Boëlle P-Y, Thomas G, Vergu E, Renault P, Valleron A-J, Flahault A
Université Pierre et Marie Curie - Parisó, UMR S 707, Paris, France.
Vector Borne Zoonotic Dis. 2008 Apr;8(2):207-17. doi: 10.1089/vbz.2006.0620.
An epidemic of Chikungunya fever, a mosquito-borne viral disease, spectacularly swept through Réunion Island (population 780,000) in 2005-2006. There were 3,000 cases in a first wave (March-June 2005) and more than 250,000 cases in a second (December 2005-April 2006). Adapting newly developed epidemiological tools to vector-borne diseases, we show that despite this massive difference in magnitude, the transmission potential as measured by the number of secondary cases per index case (or reproduction number), remained similar during the two consecutive waves. The best estimate for the initial reproduction number R(0) was 3.7, with a possible range from 2 to 11 depending on incubation duration and lifespan of the mosquito. We conclude that an increase in virulence between the two seasons was not necessary to explain the change in magnitude of the epidemics, and that the attack rate may be well over 50% in Chikungunya fever epidemics in the absence of intervention.
基孔肯雅热是一种由蚊子传播的病毒性疾病。2005年至2006年期间，一场基孔肯雅热疫情惊人地席卷了留尼汪岛（人口78万）。第一波疫情（2005年3月至6月）有3000例病例，第二波（2005年12月至2006年4月）则超过25万例。通过将新开发的流行病学工具应用于虫媒疾病，我们发现，尽管两波疫情的规模存在巨大差异，但以每例指示病例的二代病例数（即繁殖数）衡量的传播潜力在连续两波疫情期间保持相似。初始繁殖数R(0)的最佳估计值为3.7，根据蚊子的潜伏期和寿命，可能范围为2至11。我们得出结论，两季之间毒力的增加并非解释疫情规模变化的必要因素，而且在没有干预的情况下，基孔肯雅热疫情的发病率可能远超过50%。
