Project Lead(s): Jose Lopez Revilla
Issue
Tuberculosis (TB) has been declared a ‘global emergency’ by the World Health Organization (WHO).
Recent surveillance data shows a more frequent report of multidrug-resistant (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) cases.
Peru has the highest incidence of MDR-TB cases in the Americas: almost 16% of TB patients have primary resistance and previously treated cases reach 23%.
Poor housing conditions and overcrowded rooms contribute to the spread of TB, and environmental measures are key elements in TB control.
Solution
The objective of the project was to develop a novel UV light device for indoor use, powered by solar energy, which could purify air sustainably and be used in low-resource communities with high TB prevalence.
The project developed a prototype UV light device consisting of a 30 x 10 cm panel of UV LED light bulbs, distributed on a roof-facing reflecting plate.
Each UV LED gives a 400 nm light spectrum, in the range of medical UV lights. The plate was made of stainless steel, in concave design, to reduce the risk of non-intentional exposure.
Microbiological testing for clearance was performed with certified Mycobacterium tuberculosis H37Ra (ATCC® 25177 ™) strains (MTB strains).
For each set of lights, 24 well plates with cultures of mycobacteria, and another set for control cultures that were not exposed to UV lights, were used.
Outcome
The study successfully demonstrated that the UV-type LED lights can achieve a reduction of growth of strains of M. tuberculosis.
To reach this conclusion, strains of mycobacteria in known concentrations were used and were then exposed to light, inhibiting the growth by eight times, on average.
During the course of the study, clinical validation of the device was not performed.
While the impact of the use of the device has not yet been evaluated, the results obtained on inhibition of mycobacterial growth provides a field of research to clinical application.
The next step will be to develop a larger community study.