Scott Susana, Mossong Joel, Moss William J, Cutts Felicity T, Kasolo Francis, Sinkala Moses, Cousens Simon
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
Vaccine. 2004 Dec 21;23(6):732-8. doi: 10.1016/j.vaccine.2004.07.026.
Estimates of the force of infection (the rate at which susceptible individuals acquire infection) are essential for modelling the transmission dynamics of infectious diseases and can be a useful tool in evaluating mass vaccination strategies. Few estimates exist of the force of infection of measles virus in sub-Saharan Africa. A mathematical model was applied to age-specific recorded hospital admissions between September 1996 and September 1999 to estimate the force of measles virus infection in Lusaka, Zambia. The average force of infection was estimated to be 20% per year (95% confidence intervals (CI) 16.5, 23.5) which was insensitive to varying assumptions about vaccine coverage. The force of infection varied from year to year (P < 0.001) reflecting the cyclic pattern of measles incidence. The estimated probability of a case being hospitalised decreased with age, consistent with less severe disease in older children. Estimates of the force of infection using routinely available data were consistent with those based upon serological surveys in other sub-Saharan African countries.
感染力估计值（即易感个体获得感染的速率）对于模拟传染病的传播动态至关重要，并且在评估大规模疫苗接种策略时可能是一个有用的工具。在撒哈拉以南非洲地区，关于麻疹病毒感染力的估计值很少。应用一个数学模型对1996年9月至1999年9月期间按年龄记录的住院病例进行分析，以估计赞比亚卢萨卡市的麻疹病毒感染力。估计平均感染力为每年20%（95%置信区间为16.5, 23.5），该估计值对疫苗接种覆盖率的不同假设不敏感。感染力逐年变化（P < 0.001），反映出麻疹发病率的周期性模式。病例住院的估计概率随年龄增长而降低，这与大龄儿童病情较轻一致。利用常规可得数据得出的感染力估计值与基于撒哈拉以南非洲其他国家血清学调查得出的估计值一致。
