Medicine
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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
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Item Effect of antimicrobial agents on inflammatory cytokines in acute Leptospirosis(American Society for Microbiology, 2018) Fernando, N.; de Silva, R.; Hadunnetti, S.M.; Karunanayake, L.; de Silva, N.L.; de Silva, H.J.; Rajapakse, S.; Premawansa, S.The aim of this study was to assess the inflammatory cytokine response and possible association with antimicrobial treatment with penicillin, ceftriaxone, and doxycycline in acute leptospirosis. In the early acute stage, interleukin-10 (IL-10) levels were higher in mild cases than in severe cases (P = 0.01). IL-6 and IL-8 levels were low in patients who received >5 antimicrobial doses (P < 0.01). IL-8 levels were negatively correlated with the number of ceftriaxone doses administered (r = -0.315; P = 0.031). Further studies are needed to evaluate the possible downregulation of proinflammatory cytokines by ceftriaxone in leptospirosis.Item Leptospirosis: challenges in diagnosis, and predictors of severity(Ceylon College of Physicians, 2016) Rajapakse, S.; Fernando, N.; Niloofa, M.J.R.; de Silva, H.J.; Karunanayake, L.; Premawansa, S.; Handunnetti, S.M.No Abstract availableItem A Diagnostic scoring model for Leptospirosis in resource limited settings(Public Library of Science, 2016) Rajapakse, S.; Weeratunga, P.; Niloofa, R.; Fernando, N.; de Silva, N.L.; Rodrigo, C.; Maduranga, S.; Nandasiri, N.; Premawansa, S.; Karunanayake, L.; de Silva, H.J.; Handunnetti, S.Leptospirosis is a zoonotic infection with significant morbidity and mortality. The clinical presentation of leptospirosis is known to mimic the clinical profile of other prevalent tropical fevers. Laboratory confirmation of leptospirosis is based on the reference standard microscopic agglutination test (MAT), direct demonstration of the organism, and isolation by culture and DNA detection by polymerase chain reaction (PCR) amplification. However these methods of confirmation are not widely available in resource limited settings where the infection is prevalent, and reliance is placed on clinical features for provisional diagnosis. In this prospective study, we attempted to develop a model for diagnosis of leptospirosis, based on clinical features and standard laboratory test results. METHODS: The diagnostic score was developed based on data from a prospective multicentre study in two hospitals in the Western Province of Sri Lanka. All patients presenting to these hospitals with a suspected diagnosis of leptospirosis, based on the WHO surveillance criteria, were recruited. Confirmed disease was defined as positive genus specific MAT (Leptospira biflexa). A derivation cohort and a validation cohort were randomly selected from available data. Clinical and laboratory manifestations associated with confirmed leptospirosis in the derivation cohort were selected for construction of a multivariate regression model with correlation matrices, and adjusted odds ratios were extracted for significant variables. The odds ratios thus derived were subsequently utilized in the criteria model, and sensitivity and specificity examined with ROC curves. RESULTS: A total of 592 patients were included in the final analysis with 450 (180 confirmed leptospirosis) in the derivation cohort and 142 (52 confirmed leptospirosis) in the validation cohort. The variables in the final model were: history of exposure to a possible source of leptospirosis(adjusted OR = 2.827; 95% CI = 1.517-5.435; p = 0.001) serum creatinine > 150 micromol/l (adjusted OR = 2.735; 95% CI = 1.374-4.901; p = 0.001), neutrophil differential percentage > 80.0% of total white blood cell count (adjusted OR 2.163; 95% CI = 1.309-3.847; p = 0.032), serum bilirubin > 30 micromol/l (adjusted OR = 1.717; 95% CI 0.938-3.456; p = 0.049) and platelet count < 85,000/mm3 (adjusted OR = 2.350; 95% CI = 1.481-4.513; p = 0.006). Hosmer-Lemeshow test for goodness of fit was 0.931. The Nagelkerke R2 was 0.622. The area under the curve (AUC) was noted as 0.762. A score value of 14 reflected a sensitivity of 0.803, specificity of 0.602, a PPV of 0.54, NPV of 0.84, a positive LR of 2.01 and a negative LR of 0.32. CONCLUSIONS: The above diagnostic model for diagnosis of leptospirosis is suggested for use in clinical settings. It should