Background. Tuberculosis (TB) disease diagnosis in Vietnam relies on symptom screening, chest radiography (CXR), and acid fast bacilli (AFB) sputum smear which have a poor sensitivity in HIV patients. We evaluated the performance of clinical algorithms in screening and diagnosing AFB smear-negative TB in HIV patients. Methods. We enrolled 399 HIV-positive patients seeking care at a HIV clinic in Ho Chi Minh City (HCMC), Vietnam. Participants’ demographics, medical history, common TB symptoms, CXR, and laboratory tests were collected. Results. Of 399 HIV patients, 390 had initial AFB-negative smears and 22/390 patients had positive cultures. Symptom screening missed 54% (12/22) of smear-negative pulmonary TB (PTB) cases. Multivariate analysis found CD4+ cell level and CXR were significant PTB predictors. An algorithm combining four TB symptoms and TST presented a high sensitivity (100%), but poorly specific (24%) diagnostic performance for smear-negative PTB. Conclusion. Up to 54% of PTB cases in the HIV-infected population may be missed in the routine screening and diagnostic procedures used in Vietnam. Symptom screening was a poor overall diagnostic measure in detecting smear-negative TB in HIV patients. Our study results suggest that routine sputum cultures should be implemented to achieve a more accurate diagnosis of TB in HIV patients. 1. Introduction HIV-infected patients with tuberculosis (TB) coinfection may present with atypical manifestations of pulmonary TB (PTB) and a higher rate of negative sputum smears for acid fast bacilli (AFB) [1–3]. Though being less infectious than AFB smear-positive PTB, AFB smear-negative PTB is still a potentially important source of TB transmission and predicts a worse prognosis for HIV-infected patients [4–6]. Therefore, early and accurate diagnosis of sputum smear-negative PTB for HIV-infected patients is urgently important for not only improving the patient’s life expectancy, but also preventing disease transmission to the general population. The diagnosis of TB disease in developing countries like Vietnam relies mainly on symptom screening, chest radiography (CXR), and AFB sputum smear, which have a poor sensitivity in HIV-positive patients [3, 7]. Sputum culture is not routinely available for smear-negative patients, especially at district-level public health institutions [7]. Moreover, current data on the performance of clinical, radiographic, and laboratory characteristics in predicting AFB smear-negative PTB for HIV-infected patients are still limited and inconsistent [6, 8]. This reasoning led us to
References
[1]
C. D. Wells, J. P. Cegielski, L. J. Nelson et al., “HIV infection and multidrug-resistant tuberculosis—the perfect storm,” Journal of Infectious Diseases, vol. 196, supplement 1, pp. S86–S107, 2007.
[2]
P. Monkongdee, K. D. McCarthy, K. P. Cain et al., “Yield of acid-fast smear and mycobacterial culture for tuberculosis diagnosis in people with human immunodeficiency virus,” American Journal of Respiratory and Critical Care Medicine, vol. 180, no. 9, pp. 903–908, 2009.
[3]
K. P. Cain, K. D. McCarthy, C. M. Heilig et al., “An algorithm for tuberculosis screening and diagnosis in people with HIV,” New England Journal of Medicine, vol. 362, no. 8, pp. 707–716, 2010.
[4]
M. A. Behr, S. A. Warren, H. Salamon et al., “Transmission of Mycobacterium tuberculosis from patients smear-negative for acid-fast bacilli,” The Lancet, vol. 353, no. 9151, pp. 444–449, 1999.
[5]
N. J. Hargreaves, O. Kadzakumanja, C. J. M. Whitty, F. M. L. Salaniponi, A. D. Harries, and S. B. Squire, “'Smear-negative' pulmonary tuberculosis in a DOTS programme: poor outcomes in an area of high HIV seroprevalence,” International Journal of Tuberculosis and Lung Disease, vol. 5, no. 9, pp. 847–854, 2001.
[6]
A. Tamhane, P. Chheng, T. Dobbs, S. Mak, B. Sar, and M. E. Kimerling, “Predictors of smear-negative pulmonary tuberculosis in HIV-infected patients, Battambang, Cambodia,” International Journal of Tuberculosis and Lung Disease, vol. 13, no. 3, pp. 347–354, 2009.
