Measles outbreak among internationally adopted children arriving in the United States, February-March 2001

Morbidity and Mortality Weekly Report, Dec 13, 2002

On February 16, 2001, the Texas Department of Health was notified about a child aged 10 months adopted from orphanage A in China who was taken to a Texas hospital with fever, conjunctivitis, coryza, Koplik spots, and a maculopapular rash. Measles was confirmed by serologic testing. Public health authorities in Texas notified CDC, which then collaborated with health officials in other states to contact other recently adopted children from China and their adoptive families. This report summarizes the results of multistate contact investigations that identified 14 U.S. measles cases and outlines measures taken in the United States and China to control and prevent measles transmission.

The index patient had traveled with prodromal fever on international (China to Los Angeles) and domestic (Los Angeles to Houston) flights on commercial airlines and had been part of a cohort of adopted children from China who had resided in orphanage A. These children and their adoptive families had spent [greater than or equal to] 2 weeks together in China while the families were visiting the orphanage and completing the immigrant visa process. The index patient potentially exposed multiple persons during the communicable period, including members of 63 families who had traveled to China to adopt children, representatives from 16 international adoption agencies who accompanied the families, staff at the local medical facility in China at which the patient was examined as a requirement for a U.S. immigrant visa, staff at the U.S. Consulate, passengers and crew members of the international and domestic flights on which the patient traveled, and adoption-agency representatives who met the returning family.

By February 22, consulate staff in China, staff at the medical facility, administrators at orphanage A, and all adoption agencies involved received information from CDC about measles exposure and prevention. Through the U.S. Consulate in China, the Central China Adoption Agency (CCAA) and CDC developed a collaborative strategy to control and prevent further spread of measles. The strategy included nine steps: 1) retrospective notification of families of adopted children from orphanage A who were interviewed at the U.S. Consulate during January 30-February 12; 2) prospective notification of families planning to travel to orphanage A advising them to delay travel to China until further notice; 3) distribution of alerts to adoptive families already in China; 4) notification of international adoption agencies in China to advise prospective adoptive families to verify and update the vaccination status of household members; 5) active screening for febrile and rash illnesses among adopted children examined at the m edical facility in China; 6) isolation of children suspected to have measles and restriction of their travel on commercial conveyances; 7) temporary suspension of adoption proceedings at orphanage A until no new measles cases were identified; 8) evaluation of children at orphanage A for measles; and 9) initiation of a vaccination campaign in orphanage A under the direction of CCAA.

Contact investigations identified 14 U.S. measles cases (13 confirmed serologically and one linked epidemiologically) among children who were recently adopted from China and their family members and close contacts in eight states, including 10 recently adopted children aged 9-12 months from seven states (New York [three], Ohio [two], Illinois [one], Indiana [one]), Minnesota [one], Missouri [one], and Texas [one]), two U.S.-born adoptive mothers (Indiana [aged 46 years] and Missouri [aged 39 years]), a U.S.-born caretaker (Connecticut [aged 47 years]) who had lived for a week in the same household as an adopted child with measles, and a sibling (Georgia [aged 28 months]) of a healthy adopted child from China. Thirteen U.S. measles cases were imported; the case of the U.S.-born caretaker was an indigenous, import-linked case.

All 14 cases of measles were identified during multistate investigations during February-March 2001. Among the 13 imported cases in adopted children and their family members, dates of onset of measles rash ranged from February 15 to March 7, 2001. These dates suggest incubation periods consistent with measles exposure in China, most likely at orphanage A but possibly during the medical screening or travel. The one indigenous, epidemiologically linked measles case was consistent with secondary transmission of measles in the United States from an adopted child. During the investigation, representatives of orphanage A retrospectively identified cases of suspected measles that preceded the index patient's illness and reported that newly arrived children at orphanage A had not been vaccinated adequately against measles. After completion of a measles vaccine campaign at orphanage A, no additional cases were reported, and the adoption of children from the orphanage resumed on March 29, a total of 3 weeks after the onset of the last known case of measles.