be further validated in clinical practice.Item Protein Carbonyl as a biomarker of oxidative stress in severe Leptospirosis, and its usefulness in differentiating Leptospirosis from Dengue Infections(Public Library of Science, 2016) Fernando, N.; Wickremesinghe, S.; Niloofa, R.; Rodrigo, C.; Karunanayake, L.; de Silva, H.J.; Wickremasinghe, A.R.; Premawansa, S.; Rajapakse, S.; Handunnetti, S.M.Pathogenesis of disease severity in leptospirosis is not clearly understood whether it is due to direct damage by pathogen or by adverse immune responses. Knowledge on biomarkers of oxidative stress which could be used in identifying patients with severe illness has shown to be of great value in disease management. Thus, the main aim of this study was to assess the damage to serum proteins and lipids, and their significance as biomarkers of oxidative stress in severe leptospirosis. In regions endemic for both leptospirosis and dengue, leptospirosis cases are often misdiagnosed as dengue during dengue epidemics. Therefore, the second aim was to assess the potential of the oxidative stress markers in differentiating severe leptospirosis from critical phase dengue. We measured serum antioxidants (uric acid and bilirubin), total antioxidant capacity (AOC), protein carbonyl (PC) and lipid hydroperoxide (LP) in patients with severe leptospirosis (n = 60), mild leptospirosis (n = 50), dengue during the critical phase (n = 30) and in healthy subjects (n = 30). All patient groups had similar total antioxidant capacity levels. However, the presence of significantly high uric acid and total bilirubin levels may reflect the degree of renal and hepatic involvement seen in severe leptospirosis patients (p<0.02). Serum PC and LP levels were significantly higher in leptospirosis patients compared to critical phase dengue infections (p<0.005). Moreover, high serum PC levels appear to differentiate SL from DC [area under the curve (AUC) = 0.96; p<0.001]. Serum PC may be a reliable biomarker of oxidative damage to serum proteins to identify severe leptospirosis patients (AUC = 0.99) and also to differentiate severe leptospirosis from mild cases (AUC = 0.78; p<0.005) indicating its contribution to pathogenesis. Use of serum PC as an indicator of leptospirosis severity and as an oxidative stress biomarker in differentiating leptospirosis from dengue would provide the opportunity to save lives via prompt patient management.Item A diagnostic model for Leptospirosis for use in resource limited settings(Sri Lanka Medical Association, 2015) Rajapakse, S.; Weeratunga, P.N.; Rodrigo, C.; Sriharan, S.; Niloofa, M.J.R.; Fernando, N.; de Silva, H.J.; Karunanayake, L.; Premawansa, S.INTRODUCTION AND OBJECTIVES: Leptospirosis is a zoonotic infection with significant morbidity and mortality. In this prospective study, we attempted to develop a model for diagnosis of leptospirosis. METHOD: Data was extracted from a prospective multicentre study. All patients with a suspected diagnosis of leptospirosis based on the WHO surveillance criteria were recruited. A derivation cohort and a validation cohort were selected. Positive MAT was used as the gold standard and significant associations in the derivation cohort were selected for construction of a multivariate regression model. Adjusted odds ratios were extracted for significant variables. ROC curves were generated. RESULTS: A total of 592 patients were included with 450 (180 confirmed leptospirosis) in the derivation cohort and 142 (52 confirmed leptospirosis) in the validation cohort. The variables in the final model were: history of exposure to possible source of leptospirosis (OR=2.878;95% Cl=1.527-5.425;p=0.001), serum creatinine>150u.mol/L (OR =2.742; 95% CN1.474-5.101; p=0.001), neutrophil differential percentage (on day 3 of illness) > 82.8% of total WBC count (OR 2.063; 95% Cl = 1.109 - 3.837; p =0.022), serum bilirubin > 27 U/L (OR = 1.767;95%CI 0.968 - 3.226; p=0.050) and platelet count (on day 3 of illness)< 85,000/mm3 (OR=2.350; 95%CI=1.281 -4.313;p=0.006). The Nagelkerke R2 was 0.654. ROC analysis demonstrated a diagnostic model score >14 to have a sensitivity of 80% and a specificity of 60% in the diagnosis of leptospirosis against MAT as the gold standard. CONCLUSION: This proposed diagnostic model for diagnosis of leptospirosis is of potential value to clinicians treating acute febrile illness in areas with