Four cases of measles were reported during 2001. Three cases were laboratory-confirmed by a positive serologic test for measles IgM; one case was confirmed by viral culture for measles. No further transmission from any of the four cases was identified.
The first case-patient was a 13-month-old adoptee from China. The child
had not been vaccinated and was exposed to measles in a Chinese orphanage
2 weeks prior to rash onset. Serology for measles IgM and the viral culture
for measles were positive. The specimen was not viable after initial testing
and so could not be sent to CDC for genotype analysis. This child was
one of nine measles cases reported in the U. S. during February and March
among recent adoptees from China.
The second case-patient was a 31-year-old male who reported repeated domestic travel during February and March. He reported an unknown vaccination history, and laboratory results included both a positive serologic test for measles IgM and a positive viral culture for measles. Genotyping performed at CDC identified the same genotype as another imported case from China, which was reported in Washington state. The Minnesota case had no airplane flights in common with any of the known cases from China.
The third case-patient was a 10-year-old female who was exposed to measles in a refugee camp in Nairobi prior to arrival in the U.S. The child had an unknown vaccination history. The case was laboratory-confirmed by positive serology for measles IgM. Polymerase chain reaction (PCR) testing performed at CDC identified a measles genotype common in Somalia. Serological testing was performed on all household contacts, and all showed immunity to measles.
The final case-patient was a 2-week-old infant. The infant's laboratory tests were incongruent. The measles IgM test was negative; however, the viral culture was positive for measles. Genotyping performed at CDC identified a measles genotype common in Vietnam. Serologic testing of family members, including the child's mother, indicated that all were immune to measles. No source case was identified.
International importation is an important source of measles transmission in the U.S. Two of the four measles cases reported in Minnesota during 2001 were international importations, and at least one likely was exposed to an imported case. During the past 5 years, eight (57%) of the 14 measles cases reported in Minnesota were imported.