[7]
Vietnamese Ministry of Health, Guidelines for Diagnosis and Treatment of Tuberculosis 03/24/2009.
[8]
J. L. Davis, W. Worodria, H. Kisembo et al., “Clinical and radiographic factors do not accurately diagnose smear-negative tuberculosis in HIV-infected inpatients in Uganda: a cross-sectional study,” PLoS One, vol. 5, no. 3, article e9859, 2010.
[9]
People Committee of District 6, HCMC. District 6 Official Website 2010, http://www.quan6.hochiminhcity.gov.vn/pages/gioi-thieu-tong-quat.aspx.
[10]
Q. H. Nguyen, “An Hoa Clinic's annul report to the HCMC Provincial AIDS Committee 2009,” 2009.
[11]
D. T. M. Nguyen, N. Q. Hung, and L. T. Giang, “Improving the diagnosis of pulmonary tuberculosis in HIV-infected individuals in Ho Chi Minh City, Vietnam,” The International Journal of Tuberculosis and Lung Disease, vol. 15, no. 11, pp. 1528–1535, 2011.
[12]
World Health Organization (WHO), “The WHO standard tuberculin test,” WHO/TB/Technical Guide 3, 1963.
[13]
Centers for Disease Control and Prevention (CDC), Tuberculin Skin Testing 2010 07/01.
[14]
World Health Organization (WHO), “Improving the diagnosis and treatment of smear-negative pulmonary and extra-pulmonary tuberculosis among adults and adolescents,” 2007.
[15]
D. T. M. Ha, N. T. N. Lan, V. S. Kiet, et al., “Diagnosis of pulmonary tuberculosis in HIV-positive patients by microscopic observation drug susceptibility assay,” Journal of Clinical Microbiology, vol. 48, no. 12, pp. 4573–4579, 2010.
[16]
Centers for Disease Control and Prevention (CDC), Tuberculosis (TB) 2009 06/01/2009.
[17]
G. Canetti, S. Froman, J. Grosset, et al., “Mycobacteria: laboratory methods for testing drug sensitivity and resistance,” Bulletin of the World Health Organization, vol. 29, pp. 565–578, 1963.
[18]
D. A. Grimes and K. F. Schulz, “Refining clinical diagnosis with likelihood ratios,” The Lancet, vol. 365, no. 9469, pp. 1500–1505, 2005.
[19]
D. Hosmer and S. Lemeshow, Model-Building Strategies and Methods for Logistic Regression. Applied logistic regression, John Wiley & Son, New York, NY, USA, 2nd edition, 2000.
[20]
World Health Organization (WHO), Department of HIV/AIDS Stop, TB Department, “Guidelines for intensified tuberculosis case-finding and isoniazid preventive therapy for people living with HIV in resource-constrained settings,” WHO Guidelines 2010.
[21]
World Health Organization (WHO), Strategic and Technical Advisory Group for Tuberculosis, 2008.
[22]
D. E. Griffith, T. Aksamit, B. A. Brown-Elliott et al., “An official ATS/IDSA statement: diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases,” American Journal of Respiratory and Critical Care Medicine, vol. 175, no. 4, pp. 367–416, 2007.
[23]
Q. H. Nguyen, “An overview of 2 Years of ARV Treatment 9/2005—8/2007,” Updated In 7/2007.
[24]
P. Monkongdee, K. D. McCarthy, K. P. Cain et al., “Yield of acid-fast smear and mycobacterial culture for tuberculosis diagnosis in people with human immunodeficiency virus,” American Journal of Respiratory and Critical Care Medicine, vol. 180, no. 9, pp. 903–908, 2009.
[25]
World Health Organization (WHO), “Strategic and technical advisory group for tuberculosis,” Report on Conclusion and Recomendations, 2007.
[26]
J. L. Davis, L. Huang, W. Worodria et al., “Nucleic acid amplification tests for diagnosis of smear-negative TB in a high HIV-prevalence setting: a prospective cohort study,” PloS One, vol. 6, no. 1, article e16321, 2011.
