Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2018 Sep;24(9):1017.e1-1017.e7.
doi: 10.1016/j.cmi.2017.10.017. Epub 2017 Oct 26.

A comparison of two molecular methods for diagnosing leptospirosis from three different sample types in patients presenting with fever in Laos

K Woods  1 , C Nic-Fhogartaigh  2 , C Arnold  3 , L Boutthasavong  4 , W Phuklia  4 , C Lim  5 , A Chanthongthip  4 , S M Tulsiani  6 , S B Craig  7 , M-A Burns  6 , S L Weier  8 , V Davong  4 , S Sihalath  4 , D Limmathurotsakul  9 , D A B Dance  10 , N Shetty  3 , M Zambon  3 , P N Newton  11 , S Dittrich  12
Affiliations
Comparative Study

A comparison of two molecular methods for diagnosing leptospirosis from three different sample types in patients presenting with fever in Laos

K Woods et al. Clin Microbiol Infect. 2018 Sep.

Abstract

Objectives: To compare two molecular assays (rrs quantitative PCR (qPCR) versus a combined 16SrRNA and LipL32 qPCR) on different sample types for diagnosing leptospirosis in febrile patients presenting to Mahosot Hospital, Vientiane, Laos.

Methods: Serum, buffy coat and urine samples were collected on admission, and follow-up serum ∼10 days later. Leptospira spp. culture and microscopic agglutination tests (MAT) were performed as reference standards. Bayesian latent class modelling was performed to estimate sensitivity and specificity of each diagnostic test.

Results: In all, 787 patients were included in the analysis: 4/787 (0.5%) were Leptospira culture positive, 30/787 (3.8%) were MAT positive, 76/787 (9.7%) were rrs qPCR positive and 20/787 (2.5%) were 16SrRNA/LipL32 qPCR positive for pathogenic Leptospira spp. in at least one sample. Estimated sensitivity and specificity (with 95% CI) of 16SrRNA/LipL32 qPCR on serum (53.9% (33.3%-81.8%); 99.6% (99.2%-100%)), buffy coat (58.8% (34.4%-90.9%); 99.9% (99.6%-100%)) and urine samples (45.0% (27.0%-66.7%); 99.6% (99.3%-100%)) were comparable with those of rrs qPCR, except specificity of 16SrRNA/LipL32 qPCR on urine samples was significantly higher (99.6% (99.3%-100%) vs. 92.5% (92.3%-92.8%), p <0.001). Sensitivities of MAT (16% (95% CI 6.3%-29.4%)) and culture (25% (95% CI 13.3%-44.4%)) were low. Mean positive Cq values showed that buffy coat samples were more frequently inhibitory to qPCR than either serum or urine (p <0.001).

Conclusions: Serum and urine are better samples for qPCR than buffy coat, and 16SrRNA/LipL32 qPCR performs better than rrs qPCR on urine. Quantitative PCR on admission is a reliable rapid diagnostic tool, performing better than MAT or culture, with significant implications for clinical and epidemiological investigations of this global neglected disease.

Keywords: Bayesian; Buffy coat; Laos; Latent class model; Leptospira; Leptospirosis; Molecular diagnosis; Quantitative PCR; Serum; Urine.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Participant flow and diagnostic test results.
Fig. 2
Fig. 2
Fever duration at admission in patients qPCR positive for pathogenic Leptospira DNA, according to admission sample type which was qPCR positive.
See this image and copyright information in PMC

References

    1. Costa F., Hagan J.E., Calcagno J., Kane M., Torgerson P., Martinez-Silveira M.S. Global morbidity and mortality of leptospirosis: a systematic review. PLoS Negl Trop Dis. 2015;9(9) - PMC - PubMed
    1. Jensenius M., Han P.V., Schlagenhauf P., Schwartz E., Parola P., Castelli F. Acute and potentially life-threatening tropical diseases in western travelers—a GeoSentinel multicenter study, 1996-2011. Am J Trop Med Hyg. 2013;88:397–404. - PMC - PubMed
    1. Dittrich S., Rattanavong S., Lee S.J., Panyanivong P., Craig S.B., Tulsiani S.M. Orientia, rickettsia, and leptospira pathogens as causes of CNS infections in Laos: a prospective study. Lancet Glob Health. 2015;3:e104–e112. - PMC - PubMed
    1. Gouveia E.L., Metcalfe J., de Carvalho A.L., Aires T.S., Villasboas-Bisneto J.C., Queirroz A. Leptospirosis-associated severe pulmonary hemorrhagic syndrome, Salvador, Brazil. Emerg Infect Dis. 2008;14:505–508. - PMC - PubMed
    1. Hery G., Letheulle J., Flecher E., Quentin C., Piau C., Le Tulzo Y. Massive intra-alveolar hemorrhage caused by Leptospira serovar Djasiman in a traveler returning from Laos. J Travel Med. 2015;22:212–214. - PubMed

Publication types

MeSH terms