Leptospirosis in Kuala Lumpur and the comparative evaluation of two rapid commercial diagnostic kits against the MAT test for the detection of antibodies to leptospira interrogans (original) (raw)
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BMC Infectious Diseases, 2014
Background: Leptospirosis is a zoonotic disease caused by Leptospira species and is distributed globally. Microscopic agglutination test (MAT) is the serological 'gold standard' for diagnosis of leptospirosis but it is time-consuming and labour-intensive. An alternative serological method that is rapid, sensitive and specific is important for early treatment to reduce morbidity and mortality. The use of local Leptospira isolation may improve the sensitivity and specificity of the test because it may varies from one geographical region to another region. The objective of this study was to determine the sensitivity, specificity and cutoff points for an in-house Immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) using a locally isolated Leptospiral strain IMR/175 as the antigen for the detection of anti-Leptospiral IgM. Methods: Serum samples from 270 patients with clinical symptoms of leptospirosis were subjected to the in-house IgM ELISA, MAT and Leptospirosis rapid test. The optimal cutoff values for positivity and negativity of the IgM ELISA were determined by Receiver Operating Characteristic curves and mean ± 2 standard deviation (SD) analyses of the ELISA values. Results: The area under the curve (AUC) which indicates the diagnostic performance of the in-house IgM ELISA was 0.953 (95% Confidence Interval, CI: 0.928, 0.978). The sensitivity and specificity of 90.38% and 87.72% respectively were obtained with the cutoff point of 0.55. A higher sensitivity (96.15%) was obtained when the cutoff point was set at 0.45. Conclusions: The in-house IgM ELISA assay using local Leptospira isolation was shown to be sensitive and may be suitable to use for the serological diagnosis of leptospirosis for our local hospital setting.
National Journal of Community Medicine, 2011
The study was conducted to evaluate the two rapid tests for the serologic diagnosis of leptospirosis namely Microplate Immunoglobulin M(IgM)-Enzyme Linked Immunosorbent Assay(ELISA) and IgM Rapid Leptocheck WB and the performance of each assay compared with that of the current standard, the microscopic agglutination test (MAT). The panels of 188 sera from 130 cases of leptospirosis from three different geographical locations were tested as well as 310 sera from healthy individual or individual with other infectious disease other than leptospirosis. Acute phase sera from cases (n=130) were collected <14 days after the onset of symptoms and convalescent phase sera (n=58) were collected ≥14 days after the onset of symptoms. By traditional method (two-by-two) contingency table, the sensitivity, specificity, PPV(Positive predictive value), NPV(Negative predictive value), Efficiency of test and (Kappa) value for agreement (with MAT) for the Rapid Leptocheck WB were 98.36%, 86.95%, 86.95%, 98.36%, 92.37% and 0.81 in acute phase of disease. Corresponding values for IgM ELISA were 96.82%, 88.05%, 88.40%, 96.72%, 91.53% and 0.88 respectively. The sensitivity, specificity, PPV(Positive predictive value), NPV(Negative predictive value), Efficiency of test and (Kappa) value for agreement (with MAT) for the Rapid Leptocheck WB were 87.87%, 88%, 90.82%, 84.61%,86.20% and 0.85 in convalescent phase of the disease. Corresponding values for IgM ELISA were 91.42%, 95.65%, 96.96%, 88%, 93.10% and 0.81 respectively. These values for the 2 tests were comparable, indicating that there was no difference in their efficacies. The second-generation assay included in study (Leptocheck and ELISA) showed significantly higher sensitivity with early acute phase sera than the reference or first generation method (MAT) while retaining high specificity and should greatly improve the rapid detection of leptospirosis in the field.
Clinical and Vaccine Immunology, 2006
The diagnostic utility of immunochromatographic (Leptotek) and enzyme-linked immunosorbent assay (ELISA; Panbio) tests for the detection of Leptospira immunoglobulin M antibodies was assessed in febrile adults admitted in Vientiane, Laos. Both tests demonstrated poor diagnostic accuracy using admission serum (Leptotek sensitivity of 47.3% and specificity of 75.5%: ELISA sensitivity of 60.9% and specificity of 65.6%) compared to the Leptospira "gold standard" microscopic agglutination test.
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2012
The diagnostic utility of the Standard Diagnostics Leptospira IgM ELISA for detection of acute leptospirosis was assessed in febrile adults admitted in Vientiane, Laos. Using the cut-off suggested by the manufacturer [optical density (OD) ≥0.75], the assay demonstrated limited diagnostic capacity with a sensitivity of 95% and a specificity of 41% compared with the Leptospira microscopic agglutination test, which is the serological gold standard. However, re-evaluation of the diagnostic cut-off to an OD of 1.7 demonstrated improved diagnostic accuracy overall (sensitivity 70%; specificity 78%).
