Screening for tuberculosis prior to isoniazid preventive therapy among HIV-infected gold miners in South Africa

London School of Hygiene and Tropical Medicine, London, United Kingdom.
The International Journal of Tuberculosis and Lung Disease (Impact Factor: 2.32). 06/2006; 10(5):523-9.
Source: PubMed


Human immunodeficiency virus (HIV) clinic for employees of a gold mine, Free State, South Africa.
To evaluate the process of screening for active tuberculosis (TB) prior to commencing TB preventive therapy in HIV-infected individuals.
Cross-sectional study comparing performance of various combinations of screening tests for TB against a gold standard diagnosis of TB based on symptoms, chest radiograph (CXR), sputum microscopy and culture.
Of 899 individuals, 44 (4.9%) had TB. The most sensitive symptom combination (59.1%) was any of night sweats, new or worsening cough or reported weight loss; measured weight loss > 5% or abnormal CXR increased sensitivity to 90.9%. Sputum microscopy did not increase sensitivity further, but including World Health Organization HIV clinical staging or CD4 count did. As the specificity of all these combinations was low, many individuals required further investigation to rule out TB. TB prevalence was high (11.7%) among individuals with a CD4 count < 200/mm3.
CXR greatly increased the sensitivity of screening for TB in this population. Sputum microscopy conferred no additional benefit among asymptomatic patients with a normal CXR. The high prevalence of TB amongst those with a low CD4 count underlines the importance of screening for active TB prior to commencing TB preventive therapy, and before antiretroviral therapy.

Full-text preview

Available from:
    • "Currently there is no internationally accepted evidence-based tool to screen for TB in PLWH. Multiple studies have been conducted to develop a simple method for ruling out TB in people with HIV infection, but methodological issues preclude the use of any of these as the basis for global health policy12–14. In 2007, a WHO International Expert Committee issued new guidelines to improve the diagnosis of TB in HIV infected individuals15. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Human immunodeficiency virus (HIV) associated tuberculosis (TB) remains a major global public health challenge, with an estimated 1.4 million patients worldwide. Co-infection with HIV leads to challenges in both the diagnosis and treatment of tuberculosis. Further, there has been an increase in rates of drug resistant tuberculosis, including multi-drug (MDR-TB) and extensively drug resistant TB (XDRTB), which are difficult to treat and contribute to increased mortality. Because of the poor performance of sputum smear microscopy in HIV-infected patients, newer diagnostic tests are urgently required that are not only sensitive and specific but easy to use in remote and resource-constrained settings. The treatment of co-infected patients requires antituberculosis and antiretroviral drugs to be administered concomitantly; challenges include pill burden and patient compliance, drug interactions, overlapping toxic effects, and immune reconstitution inflammatory syndrome. Also important questions about the duration and schedule of anti-TB drug regimens and timing of antiretroviral therapy remain unanswered. From a programmatic point of view, screening of all HIV-infected persons for TB and vice-versa requires good co-ordination and communication between the TB and AIDS control programmes. Linkage of co-infected patients to antiretroviral treatment centres is critical if early mortality is to be prevented. We present here an overview of existing diagnostic strategies, new tests in the pipeline and recommendations for treatment of patients with HIV-TB dual infection.
    No preview · Article · Dec 2011 · The Indian Journal of Medical Research
  • Source
    • "Coughing duration with the most controversial predictor, and has been found inconsistently across studies (Day et al, 2006; Were et al, 2009; Cain et al, 2010). Some predictors found associated with active TB in other studies but did not reach significance in this study were weight loss (Mohammed et al, 2004; Day et al, 2006), night sweats (Mohammed et al, 2004; Day et al, 2006; Cain et al, 2010), fever (Mohammed et al, 2004; Were et al, 2009; Cain et al, 2010), lymphadenopathy (Were et al, 2009), and general weakness (Were et al, 2009). An abnormal chest Xray has been used as a predictor (Were et al, 2009; Cain et al, 2010) and helped to increase the sensitivity of active TB detection in some studies. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The objective of this study was to develop and evaluate a simple scoring scheme to screen for active tuberculosis (TB) among HIV-infected patients. Two hundred fifty-seven HIV-infected patients were enrolled in the study between April 2009 and May 2010 from Mae Sai District Hospital and Lampang Regional Hospital. Participants underwent routine evaluations to diagnose TB. Data collection included demographics, medical history, signs and symptoms and laboratory results. Of the 257 HIV-infected patients enrolled, 66 (25.7%) were diagnosed with active TB. Six variables were statistically significant predictors of active TB (p < 0.05): BMI < or = 19 kg/m2, cough > 2 weeks, shaking chills > or = 1 week not taking antiretroviral drugs, a CD4+ cell count level < 200 cells/microl, and had a history of TB. A risk score (ranging from 0 to 16) gave a 92.1% sensitivity of being associated with active TB. A low risk score (< or = 2.0), a moderate risk score (3.0-7.0), and a high risk score (>7.0) gave positive likelihood ratios (LHR+) of 0.04 (95% CI 0.01-0.24), 2.56 (95% CI 1.71-3.85), and 11.72 (95% CI 4.91-27.96), respectively. This screening tool may be useful to identify patients who should have further diagnostic testing for TB, but requires further validation before adoption due to the variability of predicting factors and the prevalence of TB in the target population.
    Preview · Article · Jul 2011 · The Southeast Asian journal of tropical medicine and public health
  • Source
    • "Current microbiologic methods often fail to confirm disease in subjects who have classic TB symptoms with x-ray changes and subsequent radiologic and clinical response to therapy for TB. In other published series of HIV-associated TB 19–66% of subjects have met a "clinical" definition of TB with negative microbiology [21,33,34]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Active tuberculosis (TB) is common among HIV-infected persons living in tuberculosis endemic countries, and screening for tuberculosis (TB) is recommended routinely. We sought to determine the role of chest x-ray and sputum culture in the decision to treat for presumptive TB using active case finding in a large cohort of HIV-infected patients. Ambulatory HIV-positive subjects with CD4 counts > or = 200/mm3 entering a Phase III TB vaccine study in Tanzania were screened for TB with a physical examination, standard interview, CD4 count, chest x-ray (CXR), blood culture for TB, and three sputum samples for acid fast bacillus (AFB) smear and culture. Among 1176 subjects 136 (12%) were treated for presumptive TB. These patients were more frequently male than those without treatment (34% vs. 25%, respectively; p = 0.049) and had lower median CD4 counts (319/microL vs. 425/microL, respectively; p < .0001). Among the 136 patients treated for TB, 38 (28%) had microbiologic confirmation, including 13 (10%) who had a normal CXR and no symptoms. There were 58 (43%) treated patients in whom the only positive finding was an abnormal CXR. Blood cultures were negative in all patients. Many ambulatory HIV-infected patients with CD4 counts > or = 200/mm3 are treated for presumptive TB. Our data suggest that optimal detection requires comprehensive evaluation, including CXR and sputum culture on both symptomatic and asymptomatic subjects.
    Full-text · Article · Feb 2008 · BMC Infectious Diseases
Show more