Lyons R A, Jones H I, Salmon R L
PHLS Communicable Disease Surveillance Centre (Welsh Unit), Cardiff.
Epidemiol Infect. 1994 Oct;113(2):367-75. doi: 10.1017/s0950268800051797.
In an outbreak of measles in North Wales centred on a secondary school in 1991, 74 cases occurred over a period of 51 days. Before the outbreak started, 27% pupils did not have a history of measles or immunization and were considered susceptible. Active case finding and identification and vaccination of susceptible contacts commenced after the fourth generation of cases and further reduced the pool of susceptible schoolchildren from 17%, at the onset of the vaccination campaign, to 8%. A fifth generation of cases did not occur. Delays in diagnosis (mean 2.8 days) and notification (mean 6.1 days) hampered control. There was no evidence of primary vaccine failure (observed vaccine efficacy 97%). Sixty-nine (93%) cases were considered preventable. Reasons for the apparent success of the intervention are discussed.
1991年，在北威尔士以一所中学为中心爆发了麻疹疫情，在51天内出现了74例病例。疫情爆发前，27%的学生没有麻疹病史或免疫接种史，被视为易感人群。在第四代病例出现后，开展了主动病例排查以及对易感接触者的识别和疫苗接种工作，使易感学童群体从疫苗接种运动开始时的17%进一步减少到8%。没有出现第五代病例。诊断延迟（平均2.8天）和报告延迟（平均6.1天）阻碍了疫情控制。没有原发性疫苗失败的证据（观察到的疫苗效力为97%）。69例（93%）病例被认为是可以预防的。文中讨论了干预措施明显成功的原因。
