Biomedical subjects

Vidya A Arankalle

Publications and source records attributed to Vidya A Arankalle.

14 recordsLinked to original sources

PubMed2006

Quantitation of hepatitis B virus DNA by real-time PCR using internal amplification control and dual TaqMan MGB probes.

Hepatitis B virus (HBV) DNA quantitation is used extensively for monitoring of antiviral treatment of HBV infection. A real-time PCR assay was developed using a TaqMan minor groove binder probe and primers corresponding to HBV pre-core region for HBV DNA quantitation. A 228 bp fragment from this genomic region of HBV was cloned and serial dilutions of plasmid DNA were used as an external DNA standard. Comparison of the real-time PCR quantitation results from 35 clinical serum samples with those obtained by COBAS Amplicor HBV DNA monitor kit (Roche Diagnostics) revealed a significant correlation (r = 0.92) for all the samples. The assay showed wide dynamic linear range between 2.5 x 10(2) and 2.5 x 10(10) copies/ml serum. Sera from 25 healthy individuals tested negative indicating the high specificity of the assay. The median coefficients of variation for both intra- and inter-experimental variability were 4.9% and 10.6%, respectively, which indicated remarkable reproducibility. An internal amplification control (IC) was developed to detect the presence of PCR inhibitors in the samples to avoid false negative results. The IC had the same primer binding sites but different internal sequence and it competed with the virus-derived target. The optimum concentration of IC was found to be 100 copies/reaction. The assay was validated by testing serial dilutions of the WHO international HBV DNA standard. Since conserved regions were considered during primer and probe design, the assay should be applicable to all HBV genotypes. The real-time assay will be useful for monitoring HBV-infected patients in routine diagnostic laboratories and in clinical practice enabling analysis of a wide dynamic range of HBV DNA in a single, undiluted sample.

Analysis of Variance↗

PubMed2006

Full genome sequence and analysis of Indian swine hepatitis E virus isolate of genotype 4.

The full-length genomic sequence of an Indian swine hepatitis E virus (HEV) isolate (IND-SW-00-01) recovered from feces of a pig experimentally infected with swine HEV pool from western India was determined. The genome consisted of 7,240 nucleotides, excluding the poly (A) tail of at least 22 residues and contained three open reading frames (ORFs), ORF-1 encoding 1,707 amino acids, ORF-2 encoding 674 amino acids and ORF-3 encoding 114 amino acids. Comparative full-length genome sequence and phylogenetic analyses suggested that the Indian swine HEV represents a distinct variant among the genotype 4 isolates with a divergence of 15-16.6%. Analyses based on ORF-1, 2 and 3 as well as partial ORF-2 (227 nucleotides) yielded similar results. As compared to type 4 HEV isolates, 26 unique amino acid substitutions were recorded, 16 in ORF-1, 8 in ORF-2 and 2 in ORF-3. IND-SW-00-01 showed insertion of 'C' at 5159 position while all other type 4 isolates have insertion of 'U' at the same position. Whether these changes contribute towards observed absence of type 4 HEV infections in Indian patients needs to be determined.

3' Untranslated Regions↗

PubMed2006

Putative neutralization epitopes and broad cross-genotype neutralization of Hepatitis E virus confirmed by a quantitative cell-culture assay.

Monolayers of Hep G2/C3A cells were inoculated with genotype 1 Hepatitis E virus (HEV) mixed with either anti-HEV or an appropriate control. After 5 or 6 days, cell monolayers were stained with anti-HEV and infected cells were identified by immunofluorescence microscopy and counted. Anti-HEV from vaccinated or infected rhesus monkeys neutralized the virus, as did mAbs that recognized epitopes on the C terminus of a recombinant vaccine protein. Antibodies were broadly cross-reactive, since convalescent serum from animals infected with any one of the four mammalian genotypes all neutralized the genotype 1 virus.

Animals↗

PubMed2006

Chikungunya outbreaks caused by African genotype, India.

