Background

Isoniazid (INH) is an important first-line medication for the treatment of tuberculosis.

Aims and Objectives

The impact that tuberculosis drug resistance has on treatment outcomes is a topic that is receiving a lot of attention because of the rising incidence of INH-resistant cases.   

Methods

The study involves a single group of patients diagnosed with Isoniazid monoresistant tuberculosis. The mutation patterns of isoniazid were observed after multiplex PCR and Line Probe Assay (LPA). Between 2012-20, a total of 101 patient records at the IRL, Puducherry was analyzed.

Results

The predominant gene responsible for TB was KATG (67.3%) and it was a prime mutation observed in the present study population (58.41%). The study showed a positive association with males (74%), occupation as coolie (88%), diabetes as comorbidity (33%), pulmonary tuberculosis as the TB site (98.01%), history of previous ATT intake in 43 patients (42.6%), katG mutation (67.3%), katG Mut 1 was the prime mutation (58.4%). The cure rate was high in INH high-concentration resistance patients which were statistically significant (p=0.0167). INH monoresistance mutations are seen in 64.3% of the patients with katG, compared to inhA (34.65%).  Similar to katG mutations, inhA mutations also have MUT1 as their most frequent gene pattern.

Conclusion

There is a significant association between males, diabetes, smoking, and alcohol addictions associated with a high risk of developing high-dose INH monoresistance (katG). Patients who have microbiologically confirmed tuberculosis with rifampicin sensitivity need to be checked for LPA for prevention of treatment failure and relapse.