India has the world’s largest burden of tuberculosis (TB) and multidrug-resistant (MDR) TB; estimated community TB incidence is 167 cases/100,000 person-years (1,2). Occupational TB risk is elevated worldwide; however, limited available data suggest that healthcare workers (HCWs), specifically medical trainees, may be at particularly high risk in India and other countries with high TB incidence (3–5). Although the World Health Organization (WHO) has long recommended infection control guidelines for TB prevention among HCWs, implementation globally has been suboptimal (6). To prioritize improved local implementation of WHO guidelines, documenting TB risk among HCWs and medical trainees is urgently needed. We estimated TB prevalence and TB incidence and investigated the frequency of key TB treatment outcomes among medical trainees at a public teaching hospital in India.

The Study

During June 2012–December 2013, we conducted a retrospective study among HCWs at Byramjee-Jeejeebhoy Government Medical College–Sassoon General Hospital (BJGMC-SGH), a 1,300-bed public teaching hospital in Pune in the state of Maharashtra, India. All major clinical and preclinical departments were made aware of the study objectives and referred HCWs who self-identified as having TB to the study team. After obtaining written consent, we entered demographic and clinical data from HCW interviews and clinical and laboratory data from medical records into case report forms. Medical trainees were defined as medical residents or interns.

Routine sputum acid-fast bacilli (AFB) smear and culture were performed at baseline for suspected pulmonary TB (PTB) and repeated at 2 months and, if positive, at 3 months and at the end of treatment. Participants with suspected extrapulmonary TB (EPTB) (e.g., pleural TB, meningitis, or lymphadenitis) underwent additional AFB smear, culture, or histopathologic evaluation of the affected sites as appropriate. All AFB cultures were performed on Lowenstein-Jenson media. Drug-susceptibility testing was performed routinely on all positive sputum and EPTB cultures at baseline and at each follow-up evaluation by using the proportion method (7). Routine HIV testing was performed under the national program (2). The BJGMC-SGH Institutional Ethics Committee approved all study methods.

Primary end points included estimated TB prevalence and TB incidence per 100,000 person-years among medical trainees. To estimate prevalence and incidence, we obtained the denominator (the total number of medical trainees) from employment records. TB prevalence was calculated by dividing the number of TB cases by the total number of medical trainees. Estimated incidence was calculated as the number of TB cases multiplied by 100,000 and divided by the duration of exposure and the total number of medical trainees. Duration of exposure was 18 months for medical residents and 12 months for interns.

Secondary end points included cure (smear- or culture-negative at the end of treatment), treatment failure (smear- or culture-positive at month 5 or later), death (of any cause during treatment), and treatment success (cured and completed treatment) (1). We also evaluated positive AFB smear or cultures at month 2 of treatment, resistance to any anti-TB drug, MDR TB, and adverse events. MDR TB was defined as resistance to at least isoniazid and rifampin (3). Descriptive statistics were used to measure secondary outcomes. All analyses were conducted by using Stata version 10 (Stata Corp LP, College Station, TX, USA).

Figure

Among the 1,886 HCWs assessed in the study, 47 cases of TB were identified (8); 26 cases (14 in residents and 12 in interns) were identified among 662 medical trainees, who had 793 person-years of follow-up. Overall among medical trainees, TB prevalence was 3.9%, and estimated TB incidence was 3,279 cases/100,000 person-years (Table). The median age of trainees with TB was 27 (interquartile range 26–28) years; 14 (54%) were male, 9 (35%) had PTB, 17 (65%) had EPTB (6 [35%] with microbiological confirmation), and 17 (65%) had presumptive TB. Most worked in the general medicine (46%) or radiology (15%) departments (Figure). All trainees with TB were HIV negative.

The frequency of MDR TB was 44% (4/9 cases of culture-positive TB); 3 trainees had TB with single-drug resistance to isoniazid and had their disease successfully treated with first-line anti-TB drugs, and 1 had MDR TB that was successfully treated with second-line anti-TB drugs. All other trainees with TB had their disease successfully treated with first-line anti-TB drugs, except 1 who experienced acute fulminant hepatic failure during TB treatment and required liver transplant and treatment with levofloxacin, ethambutol, and streptomycin. The frequency of adverse drug reactions was 62% (16/26), including 14 cases of gastritis. No cases of treatment failure or death were reported.