Increased Nasopharyngeal Density and Concurrent Carriage of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis Are Associated with Pneumonia in Febrile Children

BackgroundWe assessed nasopharyngeal (NP) carriage of five pathogens in febrile children with and without acute respiratory infection (ARI) of the upper (URTI) or lower tract, attending health facilities in Tanzania.MethodsNP swabs collected from children (N = 960) aged 2 months to 10 years, and with a temperature ≥38°C, were utilized to quantify bacterial density of S. pneumoniae (Sp), H. influenzae (Hi), M. catarrhalis (Mc), S. aureus (Sa), and N. meningitidis (Nm). We determined associations between presence of individual species, densities, or concurrent carriage of all species combination with respiratory diseases including clinical pneumonia, pneumonia with normal chest radiography (CXR) and endpoint pneumonia.ResultsIndividual carriage, and NP density, of Sp, Hi, or Mc, but not Sa, or Nm, was significantly associated with febrile ARI and clinical pneumonia when compared to febrile non-ARI episodes. Density was also significantly increased in severe pneumonia when compared to mild URTI (Sp, pHi pMc, p = 0.014). Accordingly, concurrent carriage of Sp+, Hi+, and Mc+, in the absence of Sa- and Nm-, was significantly more prevalent in children with ARI (p = 0.03), or clinical pneumonia (pp = 0.0007) than URTI. Furthermore, Sp+, Hi+, and Mc+ differentiated children with pneumonia with normal CXR, or endpoint pneumonia, from those with URTI, and non-ARI cases.ConclusionsConcurrent NP carriage of Sp, Hi, and Mc was a predictor of clinical pneumonia and identified children with pneumonia with normal CXR and endpoint pneumonia from those with febrile URTI, or non-ARI episodes.

背景 本研究针对就诊于坦桑尼亚医疗机构的发热儿童开展研究，纳入伴上呼吸道急性感染（upper respiratory tract infection, URTI）或下呼吸道急性感染的发热儿童，以及无急性呼吸道感染的发热儿童，评估5种病原体的鼻咽（nasopharyngeal, NP）定植情况。
方法 本研究共纳入960名年龄介于2个月至10岁、体温≥38℃的儿童，采集其鼻咽拭子样本，用于定量分析肺炎链球菌（Streptococcus pneumoniae, Sp）、流感嗜血杆菌（Haemophilus influenzae, Hi）、卡他莫拉菌（Moraxella catarrhalis, Mc）、金黄色葡萄球菌（Staphylococcus aureus, Sa）及脑膜炎奈瑟菌（Neisseria meningitidis, Nm）的菌落密度。本研究旨在明确单种病原体的定植状态、菌落密度，或所有病原体组合的共同定植情况，与各类呼吸道疾病（包括临床肺炎、胸部X线片（chest radiography, CXR）正常的肺炎及终点肺炎）之间的关联。
结果 相较于无急性呼吸道感染的发热病例，肺炎链球菌（Sp）、流感嗜血杆菌（Hi）或卡他莫拉菌（Mc）的单独定植及鼻咽菌落密度，与发热伴急性呼吸道感染及临床肺炎呈显著相关，而金黄色葡萄球菌（Sa）及脑膜炎奈瑟菌（Nm）则未观察到此类关联。与轻度上呼吸道急性感染患儿相比，重症肺炎患儿的上述三种病原体菌落密度亦显著升高（Sp、Hi、Mc，p=0.014）。进一步分析显示，在无金黄色葡萄球菌（Sa）及脑膜炎奈瑟菌（Nm）定植的前提下，同时携带Sp+、Hi+及Mc+的儿童，其急性呼吸道感染（ARI）发生率（p=0.03）或临床肺炎发生率（p=0.0007）显著高于上呼吸道急性感染（URTI）患儿。此外，同时携带Sp+、Hi+及Mc+的特征，可将胸部X线片正常的肺炎或终点肺炎患儿，与上呼吸道急性感染及无急性呼吸道感染的发热患儿有效区分。
结论 鼻咽同时定植肺炎链球菌、流感嗜血杆菌及卡他莫拉菌，可作为临床肺炎的预测指标，并可区分胸部X线片正常的肺炎、终点肺炎患儿与发热伴上呼吸道急性感染或无急性呼吸道感染的发热儿童。