Rapid Diagnosis of Leptospirosis by IgM ELISA in Resource Poor Settings. P (original) (raw)
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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.
Sri Lankan Journal of Infectious Diseases, 2014
Introduction Lack of point of care diagnostics is a major challenge for control of human leptospirosis. Immunoglobulin M enzyme linked immunosorbent assays (IgM ELISA) have been widely used for the diagnosis of leptospirosis. The purpose of the present study was to determine the validity of IgM ELISA in the diagnosis of leptospirosis in a Sri Lankan context. Methods Confirmed cases of leptospirosis from the 2008 Sri Lankan outbreak of leptospirosis and a group of leptospirosis excluded febrile patients were selected for the validation study. Disease confirmation and exclusion was carried out using either paired sample MAT (optimized for the region) or qPCR or both. A commercially available IgM ELISA kit was used and the procedure performed according to the manufacturers' instruction in the Department of Microbiology, Faculty of Medicine, University of Peradeniya. Results The study sample included 88 confirmed cases of leptospirosis and a comparison group of 71 acute fever patients. Of the 88 confirmed cases selected, 53 reacted in IgM ELISA and of the comparison group, 38 gave a positive reaction. Sensitivity and specificity of IgM ELISA, as a point of care diagnostic test for patients in this sample with acute leptospirosis, was 60.23% (95% CI 49.78, 69.82) and 46.48% (95% CI (35.36, 57.96) respectively. Diagnostic accuracy of the test was 54.09% (95% CI 46.34, 61.65 %). The ROC (Receiver-operator characteristic curve) curve for the IgM ELISA showed a value of .669 for area under the curve. Optimal cut off points were not detected due to the poor test parameters in this sample. Conclusion This study shows the limited diagnostic capabilities of IgM ELISA during the acute phase of leptospirosis in high endemic settings
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.
International Journal of Microbiology, 2016
Leptospirosis is a globally distributed zoonosis with varied clinical outcomes and multiorgan involvement in humans. In this study conducted from July 2011 to December 2011, 178 serum samples from patients suspected of leptospirosis were tested by Panbio IgM ELISA at National Public Health Laboratory, Kathmandu, out of which 51 (28.65%) were positive for anti-Leptospira IgM antibody. Leptospirosis was more common in people in their 2nd and 3rd decades of their life which together comprised 56.86% of the total positive cases. Most of those tested positive were farmers followed by students and housewives. Both animal contact and water contact seemed to play significant roles in disease transmission. Symptoms were vague with the most common being fever, headache, myalgia, abdominal pain, vomiting, jaundice, and diarrhoea. Life style heavily dominated by agronomical and farming activities in Nepal is conducive to leptospirosis transmission. Leptospirosis seems to be a significant public...
Indian Journal of Medical Microbiology, 2007
Purpose: Leptospirosis is a zoonotic disease with humans getting the infection either from rodent hosts or from domestic animals. Urine contaminated environment is the common source of infection. This is an under-reported disease in Andhra Pradesh. We report a retrospective hospital-based study on 55 patients with suspected leptospirosis. Methods: A total of 55 serum samples were collected from patients with suspected leptospirosis and subjected to serological testing by LeptoTek Dri-dot, microscopic agglutination test (MAT) and IgM enzyme-linked immunosorbent assay (ELISA). Identification of the predominant infecting serotype was done using a panel of 12 serovars. Results: MAT analysis of all the 55 samples identified all cases to be positive. The predominant serogroup was Icterohaemorrhagiae (68%) followed by Australis (22%), Autumnalis (8%) and Javanica (2%). LeptoTek Dri-dot showed a sensitivity of 96% as compared to MAT. IgM ELISA done on 32 samples showed a sensitivity of 86.7% compared to MAT. Conclusions: MAT helped to identify Icterohemorrhagiae as the predominant serovar in this study. Despite the small number of samples analyzed, the data obtained establishes a need for a prospective study in this region.
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...
