Evaluation of surveillance case definition in the diagnosis of leptospirosis, using the Microscopic Agglutination Test: a validation study

<p>Abstract</p> <p>Background</p> <p>Leptospirosis is endemic in both urban and rural areas of Sri Lanka and there had been many out breaks in the recent past. This study was aimed at validating the leptospirosis surveillance case definition, using the Microscopic Agglutination Test (MAT).</p> <p>Methods</p> <p>The study population consisted of patients with undiagnosed acute febrile illness who were admitted to the medical wards of the Teaching Hospital Kandy, from 1^stJuly 2007 to 31^stJuly 2008. The subjects were screened to diagnose leptospirosis according to the leptospirosis case definition. MAT was performed on blood samples taken from each patient on the 7^thday of fever. Leptospirosis case definition was evaluated in regard to sensitivity, specificity and predictive values, using a MAT titre ≥ 1:800 for confirming leptospirosis.</p> <p>Results</p> <p>A total of 123 patients were initially recruited of which 73 had clinical features compatible with the surveillance case definition. Out of the 73 only 57 had a positive MAT result (true positives) leaving 16 as false positives. Out of the 50 who didn't have clinical features compatible with the case definition 45 had a negative MAT as well (true negatives), therefore 5 were false negatives. Total number of MAT positives was 62 out of 123. According to these results the test sensitivity was 91.94%, specificity 73.77%, positive predictive value and negative predictive values were 78.08% and 90% respectively. Diagnostic accuracy of the test was 82.93%.</p> <p>Conclusion</p> <p>This study confirms that the surveillance case definition has a very high sensitivity and negative predictive value with an average specificity in diagnosing leptospirosis, based on a MAT titre of ≥ 1: 800.</p

Predictors of the development of myocarditis or acute renal failure in patients with leptospirosis: An observational study

<p>Abstract</p> <p>Background</p> <p>Leptospirosis has a varied clinical presentation with complications like myocarditis and acute renal failure. There are many predictors of severity and mortality including clinical and laboratory parameters. Early detection and treatment can reduce complications. Therefore recognizing the early predictors of the complications of leptospirosis is important in patient management. This study was aimed at determining the clinical and laboratory predictors of myocarditis or acute renal failure.</p> <p>Methods</p> <p>This was a prospective descriptive study carried out in the Teaching Hospital, Kandy, from 1st July 2007 to 31st July 2008. Patients with clinical features compatible with leptospirosis case definition were confirmed using the Microscopic Agglutination Test (MAT). Clinical features and laboratory measures done on admission were recorded. Patients were observed for the development of acute renal failure or myocarditis. Chi-square statistics, Fisher's exact test and Mann-Whitney <it>U </it>test were used to compare patients with and without complications. A logistic regression model was used to select final predictor variables.</p> <p>Results</p> <p>Sixty two confirmed leptospirosis patients were included in the study. Seven patients (11.3%) developed acute renal failure and five (8.1%) developed myocarditis while three (4.8%) had both acute renal failure and myocarditis. Conjunctival suffusion - 40 (64.5%), muscle tenderness - 28 (45.1%), oliguria - 20 (32.2%), jaundice - 12 (19.3%), hepatomegaly - 10 (16.1%), arrhythmias (irregular radial pulse) - 8 (12.9%), chest pain - 6 (9.7%), bleeding - 5 (8.1%), and shortness of breath (SOB) 4 (6.4%) were the common clinical features present among the patients. Out of these, only oliguria {odds ratio (OR) = 4.14 and 95% confidence interval (CI) 1.003-17.261}, jaundice (OR = 5.13 and 95% CI 1.149-28.003), and arrhythmias (OR = 5.774 and 95% CI 1.001-34.692), were predictors of myocarditis or acute renal failure and none of the laboratory measures could predict the two complications.</p> <p>Conclusions</p> <p>This study shows that out of clinical and laboratory variables, only oliguria, jaundice and arrhythmia are strong predictors of development of acute renal failure or myocarditis in patients with leptospirosis presented to Teaching Hospital of Kandy, Sri Lanka.</p

Transverse myelitis secondary to Melioidosis; A case report

<p>Abstract</p> <p>Background</p> <p>Melioidosis has become an emerging infection in Sri Lanka; a country which is considered non endemic for it. Paraplegia due to <it>Burkholderia pseudomallei</it> is a very rare entity encountered even in countries where the disease is endemic. There are no reported cases of transverse myelitis due to melioidosis in Sri Lankan population thus we report the first case.</p> <p>Case presentation</p> <p>A 21 year old farmer presented with sudden onset bi lateral lower limb weakness, numbness and urine retention. Examination revealed flaccid areflexic lower limbs with a sensory loss of all modalities and a sensory level at T₁₀ together with sphincter involvement. MRI of the thoracolumbar spine showed extensive myelitis of the thoracic spine complicating left psoas abscess without definite extension to the spinal cord or cord compression. <it>Burkholderia pseudomallei</it> was isolated from the psoas abscess pus cultures and the diagnosis of melioidosis was confirmed with high titers of <it>Burkholderia pseudomallei</it> antibodies and positive PCR. He was treated with high doses of IV ceftazidime and oral cotrimoxazole for one month with a plan to continue cotrimoxazole and doxycycline till one year. Patient’s general condition improved but the residual neurological problems persisted.</p> <p>Conclusion</p> <p>The exact pathogenesis of spinal cord melioidosis is not quite certain except in the cases where there is direct microbial invasion, which does not appear to be the case in our patient. We postulate our patient’s presentation could be due to ischemia of the spinal cord following septic embolisation or thrombosis of spinal artery due to the abscess nearby. A neurotrophic exotoxin causing myelitis or post infectious immunological demyelination is yet another possibility. This emphasizes the necessity of further studies to elucidate the exact pathogenesis in this type of presentations.</p> <p>Health care professionals in Sri Lanka, where this is an emerging infection, need to improve their knowledge regarding this disease and should have high degree of suspicion to make a correct and a timely diagnosis to reduce the morbidity and mortality due to <it>Burkholderia pseudomallei</it> infection. It is highly likely that this infection is under diagnosed in developing countries where diagnostic facilities are minimal. Therefore strategies to improve the awareness and upgrade the diagnostic facilities need to be implemented in near future.</p