Muñoz-Almagro Carmen, Jordan Iolanda, Gene Amadeo, Latorre Cristina, Garcia-Garcia Juan J, Pallares Roman
Department of Microbiology, Hospital Universitari Sant Joan de Deu, Esplugues, Spain.
Clin Infect Dis. 2008 Jan 15;46(2):174-82. doi: 10.1086/524660.
Little is known about the epidemiology of invasive pneumococcal disease (IPD) after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7) in Spain and other European countries.
We performed a 10-year prospective study including all children with culture-proven IPD admitted to Sant Joan de Deu Hospital, a children's center in the southern area of Barcelona, Catalonia, Spain. PCV7 was introduced in June 2001, and the current estimate of PCV7 coverage is 45%-50%.
Comparing the prevaccine period (1997-2001) with the vaccine period (2002-2006), among children aged <2 years, the rate of IPD increased from 32.4 episodes per 100,000 population to 51.3 episodes per 100,000 population (an increase of 58%; 95% confidence interval, 2%-145%), and among children aged 2-4 years, the rate increased from 11.3 episodes per 100,000 population to 26.5 episodes per 100,000 population (an increase of 135%; 95% confidence interval, 31%-320%). At clinical presentation, the rate of pneumonia and/or empyema among children aged <5 years increased from 3.6 episodes per 100,000 population to 15.1 episodes per 100,000 population (an increase of 320%; 95% confidence interval, 98%-790%). These increased rates of IPD were caused by non-PCV7 serotypes, which represented 38% and 72% of infecting serotypes in the prevaccine and vaccine periods, respectively (P=.001). Penicillin resistance decreased from 48% in the prevaccine period to 27% in the vaccine period (P=.005). In the vaccine period, there was an emergence of previously established virulent clones of non-PCV7 serotypes 1 and 5. There was also an increase in the prevalence of serotypes 19A and 6A expressed with different clonal types, including Spain(23F)-1 and Spain(6B)-2.
Since the introduction of PCV7 for children, there has been an emergence of IPD caused by virulent clones of non-PCV7 serotypes that has been associated with significant clinical changes and a decrease in antibiotic resistance.
在西班牙及其他欧洲国家引入7价肺炎球菌结合疫苗（PCV7）后，侵袭性肺炎球菌疾病（IPD）的流行病学情况鲜为人知。
我们进行了一项为期10年的前瞻性研究，纳入了所有在西班牙加泰罗尼亚巴塞罗那南部地区的儿童中心圣琼·德乌医院确诊为IPD且有培养结果的儿童。PCV7于2001年6月引入，目前估计PCV7的覆盖率为45%-50%。
将疫苗接种前时期（1997-2001年）与疫苗接种时期（2002-2006年）进行比较，在2岁以下儿童中，IPD发病率从每10万人口32.4例增至每10万人口51.3例（增加了58%；95%置信区间为2%-145%），在2-4岁儿童中，发病率从每10万人口11.3例增至每10万人口26.5例（增加了135%；95%置信区间为31%-320%）。在临床表现方面，5岁以下儿童中肺炎和/或脓胸的发病率从每10万人口3.6例增至每10万人口15.1例（增加了320%；95%置信区间为98%-790%）。这些IPD发病率的增加是由非PCV7血清型引起的，在疫苗接种前和接种时期，非PCV7血清型分别占感染血清型的38%和72%（P=0.001）。青霉素耐药率从疫苗接种前时期的48%降至疫苗接种时期的27%（P=0.005）。在疫苗接种时期，出现了之前已确定的非PCV7血清型1和5的强毒株克隆。血清型19A和6A以不同克隆类型表达的患病率也有所增加，包括西班牙型（23F）-1和西班牙型（6B）-2。
自儿童接种PCV7以来，出现了由非PCV7血清型强毒株克隆引起的IPD，这与显著的临床变化及抗生素耐药性降低有关。
