Black Steven, France Eric K, Isaacman Daniel, Bracken Laura, Lewis Edwin, Hansen John, Fireman Bruce, Austrian Robert, Graepel Jay, Gray Sharon, Klein Nicola P
Division of Pediatric Infectious Diseases, Stanford University School of Medicine, Stanford, CA, USA.
Pediatr Infect Dis J. 2007 Sep;26(9):771-7. doi: 10.1097/INF.0b013e318124a494.
To assess the incidence of invasive pneumococcal disease (IPD) in all children younger than 5 years of age in the Northern California Kaiser Permanente (NCKP) health care system during a 5-year surveillance period (2000-2005) after the introduction in April 2000 of routine use of 7-valent pneumococcal conjugate vaccine (PCV7).
This was a laboratory-based surveillance study of all children younger than 5 years of age in the NCKP health care system from April 2000 to March 2005. The comparison group was all children younger than 5 years of age in the NCKP health care system from April 1996 to March 2000. Data obtained from clinical databases included microbiologic identification and susceptibility testing; serotyping of isolates; immunization records; and IPD diagnoses for inpatients and outpatients. IPD was defined as a positive culture of Streptococcus pneumoniae from a normally sterile body site.
For all serotypes, the mean annual incidence of IPD during the postlicensure surveillance period was 15.3 cases/100,000 person-years (10(5) p-y) compared with 62.5 cases/10(5) p-y in the prelicensure years of 1996-2000. The average incidence of IPD caused by vaccine serotypes was reduced from 50.1 cases/10(5) p-y during the prelicensure years to 4.9 cases/10(5) p-y during the postlicensure period. The average incidences of IPD caused by cross-reactive and by nonvaccine serotypes were 5.8 and 5.3 cases/10(5) p-y, respectively, during the prelicensure years and 2.5 and 6.2 cases/10(5) p-y, respectively, during the postlicensure period. Of the 131 IPD cases observed during the postlicensure surveillance period, bacteremia (50.4%) and pneumonia (31.3%) were the most common diagnoses. During the 5-year postlicensure surveillance period, only 3 subjects who were identified to be fully vaccinated for age with PCV7 (3 doses by 7 months of age or 4 doses by 18 months of age) developed vaccine-serotype IPD.
The incidence of IPD has significantly decreased in a large population of children after the introduction of PCV7. Vaccine-type IPD was rare in patients who received full 4-dose immunization with PCV7. There is no clear evidence of a significant increase in nonvaccine-serotype IPD. Introduction of a 4-dose infant schedule of PCV7 into this population has resulted in a marked and sustained reduction of IPD in children.
评估在2000年4月引入7价肺炎球菌结合疫苗（PCV7）进行常规接种后的5年监测期（2000 - 2005年）内，北加利福尼亚凯撒医疗集团（NCKP）医疗系统中所有5岁以下儿童侵袭性肺炎球菌疾病（IPD）的发病率。
这是一项基于实验室的监测研究，对象为2000年4月至2005年3月在NCKP医疗系统中所有5岁以下儿童。对照组为1996年4月至2000年3月在NCKP医疗系统中所有5岁以下儿童。从临床数据库获取的数据包括微生物鉴定和药敏试验；分离株的血清分型；免疫接种记录；以及住院患者和门诊患者的IPD诊断。IPD定义为从正常无菌身体部位培养出肺炎链球菌阳性。
对于所有血清型，许可后监测期内IPD的年平均发病率为15.3例/100,000人年（10⁵人年），而1996 - 2000年许可前几年为62.5例/10⁵人年。疫苗血清型引起的IPD平均发病率从许可前几年的50.1例/10⁵人年降至许可后时期的4.9例/10⁵人年。交叉反应血清型和非疫苗血清型引起的IPD平均发病率在许可前几年分别为5.8例/10⁵人年和5.3例/10⁵人年，在许可后时期分别为2.5例/10⁵人年和6.2例/10⁵人年。在许可后监测期观察到的131例IPD病例中，菌血症（50.4%）和肺炎（31.3%）是最常见的诊断。在许可后的5年监测期内，只有3名经确认按年龄完成PCV7全程接种（7个月龄时接种3剂或18个月龄时接种4剂）的儿童发生了疫苗血清型IPD。
引入PCV7后，大量儿童中IPD的发病率显著下降。接受PCV7全程4剂免疫的患者中疫苗型IPD罕见。没有明确证据表明非疫苗血清型IPD有显著增加。在该人群中引入4剂婴儿PCV7接种方案已使儿童IPD显著且持续减少。