Chikungunya fever is reported in India after 32 years. Immunoglobulin M antibodies and virus isolation confirmed the cause. Phylogenic analysis based on partial sequences of NS4 and E1 genes showed that all earlier isolates (1963-1973) were Asian genotype, whereas the current and Yawat (2000) isolates were African genotype.

Aedes↗

PubMed2005

Thermal stability of hepatitis E virus.

The thermal stability of virulent hepatitis E virus (HEV) and hepatitis A virus (HAV) was compared. Fecal suspensions of virus were heated to temperatures between 45 degrees C and 70 degrees C, and residual infectivity was determined in a cell culture system that was permissive for both viruses. Although HEV was less stable than was HAV, some HEV would most likely survive the internal temperatures of rare-cooked meat.

Cell Line↗

PubMed2005

An outbreak of Chandipura virus encephalitis in the eastern districts of Gujarat state, India.

An outbreak of encephalitis with a case fatality rate of 78.3% was investigated among children in Gujarat State, India. Twenty-six cases were reported. Three patients had IgM antibodies to Chandipura virus. Virus was isolated from one patient with rhabdomyosarcoma in porcine stable cell lines and in suckling mice. Chandipura virus RNA was present in 9 of 20 acute-phase serum samples, and virus sequences from the present outbreak were closely related to prototype strain (1965) and Andhra Pradesh, India (2003) isolates. Serologic and molecular assays documented the absence of Japanese encephalitis virus, West Nile virus, dengue virus, and paramyxoviruses in clinical samples. The etiologic agent was Chandipura virus, which has become an important encephalitis-causing virus in India.

Adolescent↗

PubMed2003

Hepatitis B virus genotypes and serotypes in western India: lack of clinical significance.

To determine hepatitis B virus genotype and subtype distribution among HBV infected individuals with different clinical manifestations in western India, serum samples from 19 asymptomatic hepatitis B surface antigen carriers, 30 chronic hepatitis B patients, 8 acute hepatitis B patients, 5 fulminant hepatitis B patients, and with circulating HBV DNA were genotyped and subtyped on the basis of the nucleotide sequence analysis of S region of the HBV genome. Genotype D was the predominant genotype circulating in western India (57/62; 91.93%). All 19 asymptomatic hepatitis B surface antigen carriers, 8 acute hepatitis B patients, 5 fulminant hepatic failure patients and 25/30 chronic hepatitis B patients were circulating genotype D and ayw3/ayw2 subtypes. HBV genotype A was prevalent in 8% (5/62) of the total number of patients and all belonged to chronic hepatitis B category. Subtyping analysis showed that all genotype A isolates were of subtype adw2. As most of the patients from different clinical categories were infected with HBV genotype D, it is concluded that this genotype did not influence the outcome of HBV infection.

Acute Disease↗

PubMed2003

Increased risk of hepatitis E in sewage workers from India.

Considering feco-oral transmission of hepatitis E virus (HEV), the risk of the infection was assessed among sewage workers. On the basis of the close contact with sewage, the participants (n = 147) were divided into sewage workers (n = 92) and others (n = 55); none used personal protective equipment (eg, coveralls, boots, gloves) Age-matched individuals from lower socioeconomic status and without any exposure to sewage were used as controls. IgG-anti-HEV positivity in enzyme-linked immunosorbent assay was significantly higher (P < 0.01) among staff members (83/147, 56.5%) than the controls (19%). A significant rise in anti-HEV positivity (P < 0.05) was recorded in sewage workers working for >5 years. Multivariate regression analysis identified contact with sewage as the independent variable associated with anti-HEV positivity. Strict adherence to good working practices must take top priority for protection of these workers from sewage pathogens.

Adult↗

PubMed2003

Comparison of hepatitis C virus genotyping by 5' noncoding region- and core-based reverse transcriptase PCR assay with sequencing and use of the assay for determining subtype distribution in India.

