Union 2012 poster meet tb 20121010


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Union 2012 poster meet tb 20121010

  1. 1. Intensive Tuberculosis screening in HIV infected persons not yet on Antiretroviral Treatment in Macha, Rural Zambia J.F.M. Sikalima1 , J.H. van Dijk2,3 , G.M. Hagoort2 , L.M. Chikobolo1 , M. Musonda1 , J.L. Nouwen2 1 Macha Research Trust, Clinical Research Department, Choma, Zambia; 2 Erasmus University Rotterdam, Internal Medicine - Infectious Diseases, Rotterdam, The Netherlands; 3 Macha Research Trust / Macha Hospital, Clinical Research Department, Choma, Zambia . Erasmus MC University Medical Center Rotterdam Medical Microbiology & Infectious Diseases ‘s Gravendijkwal 230 3015 CE Rotterdam The Netherlands Phone +31 10 463 3511 Fax +31 10 463 3875 E-mail j.l.nouwen@erasmusmc.nl Introduction Tuberculosis (TB) is the most common cause of morbidity and mortality in individuals with HIV-1 infection in sub-Saharan Africa. World Health Organization (WHO) estimates that only 50% of TB cases are detected, creating a need to intensify active case finding via HIV patient screening using more sensitive laboratory diagnostics. In this study, we aimed to determine the additional value of screening Antiretroviral Treatment (ART)-naïve HIV patients presenting with a cough, comparing Fluorescent Light Emitting Diode (LED) microscopy (FM) with the traditional Ziehl-Neelsen Staining light microscopy (ZN), using TB culture as the Gold Standard. Methods All new HIV-infected pre-ART adult patients seeking care at Macha Hospital in rural southern Zambia between April 2010 and March 2012 were screened. Those presenting with a cough, were invited to enroll in the study and asked to produce 3 sputum samples. Information on TB history and exposure was collected from medical records. Laboratory procedures: •ZN and FM staining to all sputum samples •Decontamination and inoculation onto MGIT media. •Confirmation of mycobacterial growth when MGIT positive by ZN smear. • Inoculation of blood agar to exclude bacterial contamination Results of ZN and FM staining were compared to the outcomes of the MGIT cultures. Species identification was done using HAIN genotyping. Results 173 patients were enrolled, submitting a total of 493 sputum samples. In 41 (8%) samples of 28 (16%) patients mycobacteria were cultured (by MGIT or LJ); in only 28 (6%) samples of 10 (6%) patients these were shown to be M. tuberculosis complex (TB, table 5). Sensitivity to detect TB was 50% for ZN and 70% for FM, with a specificity of 99% and 83% for ZN and FM respectively (table 3). 110 (64%) patients started on ARV drugs between enrollment and April 2012. 18 (10%) patients died, of whom 7 (39%) were confirmed TB patients, 3 of them were on TB treatment. Conclusion: The prevalence of TB in this cohort of HIV-infected pre-ART patients was lower than anticipated and reported earlier. This could be related to the strict definition of TB (positive culture with M. tuberculosis complex), but could also be associated with the extensive roll-out of ART since 2005 in this area. Using ZN only, 50% of TB cases would have been missed. Although FM has a much higher sensitivity than ZN to detect mycobacteria, it also overestimates the number of ‘TB’ cases, potentially leading to unnecessary TB treatment. The study was approved by the Research Ethics Committee of the Macha Research Trust (Ref: 1.2010.01). Acknowledgements: Study participants, staff at the HIV Clinic, TB office and laboratory in Macha, and students from the EUR Rotterdam (V. Kraak, G. Brouwer, F. de Vries, and L. de Vries). N=173 ZN slide positive for AFB ZN slide negative for AFB TB Culture positive 6 18 Sensitivity ZN 33% TB Culture negative 1 148 Specificity ZN 99% N=173 FM slide positive for AFB FM slide negative for AFB TB Culture positive 19 5 Sensitivity FM 79% TB Culture negative 17 132 Specificity FM 89% Table 3. Patient’s ZN and FM results compared against TB culture results N=173 ZN slide positive for AFB ZN slide negative for AFB Confirmed M. tuberculosis 5 5 Sensitivity ZN 50% Not confirmed M. tuberculosis 1 162 Specificity ZN 99% N=173 FM slide positive for AFB FM slide negative for AFB Confirmed M. tuberculosis 7 3 Sensitivity FM 70% Not confirmed M. tuberculosis 28 135 Specificity FM 83% Table 4. Patient’s ZN and FM results compared against HAIN confirmation of Mycobacteria TB Number Patients screened 1012 Patients enrolled 240 Patients withdrawn 67 • Only 1 sample submitted 24 • 1 of 2 submitted samples contaminated 4 • > 2 of 3 submitted samples contaminated 22 • Already on TB treatment 1 • Already on ART 1 • Unknown 8 • Pending results at time of analysis 7 Patients included in analysis 173 Table 1. Number of study patients screened and enrolled between March 2010 and March 2012 Figure 1. Flowchart on sample processing