Ultraviolet lights fends off TB infection in hospital wards

London, March 17 (IANS) The simple expedient of using ultraviolet or UV lights while having the fan on potentially cuts down the spread of tuberculosis in hospitals.

TB transmission in overcrowded healthcare facilities is an important public health problem, especially in low resource settings, populations affected by HIV and locations where drug-resistant TB occurs frequently.

Rod Escombe of Imperial College, London, and colleagues used guinea pigs housed on the roof of a hospital in Lima, Peru, to test whether simple approaches to disinfecting air could reduce transmission of TB.

With results from more than 900 guinea pigs, the researchers found that 35 percent of those exposed to untreated air from patient rooms developed TB infection, compared to 14 percent in the treatment group, and only 9.5 percent of those breathing air vented from rooms during treatment with upper-room UV lights and mixing fans.

Guinea pigs are susceptible to airborne infection with M. tuberculosis, the bacterium that causes TB, and they can therefore be used as a sensitive detection system for infectious particles, said an Imperial College release.

By venting air from the rooms of patients with active TB through the guinea pig enclosures, the researchers were able to compare guinea pigs exposed on days when UV lights and air mixing fans were turned on in the patient rooms to other guinea pigs exposed when UV lights were off.

These findings were published in PLoS Medicine.