North Texas Measles Outbreak, 2013

BACKGROUND:  Measles has become a rare notifiable condition in Texas. From 2000-2012, Texas had an average of one case each year (range: 0-7), with no cases reported in seven of those years. According to the National Immunization Survey, 90% of Texas children 19-35 months have received at least one measles vaccine.

METHODS:  Passive surveillance is used to identify measles suspects. Patients with clinical or laboratory findings consistent with measles are investigated by local health departments. Additional testing is performed at the Texas Department of State Health Services Laboratory and the Minnesota Department of Health Laboratory. Texas uses the Council of State and Territorial Epidemiologists’ case definition for measles, except Texas does not use a probable case status. Vaccination status is confirmed through obtaining records from the state immunization database or from healthcare providers. When cases of measles are identified in Texas, healthcare professionals are asked through health alerts to look for additional cases. Additionally, contacts are identified for each case and notified of their exposure. Post-exposure prophylaxis is offered to all susceptible contacts identified within six days of exposure.

RESULTS: In August, 2013 a clinician in Tarrant County reported three patients with measles-like illnesses, one of whom had a family member with a similar illness that had resolved a week prior. Further investigation indicated that the family member had returned from Indonesia prior to illness and was connected through a church to the currently ill patients. Laboratory testing eventually confirmed the measles diagnosis in all four patients. Additional reports of measles in church members or people exposed to church members, quickly surfaced. A total of 21 cases, representing at least three waves of transmission, were confirmed. Sixteen (76%) of the cases were unvaccinated. Transmission was identified at the church, in households, and at one provider’s office. At the church, measles vaccine was administered to 200 susceptible contacts and immune globulin was given to another 20. Three individuals exposed in healthcare facilities also received IG. Health alerts were issued locally, regionally and state-wide asking providers to suspect and test for measles and to ensure all patients were current with measles vaccine. Area schools were notified of the situation and asked to review vaccine records of all children.

CONCLUSIONS: Unvaccinated communities exist in Texas and measles can spread rapidly if introduced. Responding to a measles outbreak requires rapid mobilization of extensive resources. Maintaining high vaccination coverage is critical to preventing a resurgence of measles.