In December 2010 the World Health Organization (WHO) endorsed Xpert® MTB/RIF (Cepheid, Sunnyvale, California, USA) (XP), the first fully automated, real-time nucleic acid amplification technology for the rapid detection of TB which can be performed with only 1 day of training by most health care workers. Because of its low cost, it is the mainstay of diagnosis in many high burden countries. Sputum smear microscopy has a low sensitivity for detecting TB particularly among people living with HIV. Tuberculosis (TB) remains the main cause of death among HIV-infected patients in sub-Saharan Africa. The lower sensitivity of XP in smear-negative HIV-positive patients led experienced clinicians to use XP as a “rule-in” rather than “rule-out” test, with the majority of patients still treated empirically. When adjusted for CD4 count, empirical treatment was not associated with higher mortality compared to no or microbiologically confirmed treatment. Despite XP testing high levels of empirical treatment prevailed (18%), although XP results did change who ultimately was treated for TB. XP positivity was similar in patients with a pre-XP empirical diagnosis and those without (9/29 versus 14/142, P = 0.23). Of 411 smear-negative presumptive TB patients, 175 (43%) received an XP their baseline characteristics did not differ. We compared empirical and XP-informed treatment decisions and all-cause mortality in the first year. Prior to testing clinicians were asked to decide whether they would treat empirically prior to Xpert result actual treatment was decided upon receipt of the XP result. Prospective cohort study of HIV-positive smear-negative presumptive TB patients during a 12-month period after XP implementation in a well-staffed and trained integrated TB/HIV clinic in Kampala, Uganda. We determined the change in diagnosis, treatment and mortality of smear-negative presumptive TB with routine use of Xpert MTB/RIF (XP). Its impact on the diagnosis of smear-negative TB in a routine care setting is unclear. The Xpert® MTB/RIF (XP) has a higher sensitivity than sputum smear microscopy (70% versus 35%) for TB diagnosis and has been endorsed by the WHO for TB high burden countries to increase case finding among HIV co-infected presumptive TB patients.
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