河北省2020年1例接种麻疹风疹联合减毒活疫苗后D8基因型麻疹野病毒感染的鉴定

Identification of a D8 genotype measles case infected after receiving measles and rubella combined attenuated live vaccine in Hebei province, 2020

目的对河北省2020年1例接种麻疹风疹联合减毒活疫苗(MR)后发热出疹病例进行麻疹病毒基因型鉴定。方法对该病例进行流行病学调查,采集血清和咽拭子标本,分别检测麻疹IgM抗体和麻疹病毒核酸,麻疹病毒核酸阳性标本进行核苷酸序列测定和分析。结果该病例8月龄,接种MR后8d出现发热、出疹、咳嗽、卡他、结膜炎、柯氏斑和淋巴结肿大;血清麻疹IgM抗体阳性,咽拭子标本麻疹病毒核酸阳性;该例麻疹病毒株与WHO D8基因型参考株的核苷酸、氨基酸同源性分别为98.6%、97.3%,与中国香港D8基因型株的核苷酸和氨基酸同源性均为100%。结论该例接种MR后麻疹病例为非本土的D8基因型麻疹野病毒感染所致,与MR接种无关。

Objective To identif y the measles virus genotype of a rash and f ever case who had received measles and r u bella combined attenuated live vaccine(MR) in 2020 in Hebei province. Methods We cond ucted an epidemiological case investigation and collected serum and throat swab samples to detect measles IgM antibody and measles virus RNA. We conducted a nucleotide sequence analysis of measles virus for RNA-positive samples. Results The patient, 8 months old, had fever, rash, cough, catarrh, conjunctivitis, Koplik spots, and lymphadenectasis 8 days af ter MR vaccination. Her serum tested positive for measles IgM antibody, and measles virus RNA was detected in a throat swab. The nucleotide and amino acid homologies with measles virus strain f rom the patient were 98.6% and 97.3%, respectively, compared with the WHO D8 genotype ref erence strain, and were 100% homologous with Chinese Hong Kong D8 genotype measles virus strain. Conclusion Measles in this child, who had received MR vaccine, was caused by a non-indigenous, D8 genotype measles virus, not by MR vaccine.