PLoS Negl Trop Dis, 2022
Leptospirosis is among the most important zoonotic diseases in (sub-)tropical countries. The research objective was to evaluate the accuracy of the Serion IgM ELISA EST125M against the Microscopic Agglutination Test (MAT = imperfect reference test); to assess its ability to diagnose acute leptospirosis infections and to detect previous exposure to leptospires in an endemic setting. In addition, to estimate the overall Leptospira spp. seroprevalence in the Wiwa indigenous population in North-East Colombia. We analysed serum samples from confirmed leptospirosis patients from the Netherlands (N = 14), blood donor sera from Switzerland (N = 20), and sera from a cross-sectional study in Colombia (N = 321). All leptospirosis ELISA-positive, and a random of negative samples from Colombia were tested by the MAT for confirmation. The ELISA performed with a sensitivity of 100% (95% CI 77% - 100%) and a specificity of 100% (95% CI 83% - 100%) based on MAT confirmed Leptospira spp. positive and negative samples. In the cross-sectional study in Colombia, the ELISA performed with a sensitivity of 100% (95% CI 2-100%) and a specificity of 21% (95% CI 15-28%). Assuming a 5% Leptospira spp. seroprevalence in this population, the positive predictive value was 6% and the negative predictive value 100%. The Leptospira spp. seroprevalence in the Wiwas tested by the ELISA was 39%; however, by MAT only 0.3%. The ELISA is suitable to diagnose leptospirosis in acutely ill patients in Europe several days after onset of disease. For cross-sectional studies it is not recommended due to its low specificity. Despite the evidence of a high leptospirosis prevalence in other study areas and populations in Colombia, the Wiwa do not seem to be highly exposed to Leptospira spp.. Nevertheless, leptospirosis should be considered and tested in patients presenting with febrile illness.
PLOS Neglected Tropical Diseases, 2021
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 a...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2011
Given the protean manifestations of leptospirosis, adequate laboratory support for diagnosis is necessary. Traditionally, the gold standard is the microscopic agglutination test (MAT) using a panel of Leptospira isolates representing a broad range of serogroups and serovars. It has been proposed that screening with serovars circulating in a region would enhance test performance. We assessed the diagnostic usefulness of MAT using both regionally obtained clinical Leptospira isolates and the specific isolates recovered from the tested patients. Serum obtained from 41 acute febrile patients (obtained on average 7.2 days [SD ± 5.2] after onset of fever) was tested using a standard panel of 24 serovars along with regional isolates recovered from human and animal blood cultures from different regions in Egypt and a patient's own isolate, if available, to establish additional MAT panels. Serum samples tested by a standard 24 panel with a cut-off of >1:800 revealed five patients with positive serology. Only one patient had a positive result using a regional panel or patient's own culture developed MAT. However, the serovar with the highest titers did not match the cultured serovar. Region-specific MATs did not appear to be reliable in detection of infection or in identifying the infecting serovar.
Rapid Diagnosis of Leptospirosis by IgM ELISA in Resource Poor Settings
https://www.ijhsr.org/IJHSR\_Vol.6\_Issue.3\_March2016/12.pdf, 2016
Background & Objectives: Early and accurate diagnosis of leptospirosis is important for proper and prompt treatment, which is life saving for patients with severe illness. IgM ELISA is particularly useful in making an early diagnosis, since it is positive in the first week of illness, a time when the clinical manifestations may be nonspecific. This study was done to evaluate the prevalence of leptospirosis in Aligarh and to compare the efficacy of IgM ELISA to PCR and MAT as a rapid, sensitive and cost effective diagnostic tool for leptospirosis. Methods: Patients with acute febrile illness, acute renal failure and acute hepatitis were included in the study. Clinical & epidemiological history was evaluated on the basis of modified Faine's criteria. ELISA, MAT and PCR using G1/G2 primer which amplifies a 285 bp fragment was done for confirmation of diagnosis. Results: Thirty one (14.9%) patients were found positive for specific anti-leptospira IgM antibodies by ELISA. On comparing the results of IgM ELISA to MAT the sensitivity was 100% while specificity was 87.6%, while it was 100% and 97.3% respectively in relation to PCR. None of the patients had a Faine's score > 25 and 21(67.7%) patients had a score between 20-25. Interpretations &Conclusions: ELISA is a cost-effective, sensitive and specific test that can be used as a first line diagnostic test for early diagnosis of leptospirosis.
Journal of clinical microbiology, 1997
We studied a dipstick assay for the detection of Leptospira-specific immunoglobulin M (IgM) antibodies in human serum samples. A high degree of concordance was observed between the results of the dipstick assay and an IgM enzyme-linked immunosorbent assay (ELISA). Application of the dipstick assay for the detection of acute leptospirosis enabled the accurate identification, early in the disease, of a high proportion of the cases of leptospirosis. Analysis of a second serum sample is recommended, in order to determine seroconversion or increased staining intensity. All serum samples from the patients who were confirmed to be positive for leptospirosis by either a positive microscopic agglutination test or a positive culture but were found to be negative by the dipstick assay were also judged to be negative by the IgM ELISA or revealed borderline titers by the IgM ELISA. Some cross-reactivity was observed for sera from patients with diseases other than leptospirosis, and this should b...