The Journal of Infection in Developing Countries, 2017
Introduction: Leptospirosis is a major public health problem in India. However, it has been underreported and under-diagnosed due to a lack of awareness of the disease, a functional surveillance system, and appropriate laboratory diagnostic facilities. Methodology: This multicenter study aimed to understand the Leptospira serovars causing leptospirosis in seven secondary-level hospitals in six states in India. Since early and accurate diagnosis of leptospirosis is one of the challenges faced by clinicians in India due to the poor specificity and sensitivity of commercially available diagnostic systems, an in-house indirect enzyme-linked immunosorbent assay (ELISA) was developed. Genomic DNA from L. interrogans serovar Canicola was used for polymerase chain reaction amplification, cloning, and expression of the lipL32 gene in E. coli to amplify, clone, and express the lipL32 gene. Results: Australis was the common serovar seen at all the study centers. Serovar Icterohaemorrhagiae was...
Serological Evaluation of Clinically Suspected Leptospirosis Cases in a Tertiary Care Hospital
Journal of Evolution of Medical and Dental Sciences
BACKGROUND Leptospirosis is a zoonotic infection caused by the spirochaete Leptospira, which has worldwide distribution. Laboratory diagnosis is routinely performed by serological tests like dipstick assay, lateral flow assay and latex agglutination which are rapid tests recommended for screening the disease. Microscopic Agglutination Test (MAT) is the standard test for serological diagnosis of leptospiral infection which is not included in the test panel in most of the peripheral laboratories as the procedure is laborious and it requires to maintain live leptospira. Therefore, one of the rapid tests is routinely employed for demonstration of leptospiral antibodies. Our objective was to screen the acute cases of leptospirosis by Leptochek WB IgM and PanBio IgM Elisa and compare the findings with the MAT and correlate the clinical findings with the serological tests. METHODS This study was conducted in a tertiary care hospital in Mangalore from August 2010 to September 2013. A total of 314 cases of clinically suspected leptospirosis were included based on the Faine's criteria. Patients' serum was screened for leptospiral antibodies by Leptochek WB IgM, PanBio IgM ELISA and Microscopic Agglutination Test (MAT). RESULTS Out of 314 clinically suspected cases screened, seropositivity for leptospirosis by Leptochek WB-IgM, PanBio IgM ELISA and MAT was found to be 49 (15.6%), 65 (20.7%) and 78 (24.8%) respectively. Thus, an overall prevalence rate of leptospirosis was 24.8% (78/314) based on the MAT test. Sensitivity, specificity, positive predictive value and negative predictive value of Leptocheck WB IgM was 53.8%, 97%, 85.7 and 86.4% with MAT while the comparative values of PanBio-ELISA IgM with respect to MAT test was 74.5%, 97 %, 89.2% and 92% respectively. Common clinical features among MAT positive cases were fever, chills and rigors, oliguria, vomiting, jaundice and headache. CONCLUSIONS MAT is a standard serological test for Leptospirosis. This test is not always available for peripheral health centres, as the test is time consuming and cumbersome. Thus, screening tests are now being employed for screening the patients. Rapid tests like Leptocheck-WB can be supplemented with an ELISA test for screening of clinically suspected cases of Leptospirosis and later confirmed with the MAT at reference centres.
Varied presentations of leptospirosis: experience from a tertiary care hospital in north India
Leptospirosis has been recognised as an emerging global public health problem. The aim of our study was to explore the epidemiological and clinical pattern of disease occurrence in suspected cases and to search for any existing co-infections. Ours was a retrospective study in patients with acute febrile illness in north India over a period of three years (April 2011 to June 2014). Serological diagnosis of leptospirosis was made using the PanBio IgM ELISA kit. Using modified Faine's criteria, presumptive and possible diagnosis was made in 57% and 34% cases, respectively. Most of the affected population was resident in north and central India. Nineteen patients showed co-infection with other common pathogens prevailing locally. There is a need to increase awareness and understand the local sero-epidemiological pattern of leptospirosis so that timely preventive and curative action may be taken by healthcare authorities.