limited diagnostic facilities.Item Clinical and laboratory associations of severity in a Sri Lankan cohort of patients with serologically confirmed Leptospirosis - a prospective study(Sri Lanka Medical Association, 2015) Rajapakse, S.; Weeratunga, P.N.; Rodrigo, C.; Sriharan, S.; Niloofa, M.J.R.; Fernando, N.; de Silva, H.J.; Karunanayake, L.; Premawansa, S.; Handunnetti, S.INTRODUCTION AND OBJECTIVES: Leptospirosis is a zoonotic infection of significant morbidity and mortality. This study elucidates the markers of severity in a cohort of Sri Lankan patients with serologically confirmed leptospirosis. METHOD: Prospectively recruited patients presenting to three healthcare institutions in the Western province of Sri Lanka with serological confirmation of leptospirosis with the microscopic agglutination test were included. Data regarding the socio-deruographic profile, clinical presentation, complications and biochemical parameters were recorded. Univariate associations and subsequent multivariate logistic regression models were constructed with severity as the dependent variable. RESULTS: A total of 232 patients were included. Majority were male (86.6%). Severe disease was noted in 68.5%. Significant clinical associations of severe disease included fever > 38.8°C on presentation (p=0.008), age>40 yrs; (p = 0.033), muscle tenderness (p=0.04) and tachycardia on admission (p=0.05). Laboratory associations of severe disease were highest white cell count > 12,350/mm3 (p<0.001) and < 7900/mm3 (p = 0.009), highest neutrophil percentage > 84% {p < 0.001). Hemoglobin > 11.2g/dL (p<0.001) and < 10.2 (p<0.001), packed cell volume > 33.8% (p <0.001) and <29.8% (p <0.001), lowest platelet count <63,500/mm3 (p = 0.01), highest ALT > 70 IU/L {p = 0.02) and hyponatremia with sodium <131mEq/L (p=0.004) On multivariate analysis, PCV < 29.8 (P = 0.011; adjusted OR =3.750; Cl = 1.394 - 10.423), ALT >70 P =0.044 adjusted OR =2.639; Cl =1.028-6.774 and hyponatremia< 131 (p=0.019 adjusted OR=6.413; Cl=1.353 -30.388) were found to be independent associations of severe disease. CONCLUSION: Severity associations were demonstrated with both clinical and laboratory parameters.Item Clinical and laboratory associations of severity in a Sri Lankan cohort of patients with serologically confirmed leptospirosis: a prospective study(Oxford : Oxford University Press, 2015) Rajapakse, S.; Weeratunga, P.; Niloofa, M.J.; Fernando, N.; Rodrigo, C.; Maduranga, S.; de Silva, N.L.; de Silva, H.J.; Karunanayake, L.; Handunnetti, S.BACKGROUND: Leptospirosis results in significant morbidity and mortality. This study elucidates markers of severity in a cohort of Sri Lankan patients. METHODS: Patients presenting to three healthcare institutions in the Western province of SriLanka with leptospirosis serological confirmed by the microscopic agglutination test (MAT) were included. Prospective data regarding demographic, clinical and laboratory parameters was extracted. Univariate associations and subsequent multivariate logistic regression models were constructed. RESULTS: The study included 232 patients, with 68.5% (159) demonstrating severe disease. Significant associations of severe disease at a significance level of p<0.05 were fever >38.8°C on presentation, age >40 years, muscle tenderness, tachycardia on admission, highest white cell count >12 350/mm(3) and <7900/mm(3), highest neutrophil percentage >84%, haemoglobin >11.2 g/dL and <10.2 g/dL, packed cell volume (PCV) >33.8% and <29.8%, lowest platelet count <63 500/mm(3), highest alanine transaminase (ALT) >70 IU/L and hyponatremia with sodium <131mEq/L. On multivariate analysis, PCV <29.8% (p=0.011; OR 3.750; CI: 1.394-10.423), ALT >70 IU/L (p=0.044; OR 2.639; CI: 1.028-6.774) and hyponatremia <131mEq/L (p=0.019; OR 6.413; CI: 1.353-30.388) were independent associations of severe disease. CONCLUSIONS: Severity associations were demonstrated with both clinical and laboratoryparameters. There is a need for novel biomarkers for prediction of severity in leptospirosis. