Researchers conducted a systematic review of the literature to analyze the diagnostic accuracy of rapid diagnostic tests for EVD. Publication databases were searched from inception through May 2021, and the review included only diagnostic accuracy studies conducted among a live patient population with confirmed or suspected EVD.
Among 1054 studies identified, 15 were included in the review. Of the included studies, 10 assessed lateral flow-based testing and 5 assessed polymerase chain reaction (PCR)-based testing for the rapid diagnosis of EVD. Reverse transcription (RT)-PCR testing was used as the reference test in all included studies, with variations in regard to the specific assay used.
Lateral flow-based rapid testing demonstrated and overall estimated sensitivity of 86.0% (95% CI, 86.0%-86.2%) and a specificity of 97% (95% CI, 96.1%-97.9%) for diagnosing EVD. The lowest reported sensitivity associated with lateral flow testing was 62% (95% CI, 53%-73%). The researchers found significant variation in the specificity (range, 73%-100%) of lateral flow tests used across all studies. There were 2 studies that reported a sensitivity of 100% for lateral flow testing, both of which used whole blood samples obtained from patients that were tested either at the point of care or in a laboratory.
Compared with RT-PCR testing, rapid PCR testing was highly accurate for diagnosing EVD, with a sensitivity of 96.2% (95% CI, 92.4%-98.1%) and a specificity of 96.8% (95% CI, 95.3%-97.9%).
Rapid diagnostic tests were found to be highly accurate for diagnosing EVD across a range of specimen types, including whole blood, plasma, and buccal swabs.
Limitations were the inclusion of some studies with high selection bias, the lack of data on cycle threshold counts, and potential specimen degradation among studies that evaluated specimens several years following collection.
According to the researchers, “Our findings support the use of RDTs [rapid diagnostic tests] as a ‘rule in’ test to expedite treatment and vaccination” in patients with suspected EVD.
Reference
Dagens AB, Rojek A, Sigfrid L, Plüddemann A. The diagnostic accuracy of rapid diagnostic tests for Ebola virus disease: a systematic review. Clin Microbiol Infect. Published online September 23. doi:10.1016/j.cmi.2022.09.014