Meltzer M I, Damon I, LeDuc J W, Millar J D
Centers for Disease Control and Prevention, Atalnta, Georgia 30333,
Emerg Infect Dis. 2001 Nov-Dec;7(6):959-69. doi: 10.3201/eid0706.010607.
We constructed a mathematical model to describe the spread of smallpox after a deliberate release of the virus. Assuming 100 persons initially infected and 3 persons infected per infectious person, quarantine alone could stop disease transmission but would require a minimum daily removal rate of 50% of those with overt symptoms. Vaccination would stop the outbreak within 365 days after release only if disease transmission were reduced to <0.85 persons infected per infectious person. A combined vaccination and quarantine campaign could stop an outbreak if a daily quarantine rate of 25% were achieved and vaccination reduced smallpox transmission by > or = 33%. In such a scenario, approximately 4,200 cases would occur and 365 days would be needed to stop the outbreak. Historical data indicate that a median of 2,155 smallpox vaccine doses per case were given to stop outbreaks, implying that a stockpile of 40 million doses should be adequate.
我们构建了一个数学模型来描述天花病毒在蓄意释放后传播的情况。假设最初有100人感染，每个感染者可传染3人，仅靠隔离就能阻止疾病传播，但这需要对有明显症状者的每日隔离率至少达到50%。只有当疾病传播率降低到每个感染者感染人数小于0.85人时，接种疫苗才能在病毒释放后的365天内阻止疫情爆发。如果每日隔离率达到25%且接种疫苗使天花传播率降低≥33%，那么疫苗接种和隔离相结合的行动就能阻止疫情爆发。在这种情况下，大约会出现4200例病例，需要365天来阻止疫情爆发。历史数据表明，每例病例平均需要接种2155剂天花疫苗来阻止疫情爆发，这意味着储备4000万剂疫苗应该足够。