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.Item Changes in full blood count parameters in leptospirosis: a prospective study(BioMed Central, 2014) de Silva, N.L.; Niloofa, M.; Fernando, N.; Karunanayake, L.; Rodrigo, C.; de Silva, H.J.; Premawansa, S.; Handunnetti, S.M.; Rajapakse, S.BACKGROUND: Leptospirosis presents diagnostic challenges to clinicians, in settings where other acute febrile illness are prevalent. The patterns of serial changes in haematological parameters in leptospirosis has not been evaluated previously. METHODS: Clinical and laboratory data were collected prospectively from patients with leptospirosis in two hospitals in Sri Lanka. Leptospirosis was diagnosed based on WHO clinical criteria with confirmation using Microscopic Agglutination Test titre > 400 or 4 fold rise between acute and convalescent samples. Full blood count parameters were analysed up to the 14th day of illness. RESULTS: Data from 201 patients with leptospirosis were available. Leukocyte counts and absolute neutrophil counts showed a decline over the first 5 days of illness, then rose until the end of the second week. On day 3 of fever, the majority (75%) had normal leukocyte counts, and by day 5, leukocytosis was seen only in 38.1%; leucopenia was an uncommon finding. Lymphopenia was seen in over half on day 5, declining to just under a quarter of patients by day 10. Platelets declined over the first 6 days and then gradually rose. Thrombocytopenia was seen in nearly three-fourths of patients by day 5. Haemoglobin and haematocrit levels declined over the course of illness. Total white cell and neutrophil counts were higher, and haemoglobin and haematorcrit were significantly lower, in patients with severe disease. CONCLUSIONS: Neither leukocytosis nor lymphopenia were prominent features, while thrombocytopenia was seen during the 3rd to 5th day of illness, with dropping haemoglobin levels. Neutrophilia and low haemoglobin levels appear to predict severe disease. These findings may be of use to clinicians in differentiating leptospirosis from other acute infections like dengue, and could help in predicting severe leptospirosis.Item Diagnosis of leptospirosis: comparison between microscopic agglutination test, IgM-ELISA and IgM rapid immunochromatography test(Public Library of Science, 2015) Niloofa, R.; Fernando, N.; de Silva, N.L.; Karunanayake, L.; Wickramasinghe, H.; Dikmadugoda, N.; Premawansa, G.; Wickremasinghe, A.R.; de Silva, H.J.; Premawansa, S.; Rajapakse, S.; Handunnetti, S.BACKGROUND: Leptospirosis is diagnosed on clinical grounds, and confirmed by microscopic agglutination test (MAT). IgM-ELISA (Serion-Virion) and immunochromatography test (Leptocheck-WB) are two immunodiagnostic assays for leptospirosis. Their sensitivity, specificity and applicability in Sri Lanka have not been systematically evaluated. METHODS: Clinically diagnosed leptospirosis patients (n = 919) were recruited from three hospitals in the Western Province of Sri Lanka, during June 2012 to December 2013. MAT, IgM-ELISA and Leptocheck-WB were performed on all patient sera. MAT titer of ≥400 in single sample, four-fold rise or seroconversion ≥100 in paired samples were considered as positive for MAT. For diagnostic confirmation, MAT was performed during both acute and convalescent phases. Anti-leptospiral IgM ≥20 IU/ml and appearance of a band in the test window were considered as positive for IgM-ELISA and Leptocheck-WB test respectively. Patients with an alternative diagnosis (n = 31) were excluded. Data analysis was performed using two methods, i) considering MAT as reference standard and ii) using Bayesian latent class model analysis (BLCM) which considers each test as imperfect. RESULTS: MAT, IgM-ELISA and Leptocheck-WB positivity were 39.8%, 45.8% and 38.7% respectively during the acute phase. Acute-phase MAT had specificity and sensitivity of 95.7% and 55.3% respectively, when compared to overall MAT positivity. IgM-ELISA and Leptocheck-WB had similar diagnostic sensitivity when compared with acute-phase MAT as the gold standard, although IgM-ELISA showed higher specificity (84.5%) than Leptocheck-WB (73.3%). BLCM analysis showed that IgM-ELISA and Leptocheck-WB had similar sensitivities (86.0% and 87.4%), while acute-phase MAT had the lowest sensitivity (77.4%). However, acute-phase MAT had high specificity (97.6%), while IgM-ELISA and Leptocheck-WB showed similar but lower specificity (84.5% and 82.9%). CONCLUSIONS: Both IgM-ELISA and Leptocheck-WB shows similar sensitivities and specificities. IgM-ELISA may be superior to MAT during the acute phase and suitable for early diagnosis of leptospirosis. Leptocheck-WB is suitable as a rapid immunodiagnostic screening test for resource limited settings.