Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia.
J Infect Dis. 2013 Oct 15;208(8):1266-73. doi: 10.1093/infdis/jit315. Epub 2013 Jul 12.
We examined whether observed increases in antibiotic nonsusceptible nonvaccine serotypes after introduction of pneumococcal conjugate vaccine in the United States in 2000 were driven primarily by vaccine or antibiotic use.
Using active surveillance data, we evaluated geographic and temporal differences in serotype distribution and within-serotype differences during 2000-2009. We compared nonsusceptibility to penicillin and erythromycin by geography after standardizing differences across time, place, and serotype by regressing standardized versus crude proportions. A regression slope (RS) approaching zero indicates greater importance of the standardizing factor.
Through 2000-2006, geographic differences in nonsusceptibility were better explained by within-serotype prevalence of nonsusceptibility (RS 0.32, 95% confidence interval [CI], .08-.55 for penicillin) than by geographic differences in serotype distribution (RS 0.71, 95% CI, .44-.97). From 2007-2009, serotype distribution differences became more important for penicillin (within-serotype RS 0.52, 95% CI, .11-.93; serotype distribution RS 0.57, 95% CI, .14-1.0).
Differential nonsusceptibility, within individual serotypes, accounts for most geographic variation in nonsusceptibility, suggesting selective pressure from antibiotic use, rather than differences in serotype distribution, mainly determines nonsusceptibility patterns. Recent trends suggest geographic differences in serotype distribution may be affecting the prevalence of nonsusceptibility, possibly due to decreases in the number of nonsusceptible serotypes.
我们研究了 2000 年美国引入肺炎球菌结合疫苗后观察到的抗生素不敏感非疫苗血清型增加是否主要由疫苗或抗生素使用驱动。
使用主动监测数据，我们评估了 2000-2009 年期间血清型分布的地理和时间差异以及血清型内差异。通过回归标准化与粗比例来标准化跨时间、地点和血清型的差异，比较青霉素和红霉素的不敏感性在地理上的差异。接近零的回归斜率（RS）表示标准化因素的重要性更大。
通过 2000-2006 年，血清型内不敏感性的地理差异通过血清型内不敏感性的流行率（青霉素的 RS 0.32，95%置信区间[CI]，.08-.55）比血清型分布的地理差异（青霉素的 RS 0.71，95%CI，.44-.97）更好地解释。从 2007-2009 年，血清型分布差异对青霉素变得更为重要（血清型内 RS 0.52，95%CI，.11-.93；血清型分布 RS 0.57，95%CI，.14-1.0）。
个体血清型内的差异不敏感性解释了不敏感性的大部分地理差异，这表明抗生素使用的选择压力，而不是血清型分布的差异，主要决定了不敏感性模式。最近的趋势表明，血清型分布的地理差异可能会影响不敏感性的流行率，这可能是由于不敏感血清型的数量减少所致。
