title: Differential clinical symptoms among acute phase Indian patients revealed significant association with dengue viral load and serum IFN-gamma level.
abstract: BACKGROUND
  During last three decades, dengue (DF), an arthropod-borne viral disease is increasingly prevalent worldwide including India, resulting in serious public health problems.
  
  
  OBJECTIVE
  This study was carried out during 2012-2013 to evaluate the association of WHO-classified dengue disease symptoms with viral load (VL) and serum IFN-gamma levels in dengue patients from India.
  
  
  METHODS
  Blood samples were collected from dengue symptomatic febrile patients (n=127). DEN-VL was determined by quantitative real-time RT-PCR using RNA, extracted from plasma and anti-DENV-IgM was detected by ELISA. Serum IFN-gamma level was detected by ELISA among DENV infected and age-matched control individuals. Association between DEN-VL and IFN-gamma level in patient's sera with WHO-classified disease symptoms was statistically analyzed.
  
  
  RESULTS
  DENV RNA and anti-DENV-IgM was detected among 94% (n=73) and 36% (n=28) of dengue infected patients (n=78) respectively. Fever, nausea, rash, aches & pains, leucopenia and persistent vomiting were significantly correlated with DENV infection (P-value<0.05). Only patients with high-VL exhibited leucopenia, persistent vomiting, abdominal pain and clinical fluid accumulation, which were warning signs of dengue infection according to revised WHO-criteria (P-value<0.05). Clinical symptoms of DENV infected patients, viz. leucopenia, abdominal pain and persistent vomiting were significantly correlated to each other (P-value<0.05). Increased serum IFN-gamma level was detected among dengue patients compared to control individuals. DEN-VL and symptoms like nausea, leucopenia, persistent vomiting and abdominal pain were significantly negatively correlated with serum IFN-gamma level (P-value<0.05).
  
  
  CONCLUSIONS
  Serum IFN-gamma level and dengue viremia among acute stage patients might be used as early prognostic marker for disease severity prediction.
authors.affiliation: Department of Biochemistry and Medical Biotechnology, Calcutta School of Tropical Medicine, 108, C. R. Avenue, Kolkata 700073, West Bengal, India.
authors.forename: Tithi
authors.initials: T
authors.lastname: Pal
authors.affiliation: Department of Biochemistry and Medical Biotechnology, Calcutta School of Tropical Medicine, 108, C. R. Avenue, Kolkata 700073, West Bengal, India.
authors.forename: Sudip K
authors.initials: SK
authors.lastname: Dutta
authors.affiliation: Department of Epidemiology and Biostatistics, Chittaranjan National Cancer Research Institute, 37, S. P. Mukherjee Road, Kolkata 700026, West Bengal, India.
authors.forename: Syamsundar
authors.initials: S
authors.lastname: Mandal
authors.affiliation: Department of Tropical Medicine, Calcutta School of Tropical Medicine, 108, C. R. Avenue, Kolkata 700073, West Bengal, India.
authors.forename: Bibhuti
authors.initials: B
authors.lastname: Saha
authors.affiliation: Department of Biochemistry and Medical Biotechnology, Calcutta School of Tropical Medicine, 108, C. R. Avenue, Kolkata 700073, West Bengal, India. Electronic address: anusri.stm@gmail.com.
authors.forename: Anusri
authors.initials: A
authors.lastname: Tripathi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D002648:Child; D003715:Dengue / Q000276:immunology / Q000473:pathology* / Q000821:virology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D007194:India; D007371:Interferon-gamma / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D060888:Real-Time Polymerase Chain Reaction; D044967:Serum / Q000276:immunology / Q000821:virology; D012720:Severity of Illness Index; D013223:Statistics as Topic; D019562:Viral Load; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D015415:Biomarkers; C573415:IFNG protein, human; D007075:Immunoglobulin M; D007371:Interferon-gamma
keywords: Anti-DENV-IgM ELISA; Dengue viral load; IFN-gamma ELISA; RT-PCR; WHO classification