McEllistrem M Catherine, Adams Jennifer M, Patel Kartik, Mendelsohn Aaron B, Kaplan Sheldon L, Bradley John S, Schutze Gordon E, Kim K S, Mason Edward O, Wald Ellen R
Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213-2582, USA.
Clin Infect Dis. 2005 Jun 15;40(12):1738-44. doi: 10.1086/429908. Epub 2005 May 11.
The impact of the 7-valent pneumococcal conjugate vaccine (PCV7 [Prevnar]) on penicillin-nonsusceptible Streptococcus pneumoniae (PNSP) recovered from children with acute otitis media (AOM) is unclear.
At 5 hospitals, 505 pneumococcal isolates were collected from children with AOM between 1 January 1999 and 31 December 2002. Molecular subtyping was performed on 158 isolates.
Overall, the percentage of AOM cases due to non-PCV7 serogroups (including serotype 3) increased over time (from 12% in 1999 to 32% in 2002; P < .01) and according to the number of PCV7 doses received (18% [< or = 1 dose] vs. 35% [2-4 doses]; P < .01). The percentage of cases due to vaccine-related serotypes (including serotype 19A) increased according to the number of PCV7 doses received (10% [< or = 1 dose] vs. 19% [2-4 doses]; P = .05) but not over time, whereas the percentage of cases due to serotype 19F remained unchanged both over time and according to the number of PCV7 doses received. The frequency of penicillin nonsusceptibility among PCV7 serotypes (range, 65%-75%) and non-PCV7 serogroups (range, 11%-27%) did not significantly change overall. Although no change was detected among isolates collected from children with spontaneous drainage, the percentage of pneumococci recovered at the time of myringotomy and/or tympanostomy tube placement that were nonresistant to penicillin decreased over time (from 73% in 1999 to 53% in 2002; P = .03). All of the serotype 3 strains were genetically related, whereas 88% of the isolates that were either serotype 19F or serotype 23F were related to 1 of 3 international clones.
Among children with AOM, the proportion of cases due to non-PCV7 serogroups increased, vaccine-related serotypes increased, and serotype 19F remained unchanged. Although a decrease in the proportion of cases due to PNSP occurred among children who required myringotomy and/or tympanostomy tube placement, the proportion of PNSP remained unchanged overall and among children with spontaneous drainage. Because future trends in the susceptibility patterns of pneumococcal isolates recovered from children with AOM are not easy to predict, continued surveillance is essential.
七价肺炎球菌结合疫苗（PCV7 [沛儿]）对从急性中耳炎（AOM）患儿中分离出的青霉素不敏感肺炎链球菌（PNSP）的影响尚不清楚。
在5家医院，于1999年1月1日至2002年12月31日期间从AOM患儿中收集了505株肺炎球菌分离株。对158株分离株进行了分子分型。
总体而言，由非PCV7血清型（包括3型）引起的AOM病例百分比随时间增加（从1999年的12%增至2002年的32%；P <.01），且根据接种PCV7的剂量数增加（18%[≤1剂]对35%[2 - 4剂]；P <.01）。由疫苗相关血清型（包括19A 型）引起的病例百分比根据接种PCV7的剂量数增加（10%[≤1剂]对19%[2 - 4剂]；P =.05），但不随时间增加，而由19F型引起的病例百分比在时间上和根据接种PCV7的剂量数均保持不变。PCV7血清型（范围为65% - 75%）和非PCV7血清群（范围为11% - 27%）中青霉素不敏感的频率总体上没有显著变化。虽然从自发引流患儿中收集的分离株未检测到变化，但在鼓膜切开术和/或鼓膜置管时回收的对青霉素不耐药的肺炎球菌百分比随时间下降（从1999年的73%降至2002年的53%；P =.03）。所有3型菌株在基因上相关，而88%的19F型或23F型分离株与3个国际克隆之一相关。
在AOM患儿中，由非PCV7血清群引起的病例比例增加，疫苗相关血清型增加，19F型保持不变。虽然在需要鼓膜切开术和/或鼓膜置管的患儿中，由PNSP引起的病例比例有所下降，但PNSP的总体比例以及自发引流患儿中的比例保持不变。由于从AOM患儿中回收的肺炎球菌分离株药敏模式的未来趋势不易预测，持续监测至关重要。
