CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

Conclusions: Four percent of women referred from prenatal clinics as non-TB controls were found to be sputum culture positive, demonstrating that TB symptom screen alone missed cases of TB among HIV-infected pregnant women in Soweto. In a high burden TB disease setting and a population where young women have a considerable history of TB disease, prenatal care represents an opportunity for TB diagnosis and prevention, yet additional TB screening strategies are needed for identifying TB in pregnancy and earlier initiation of treatment. 823 Evaluation of WHO 4-Symptom Tool to Rule Out TB: Data From the XPHACTOR Study Yasmeen Hanifa 1 ; Katherine Fielding 1 ;Violet Chihota 2 ; Nontobeko Ndlovu 2 ; Alan Karstaedt 3 ; Lungiswa Adonis 4 ; Linda Erasmus 5 ; Mark Nicol 5 ; Gavin Churchyard 2 ; Alison Grant 1 1 London School of Hygiene & Tropical Medicine, London, United Kingdom; 2 Aurum Institute for Health Research, Johannesburg, South Africa; 3 Chris Hani Baragwanath Hospital, Johannesburg, South Africa; 4 Mamelodi Hospital, Pretoria, South Africa; 5 National Health Laboratory Service, Johannesburg, South Africa Background: The WHO 4-symptom screening tool, comprising any cough, weight loss, fever or night sweats, is a simple evidence-based tool designed for use in resource limited settings to rule out TB in people with HIV, so IPT can be safely initiated. We assessed WHO tool performance using data from the XPHACTOR study, which evaluates a novel algorithm to prioritise TB investigation amongst HIV clinic attendees in South Africa. Methods: A systematic sample of adult clinic attendees were screened for TB using WHO tool. Sputumwas tested with Xpert MTB/RIF if high priority for TB according to XPHACTOR algorithm (any of: cough, BMI<18.5, CD4<100, weight loss ≥ 10%). All were followed to 3 months, with reinvestigation if indicated. All had sputum and blood cultured for TB at 3 months. TB cases were classified as definite if Xpert+ or culture+ for M. tuberculosis at any point; probable if TB treatment commenced based on compatible radiology; possible if treated without bacteriological or radiological evidence. We calculated negative predictive value, the proportion who did not have TB out of those WHO-tool negative, to evaluate tool performance for ruling out TB. Results: Among 3460 participants, at enrolment 898 (26%) were pre-ART and 2562 (74%) on ART; 70.5%were female. Amongst pre- vs. on ART, median age was 35 vs. 41 yrs, median CD4 399 vs. 466, 38.1% (342/898) vs. 29.9% (765/2562) were WHO tool +, and 8.1% (72/893) vs. 39.7% (1015/2558) had previous TB treatment (P<0.001). Prevalence of TB in pre- and on-ART groups respectively was 56/898 (6.2%, 95%CI 4.7%-8.0%) and 67/2562 (2.6%, 95%CI 2%-3.3%). Amongst pre- vs. on ART TB diagnoses, 76.8% (43/56) vs. 89.6% (60/67) were definite, 16.1% (9/56) vs. 9% (6/67) probable, and 7.1% (4/56) vs. 1.5% (1/67) possible (P=0.13). Negative predictive value of WHO tool (Table) was greater than 98% for all TB, when restricted to definite TB, and when stratified by pre vs. on ART group. Positive predictive values were low (see Table).

Poster Abstracts

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CROI 2015