Ledrans M, Cassadou S, Chappert J-L, Quénel P
Cellule de l'Institut de Veille Sanitaire en Région Antilles-Guyane, ARS de Martinique, Centre d'Affaires AGORA, ZAC de l'Étang Z'Abricot, pointe des Grives, BP 656, 97261 Fort-de-France cedex, France.
Rev Epidemiol Sante Publique. 2011 Dec;59(6):401-8. doi: 10.1016/j.respe.2011.07.003. Epub 2011 Oct 19.
Sentinel general practitioner networks monitor influenza-like infections (ILI) in Martinique and in Guadeloupe (French West Indies). During the A(H1N1)2009 pandemic, they gave an ILI incidence estimation higher in Martinique than in Guadeloupe. In October 2009, a telephonic survey was launched in both islands to assess the number of ILI diagnoses performed by general practitioners since the beginning of the pandemic. This paper compares the results of sentinel surveillance, of telephonic survey and of hospital surveillance in Guadeloupe and in Martinique.
On each island, the sentinel network gathers a representative sample of voluntary general practitioners. Each week, they report the number of ILI they diagnosed the past week. Times series of these weekly numbers were modelized using the Serfling method with the upper limit of the confidence interval of the expected value representing the epidemic threshold. The telephone survey was conducted from October 2, 2009 to October 12, 2009 in Martinique and from October 13, 2009 to October 21, 2009 in Guadeloupe. The quota method was used for sampling individuals older than 14 years, leading to 507 interviews in Guadeloupe and 508 in Martinique.
The epidemic lasted 12 weeks in both islands, from August 3 to October 25 in Martinique and from August 17 to November 8 in Guadeloupe. During August and September, estimated attack rate in Martinique was 5.52% (CI95: 5.23-5.83) from the sentinel network versus 8.3% (CI95: 6.0-11.0) from the telephone survey. In Guadeloupe, it was 2.13% (CI95: 1.97-2.24) from the sentinel network versus 6.9% (CI95: 4.8-9.5) from the telephone survey. An equivalent number of confirmed hospitalized cases was observed in the two islands.
These results suggest that the sentinel network underestimates ILI incidence in Guadeloupe. According to Emergency Room activity for ILI, it seems possible that ILI incidence was actually higher in Martinique. A lower proportion of swab sampling among ILI hospitalized people could partly explain the observed differences in hospitalization ratio, in severity and in lethality between the two islands.
哨点全科医生网络监测马提尼克岛和瓜德罗普岛（法属西印度群岛）的流感样感染（ILI）情况。在2009年甲型H1N1流感大流行期间，他们给出的ILI发病率估计值在马提尼克岛高于瓜德罗普岛。2009年10月，在这两个岛屿同时开展了一项电话调查，以评估自疫情开始以来全科医生做出的ILI诊断数量。本文比较了瓜德罗普岛和马提尼克岛哨点监测、电话调查及医院监测的结果。
在每个岛屿上，哨点网络收集了具有代表性的志愿全科医生样本。每周，他们报告过去一周诊断出的ILI病例数。这些每周病例数的时间序列使用塞尔弗林方法进行建模，预期值置信区间的上限代表流行阈值。电话调查于2009年10月2日至12日在马提尼克岛进行，于2009年10月13日至21日在瓜德罗普岛进行。采用配额抽样法对14岁以上个体进行抽样，在瓜德罗普岛进行了507次访谈，在马提尼克岛进行了508次访谈。
两个岛屿的疫情均持续了12周，在马提尼克岛为8月3日至10月25日，在瓜德罗普岛为8月17日至11月8日。8月和9月期间，马提尼克岛哨点网络估计的发病率为5.52%（95%置信区间：5.23 - 5.83），而电话调查得出的发病率为8.3%（95%置信区间：6.0 - 11.0）。在瓜德罗普岛，哨点网络得出的发病率为2.13%（95%置信区间：1.97 - 2.24），电话调查得出的发病率为6.9%（95%置信区间：4.8 - 9.5）。在两个岛屿观察到确诊住院病例数相当。
这些结果表明，哨点网络低估了瓜德罗普岛的ILI发病率。根据ILI的急诊室活动情况，马提尼克岛的ILI发病率实际可能更高。ILI住院患者中较低的拭子采样比例可能部分解释了两个岛屿在住院率、严重程度和致死率方面观察到的差异。
