PubMed Health⌕ Search

Biomedical subjects

Anita Chakravarti

Publications and source records attributed to Anita Chakravarti.

10 recordsLinked to original sources
PubMed2006

Circulating levels of tumour necrosis factor-alpha & interferon-gamma in patients with dengue & dengue haemorrhagic fever during an outbreak.

BACKGROUND & OBJECTIVE: Dengue haemorrhagic fever (DHF) is a severe illness caused by dengue viruses, the pathogenesis of which is not fully understood. Immune enhancement caused by cytokines, interferon and activated complement system is one of the hypotheses proposed to explain the haemorrhagic form of disease. This study was undertaken to investigate the role of pro-inflammatory cytokines tumour necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) in dengue infection, and their possible association with disease severity. METHODS: Blood samples were collected from 60 patients; 28 patients of DF and 32 of DHF (clinically categorized into DF or DHF as per WHO criteria) from September to November 2003 at Delhi. Fifteen healthy individuals were included as control. All the patients were confirmed positive for dengue infection by serology or by reverse transcriptase-polymerase chain reaction (RT-PCR). Serum levels of TNF-alpha and IFN-gamma were determined by ELISA. RESULTS: The levels of both the cytokines were significantly elevated in the disease group as compared to the control group. Significantly higher levels of TNF-alpha; 258.02 pg/ml (P<0.005) were seen in patients having secondary infection, while patients with primary infection had higher level of IFN-gamma; 29.47 pg/ml (P<0.005). TNF-alpha was elevated in the later phase of illness, while IFN-gamma was elevated in early phase also. INTERPRETATION & CONCLUSION: Overproduction of TNF-alpha during secondary infection may have a role in immunopathogenesis of DHF, however, study of other cytokines produced along with IFN-gamma;, during the course of dengue infection is required to know the specific role of IFN-gamma in DI.

Adolescent↗
PubMed2006

Rubella prevalence and its transmission in children.

Rubella is a major cause of birth defects among the TORCH group of agents causing congenital anomalies. Almost all the symptomatic infected infants have long-term neurological sequelae & many asymptomatic infants also develop deafness or psychomotor retardation later in life. In India need for rubella prevention & control is being recognized. Before formulating any kind of rubella vaccination policies, data on the burden of disease is important. Hence the prevalence of rubella in children and their transmission was evaluated. Paired sera of 146 babies with suspected intra uterine infection and their mothers from lower socioeconomic strata was tested for IgM antibodies by commercially available Enzyme immunoassay (EIA) kits. Congenital Rubella Syndrome (CRS) was confirmed in babies presenting with rubella compatible defects with positive IgM antibodies against rubella. It was seen that out of 146-paired samples evaluated, 15-paired samples (10.27%) were positive for IgM antibodies. The transmission rate of rubella virus from mother to child when the mother was infected was around 55.55% according to this study. CRS prevalence of 10.27% among symptomatic infants is significant as a large majority of rubella infection remains undetected and hence the actual burden of the disease may be higher. Since the disease is preventable by an effective vaccination, strategies for rubella immunization should be developed and enhanced.

Antibodies, Viral↗
PubMed2005

Eco-epidemiological analysis of dengue infection during an outbreak of dengue fever, India.

BACKGROUND: This study was designed to find out a relationship of dengue infection with climatic factors such as rainfall, temperature and relative humidity during the dengue fever epidemic in the year 2003. Blood samples were collected from 1550 patients experiencing a febrile illness clinically consistent with dengue infection. Serological confirmation of Dengue Infection was done using Dengue Duo IgM and IgG Rapid Strip test (Pan Bio, Australia), which detected dengue-specific antibodies. Monthly data of total rainfall, temperature and relative humidity for the year 2003 was obtained from Meteorological Department of Delhi, New Delhi and retrospectively analyzed. RESULTS: Out of 1550 suspected cases, 893 cases (57.36%) were confirmed as serologically positive. The difference between numbers of serologically positive cases during different months was significant (p < 0.05). Larger proportions of serologically positive cases were observed among adults. Outbreak coincided mainly with the post monsoon period of subnormal rainfall. The difference between serologically positive cases as compared to serologically negative ones in post monsoon period was significantly higher (p < 0.001). The difference in the rainfall and temperature between three seasonal periods was significant (p < 0.05). CONCLUSION: This prospective study highlighted rain, temperature and relative humidity as the major and important climatic factors, which could alone or collectively be responsible for an outbreak. More studies in this regard could further reveal the correlation between the climatic changes and dengue outbreaks, which would help in making the strategies and plans to forecast any outbreak in future well in advance.

Dengue↗
PubMed2005

Molecular detection and serotypic characterization of dengue viruses by single-tube multiplex reverse transcriptase-polymerase chain reaction.

This study was designed to develop a reverse transcriptase-polymerase chain reaction (RT-PCR)-based rapid and cost-effective diagnostic test for detection as well as serotypic characterization of dengue viruses in the acute phase of illness. In this regard, 2 methods of RT-PCR, namely, 2-step nested RT-PCR and 1-tube multiplex RT-PCR, have been evaluated. One-tube multiplex RT-PCR was found superior; thus, its sensitivity and specificity were compared with gold standard "cell culture". In the present study, serum samples of all individuals were evaluated by cell culture and RT-PCR. Of 200 clinically suspected patients tested, 66 were found to be positive for the dengue virus RNA and could be successfully characterized into the serotypes. Of these 66, 62 patients were found to be serologically positive by Dengue Duo IgM and IgG Rapid Strip test (Pan Bio, Windsor, Australia). The sensitivity of the cell culture procedure was found to be lower; 63% as compared with multiplex RT-PCR, with predictive value of positive test being 100% and predictive value of negative test being 84.8%. Specificity was found to be 100% for both the assays. It is thus proposed that 1-tube multiplex RT-PCR-based assay would prove to be an extremely useful tool for routine laboratory diagnosis.

