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BACKGROUND AND OBJECTIVE: Dengue is a major infectious disease with potential for outbreaks and epidemics. A specific and sensitive diagnosis is a prerequisite for clinical management of the disease. We designed our study to identify epitopes on the Dengue virus (DENV) envelope (E) and non-structural protein 1 (NS1) with potential for diagnosis. METHODS: Serology and immunoinformatic approaches were employed. We collected DENV-positive, DENV-negative and Japanese encephalitis virus-positive samples from collaborating hospitals in 2019 and 2022-2023. Seropositive peptides in 15-18 mer peptide arrays of E and NS1 proteins of DENV2 were determined by an indirect enzyme-linked immunosorbent assay. B-cell linear and conformational epitopes were predicted using BepiPred2.0 and ElliPro, respectively. A consensus recombinant peptide was designed, synthesised and evaluated for its diagnostic potential using patient sera. RESULTS: Eight peptides of E protein and six peptides of NS1 protein were identified to be the most frequently recognised by Dengue-positive patients. These peptide sequences were compared with B-cell epitope regions and found to be overlapped with predicted B-cell linear and conformational epitopes. EP11 and NSP15 showed a 100% amino acid sequence overlap with B-cell epitopes. EP1 and NSP15 had 14 whereas EP28, EP31, EP60 16, NSP12 and NSP32 had more than 15 interacting interface residues with a neutralising antibody, suggesting a strength of interaction. Interestingly, potential epitopes identified were localised on the surface of proteins as visualised by PyMOL. Validation with a recombined synthetic peptide yielded 92.3% sensitivity and 91.42% specificity. CONCLUSIONS: Immunodominant regions identified by serology and computationally predicted epitopes overlapped, thereby showing the robustness of the methodology and the peptide designed for diagnosis.
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INTRODUCTION: Sepsis is the primary cause of death from infection worldwide. In resource-limited countries, increasing number of sepsis is managed in non-ICU settings, in Medical Wards (MW). AIM: To compare the burden, aetiology and short term outcome of sepsis treated in MW with ICU. MATERIALS AND METHODS: Prospective, observational, analytical study in sepsis patients in general MW and medical ICU in a tertiary care hospital. Two hundred forty five sepsis patients (MW=150, ICU=95), ≥18 years, selected randomly, were studied to compare aetiology, co-morbidities, clinical & microbiological profile and short-term outcome between MW and ICU sepsis. Sepsis following surgery, trauma, those transferred to/from ICU, those with other life threatening diseases were excluded. Chi-square test/Fisher's-exact test was used for comparing ratios. A 'p-value' <0.05 was considered statistically significant. RESULTS: Sepsis was more common in elderly males, both in MW and ICU (median age: 56.7, 59.2 years; male: female ratios = 1.34:1, 1.63:1 respectively). Frequency of presenting symptoms, co-morbidities and sources of sepsis were similar in both groups (p>0.05). Frequency of positive microbiological culture, pattern of microbial flora and antimicrobial resistance patterns were similar in both groups (p>0.05). Number of antibiotics used was significantly higher in ICU compared to MW (p<0.01); multi-organ dysfunction and mortality were significantly higher in ICU settings (55.8% vs. 38.7%, p=0.04; 48.4% vs. 32.6%, p=0.041 respectively). While sepsis and severe sepsis were significantly higher in MW (34.6% vs. 22.1 %, p=0.03; 47.3% vs. 26.3%, p<0.01 respectively), septic shock was significantly higher in ICU (51.6% vs. 18.0%, p<0.01). Mortality in both settings was highest in septic shock (55.5% and 61.2%, p>0.05) and multi-organ dysfunction (55.1% and 64.2%, p>0.05). Duration of hospital stay was significantly shorter in MW than ICU (7.3 vs. 11.0 days, p<0.01). CONCLUSION: Our study aimed to identify determinants and outcome of sepsis in MW and compare with ICU settings. Antibiotic usage in the two settings differed: concurrent use of ≥3 antibiotics, and carbapenems & linezolid usage were significantly higher in ICU compared to MW. Sepsis in MW had significantly lower incidence of multi-organ failure, lower mortality and shorter hospital stay compared to ICU.
