Hearing loss screening for patients with TB and diabetes urged

On this World Tuberculosis Day, Bangladesh remains one of 30 high TB and MDR-TB burden countries with 221 people affected in every of the 100,000 population, according to the 2017 Global Tuberculosis Report by World Health Organization (WHO).

X-ray image showing the lungs at icddr,b TB screening facility. Photo: Mark Blonk / icddr,b

In Bangladesh, icddr,b researchers have been at the forefront of tackling the spread of TB with the most recent on-the-ground initiative for TB diagnosis through screening and treatment centres and with over two-decades of experience of conducting studies on the infectious disease.

A new study conducted by icddr,b in collaboration with the National TB Control Program (NTP) has found that patients with multidrug-resistant tuberculosis (MDR-TB) also having diabetes may be more likely to experience early hearing loss (HL).

Audiometry test undergoing at NTP-icddr,b screening facility. Photo: icddr,b

Published in European Respiratory Journal, the new study found that around 77 percent of patients with MDR-TB undergoing WHO-recommended treatment had experienced HL and all patients with diabetes acquired HL early.

The patients were receiving treatment at the National Institute of Diseases of the Chest and Hospital (NIDCH), Dhaka, Bangladesh where they have undergone audiometry test with equipment provided by icddr,b to ascertain HL.

“Hearing loss screening is warranted for all MDR-TB patients because certain drugs like Kanamycin, recommended by WHO as part of MDR-TB treatment, have been showing to affect hearing,” observes Dr Sayera Banu, icddr,b senior scientist and acting head of emerging infections programme, and senior author of the study supported by National Institutes of Health (NIH) via University of Virginia.

“Recent findings on therapeutic drug monitoring for treatment with Kanamycin suggest that alternative median doses can still be effective for MDR-TB treatment without affecting HL. Therefore, HL screening must be in place with careful attention to not exceeding the WHO recommended dose,” she adds.


icddr,b expanding screening to find patients with MDR-TB

The WHO considers MDR-TB as a public health crisis with an estimated 600,000 new cases with resistance to rifampicin. MDR-TB is defined as resistance to two anti-TB medications: rifampicin and isoniazid. A recent sentinel survey by icddr,b, published in the International Journal of Tuberculosis and Lung Disease, has indicated that the number of new MDR-TB patients in Bangladesh may be growing.

Initially located at six places in Bangladesh’s capital Dhaka, icddr,b’s TB screening and treatment centres (TBSTCs) were actively identifying underreported TB cases contributing towards the goal of the NTP of Bangladesh.

Now icddr,b and NTP have expanded under this initiative to reach out to TB patients beyond the capital. The two newly opened TBSTCs in Chittagong in south-eastern Bangladesh have already screened hundreds of patients while another TBSTC is about to be launched in the north-eastern Sylhet district.

New icddr,b TBSTC recently opened in Chittagong. Photo: icddr,b

“As per the National Strategic Plan (2016-2020) for Public Private Mix (PPM) initiative in TB and the corresponding PPM Operational Plan (2017-2020) of the NTP, icddr,b has established TBSTCs in Chittagong and Sylhet, the second and third highest populous metropolitan cities of Bangladesh"

icddr,b TBSTCs use state-of-the-art diagnostic called GeneXpert that can identify rifampicin-resistant TB (RR-TB) cases in two hours, which is a valid marker for MDR-TB suspects.

The TBSTCs network with thousands of doctors in Dhaka and across the country to facilitate referral of TB suspects to the TBSTCs for confirming the cases. If found positive, the patients are then counselled to take free treatment at NTP linked DOTS (directly observed treatment, short-course) facilities, those who prefer to buy anti-TB drug from pharmacy are reported to the NTP. The TBSTCs also ensure free treatment through DOTS as part of a social enterprise initiative and public-private partnership.

The WHO is committed to end TB and has outlined ‘Integrated, patient-centred care and prevention’ as a pillar of the end TB strategy. icddr,b TBSTCs work in line with this aim by working with doctors closely and identifying more patients to prevent the spread of this infectious disease in Bangladesh.

Muhamamd Zahir Hassan Nabil