Copy number variation of Chikungunya ECSA virus with disease symptoms among Indian patients.

After a gap of three decades, from 2005 onwards, a series of Chikungunya virus (CHIKV) outbreaks occurred worldwide. This study was performed to detect CHIKV infection, its genotype among symptomatic Eastern Indian patients and to analyze any association between the presence of CHIKV genome in patient body with appearance of disease symptoms (n = 199). Plasma-extracted viral RNA was reverse transcribed to cDNA and PCR-amplified followed by agarose gel electrophoresis. Viral load among CHIKV-positive patients was determined by real time RT-PCR. CHIKV-IgM in sera was detected by ELISA. Sequencing and phylogenetic analysis of plasma-extracted PCR products was done. CHIKV genome and IgM were detected among 65.3% (n = 130) and 41.2% (n = 82) patients respectively. Joint swelling was significantly associated with CHIKV infection (P-value: 0.0003). CHIKV PCR positive patients were grouped in two categories: Group-I: viral load <10(4) copies/ml and Group-II: viral load ≥10(4) copies/ml. Higher number of acute stage patients clustered in Group-II. Fever and joint swelling were significantly more prevalent among Group-II patients, whereas rash and diarrhoea among Group-I patients (P-value <0.05). Patient-isolated CHIKV sequences clustered with CHIKV ECSA genotypes in the phylogenetic tree, with two types of CHIKV strains found to circulate among them-as indicated by their different nucleotide sequences. This is the first study detecting the presence of CHIKV ECSA genotype among Eastern Indian patients. Fever and joint swelling might have appeared first followed by rash, diarrhea during disease progression-as indicated by CHIK viral load in patients. Thus, viral load can be used as unique diagnostic and prognostic marker of Chikungunya disease pathogenesis.

Differential clinical symptoms among acute phase Indian patients revealed significant association with dengue viral load and serum IFN-gamma level.

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. STUDY DESIGN: 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). CONCLUSION: Serum IFN-gamma level and dengue viremia among acute stage patients might be used as early prognostic marker for disease severity prediction.