Serotype-specific data.

Significant differences between study years within a serotype include:*p = 0.05 compared to 2004.**p = 0.02 compared to 2004.†p = 0.03 compared to 2006.‡p = 0.03 compared to 2006. Significant differences in disease severity between study years overall include:§most severe study year is used as reference.##least severe study year is used as reference.#Discrepancies in totals are due to the 7 cases that were not serotyped and the single case that did not receive a serological response profile.同一血清型（serotype）内不同研究年份间存在显著差异，具体如下：*与2004年相比，p=0.05。**与2004年相比，p=0.02。†与2006年相比，p=0.03。‡与2006年相比，p=0.03。整体而言，不同研究年份间疾病严重程度存在显著差异，具体如下：§以病情最严重的研究年份作为参照组。##以病情最轻微的研究年份作为参照组。#总计数值存在差异，原因是有7例样本未完成血清分型，另有1例未获得血清学应答谱（serological response profile）。