Title |
Diagnostic accuracy of the rapid urine lipoarabinomannan test for pulmonary tuberculosis among HIV-infected adults in Ghana–findings from the DETECT HIV-TB study
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Published in |
BMC Infectious Diseases, October 2015
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DOI | 10.1186/s12879-015-1151-1 |
Pubmed ID | |
Authors |
Stephanie Bjerrum, Ernest Kenu, Margaret Lartey, Mercy Jemina Newman, Kennedy Kwasi Addo, Aase Bengaard Andersen, Isik Somuncu Johansen |
Abstract |
Rapid diagnostic tests are urgently needed to mitigate HIV-associated tuberculosis (TB) mortality. We evaluated diagnostic accuracy of the rapid urine lipoarabinomannan (LAM) test for pulmonary TB and assessed the effect of a two-sample strategy. HIV-infected adults eligible for antiretroviral therapy were prospectively enrolled from Korle-Bu Teaching Hospital in Ghana and followed for minimum 6 months. We applied the LAM test on urine collected as a spot and early morning sample. Diagnostic accuracy was analysed for a microbiological TB reference standard based on sputum culture and Gene Xpert MTB/RIF results and for a composite reference standard including clinical follow-up data. Performance of sputum smear microscopy was included for comparison. Of 469 patients investigated for TB, the LAM test correctly identified 24/55 (44 %) of microbiologically confirmed TB cases. Sensitivity of the LAM test was positively associated with hospitalisation (67 %), Modified Early Warning Score > 4 (57 %) and subsequent death (71 %). LAM test specificity was 95 % increasing to 98 % for the composite reference standard. A two-sample LAM test strategy did not improve test performance. Using concentrated sputum for Ziehl-Neelsen and fluorescence microscopy in combination yielded a sensitivity of 31/55 (56 %) that increased to 35/55 (64 %) when the LAM test was added. Surprisingly, nontuberculous mycobacteria were cultured in 34/469 (7 %) and associated with a positive LAM test (p = 0.008). LAM test sensitivity was highest in patients with poor prognosis and subsequent death and did not increase with a two-sample strategy. A rigorous sputum microscopy strategy had superior sensitivity, but the simplicity of the LAM test holds operational possibilities as a TB screening method among severely sick patients. |
X Demographics
Geographical breakdown
Country | Count | As % |
---|---|---|
United States | 2 | 17% |
United Kingdom | 1 | 8% |
Guyana | 1 | 8% |
South Africa | 1 | 8% |
Unknown | 7 | 58% |
Demographic breakdown
Type | Count | As % |
---|---|---|
Members of the public | 9 | 75% |
Practitioners (doctors, other healthcare professionals) | 3 | 25% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
South Africa | 1 | <1% |
Unknown | 187 | 99% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Researcher | 45 | 24% |
Student > Master | 24 | 13% |
Student > Ph. D. Student | 18 | 10% |
Student > Postgraduate | 17 | 9% |
Student > Bachelor | 17 | 9% |
Other | 30 | 16% |
Unknown | 37 | 20% |
Readers by discipline | Count | As % |
---|---|---|
Medicine and Dentistry | 66 | 35% |
Nursing and Health Professions | 19 | 10% |
Immunology and Microbiology | 12 | 6% |
Agricultural and Biological Sciences | 11 | 6% |
Biochemistry, Genetics and Molecular Biology | 10 | 5% |
Other | 30 | 16% |
Unknown | 40 | 21% |