Accounting for over a million deaths in 2018, tuberculosis (TB) remains a major healthcare burden for most developing countries, and India still leads the list with the largest number of cases. “The World Health Organization has aimed at eliminating TB by 2035, and the Indian government has vouched to do this by 2025. If this ambitious plan has to succeed, we should be concentrating on not missing out on any case,” says Dr. Sayed E. Hasnain from Jamia Hamdard University in New Delhi.
With this aim in mind, he and his collaborators have developed a small device that can be attached to a simple optical microscope to convert it into a fluorescence microscope, thus enabling better TB diagnosis at the point-of-care.
Battery-operated device
Named SeeTB, the device is battery operated and allows quick identification of the bacteria. The team has also developed a clearing reagent called CLR which helps in thinning the collected sputum thus enhancing the bacteria detection. A patent has been filed for both the reagent and the device.
“CLR-SeeTB is a highly economical platform and is most suited for a country like India which has a high TB burden,” adds Dr. Nasreen Z Ehtesham, Director-in-Charge at the Indian Council of Medical Research–National Institute of Pathology and one of the authors of the paper published in Scientific Reports.
“Also, the currently used fluorescence microscopy requires infrastructure, an air-conditioned room, trained professionals and is functional only in tertiary health care centers. SeeTB can be used at the primary health care centres in the villages, and once diagnosed, the treatment can be started.”
The device was used to test more than 300 suspected pulmonary patients. The results showed that compared to fluorescence microscopy, the CLR-SeeTB system had higher sensitivity.
Relative performance
Against bacterial culture studies, fluorescence microscopy showed 63.38% sensitivity while SeeTB system showed improved sensitivity of 76.05%.
When the performance was compared against GeneXpert, another diagnosis tool that looks for DNA markers of TB bacteria, SeeTB showed improved sensitivity. Also, while GeneXpert method takes about two hours, SeeTB can help find the bacteria in about 30 minutes.
3D printing
Dr. Ravikrishnan Elangovan from Indian Institute of Technology Delhi and one of the team members explains: “We used 3D printing to rapidly prototype this compact optical platform, and now we are using injection moulding to produce these components in large scale. This can help drastically bring down the cost, thus making it feasible for large scale distributions across the country.”
The Indian Council of Medical Research has planned to start large scale validation of the CLR-SeeTB in its primary health research units at different locations in the country.
