Carrim Maimuna, Kleynhans Jackie, Tempia Stefano, Hellferscee Orienka, Treurnicht Florette K, McMorrow Meredith L, Moyes Jocelyn, Wafawanaka Floidy, Cohen Cheryl, von Gottberg Anne, Wolter Nicole
Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.
School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Open Forum Infect Dis. 2025 May 31;12(6):ofaf267. doi: 10.1093/ofid/ofaf267. eCollection 2025 Jun.
Respiratory syncytial virus (RSV) and influenza infections are associated with increased pneumococcal colonization and disease risk. We assessed the impact of RSV and influenza on pneumococcal colonization density and factors influencing density changes during viral infection.
Over 3 years, 1658 individuals from 325 households were enrolled, with nasopharyngeal swabs collected twice weekly for pneumococcus, RSV, and influenza A/B detection by real-time polymerase chain reaction. We analyzed samples from 2 weeks before, during, and 2 and 8 weeks after infection. Pneumococcal density was compared across infection periods by tests, and multivariable regression identified factors influencing density changes.
Pneumococcal density increased during RSV infection (log mean before vs during infection, 9.3 vs 10.2 genomic copies/mL; < .01) but showed no significant overall increase with influenza (log mean before vs during infection, 9.6 vs 9.9 genomic copies/mL; = .2). However, the following were correlated with increased pneumococcal density: higher influenza viral loads (cycle threshold [Ct] value <25: coefficient, 2.8; 95% CI 1.4-4.2) and RSV viral loads (viral Ct value <25: coefficient, 2.5 [95% CI, 1.1-3.9; < .01]; viral Ct value of 25-29: coefficient, 1.1 [95% CI, .1-2.2; = .04]; vs viral Ct value of 30-34). Participants who were underweight had lower pneumococcal density differences (coefficient, -1.8; 95% CI, -3.5 to -.1; = .04) than those with a normal body mass index.
RSV infection, especially with higher viral loads, increases pneumococcal colonization, while individuals who are underweight exhibit lower density changes.
呼吸道合胞病毒（RSV）和流感感染与肺炎球菌定植增加及疾病风险相关。我们评估了RSV和流感对肺炎球菌定植密度的影响以及病毒感染期间影响密度变化的因素。
在3年时间里，招募了来自325个家庭的1658名个体，每周两次采集鼻咽拭子，通过实时聚合酶链反应检测肺炎球菌、RSV和甲型/乙型流感。我们分析了感染前2周、感染期间以及感染后2周和8周的样本。通过t检验比较不同感染时期的肺炎球菌密度，并通过多变量回归确定影响密度变化的因素。
RSV感染期间肺炎球菌密度增加（感染前与感染期间的对数均值，分别为9.3与10.2基因组拷贝/毫升；P<0.01），但流感感染时总体无显著增加（感染前与感染期间的对数均值，分别为9.6与9.9基因组拷贝/毫升；P = 0.2）。然而，以下因素与肺炎球菌密度增加相关：较高的流感病毒载量（循环阈值[Ct]值<25：系数为2.8；95%置信区间为1.4 - 4.2）和RSV病毒载量（病毒Ct值<25：系数为2.5[95%置信区间为1.1 - 3.9；P<0.01]；病毒Ct值为25 - 29：系数为1.1[95%置信区间为0.1 - 2.2；P = 0.04]；与病毒Ct值为30 - 34相比）。体重过轻的参与者肺炎球菌密度差异低于体重指数正常者（系数为 - 1.8；95%置信区间为 - 3.5至 - 0.1；P = 0.04）。
RSV感染，尤其是病毒载量较高时，会增加肺炎球菌定植，而体重过轻的个体密度变化较小。
