ABSTRACT
To improve understanding about the epidemiology and clinical features of HIV-associated tuberculosis (TB) infection we conducted a prospective, multi-center observational study of HIV-infected TB patients in Thailand. We enrolled HIV-infected patients diagnosed with TB at public health facilities from three provinces and the national infectious diseases referral hospital in Thailand. Patients underwent standardized interviews, evaluations, and laboratory testing at the beginning of TB treatment. We analyzed demographic and clinical characteristics of patients and stratified our findings by level of immune-suppression and whether antiretroviral therapy (ART) was used before TB diagnosis. Of 769 patients analyzed, pulmonary TB was diagnosed in 461 (60%). The median CD4+ T-lymphocyte (CD4) count was 63 cells/microl [interquartile range (IQR), 23-163.5] and the median HIV RNA viral load was 308,000 copies/ml (IQR, 51,900-759,000) at the time of TB diagnosis. Methamphetamine use was reported by 304 patients (40%), marijuana by 267 patients (35%), and injection drug use by 199 patients (26%). Three hundred three patients (40%) reported having been previously incarcerated. Among sexually active patients, 142 (42%) reported never using condoms at all. Patients with CD4 counts <200 cells/microl were significantly more likely than patients with CD4 counts > or =200 cells/microl to have extra-pulmonary TB, fever, fatigue, muscle weakness, no hemoptysis, tachycardia, low body mass index, jaundice, or no pleural effusion. Of the 94 patients that received ART before TB diagnosis, the median time from ART initiation to TB diagnosis was 105 days (IQR, 31-468). HIV-infected patients who developed TB after ART initiation were more likely than other HIV-infected TB patients to have extra-pulmonary TB, a normal chest radiograph, low HIV RNA viral load, or a history of previous TB treatment.