UV light could reduce spread of TB

Washington, Mar 17 (ANI): Ultraviolet lights, combined with air mixing, could reduce airborne transmission of tuberculosis by about 70 percent, says a new study.

The research, which explored the transmission of tuberculosis (TB) from infected patients to guinea pigs, was published in PLoS Medicine.

The study suggests that installing simple ultraviolet C (UVC) lights in hospitals could help reduce the transmission of TB, including drug-resistant strains.

When a tuberculosis patient coughs, bacteria are sprayed into the air in tiny droplets, floating around the room and infecting other patients, visitors and healthcare staff.

These bacteria can be killed by hanging a shielded UVC light from the ceiling with a fan to mix the air, say the researchers, from Imperial College London, the University of Leeds, Hospital Nacional Dos de Mayo, Lima, Perú and other international institutions.

UVC light kills tuberculosis bacteria, including drug-resistant strains, by damaging their DNA so they cannot infect people, grow or divide. It is already used at high intensity to disinfect empty ambulances and operating theatres.

To reach their conclusions, scientists hung UVC lights in a hospital ward in Lima, Perú where 69 patients with HIV and TB were being treated. The researchers pumped air from the ward up to a guinea pig enclosure on the roof of the hospital for 535 consecutive days.

The guinea pigs were split into three groups of approximately 150: the first group received air exposed to the UV lights in the ward, the second group received ward air treated with negative ionisers, and the third control group was given untreated air straight from the ward.

The guinea pigs were given skin tests for tuberculosis once a month.

By the end of the experiment, 35 percent of the control group were infected with TB, compared to 14 percent of the ionised air group and 9.5 percent of the UVC group. 8.6 percent of the control group developed the active form of the disease after being infected with TB, compared to 4.3 percent of the ionised air group and 3.6 percent of the UVC group. (ANI)