RT Journal Article
SR Electronic
T1 Comparative cost and performance of light-emitting diode microscopy in HIV–tuberculosis-co-infected patients
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 1393
OP 1397
DO 10.1183/09031936.00023211
VO 38
IS 6
A1 Whitelaw, A.
A1 Peter, J.
A1 Sohn, H.
A1 Viljoen, D.
A1 Theron, G.
A1 Badri, M.
A1 Davids, V.
A1 Pai, M.
A1 Dheda, K.
YR 2011
UL http://erj.ersjournals.com/content/38/6/1393.abstract
AB Light-emitting diode (LED) microscopy has recently been endorsed by the World Health Organization (WHO). However, it is unclear whether LED is as accurate and cost-effective as Ziehl–Neelsen (ZN) microscopy or mercury vapour fluorescence microscopy (MVFM) in tuberculosis (TB)–HIV-co-infected subjects. Direct and concentrated sputum smears from TB suspects were evaluated using combinations of LED microscopy, ZN microscopy and MVFM. Median reading time per slide was recorded and a cost analysis performed. Mycobacterial culture served as the reference standard. 647 sputum samples were obtained from 354 patients (88 (29.8%) were HIV-infected and 161 (26%) were culture-positive for Mycobacterium tuberculosis). Although overall sensitivity of LED compared with ZN microscopy or MVFM was similar, sensitivity of all three modalities was lower in HIV-infected patients. In the HIV-infected group, the sensitivity of LED microscopy was higher than ZN microscopy using samples that were not concentrated (46 versus 39%; p=0.25), and better than MVFM using concentrated samples (56 versus 44; p=0.5). A similar trend was seen in the CD4 count <200 cells·mL−1 subgroup. Median (interquartile range) reading time was quicker with LED compared with ZN microscopy (1.8 (1.7–1.9) versus 2.5 (2.2–2.7) min; p≤0.001). Average cost per slide read was less for LED microscopy (US$1.63) compared with ZN microscopy (US$2.10). Among HIV–TB-co-infected patients, LED microscopy was cheaper and performed as well as ZN microscopy or MVFM independent of the staining (ZN or auramine O) or processing methods used.