Numerical investigation of airborne infection in naturally ventilated hospital wards with central-corridor type

Natural ventilation is believed to control airborne infection due to high ventilation rates while an undesired flow pattern may cause infection transmission in hospital wards. A computational fluid dynamics simulation was carried out in this study to investigate the impact of airflow pattern on cross infection in a real central-corridor hospital ward with natural ventilation in Nanjing, China. The simulation results demonstrate that the predicted infection risks of the downstream cubicle are up to 10.48% and 11.59% as the index patient is located in the corridor and in the opposite upstream cubicle, respectively. Under this circumstance, the downstream cubicle should be listed on the high-risk list and the central-corridor type is not recommended in a naturally ventilated ward. Measures such as keeping cubicle doors closed should be taken in order to cut off the transmission route. The results not only give direct evidence to strongly support World Health Organization's recommendation but also suggest required amendment of the Chinese standard GB 51039-2014 to improve ventilation arrangement in general hospital wards in China. Our findings are useful for improving the future design of general hospital wards for airborne infection control.