Despite evidence that airborne transmission contributes to influenza epidemics, limited knowledge of the infectiousness of human influenza cases hinders pandemic preparedness. We used airborne viral source strength and indoor CO₂ monitoring from the largest human influenza challenge‐transmission trial (EMIT: Evaluating Modes of Influenza Transmission, ClinicalTrials.gov number NCT01710111) to compute an airborne infectious dose generation rate q = 0.11 (95% CI 0.088, 0.12)/h and calculate the quantity of airborne virus per infectious dose σ = 1.4E + 5 RNA copies/quantum (95% CI 9.9E + 4, 1.8E + 5). We then compared these calculated values to available data on influenza airborne infectious dose from several previous studies, and applied the values to dormitory room environments to predict probability of transmission between roommates. Transmission risk from typical, moderately to severely symptomatic influenza cases is dramatically decreased by exposure reduction via increasing indoor air ventilation. The minority of cases who shed the most virus (ie, supershedders) may pose great risk even in well‐ventilated spaces. Our modeling method and estimated infectiousness provide a ground work for (a) epidemiologic studies of transmission in non‐experimental settings and (b) evaluation of the extent to which airborne exposure control strategies could limit transmission risk.

中文翻译：

---

流感人类挑战-传播试验的定量航空生物学分析。

尽管有证据表明空中传播是造成流感流行的原因，但对人类流感病例传染性的了解有限，阻碍了大流行的防范。我们使用了最大的人类流感挑战传播试验（EMIT：评估流感传播模式，ClinicalTrials.gov号NCT01710111）中的机载病毒源强度和室内CO ₂监测来计算机载传染剂量的产生率q  = 0.11（95％CI 0.088，0.12）/ h并计算每感染剂量σ传播的空中病毒数量 = 1.4E + 5个RNA拷贝/量子（95％CI 9.9E + 4，1.8E + 5）。然后，我们将这些计算值与先前几项研究中有关流感空气传播感染剂量的可用数据进行了比较，并将这些值应用于宿舍房间环境，以预测室友之间传播的可能性。通过增加室内空气流通，减少接触，可以大大降低典型，中度至重度症状性流感病例的传播风险。即便是在通风良好的地方，也很少有病毒脱落最多的病例（即，超级动物）。我们的建模方法和估计的传染性为（a）在非实验环境中传播的流行病学研究和（b）评估机载暴露控制策略可限制传播风险的程度提供了基础。