Phylogenetic analysis of the sequences of the 5' noncoding regions (5'NCR) of 149 samples from hepatitis C virus (HCV) RNA-positive chronic carriers representing northern, southern, eastern, and western India showed that type 3 and type 1 are the predominant genotypes circulating in India, with an overall prevalence of 53.69 and 38.25%, respectively. Type 4 viruses (6.04%) were seen only in southern India. Sequence analysis of the core region of 51 of the above isolates enabled us to classify them further into subtypes as 1b (number of isolates [n] = 10), 1a (n = 6), 3a (n = 9), 3g (n = 14), 3f (n = 1), and 4d (n = 3). Three new subtypes were identified for the first time and designated as 3i (n = 5), 3j (n = 2), and 6l (n = 1). Sequencing the 5'NCR could differentiate HCV types, whereas classification at the level of subtype was possible with sequence analysis of the core region.

Base Sequence↗

PubMed2002

Human and swine hepatitis E viruses from Western India belong to different genotypes.

BACKGROUND/AIMS: Hepatitis E is endemic in India. Earlier, we showed prevalence of IgG antibodies to hepatitis E virus (IgG-anti-HEV) in different animal species and inability of at least one human hepatitis E virus (HEV) strain to infect pigs. In the US where hepatitis E is not endemic in humans, zoonotic spread of HEV was suspected as swine and human HEV were closely related and cross-species infection was documented. The present study attempts to identify and partially characterize swine HEV from India. METHODS: Serum samples from 284 pigs were screened for the presence of HEV-RNA (nested polymerase chain reaction; PCR) and IgG-anti-HEV (enzyme-linked immunosorbent assay; ELISA). PCR products (Open Reading Frame-2 region) were sequenced and subjected to phylogenetic analysis. Two sero-negative pigs were inoculated with swine HEV-positive serum pool. RESULTS: ELISA and PCR positivity were 42.9 and 4.6%, respectively. All Indian swine HEV sequences clustered with genotype IV. Pigs could be experimentally infected with swine HEV. CONCLUSIONS: Swine HEV circulates in Indian pigs. In contrast to US and Taiwan wherein both human and swine HEV isolates belong to same genotype, Indian human HEV isolates belong to genotype I whereas genotype IV circulates in swine. Though experimental infection with Indian swine HEV was possible, at least one human HEV strain could not infect pigs.

Amino Acid Sequence↗

PubMed2002

Polymerase chain reaction-based prevalence of hepatitis A, hepatitis E and TT viruses in sewage from an endemic area.

BACKGROUND/AIMS: Hepatitis A and E viruses (HAV, HEV) are transmitted enterically and are highly endemic in India. This study aims to evaluate prevalence of these and TT virus (TTV) in the sewage. METHODS: Influent and effluent samples from a sewage treatment plant from Pune, India were collected twice a week for 1 year and subjected to nested polymerase chain reaction (PCR) for the detection of HAV RNA, HEV RNA and TTV DNA. HAV and HEV PCR products were sequenced. Effluent samples were not collected for 5 months as the plant was non-functional. RESULTS: The overall prevalence was 24.42% (21/86, HAV), 10.98% (9/82, HEV) and 12.7% (8/63, TTV). Prevalence of HAV was significantly higher than HEV (P=0.023). During summer months, significantly higher HAV RNA positivity was noted (P<0.01). A substantial reduction in HAV RNA positivity (15/48 vs. 2/48, P=0.0008) was recorded for treated sewage samples. However, HEV RNA or TTV DNA positivity did not reduce significantly. Of the 17 HAV and HEV RNA negative sewage samples concentrated using ultracentrifugation, 13 and none were positive for HAV and HEV RNA, respectively. Phylogenetic analyses grouped these viruses in IB and Ia, respectively, the genotypes most prevalent in India. CONCLUSIONS: Sewage may play an important role in maintaining hyper-endemicity of these infections. Sustained efforts are obligatory to render sewage less/non-infectious.

DNA Virus Infections↗

PubMed2002

Evaluation of urine as a clinical specimen for diagnosis of hepatitis a.

