ELISA for leptospiral 3-hydroxyacyl-CoA dehydrogenase in urine is a promising screening tool for acute leptospirosis.

Introduction. Leptospirosis is a zoonotic disease that is prevalent worldwide. Leptospiral 3-hydroxyacyl-CoA dehydrogenase (3-HADH) is excreted in the urine of infected individuals. However, the potential use of 3-HADH as a biomarker for the diagnosis of leptospirosis using enzyme-linked immunosorbent assay (ELISA) has not been investigated. A technique that identifies Leptospira in a patient in urine sample will be valuable in regular diagnostics and epidemic scenarios, as opposed to existing serological approaches. This study aimed to develop and evaluate an ELISA that can detect 3-HADH in the urine of patients with confirmed acute leptospirosis and to assess its potential as a screening test for leptospirosis. Methods. Laboratory confirmation of acute leptospirosis was done by flaB-nested polymerase chain reaction (PCR) of plasma samples from suspected patients. ELISA-based determination of the presence of 3-HADH in the urine of PCR-positive patients versus PCR-negative patients matched for fever date was performed by coating ELISA plates with urine supernatants and using rabbit anti-3-HADH as the primary antibody. Receiver operating characteristic curve analysis was used to determine the cutoff values for the ELISA. The diagnostic measures between the PCR-positive and PCR-negative patients were compared using the Mann-Whitney U test. Results. In total, 158 febrile patients were assessed, of whom 121 (76.6 %) were male. Of the 15 flaB-nested PCR-positive patients, 12 were in the acute phase of the febrile illness. The best cutoff was an average optical density (ODav) value of 0.2200 for febrile patients. Sensitivity and specificity were 83.33% [95 % confidence interval (CI), 51.59-97.91 %) and 83.33 % (95 % CI, 76.05-89.13 %), respectively. The ODav values for PCR-positive patients in the acute phase of the disease (≤7 days of fever) were significantly higher than those for PCR-negative patients (P<0.001, U=114.0, z=-4.946). Conclusion. Detection of 3-HADH in urine by ELISA appears to be promising for the screening of acute leptospirosis in suspected patients.

Efficacy of low dose dexamethasone in severe thrombocytopenia caused by dengue fever: a placebo controlled study.

BACKGROUND: The use of corticosteroids in the management of thrombocytopenia in dengue fever remains untested. OBJECTIVES: To test whether intravenous low dose dexamethasone is efficacious in increasing platelet count in acute severe thrombocytopenia in dengue infection. METHODS: We undertook a placebo controlled study at the Teaching Hospital, Peradeniya, Sri Lanka in July 2004. Patients with thrombocytopenia (platelet count <50x10(9)/l) were allocated to the treatment and placebo groups using the sealed envelop method. The treatment group received an initial intravenous dose of 4 mg dexamethasone, followed by 2 mg doses every 8 h for 24 h, and the placebo group received normal saline. The primary outcome was the degree of mean platelet count rise. RESULTS: Each group comprised 100 patients and their baseline data and other variables (headaches, nausea, flush, temperature, pulse, blood pressure, haematocrit, white cell count and haemoglobin) were similar. The primary outcome--mean platelet count (x10(9)/l)--increased steadily in both groups from day 1 to 4 and showed no significant difference between the two groups (p>0.05): day 1, 35 vs 35 (p = 0.70); day 2, 47 vs 43 (p = 0.19); day 3, 64 vs 59 (p = 0.31); day 4, 72 vs 78 (p = 0.55). Analysis of variance (ANOVA) statistics showed a significant linear association of mean platelet counts by days in either group (p<0.001). Regression analysis identified the day of the illness and patient age as the independent predictors of platelet count change. CONCLUSION: At a low dose regimen, dexamethasone was not effective in achieving a higher rise of platelet count in dengue infection.

A case series of dengue fever with altered consciousness and electroencephalogram changes in Sri Lanka.

We describe six serology-positive dengue patients presenting sporadically over 8 years, who lapsed into coma and showed generalized irregular slow waves in consecutive electroencephalograms (EEG) in the absence of any structural brain damage. The mean age was 41 years (range 16-65). All had fever, headache and vomiting for 3 days (range 2-4) on admission and developed coma after 24 h. Five patients developed generalized convulsions and two showed generalized paroxysmal spike-wave discharges in the EEG. All regained normal consciousness within 36 h. In two patients, slow waves in the EEG persisted for 6 and 18 months.

Cardiac complications of a dengue fever outbreak in Sri Lanka, 2005.

A high incidence of cardiac complications was observed in an outbreak of dengue fever at General Hospital, Peradeniya, Sri Lanka, in 2005. This report describes 120 serologically confirmed dengue fever patients who presented during the outbreak. Seventy-five (62.5%) of these patients had electrocardiogram changes (T inversion, ST depression, bundle branch blocks) and were assigned to the 'cardiac group' (50 females, 25 males; median age 34 years, range 13-76). These patients were more susceptible to fatigue, dyspnoea, low peripheral oxygen saturation in room air (P=0.001), chest pain (P=0.001) and flushing of skin (P=0.05) than 45 (37.5%) patients who had normal electrocardiograms and made up the 'non-cardiac group'. In the cardiac group there were 31 primary and 44 secondary dengue patients. In the cardiac group, 17 (23%) patients had hypotension and 58 (77%) developed tachycardia and bradycardia (P<0.001) compared to four (9%) in the non-cardiac group, suggestive of significant cardiac dysfunction. There was no correlation between pulse rate and body temperature: cardiac group (r=0.05; P=0.63); non-cardiac group (r=0.11, P=0.46). RT-PCR detected DEN-3 in three cardiac patients.