Humidifier fever: a disease to look out for (Leading article)

This paper describes the intermittent occurrence of an influenza-like illness in a printing factory which was constructed at the turn of the century. Environmental and immunological investigations indicated that the illness was caused by inhalation of material voided from a contaminated aerosol-producing humidified air-conditioning system. Badly affected workers had precipitating antibodies to environmental extracts and consistently to those from Bacillus subiilis. New recommendations from the research unit of the printing industry may radically alter the concept of the control of the humidity levels in such premises.