Case definitions in Leptospirosis: a note to Sri Lankan researchers (original) (raw)
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BMJ Open, 2019
IntroductionSri Lanka has one of the highest incidences of leptospirosis worldwide. We hypothesised that different geographical locations and patient context will have a distinct molecular epidemiology of leptospirosis, based on microgeographical characteristics related to regiona-specificLeptospirapredominance. Our objective is to characterise the clinical, epidemiological and molecular aspects of leptospirosis in Sri Lanka to understand disease progression, risk factors and obtain isolates ofLeptospira.Methods and analysisWe designed a multicentre prospective study in Sri Lanka to recruit undifferentiated febrile patients and conduct follow-ups during hospital stays. Patients will be recruited from outpatient departments and medical wards. This study will be conducted at two main sites (Anuradhapura and Peradeniya) and several additional sites (Awissawella, Ratnapura and Polonnaruwa). Blood and urine will be collected from patients on the day of admission to the ward or presentati...
The Southeast Asian journal of tropical medicine and public health, 2012
To help formulate a local intervention for leptospirosis in Sri Lanka, we determined the serogroups of leptospiral species among 97 patients diagnosed with leptospirosis at the University of Peradeniya Teaching Hospital, Sri Lanka. Ninety-two point eight percent of the patients were men; nearly two-thirds were > or = 35 years old; the majority had secondary or higher education level, half were farmers or laborers; and 57.7% presented in the acute-phase of the illness. Twenty-five patients (25.8%) were confirmed to have leptospirosis by a positive laboratory method; 17 and 8 cases were confirmed with a positive test by quantitative MAT and nested PCR, respectively. Of the 17 MAT positive cases, infection occurred in a variety of serogroups, but the predominant groups were Sejroe and Tarassovi. Of the 8 nested PCR positive cases, 7 were seen among those with a MAT titer <200 and 1 occurred in a patient with a MAT titer > or = 200 but <400. Of the 8 PCR positive cases, 7 we...
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.
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.
Leptospirosis outbreak in Sri Lanka in 2008: lessons for assessing the global burden of disease
The American journal of …, 2011
Global leptospirosis disease burden estimates are hampered by the lack of scientifically sound data from countries with probable high endemicity and limited diagnostic capacities. We describe the seroepidemiologic and clinical characteristics of the leptospirosis outbreak in 2008 in Sri Lanka. Definitive/presumptive case definitions proposed by the World Health Organization Leptospirosis Epidemiology Reference Group were used for case confirmation. Of the 404 possible cases, 155 were confirmed to have leptospirosis. Highest titers of patient seum samples reacted with serovars Pyrogenes (28.7%), Hardjo (18.8%), Javanica (11.5%), and Hebdomadis (11.5%). Sequencing of the 16S ribosomal DNA gene identified six infections: five with Leptospira interrogans and one with L. weilli . In this patient population, acute renal failure was the main complication (14.8%), followed by myocarditis (7.1%) and heart failure (3.9%). The case-fatality rate was 1.3%. This report strengthens the urgent need for increasing laboratory diagnostic capabilities to determine the causes of epidemic and endemic infectious diseases in Sri Lanka, a finding relevant to other tropical regions.
