Notes from the Field: Measles Outbreak --- Indiana, June--July 2011

On June 20, 2011, an emergency department (ED) physician reported five epidemiologically linked measles cases to the Indiana State Department of Health. The subsequent investigation identified a total of 14 confirmed cases in northeast Indiana. Of these, 10 were laboratory-confirmed, and four were among household contacts of persons with laboratory-confirmed measles. Of the 14 patients, 13 were unvaccinated persons in the same extended family. The nonfamily member was a child aged 23 months who had received 1 dose of measles, mumps, and rubella vaccine 4 months before illness onset. Four of the 14 patients were males; median age was 11.5 years (range: 15 months--27 years). One patient was a woman in week 32 of pregnancy who was hospitalized for acute pneumonitis.

The index patient was an unvaccinated U.S. resident aged 24 years who noted a rash on June 3 during a return flight from Indonesia, where measles is endemic. The patient was admitted to an Indiana hospital during June 7--9 and treated for presumed dengue fever. Measles was not considered, and the patient was not isolated. The outbreak was unrecognized until June 20, when five family members visited an ED after experiencing onset of measles symptoms at various times over the previous few days. Subsequently, measles genotype D9, a strain endemic in Indonesia (1), was isolated from nasopharyngeal swabs from two of these patients.

A contact investigation involving approximately 780 persons included follow-up of exposures at a church (approximately 150 persons), a factory (approximately 300 persons), and in a bus ridden by school-aged children who had traveled out of state. Infectious persons attended parties, family gatherings, sports events, and meetings, and sought health care. Health-care facility exposures included two general-practice offices, one obstetric office, two EDs, one urgent-care facility, and two hospitals. Outbreak control measures were instituted, including media releases that informed the local public of the outbreak and steps to take. Messages were sent statewide to health-care providers through the Indiana Health Alert Network with recommendations on how to evaluate patients with fever and rash without exposing others and instructions on testing and reporting procedures.

For exposed persons without evidence of immunity to measles, the Indiana State Department of Health recommended vaccination of eligible persons within 3 days of exposure or immunoglobulin administration within 6 days of exposure for patients at high risk for measles complications; in addition, vaccination was recommended for all eligible persons regardless of their exposure history. Recommendations were made to health-care facilities where exposures might have occurred to exclude potentially exposed health-care personnel from patient-care responsiblities until measles immunity was documented and to exclude personnel without evidence of immunity for 21 days after their last exposure. Community testing and vaccination clinics were conducted. Preliminary estimates of the impact of the measles outbreak on the state health department are as follows: 660 personnel hours, 1,510 miles logged, and $6,243 in testing costs.

As of August 26, 198 cases and 15 outbreaks of measles had been confirmed in the United States, the highest number since 1996 (CDC, unpublished data, 2011). Of the 198 cases, 179 (90%) were associated with U.S. residents traveling internationally. Of the 15 outbreaks, the outbreak in Indiana is the second largest. With ongoing importation and suboptimal vaccination rates among specific populations, measles outbreaks might continue to occur (2). In addition to providing accurate information on the risks and benefits of vaccines and making vaccination accessible, state and local health departments should continue to investigate contacts of suspected measles patients to institute control measures to prevent measles transmission in the community. Parents should be reminded, as children return to school, to check their children's vaccination status for measles, mumps, and rubella vaccine and all other recommended vaccines.

Reported by

Noble County Health Dept, Albion; LaGrange County Health Dept, LaGrange; Indiana State Dept of Health. Div of Viral Diseases, National Center for Immunization and Respiratory Disease, CDC. Corresponding contributor: Melissa Collier, MD, EIS Officer, mcollier@isdh.in.gov, 317-233-7627.

References

1. Rota PA, Brown K, Mankertz A, et al. Global distribution of measles genotypes and measles molecular epidemiology. J Infect Dis 2011;204(Suppl 1):S514--21.
2. CDC. Notes from the field: measles outbreak---Hennepin County, Minnesota, February--March 2011. MMWR 2011;60:421.