Multisite validation of cryptococcal antigen lateral flow assay and quantification by laser thermal contrast

• Published in: Emerging infectious diseases 2014-01, Vol.20 (1), p.45-53
• Main Authors: Boulware, David R, Rolfes, Melissa A, Rajasingham, Radha, von Hohenberg, Maximilian, Qin, Zhenpeng, Taseera, Kabanda, Schutz, Charlotte, Kwizera, Richard, Butler, Elissa K, Meintjes, Graeme, Muzoora, Conrad, Bischof, John C, Meya, David B
• Format: Article
• Language: English
• Subjects: AIDS-Related Opportunistic Infections - diagnosis; Antigens; Antigens, Fungal - immunology; cryptococcal meningitis; Cryptococcus - immunology; Cryptococcus spp; Diagnosis; diagnostic techniques; fungi; Humans; Immunochromatography - methods; Meningitis; Meningitis, Cryptococcal - diagnosis; Point-of-Care Systems; Printing-ink; Reproducibility of Results; sensitivity; Sensitivity and Specificity; specificity
• ISSN: 1080-6040; 1080-6059
• DOI: 10.3201/eid2001.130906

Cryptococcal meningitis is common in sub-Saharan Africa. Given the need for data for a rapid, point-of-care cryptococcal antigen (CRAG) lateral flow immunochromatographic assay (LFA), we assessed diagnostic performance of cerebrospinal fluid (CSF) culture, CRAG latex agglutination, India ink microscopy, and CRAG LFA for 832 HIV-infected persons with suspected meningitis during 2006-2009 (n = 299) in Uganda and during 2010-2012 (n = 533) in Uganda and South Africa. CRAG LFA had the best performance (sensitivity 99.3%, specificity 99.1%). Culture sensitivity was dependent on CSF volume (82.4% for 10 μL, 94.2% for 100 μL). CRAG latex agglutination test sensitivity (97.0%-97.8%) and specificity (85.9%-100%) varied between manufacturers. India ink microscopy was 86% sensitive. Laser thermal contrast had 92% accuracy (R = 0.91, p