Isoniazid Prophylaxis of Latent Tuberculous Infection among Healthcare Workers in Bamrasnaradura Infectious Diseases Institute

Abstract

Background: Treatment of latent tuberculosis infection (LTBI) is one of the essential measures for tuberculosis (TB) control. The tuberculin skin test (TST) is an important tool for the detection of LTBI and the identification of healthcare workers (HCWs) who require chemoprophylaxis. Also, the rate of active TB should be evaluated among HCWs with and without isoniazid (INH) prophylactic treatment for LTBI.

Objective: To evaluate the rate of active TB disease among HCWs with or without INH prophylaxis for LTBI.

Methods: We retrospectively studied the clinical records of HCWs with LTBI at the employee TB screening clinic in Bamrasnaradura Infectious Diseases Institute from January 2008 to December 2010. Voluntary INH prophylaxis was recommended by physicians and nurses at the TB clinic in case of recent positive 2-step TST. The rate of active TB disease in HCWs with and without INH prophylaxis for LTBI was evaluated and followed during a period of 5 years. As well, the compliance and adverse effects of INH prophylaxis were identified by history taking.

Results:  There were 29 from 113 HCWS (25.7%) receiving INH prophylaxis for 6 months (23 HCWs) and 9 months (6 HCWs). 2 HCWs in each 6- and a 9-month group did not complete INH prophylaxis for LTBI. After 5 years of TST, no case of active TB disease was found in HCWS with or without INH prophylaxis. Moreover, no adverse drug reactions were reported.

Conclusion: No active tuberculosis disease was noted between the INH treatment and the control groups.