The present study pertains to the evaluation of urine as a specimen for detection of anti-hepatitis A virus (anti-HAV) antibodies. Immunoglobulin M (IgM), IgG, and IgA capture enzyme-linked immunosorbent assays for hepatitis A were performed on paired serum and urine specimens collected from hepatitis A patients (n = 92), healthy individuals (n = 100), non-A hepatitis patients (n = 70), and patients with nonhepatic diseases (n = 64, including 37 renal disease patients). Hepatitis A patients seropositive for anti-HAV IgM showed 95.65% uropositivity. No false-positive reactions were observed in control groups. The uropositivity of anti-HAV IgM persisted during the convalescent phase of the disease. Anti-HAV IgG uropositivity correlated well with corresponding seropositivity in all groups (P > 0.05 for each). No significant difference between the proportions of serum and urine positivity for anti-HAV IgA was noted (P > 0.05 for each). Using seroreactivity as a "gold standard," the sensitivity and specificity for anti-HAV IgM, anti-HAV IgG, and anti-HAV IgA tests with urine as a specimen were found to be 95.65 and 100%, 97.76 and 76.47%, and 92.23 and 88.18%, respectively. Urine appears to be comparable to serum for diagnosis of recent and past infection with hepatitis A.

Adolescent↗

PubMedDate not supplied

A large outbreak of acute encephalitis with high fatality rate in children in Andhra Pradesh, India, in 2003, associated with Chandipura virus.

BACKGROUND: An outbreak of acute encephalitis of unknown origin with high case fatality (183 of 329 cases) was reported in children from Andhra Pradesh state in southern India during 2003. We investigated the causative agent. METHODS: Cell lines and peripheral blood lymphocyte co-cultures were used to isolate the causative agent from clinical samples. Identity of the agent was established by electron microscopy and serological and molecular assays. FINDINGS: Clinical samples tested negative for IgM antibodies to Japanese encephalitis, West Nile, dengue, and measles viruses, and for RNA of coronavirus, paramyxovirus, enterovirus, and influenza viruses. Virus was isolated from six patients with encephalitis and was identified as Chandipura virus by electron microscopy, complement fixation, and neutralisation tests. Chandipura virus RNA was detected in clinical samples from nine patients. Sequencing of five of these RNA samples showed 96.7-97.5% identity with the reference strain of 1965. Chandipura viral antigen and RNA were detected in brain tissue of a deceased child by immunofluorescent antibody test and PCR. Neutralising, IgG, and IgM antibodies to Chandipura virus were present in some patients' serum samples. Serum samples obtained after 4 days of illness were more frequently positive for IgM to Chandipura virus than were those obtained earlier (p<0.001). A similar trend was noted for neutralising antibodies. INTERPRETATION: Our findings suggest that this outbreak of acute encephalitis in Andhra Pradesh was associated with Chandipura virus, adding to the evidence suggesting that this virus should be considered as an important emerging pathogen.

Acute Disease↗

PubMedDate not supplied

Comparison of etiology of sporadic acute and fulminant viral hepatitis in hospitalized patients in Pune, India during 1978-81 and 1994-97.

OBJECTIVE: To determine and compare the etiology of sporadic acute and fulminant viral hepatitis in two groups of patients 16 years apart. METHODS: Serologic diagnostic tests for hepatitis A, B, C, D and E, and cytomegalovirus infection were carried out in 276 patients during 1994-1997 (Group A) and 206 patients during 1978-1981 (Group B). RESULTS: Among children, hepatitis A virus was the major etiologic agent (81.6% in Group A and 51.4% in Group B), followed by hepatitis E virus (12.2%, 46.4%) and hepatitis B virus (5.4%, none). Among adults, hepatitis E virus was the main causative agent (42.4% in Group A and 71.2% in Group B) followed by HBV (28%, 25.5%) and hepatitis A virus (10.6%, 3.5%). Delta hepatitis was found only in Group A. No viral cause was found in 25% of patients in Group A and 13.5% patients in Group B. CONCLUSIONS: Hepatitis E virus is a major cause of sporadic acute and fulminant hepatitis. There has been an increase in hepatitis A in adults who developed fulminant hepatic failure. Our data points to the emergence of hepatitis A in adults and emergence of delta virus infection. Hepatitis C virus was unimportant in causing sporadic hepatitis.

Acute Disease↗