Aedes↗
PubMed2005

The 2003 outbreak of Dengue fever in Delhi, India.

Dengue fever (DF) and Dengue hemorrhagic fever (DHF) are widespread in Southeast Asia. An outbreak of DF/DHF in Delhi in 2003 started during September, reached its peak in October-November, and lasted until early December. This study describes the clinical and laboratory data of the 185 cases of DF/DHF admitted to Lok Nayak Hospital, New Delhi. The mean age of the patients was 26 +/- 10 years. Fever was present in all the cases with an average duration of fever being 4.5 +/- 1.2 days with headache (61.6%), backache, (57.8%), vomiting (50.8%) and abdominal pain (21%) being the other presenting complaints. Hemorrhagic manifestations in the form of a positive tourniquet test (21%), gum bleeding and epistaxis (40%), hematemesis (22%), skin rashes (20%) and melena (14%) were also observed. Hepatomegaly and splenomegaly were observed in 10% and 5% of cases, respectively. Laboratory investigations revealed thrombocytopenia (with a platelet count of < 100,000/microl) in about 61.39% of cases, Leukopenia (WBC <3,000/mm2) and hemoconcentration (Hct >20% of expected for age and sex) were found in 68% and 52% of the cases, respectively. The mortality rate was 2.7%. Despite widespread measures taken to control outbreaks of DF, it caused major outbreaks. More stringent measures in the form of vector control, improved sanitation and health education are needed to decrease morbidity, mortality and health care costs caused by a preventable disease.

Adolescent↗
PubMed2004

Molecular epidemiology of rotavirus in Delhi.

Rotavirus is now established as an important cause of childhood diarrhoea throughout the world. Despite the availability of more advanced techniques for HRV characterization, electropherotyping was employed in this study to demonstrate the occurrence of diverse electropherotypes & any aberrant types thereof in isolates from children with acute gastroenteritis in Delhi, keeping in mind the ease of availability, performance and discriminatory power. Faecal specimens from 1172 children suffering from acute gastroenteritis were subjected to enzyme linked immunosorbent assay (ELISA) and polyacrylamide gel electrophoresis (PAGE). A total of 158 rotavirus strains were detected and electropherotyped by PAGE. Rotavirus was detected in 13.48% of the samples. A total of 10 electropherotypic patterns were observed to be in circulation. There was predominance of the long type over the short type and long type G was the most common isolate. The present study highlights the simultaneous coexistence of different electropherotypes of Human rotavirus strains circulating in Delhi and stresses the need for constant monitoring of the genomic diversity resulting from extensive genomic variation among Rotaviruses.

Child, Preschool↗
PubMed2003

Evaluation of a rapid immunochromatographic test in the diagnosis of dengue fever.

Serology is the mainstay of diagnosis in Dengue virus infection. Various rapid tests for antibody detection have been developed. They can prove to be important diagnostic tools especially in the field set up due to technical simplicity. We evaluated a Rapid immunochromatographic assay The rapid test was performed on acute phase sera collected from patients suspected to be suffering from Dengue fever/DHF. These samples were then tested by Dengue Duo Capture ELISA and compared The rapid test showed a good sensitivity for the detection of secondary dengue infection and thus can be a good screening tool.

Antibodies, Viral↗
PubMedDate not supplied

Characteristics of dual infection of hepatitis B and C viruses among patients with chronic liver disease: a study from tertiary care hospital.

The major causes of chronic liver disease (CLD) are infection with Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) either alone or together. The clinical course of the disease varies in cases ofcoinfection with HCV and HBV as compared to single infection. The present study was carried out to determine the occurrence of coinfection of HCV with HBV in CLD patients and to look for the presence of suppressive effect of the two viruses on each other. The severity of liver disease was also assessed and correlated with biochemical profiles. Sera from 150 patients of CLD were tested serologically for the presence of HBsAg, IgG anti HBc and anti-HCV antibodies. HBV DNA and HCV RNA were also detected by amplifying surface region and 5' noncoding-core region respectively by polymerase chain reaction. Forty-seven (31.3%) cases showed the presence of HBsAg or anti IgG-HBc or HBV DNA either alone or together (Group A). Thirty-nine (26%) cases were found to be positive for HCV by detecting either anti-HCV antibodies or HCV RNA (Group B). Coinfection ofHCV with HBV (Group C) could be detected in twenty-four (16%) cases, of these twenty-one cases (87.5%) were positive both for HCV RNA and IgG anti-HBc without the presence of HBV DNA whereas in none of the cases could HBV DNA be detected in the absence of HCV RNA. Forty (26.6%) cases had neither HCV or HBV related CLD. Amongst, the biochemical parameters, the liver function test profiles were altered and found to be statistically significantly in HCV positive cases (Group B) when compared to the negative ones while in case of HBV (Group A) and coinfected (Group C) cases none of the parameters was statistically significant when compared with non-HBV and non-coinfected cases respectively. Thus, coinfection of HCV with HBV is seen in a substantial number of CLD cases. It is also revealed from the present study that HCV infection has a suppressive effect on the replication of HBV as seen by the loss of replicative markers like HBV DNA.

Comorbidity↗