Control and prevention of healthcare associated tuberculosis: the role of respiratory isolation and personal respiratory protection.

Although the prevalence of tuberculosis continues to decline in most developed countries, the risk of healthcare-associated tuberculosis, remains for patients or healthcare staff. Outbreaks of healthcare-associated tuberculosis are usually associated with delays in diagnosis and treatment, or the care of patients in sub-optimal facilities. The control and prevention of tuberculosis in hospitals is best achieved by three approaches, namely administrative (early investigation diagnosis, etc.), engineering (physical facilities e.g. ventilated isolation rooms) and personal respiratory protection (face sealing masks which are filtered). Recent guidelines on the prevention of tuberculosis in healthcare facilities from Europe and the USA have many common themes. In the UK, however, negative pressure isolation rooms are recommended only for patients with suspected multi-drug resistant TB and personal respiratory protection, i.e. filtered masks, are not considered necessary unless multi-drug resistant TB is suspected, or where aerosol-generating procedures are likely. In the US, the standard of care for patients with infectious tuberculosis is a negative pressure ventilated room and the use of personal respiratory protection for all healthcare workers entering the room of a patient with suspected or confirmed tuberculosis. The absence of clinical trials in this area precludes dogmatic recommendations. Nonetheless, observational studies and mathematical modelling suggest that all measures are required for effective prevention. Even when policies and facilities are optimal, there is a need to regularly review and audit these as sometimes compliance is less than optimal. The differences in recommendations may reflect the variations in epidemiology and the greater use of BCG vaccination in the UK compared with the United States. There is a strong argument for advising ventilated facilities and personal respiratory protection for the care of all patients with tuberculosis, as multi-drug tuberculosis may not always be apparent on admission, and these measures minimise transmission of all cases of TB to other patients and healthcare staff.