BACKGROUND Manual white blood cell (WBC) differential counts as a predictor for neonatal sepsis development in a low-resource setting have not been thoroughly evaluated. We hypothesized that manual differentiation (specifically immature:total [I:T] neutrophil ratios) would be feasible and useful as an adjunct to predict early-onset neonatal sepsis (EONS). Secondarily, we hypothesized that vaccination with bacillus Calmette-Guérin (BCG) and oral polio vaccine (OPV) could alter WBC differential counts and thus might reduce its predictive performance. METHODS We performed a prospective cohort study within a randomized trial, randomizing healthy, high-risk newborns admitted to the nursery at the national hospital in Guinea-Bissau 1:1 to BCG+OPV at admission or at discharge (usual practice). Thin capillary blood films were prepared at 2 d of age in a subset of 268 neonates. WBC counts were assessed by microscopy and neonates were followed up for sepsis development within 2 weeks. RESULTS Ninety-eight percent (264/268) of smears provided interpretable reads. Of the 264 children, 136 had been randomized to receive BCG+OPV prior to sampling; the remaining 128 were vaccinated at discharge. The I:T ratio (average 0.017) was lower among children who did not develop clinical sepsis but did not predict sepsis (p=0.70). Only three children had an I:T ratio >0.2 (associated with a higher probability of clinical sepsis in previous studies) but did not develop sepsis. Immunization did not alter WBC composition. CONCLUSIONS Manual WBC differentials are feasible in low-resource settings. WBC differentials are not affected by standard newborn immunization. However, the I:T ratio had no value in predicting subsequent development of sepsis.

中文翻译：

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在资源贫乏地区，人工白细胞计数作为新生儿败血症的预测指标的可行性。

背景技术在缺乏资源的情况下，人工白细胞（WBC）差异计数作为新生儿败血症发展的预测指标尚未得到全面评估。我们假设手动分化（特别是不成熟：总[I：T]中性粒细胞比例）将是可行的，并且可以用作预测早期发作的新生儿败血症（EONS）的辅助手段。其次，我们假设用卡介苗（BCG）和口服脊髓灰质炎疫苗（OPV）接种疫苗可能会改变白细胞计数，从而降低其预测性能。方法我们在一项随机试验中进行了一项前瞻性队列研究，将入院或出院时在几内亚比绍国立医院保育的健康，高危新生儿以BCG + OPV 1：1的比例随机分组。在268岁的新生儿中，在2 d时制备了薄的毛细血管血膜。通过显微镜评估白细胞计数，并在2周内随访新生儿败血症的发展。结果98％（264/268）的涂片提供了可解释的读物。在264名儿童中，有136名在抽样之前已被随机分配接受BCG + OPV治疗。其余的128个在出院时接种了疫苗。在没有发生临床败血症但没有预测败血症的儿童中，I：T比（平均0.017）较低（p = 0.70）。只有三名儿童的I：T比> 0.2（与先前研究中临床败血症的可能性更高相关），但并未发展为败血症。免疫并未改变白细胞的组成。结论手动WBC差异在资源贫乏地区是可行的。WBC差异不受标准新生儿免疫的影响。但是，I：T比对预测败血症的发展没有价值。