Why are GPs spending thousands of dollars on air purifiers?

Dr Bernard Shiu has purchased eight HEPA filters for his practice, saying preventing one infection among his staff will make it worthwhile
Dr Bernard Shiu
Dr Bernard Shiu.

GPs are spending thousands of dollars on air purifiers in the hope they will give staff and patients an extra layer of protection against COVID-19.   

Geelong practice owner Dr Bernard Shiu is one of them.