An algorithm for tuberculosis screening and diagnosis in people with HIV.

BACKGROUND: Tuberculosis screening is recommended for people with human immunodeficiency virus (HIV) infection to facilitate early diagnosis and safe initiation of antiretroviral therapy and isoniazid preventive therapy. No internationally accepted, evidence-based guideline addresses the optimal means of conducting such screening, although screening for chronic cough is common. METHODS: We consecutively enrolled people with HIV infection from eight outpatient clinics in Cambodia, Thailand, and Vietnam. For each patient, three samples of sputum and one each of urine, stool, blood, and lymph-node aspirate (for patients with lymphadenopathy) were obtained for mycobacterial culture. We compared the characteristics of patients who received a diagnosis of tuberculosis (on the basis of having one or more specimens that were culture-positive) with those of patients who did not have tuberculosis to derive an algorithm for screening and diagnosis. RESULTS: Tuberculosis was diagnosed in 267 (15%) of 1748 patients (median CD4+ T-lymphocyte count, 242 per cubic millimeter; interquartile range, 82 to 396). The presence of a cough for 2 or 3 weeks or more during the preceding 4 weeks had a sensitivity of 22 to 33% for detecting tuberculosis. The presence of cough of any duration, fever of any duration, or night sweats lasting 3 or more weeks in the preceding 4 weeks was 93% sensitive and 36% specific for tuberculosis. In the 1199 patients with any of these symptoms, a combination of two negative sputum smears, a normal chest radiograph, and a CD4+ cell count of 350 or more per cubic millimeter helped to rule out a diagnosis of tuberculosis, whereas a positive diagnosis could be made only for the 113 patients (9%) with one or more positive sputum smears; mycobacterial culture was required for most other patients. CONCLUSIONS: In persons with HIV infection, screening for tuberculosis should include asking questions about a combination of symptoms rather than only about chronic cough. It is likely that antiretroviral therapy and isoniazid preventive therapy can be started safely in people whose screening for all three symptoms is negative, whereas diagnosis in most others will require mycobacterial culture.

Nontuberculous mycobacterial disease in patients with HIV in Southeast Asia.

RATIONALE: Although nontuberculous mycobacteria (NTM) are widely documented as a cause of illness among HIV-infected people in the developed world, studies describing the prevalence of NTM disease among HIV-infected people in most resource-limited settings are rare. OBJECTIVES: To evaluate the prevalence of mycobacterial disease in HIV-infected patients in Southeast Asia. METHODS: We enrolled people with HIV from three countries in Southeast Asia and collected pulmonary and extrapulmonary specimens to evaluate the prevalence of mycobacterial disease. We adapted American Thoracic Society/Infectious Disease Society of America guidelines to classify patients into NTM pulmonary disease, NTM pulmonary disease suspects, NTM disseminated disease, and no NTM categories. MEASUREMENTS AND MAIN RESULTS: In Cambodia, where solid media alone was used, NTM was rare. Of 1,060 patients enrolled in Thailand and Vietnam, where liquid culture was performed, 124 (12%) had tuberculosis and 218 (21%) had NTM. Of 218 patients with NTM, 66 (30%) were classified as NTM pulmonary disease suspects, 9 (4%) with NTM pulmonary disease, and 10 (5%) with NTM disseminated disease. The prevalence of NTM disease was 2% (19 of 1,060). Of 51 patients receiving antiretroviral therapy (ART), none had NTM disease compared with 19 (2%) of 1,009 not receiving ART. CONCLUSIONS: Although people with HIV frequently have sputum cultures positive for NTM, few meet a strict case definition for NTM disease. Consistent with previous studies, ART was associated with lower odds of having NTM disease. Further studies of NTM in HIV-infected individuals in tuberculosis-endemic countries are needed to develop and validate case definitions.

Symptom screen for identification of highly infectious tuberculosis in people living with HIV in Southeast Asia.

BACKGROUND: Tuberculosis (TB) is the leading cause of death among people living with HIV and frequently transmitted among this susceptible group. Transmission can be reduced by infection control practices. Simple evidence-based methods to identify patients who should be isolated are not well described in the literature. We sought to identify a simple, sensitive symptom or symptom combination that healthcare providers in resource-limited settings can use to identify and isolate persons living with HIV with highly infectious TB. METHODS: Participants from 8 outpatient facilities in Cambodia, Thailand, and Vietnam underwent an extensive evaluation for TB. Patients with ≥1 positive sputum smear and Mycobacterium tuberculosis culture growth from a pulmonary site were defined as having highly infectious TB. We calculated sensitivity and prevalence of individual symptoms and >1000 symptom combinations. RESULTS: Of 1980 participants, 272 (14%) had TB. Forty percent (n = 109) were highly infectious. Sensitivity for detecting highly infectious TB was highest for having the following symptoms in the past month as follows: weight loss (84%), cough (83%), fever (81%), and fatigue (78%); however, these symptoms were found in 46%-54% of all participants. Having 2 or 3 of 4 symptoms (prevalence, 26%-47%)-weight loss, fever, current cough, and night sweats-was 72%-90% sensitive for highly infectious TB. CONCLUSIONS: The 2 or 3 of 4 symptom combinations of weight loss, fever, current cough, and night sweats, which are the same symptoms comprising the current World Health Organization-recommended TB diagnostic screen, are sensitive for detecting highly infectious TB in people living with HIV.

Performance of abdominal ultrasound for diagnosis of tuberculosis in HIV-infected persons living in Cambodia.

BACKGROUND: In resource-limited settings, abdominal ultrasound is often used to assist the diagnosis of tuberculosis (TB) in people with HIV (PLHIV), although data on performance characteristics are missing. METHODS: Cross-sectional study of PLHIV in Cambodia receiving a standardized TB diagnostic evaluation, including history, physical examination, chest radiography, microscopy and culture of various specimens, and abdominal ultrasound. Patients with at least one specimen culture positive for Mycobacterium tuberculosis were classified as having TB. RESULTS: TB was diagnosed in 37 (18%) of 212 PLHIV. Abdominal ultrasound was abnormal in 15 of 37 (41%) patients with TB compared with 14 of 175 (8%) without TB (P < 0.01). Predictors of TB disease included multiple enlarged (1.2 cm or greater) abdominal lymph nodes on ultrasound (adjusted odds ratio [OR], 6.4; 95% confidence interval [CI], 1.8-22.4), abnormal chest radiography (OR, 6.8; CI, 2.7-17.0), anorexia (OR, 4.6; CI, 1.8-11.7), and CD4 less than 200 cells/mm (OR, 3.3; CI, 1.2-9.1). Having multiple enlarged abdominal lymph nodes on ultrasound was 97.1% (CI, 93.5%-99.1%) specific for TB with a positive likelihood ratio of 11.4 (CI, 4.3-30.3). CONCLUSIONS: Abdominal ultrasound is a useful diagnostic test for TB disease in PLHIV, increasing the posttest probability of TB when multiple enlarged abdominal lymph nodes are visualized. Its wider use may accelerate access to TB treatment, potentially reducing mortality in PLHIV.