Clinical Features and Outcomes of Isoniazid Mono-Resistant Pulmonary Tuberculosis
Nitipatana Chierakul MD*, Vorachai Saengthongpinij MD*, Suporn Foongladda DVM, PhD**
Affiliation : * Division of Respiratory Disease and Tuberculosis, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To determine the characteristics of pulmonary tuberculosis (TB) patients harbored organisms with isoniazid
mono-resistant drug susceptibility pattern.
Material and Method: A retrospective review of medical records for all culture-proven adult pulmonary TB patients in
Siriraj Hospital between July 2009 and July 2011 was conducted. Demographic data, clinical presentations, and radiological
characteristics were recorded and compared between isoniazid mono-resistant and other-resistant groups. Treatment regimens
with outcome determination of patients infected with isoniazid mono-resistant strains were also verified.
Results : Among 489 patients during the present study period, 28 were infected with isoniazid mono-resistant strain (5.7%).
The mean age was 53+18 years, and 8% of them had a history of previous treatment in the past. When compared with those
infected with any other form of resistant strains, isoniazid mono-resistant pulmonary TB patients tended to have less
radiographic cavitary lesion (8.3% vs. 26.7%, p = 0.006) but no significant difference was seen in term of demographic data
and clinical presentations. All of them who had completed the treatment were cured. No difference in cure rate and relapse rate
among patients treated with quinolone or non-quinolone containing regimens.
Conclusion : Isoniazid mono-resistance shares common clinical features with other resistances pulmonary TB, except for
less cavitary lesion from initial chest radiograph. Appropriate drug susceptibility testing with prompt regimen adjustment can
lead to a favorable treatment outcome.
Keywords : Isoniazid mono-resistant, Pulmonary tuberculosis, Clinical feature, Treatment regimen, Treatment outcome
