Genotype Analysis of Measles Viruses, 2002
2003 Vol.19 NO.10
In 2002, through the communicable disease reporting system, 77 suspected cases of measles had been reported. Of them, 27 were confirmed by serological testing. By conventional epidemiological investigation, they could be grouped in five chains and 13 sporadic cases. The Taichung area had the largest number of 15 confirmed cases. This was second to the 31 confirmed cases identified in 1994. The first confirmed case in 2002 occurred in February. In July and August, cases were reported one by one in the Taichung area; and in mid-September till early October, cases were still reported from three junior high and primary schools in Taichung County. The outbreak was controlled in late-October after the checking of immunization records and make-up vaccination by the Disease Control Division of the Center for Disease Control. In the outbreaks in schools, wild-type measles viruses were isolated in specimens of three patients. By nucleoprotein gene sequencing, they were found to be the H1 genotype. Conventional epidemiological surveys of contact history could not always disclose associations between cases. In addition to the isolated virus strains, RNAs were extracted from clinical specimens such as sera, throat swabs or urine for RT-PCR. The products so obtained were sequenced, and compared for their nucleoprotein genes to investigate the epidemic from the viewpoint of molecular biology.