哮喘联盟

   摘要
   背景：包括铜绿假单胞杆菌在内的呼吸道疾病病原体在人-人间的传播，是许多囊性纤维化（CF）治疗中心所面临的困难之一。咳嗽产生的气溶胶内含存活的铜绿假单胞杆菌，可使该病原体经空气传播的概率提高。
   方法：利用专用仪器，我们测试了距患者1米、2米以及4米处咳出气溶胶内存活的铜绿假单胞杆菌，并将气溶胶置于缓慢旋转的转鼓内5min、15min以及45min（持续时间），以减少重力沉降和惯性碰撞。使用安德森冲击系统收集气溶胶并测量他们的直径，而后运用常规微生物培养基对这些气溶胶进行培养。试验还进行了痰培养、肺功能及呼吸肌力测试。
   结果：19名存在慢性铜绿假单胞杆菌感染，平均年龄为25.8（标准差9.2）岁的囊性纤维化患者，以及对照组中10名平均年龄为26.5（标准差8.7）岁的健康人员参与了这项研究。所有囊性纤维化患者咳出气溶胶内均检出存活的铜绿假单胞杆菌，而对照组均无。17/18（94%）名CF患者气溶胶播散了4米，14/18（78%）名患者气溶胶持续存在了45min。不同患者咳出气溶胶中铜绿假单胞菌克隆计数显著不同，且与痰培养中的细菌数量呈强相关（r=0.73-0.90）。在医务室中进行的针对存活铜绿假单胞杆菌的模拟衰减试验提示，当一名感染患者离开房间后，在推荐的通风频率下（每小时2次换气），需要近50分钟才能将90%的带菌气溶胶排出。
   结论：相较于之前确认的数据，带有存活铜绿假单胞杆菌的气溶胶播散距离更远，存在时间也更长。为CF患者间的空气传播提供了额外的证据。
 

（刘国梁 审校）
Thorax. 2014 Aug;69(8):740-5. doi: 10.1136/thoraxjnl-2014-205213. Epub 2014 Apr 17.

 

Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis.
 

Knibbs LD1, Johnson GR2, Kidd TJ3, Cheney J4, Grimwood K3, Kattenbelt JA3, O'Rourke PK5, Ramsay KA3, Sly PD3, Wainwright CE4, Wood ME6, Morawska L2, Bell SC7.
 

ABSTRACT
BACKGROUND: Person-to-person transmission of respiratory pathogens, including Pseudomonas aeruginosa, is a challenge facing many cystic fibrosis (CF) centres. Viable P aeruginosa are contained in aerosols produced during coughing, raising the possibility of airborne transmission.
METHODS: Using purpose-built equipment, we measured viable P aeruginosa in cough aerosols at 1, 2 and 4 m from the subject (distance) and after allowing aerosols to age for 5, 15 and 45 min in a slowly rotating drum to minimise gravitational settling and inertial impaction (duration). Aerosol particles were captured and sized employing an Anderson Impactor and cultured using conventional microbiology. Sputum was also cultured and lung function and respiratory muscle strength measured.
RESULTS: Nineteen patients with CF, mean age 25.8 (SD 9.2) years, chronically infected with P aeruginosa, and 10 healthy controls, 26.5 (8.7) years, participated. Viable P aeruginosa were detected in cough aerosols from all patients with CF, but not from controls; travelling 4 m in 17/18 (94%) and persisting for 45 min in 14/18 (78%) of the CF group. Marked inter-subject heterogeneity of P aeruginosa aerosol colony counts was seen and correlated strongly (r=0.73-0.90) with sputum bacterial loads. Modelling decay of viable P aeruginosa in a clinic room suggested that at the recommended ventilation rate of two air changes per hour almost 50 min were required for 90% to be removed after an infected patient left the room.
CONCLUSIONS: Viable P aeruginosa in cough aerosols travel further and last longer than recognised previously, providing additional evidence of airborne transmission between patients with CF.
 

Thorax. 2014 Aug;69(8):740-5. doi: 10.1136/thoraxjnl-2014-205213. Epub 2014 Apr 17.