Institute of Environmental Science and Research, National Centre for Biosecurity and Infectious Disease, Wallaceville, New Zealand.
Euro Surveill. 2010 Jun 17;15(24):19591.
The first wave of pandemic influenza A(H1N1) has subsided in New Zealand as in other southern hemisphere countries. This study aimed to estimate the effective reproduction number (R) of 2009 pandemic influenza A(H1N1) taking into account imported cases. It also aimed to show the temporal variation of R throughout the New Zealand epidemic, changes in age- and ethnicity-specific cumulative incidence, and the effect of school holidays. Using a new modelling method to account for imported cases, we have calculated the peak R during the containment phase of the pandemic as 1.55 (95% confidence interval: 1.16 to 1.86). This value is less than previously estimated in the country early in the pandemic but in line with more recent estimates in other parts of the world. Results also indicated an increase in the proportion of notifications among school-age children after the school holiday (3-19 July 2009). This finding provides support for the potential effectiveness of timely school closures, although such disruptive interventions need to be balanced against the severity of the pandemic.
在新西兰和其他南半球国家，第一波大流行性流感 A(H1N1)已经消退。本研究旨在估算考虑输入病例时 2009 年大流行性流感 A(H1N1)的有效繁殖数（R）。它还旨在展示整个新西兰流行期间 R 的时间变化，年龄和种族特异性累积发病率的变化，以及学校假期的影响。使用一种新的建模方法来考虑输入病例，我们计算出大流行遏制阶段的高峰 R 为 1.55（95%置信区间：1.16 至 1.86）。这一数值低于大流行早期在该国的先前估计值，但与世界其他地区的最新估计值相符。结果还表明，在学校假期（2009 年 7 月 3 日至 19 日）之后，学龄儿童中的通报比例有所增加。这一发现为及时关闭学校的潜在有效性提供了支持，尽管这种破坏性干预需要与大流行的严重程度相平衡。
