A prospective study to evaluate the accuracy of rapid diagnostic tests for diagnosis of human leptospirosis: Result from THAI-LEPTO AKI study

Abstract

Background Rapid diagnostic tests (RDTs) have become widely used in low-resource settings for leptospirosis diagnostic. This study aims to evaluate the diagnostic performance of the five commercially available RDTs to detect human IgM against Leptospira spp. in Thai population. Methodology/Principal findings Ninety-nine serum samples from Leptospirosis suspicious patients were tested with five RDTs, including Medical Science Public Health, Leptocheck-WB, SD bioline, TRUSTline, and J.Mitra. The case definition was based on MAT, qPCR, and culture results. Diagnostic accuracy was determined based on the first day of enrollment in an overall analysis and stratified according to days post-onset of fever. The five RDTs had overall sensitivity ranging from 1.8% to 75% and specificity ranging from 52.3% to 97.7%. Leptocheck-WB had high sensitivity of 75.0%. The sensitivity of five RDTs increased on days 4–6 post-onset of fever, while the specificity of all tests remained relatively stable at different days post-onset of fever. Conclusions/Significance The tested RDTs showed low sensitivity. Therefore, based on the present study, five commercially available RDTs might not be an appropriate test for acute leptospirosis screening in the Thai population.

Rapid and sensitive point-of-care detection of Leptospira by RPA-CRISPR/Cas12a targeting lipL32

“…IgM antibodies. The RDT performance was similar to that previously reported [ 9 ], but had a lower sensitivity, specificity, and accuracy than the RPA-CRISPR/Cas12a-FBDA developed in this study. The window of positivity for the RPA-CRISPR/Cas12a platform began at the first sign of infection, compared to the RDT window which started at days 6–8 [ 5 , 36 ].…”

“…Results from our study support usage of the RPA-CRISPR/Cas12a-based system to detect Leptospira with an acceptable sensitivity and high specificity. To address the sensitivity and specificity issues raised by prior studies, point-of-care testing for leptospirosis such as LAMP and RDT were created [ 9 , 10 ]. A previous study reported that having more than 1,000 Leptospira cells/mL was associated with severe leptospirosis [ 35 ].…”

“…Inclusion criteria for subjects were as follows: (i) older than 18 years old and admitted to a participating hospital; (ii) presenting with clinical suspicion of leptospirosis, high fever (body temperature higher than 38°C), severe myalgia; and (iii) history of exposure to reservoir animals [ 9 , 22 ]. The exclusion criteria were patients who suffered from other known infectious diseases.…”

“…Testing at the point of care is ideal for resource-constrained settings. Numerous studies have been conducted to investigate point-of-care tests for leptospirosis [8][9][10]. Loop-Mediated Isothermal Amplification for Diagnosis of both pathogenic Leptospira and intermediate Leptospira in humans by targeting rrs gene has been developed.…”

“…Anti- leptospira IgM rapid diagnostic tests (RDTs) are commercially available. RDTs have a limited sensitivity and may be inefficient for screening acute leptospirosis [ 9 ].…”