Shoklo Malaria Research Unit, Mae Sot, Thailand.
PLoS One. 2012;7(5):e38271. doi: 10.1371/journal.pone.0038271. Epub 2012 May 31.
Pneumococcal disease is a major cause of childhood death. Almost a third of the world's children live in Southeast Asia, but there are few data from the region on pneumococcal colonization or disease. Our aim was to document the dynamics of pneumococcal carriage in a rural SE Asian birth cohort.
We studied 234 Karen mother-infant pairs in Northwestern Thailand. Infants were followed from birth and nasopharyngeal swabs were taken from mother and infant at monthly intervals until 24 months old.
8,386 swabs were cultured and 4,396 pneumococci characterized. Infants became colonized early (median 45.5 days; 95% confidence interval [CI] 44.5-46.0) and by 24 months had a median of seven (range 0-15) carriage episodes. Maternal smoking and young children in the house were associated with earlier colonization (hazard ratio [HR] 1.5 (95% CI 1.1-2.1) and 1.4 (95% CI 1.0-1.9)). For the four commonest serotypes and non-typeable pneumococci, previous exposure to homologous or heterologous serotypes resulted in an extended interval to reacquisition of the same serotype. Previous colonization by serotypes 14 and 19F was also associated with reduced carriage duration if subsequently reacquired (HR [first reacquisition] 4.1 (95% CI 1.4-12.6) and 2.6 (1.5-4.7)). Mothers acquired pneumococci less frequently, and carried them for shorter periods, than infants (acquisition rate 0.5 vs. 1.1 /100 person-days, p<0.001; median duration 31.0 vs. 60.5 days, p = 0.001). 55.8% of pneumococci from infants were vaccine serotypes (13-valent pneumococcal conjugate vaccine, PCV13), compared with 27.5% from mothers (p<0.001). Non-typeable pneumococcal carriage was common, being carried at least once by 55.1% of infants and 32.0% of mothers.
Pneumococcal carriage frequency and duration are influenced by previous exposure to both homologous and heterologous serotypes. These data will inform vaccination strategies in this population.
肺炎球菌疾病是儿童死亡的主要原因。全球近三分之一的儿童生活在东南亚地区，但该地区关于肺炎球菌定植或疾病的数据很少。我们的目的是记录东南亚农村出生队列中肺炎球菌定植的动态。
我们研究了泰国西北部的 234 对克伦族母婴对。从婴儿出生开始对其进行随访，并在每月间隔时间内从母亲和婴儿身上采集鼻咽拭子，直到 24 个月大。
共培养了 8386 个拭子，并对 4396 株肺炎球菌进行了特征描述。婴儿早期定植（中位数 45.5 天；95%置信区间[CI]为 44.5-46.0），到 24 个月时，中位携带次数为 7 次（范围 0-15 次）。母亲吸烟和家中有幼儿与早期定植相关（风险比[HR]分别为 1.5（95%CI 1.1-2.1）和 1.4（95%CI 1.0-1.9））。对于四种最常见的血清型和非血清型肺炎球菌，以前接触同源或异源血清型会导致再次获得相同血清型的间隔时间延长。以前定植的血清型 14 和 19F 再次获得时，携带时间也会缩短（首次再感染的 HR [第一再感染]分别为 4.1（95%CI 1.4-12.6）和 2.6（1.5-4.7））。母亲获得肺炎球菌的频率较低，携带时间也较短，分别为婴儿的 0.5/100 人天与 1.1/100 人天（p<0.001），60.5 天与 31.0 天（p=0.001）。婴儿携带的肺炎球菌中有 55.8%（13 价肺炎球菌结合疫苗，PCV13）为疫苗血清型，而母亲携带的肺炎球菌中有 27.5%（p<0.001）为疫苗血清型。非血清型肺炎球菌定植很常见，55.1%的婴儿和 32.0%的母亲至少携带过一次非血清型肺炎球菌。
肺炎球菌定植的频率和持续时间受到同源和异源血清型的影响。这些数据将为该人群的疫苗接种策略提供信息。
