Detecting anti-TB drug resistance upfront is a public health imperative

Lwin Lwin Thant, CNS Correspondent, Myanmar
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TB is a curable disease, but only when treated with complete course of drugs effective for a particular individual. If a person is resistant to one or more of anti-TB drugs given in a therapy then it can spell a public health disaster. So it is a public health imperative to detect drug resistance if any at the time of TB diagnosis and treat the person with drugs-that-work for her/him.

In Myanmar, there are molecular diagnostic tools such as GeneXpert, which can diagnose TB and detect rifampicin resistance within 2 hours, with very high sensitivity and specificity. Now we also have the data from the largest study done on over 100,000 patients in India on what happens when we use a rapid molecular testing tool like GeneXpert to diagnose TB and detect drug resistance when a person with presumptive TB comes to a clinic: “Introduction of GeneXpert MTB/RIF as initial diagnostic test for TB in public health facilities significantly increased case-notification rates of all bacteriologically confirmed TB by 39% and rifampicin-resistant TB case notification by fivefold” said Dr KS Sachdeva, one of the key study authors, and Additional Director General of Central TB Division, Ministry of Health and Family Welfare, Government of India.

In 2010 the World Health Organization (WHO) had endorsed the new molecular test (Nucleic Acid Amplification Test – NAAT), known as GeneXpert, which demonstrated high sensitivity and specificity for both detection of pulmonary TB and rifampicin resistance.

Dr Mario Raviglione, Director of the WHO Global TB Progamme, informed in a webinar hosted by Citizen News Service (CNS) that 9 million people fell ill with TB in 2013 globally. 1.5 million men, women and children died from TB in 2013, and 480,000 people developed multidrug-resistant TB (MDR-TB) in 2013, with 210,000 associated deaths, globally.

Anti-TB drug resistance has been lurking in Myanmar as well. If we look at the data of the national TB programme of Myanmar, TB incidence in just one city of Myanmar is alarming: In Mandalay, the second largest city of Myanmar, there were 3,264 TB-infected patients in 2013. Out of these, 1144 were confirmed with positive sputum smear microscopy. When those with negative sputum smear microscopy results were examined using GeneXpert, 455 were diagnosed with MDR-TB. Overall situation of MDR-TB in Mandalay alone is very concerning with 3990 cases of MDR-TB by end of 2013. This data does not include people who sought diagnosis and treatment from private sector or those who were lost to follow up.

Not only is it important to ensure that a person with TB is treated with sensitive anti-TB drugs (and not drugs that he or she is resistant to) but also it is equally important to ensure that there is no preventable delay in diagnosing TB, detecting drug resistance and initiating effective anti-TB therapy.

There is no stand-alone magic bullet to end TB. We need to ensure that all components of End TB Strategy of the WHO are well implemented on the ground, globally! For example, we have GeneXpert machines working well in TB OPDs of Mandalay General Hospital, Yangon General Hospital, and other TB hospitals in Yangon and Mandalay both. But when I visited Insein prison-- the biggest prison in Myanmar with over 7000 inmates—the GeneXpert machine installed there had been sent for repairs. This obviously hampered timely diagnosis and treatment initiation in new patients of drug sensitive as well as MDR-TB as sputum samples had to be sent elsewhere for testing.

So machine maintenance is a serious issue especially in resource-limited settings such as ours. Likewise there are supply chain issues regarding cartridges of GeneXpert. Also there needs to be more collaboration between different government departments. For example, the prison health programmes come under Detention Health Department and not under Ministry of Health. So it is clear we need much better inter-departmental coordination for improving programme outcomes! We need to address these components too to ensure we maximize on public health gains of implementing good evidence-backed policies.

With strong evidence and rationale for detecting drug resistance at the time of TB diagnosis there is no reason why Myanmar’s TB programme should not begin moving towards a better public health practice. If Myanmar too starts detecting anti-TB drug resistance at the time of TB diagnosis nationwide, there could be immense public health gains, one of which would be accelerated progress towards ending TB.

Lwin Lwin Thant, Citizen News Service - CNS 
23 July 2015