cherry Street, Room 442, Reading, PA 19602-1187

Since the 1989-91 measles resurgence in the US and improved implementation of the 2-dose measles containing vaccine (MCV) schedule the incidence of measles in the US has decreased significantly. In April 2003, we investigated an outbreak of measles in a Pennsylvania boarding school. We interviewed cases to determine the magnitude of the outbreak and pattern of transmission and collected serum, throat culture, or urine specimens from cases for antibody testing and viral genotyping. We reviewed school vaccination records of all students to calculate vaccine effectiveness and surveyed students to identify risk factors for vaccine failure. The source case became ill one day after returning to the US from Lebanon. Measles was confirmed in 9 individuals at the school. Of these, 2 were unvaccinated, 1 had received only 1 dose of MCV, and 6 had received 2 doses of MCV. Genotype D4 was the only viral strain identified. Eight (1%) of all students were unvaccinated, 26 (4%) had received only 1 dose of MCV, and 629 (95%) students had received 2 MCV doses. The measles attack rate among unvaccinated students was 67% vs. 1% among recipients of two doses of MCV. The vaccine effectiveness of 2 MCV doses was 98.6%. Among recipients of 2 MCV doses, students vaccinated overseas were 6.8 times more likely to develop measles than students vaccinated in the US. This is the largest school outbreak in the US since 1998. The size of this outbreak was limited by the high immunity of the school population.

Learning Objectives: At the conclusion of the session, the participant (learner) in this session will be able to

• Describe the epidemiology of measles in the United States.
• List two measures taken to control a measles outbreak.
• Identify risk factors for measles disease in the US population.

Keywords: Outbreaks, School Health

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.

Recorded presentation