PLOS Neglected Tropical Diseases, 2020
Leptospirosis is endemic in Sri Lanka. There is a need for updated seroprevalence studies in endemic areas, to improve the understanding of disease dynamics, risk factors, control methods, and for clinical diagnosis. The cutoff titres for the microscopic agglutination test (MAT) for diagnosis of acute leptospirosis depend on community seroprevalence, and can vary based on locality and serovar. This study aimed to identify the seroprevalence, geographical determinants, and associations of seropositivity of leptospirosis in the district of Colombo in Sri Lanka, and to determine diagnostic cutoff titres for MAT in the community studied. This study utilized a stratified cluster sampling model in the Colombo district of Sri Lanka, to sample individuals living in urban and semi-urban areas. Serovar specific MAT titres were measured on recruited individuals using a panel of saprophytic (Leptospira biflexa) and 11 pathogenic Leptospira spp. serovars. Associations between environmental risk factors and MAT positivity were examined, with location mapping using GIS software. A total of 810 individuals were included. The mean age was 51.71 years (SD 14.02) with male predominance (60%). A total of 429 (53%) tested positive at a titer of 1/40 or more for the saprophytic Leptospira biflexa serovar Patoc. Pathogenic serovar MAT was positive at a titer of 1/40 or more for at least one serovar in 269 (33.2%) individuals. From the perspective of screening for clinical disease, serovar-specific cutoff titres of 1/80 for Leptospira spp. serovars Hebdomadis, Icterohaemorrhagiae, Pomona, Ratnapura and Patoc, 1/160 for serovars Pyrogenes and Cynopteri, and 1/40 for other serovars were determined, based on the 75 th quartile MAT titre for each serovar. Serovar Pyrogenes (15.9%) had the highest seroprevalence, with serovars Ratnapura, Bankinang and Australis accounting for 9.9%, 9.6% and 9.3% respectively. When the proposed new cutoffs were applied, Bankinang(9.6%)
Molecular characterisation and disease severity of leptospirosis in Sri Lanka
Memórias do Instituto Oswaldo Cruz, 2015
Leptospirosis is a re-emerging zoonotic disease all over the world, important in tropical and subtropical areas. A majority of leptospirosis infected patients present as subclinical or mild disease while 5-10% may develop severe infection requiring hospitalisation and critical care. It is possible that several factors, such as the infecting serovar, level of leptospiraemia, host genetic factors and host immune response, may be important in predisposition towards severe disease. Different Leptospira strains circulate in different geographical regions contributing to variable disease severity. Therefore, it is important to investigate the circulating strains at geographical locations during each outbreak for epidemiological studies and to support the clinical management of the patients. In this study immunochromatography, microscopic agglutination test and polymerase chain reaction were used to diagnose leptospirosis. Further restriction fragment length polymorphism and DNA sequencing methods were used to identify the circulating strains in two selected geographical regions of Sri Lanka. Leptospira interrogans, Leptospira borgpetersenii and Leptospira kirschneri strains were identified to be circulating in western and southern provinces. L. interrogans was the predominant species circulating in western and southern provinces in 2013 and its presence was mainly associated with renal failure.
Seroprevalence of leptospirosis in Chennai city, India
International Journal of Bioassays, 2016
Leptospirosis is a zoonotic disease, it occurs worldwide but is most common in tropical and subtropical countries. The magnitude of the problem varies from community to community. The serovars which cause the disease in a community change with adaptation to a new maintenance host and is epidemiologically important. Aims and Objectives: To determine the seroprevalence of leptospirosis in Chennai city. To identify the prevalent serovar in Chennai causing leptospirosis by using gold standard test Microscopic Agglutination Test (MAT). Methods: 1209 patients from Chennai, with fever of one-week duration and with signs and symptoms of Leptospirosis were the study population and were screened for Leptospirosis by Macroscopic Slide Agglutination Test (MSAT). The positive samples by MSAT were tested for the prevalent serovar and for confirmation by MAT and the results were analyzed statistically. Result: The seroprevalence of Leptospirosis is 17.8%. The prevalent serovar circulating in Chenn...
Serological study of Leptospirosis in central Nepal
International Journal of Biomedical and Advance Research, 2013
Background: Leptospirosis, an infectious disease caused by spirochetes of the genus Leptospira, is the most widespread zoonosis in the world. Humans acquire infection through contact with the urine of infected or carrier animals, either directly or through contaminated water or soil. There are only few reports documenting the serological evidence of leptospirosis in Nepal. Thus, present study aims to determine the status of leptospirosis in central Nepal. Material and Methods: A descriptive cross sectional study was conducted in 1266 patients suspected of leptospirosis in Chitwan Medical College Teaching Hospital for a period of two years. Blood samples collected from the patients were processed for qualitative detection of leptospiral IgM antibody by ELISA (Enzyme linked immunosorbent assay). Results: Of the 1266 samples subjected to ELISA, seropositivity was seen in 61 samples (4.8%) with the highest rate observed in the autumn season (63.9%) followed by summer season (21.3%). Majority (39.3%) of the seropositive individuals were agricultural workers. Leptospirosis was more common in males and in the people of 16-30 years. Conclusion: Leptospirosis is common in central Nepal. Epidemiological surveillance and laboratory capacity across the region need strengthening to determine its true prevalence in the community.