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Biomedical subjects

Sujit Kumar Bhattacharya

Publications and source records attributed to Sujit Kumar Bhattacharya.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of new-generation serologic tests for the diagnosis of typhoid fever: data from a community-based surveillance in Calcutta, India.

Although typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi, rapid and simple diagnostic serologic tests would be useful in developing countries. We examined the performance of Widal test in a community field site and compared it with Typhidot and Tubex tests for diagnosis of typhoid fever. Blood samples were collected from 6697 patients with fever for > or =3 days for microscopy, culture, and serologic testing and from randomly selected 172 consenting healthy individuals to assess the baseline Widal anti-Typhi O lipopolysaccharide antibody (anti-TO) and anti-Typhi H flagellar antibody (anti-TH) titers. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 3 serologic tests were calculated using culture-confirmed typhoid fever cases as "true positives" and paratyphoid fever and malaria cases as "true negatives". Comparing cutoff values for the Widal test, an anti-TO titer of 1/80 was optimal with 58% sensitivity, 85% specificity, 69% PPV, and 77% NPV. Sensitivity was increased to 67% when the Widal test was done on the 5th day of illness and thereafter. The sensitivity, specificity, PPV, and NPV of Typhidot and Tubex were not better than Widal test. There is a need for more efficient rapid diagnostic test for typhoid fever especially during the acute stage of the disease. Until then, culture remains the method of choice.

Antibodies, Bacterial↗
PubMed2006

Characterization of VP1, VP2 and VP3 gene segments of a human rotavirus closely related to porcine strains.

Long RNA electropherotype rotavirus strains with subgroup I specificity predominated the infantile gastroenteritis outbreak in Manipur, India, in 1987-88. One such strain (RMC321) was found to possess porcine characteristics in 7 out of 8 genes sequenced. Partial characterization of its remaining VP1, VP2 and VP3 genes along with a porcine rotavirus strain (HP140) uncovered their close genetic relation to porcine strains. VP7 was the only gene segment of this strain with significant genetic identity to human strains. This indicates that a rotavirus reassortant strain with most of its genetic material derived from a porcine strain may cause symptomatic infection in a human host.

Animals↗
PubMed2006

Increasing prevalence of Salmonella enterica serotype Paratyphi-A in patients with enteric fever in a periurban slum setting of Kolkata, India.

A sudden rise in the occurrence of Salmonella enterica serotype Paratyphi-A (SPTA) was noted in a longitudinal community-based study in Kolkata, India, during 2004 - 2005. We compared the incidence rate of Salmonella enterica serotype Typhi (ST) and SPTA and their antimicrobial susceptibility pattern. Rate of isolation of SPTA was 1.5 times higher than that of ST, a trend detected for the first time in that particular focus. Almost all the isolates were sensitive to Gentamycin and Norfloxacin. Most of the strains (90%) were sensitive to Ciprofloxacin. Two thirds of the strains were also sensitive to Chloramphenicol. The high occurrence of SPTA in the present study could be the signal of the emergence of SPTA as a pathogen in India. Quinolone derivatives (namely, Ciprofloxacin, Norfloxacin and Chloramphenicol) can be suggested as drugs of choice for treatment of enteric fever caused by SPTA. Future vaccination strategies should include bivalent vaccines with protection capacities against both ST as well as SPTA.

Anti-Infective Agents↗
PubMed2006

Epidemic of HIV coupled with hepatitis C virus among injecting drug users of Himalayan West Bengal, Eastern India, Bordering Nepal, Bhutan, and Bangladesh.

A study was conducted in June 2004 to find out the epidemiology of HIV infection among injecting drug users (IDUs) of Darjeeling District of West Bengal, eastern India. The district headquarter, Darjeeling town, also known as "Queen of Hills," is a beautiful spot situated in Himalayan West Bengal that attracts a large number of tourists each year from all over the world. Another unique feature of the district is that it has international boundaries with three countries, Nepal, Bhutan, and Bangladesh. Siliguri, the part of the district on plains, acts as a transit station for these countries as well as to the entire Himalayan region of West Bengal and neighboring state, Sikkim. It is also a transit point to all northeastern states of India: Assam, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Meghalaya, and Tripura. Two hundred twenty-eight study subjects (IDUs) were included in this community-based cross-sectional study from all four subdivisions of the district. Informed consent was obtained, and then personal interviews, followed by blood testing were performed using unlinked anonymous procedure. The study revealed that overall HIV seroprevalence among IDUs was 11.8% (n = 27; 95% confidence interval, 7.9-16.7), whereas seroprevalence of hepatitis C was found to be 47.7% (n = 97). Prevalence of HIV was higher in subjects from hill districts (13.5%) compared with subjects from the plains (9.2%). It also revealed that most IDUs (75.3%) used "brown sugar," an impure form of heroin, as their major addictive substance followed by injection norphine. Sharing of injecting equipment was found to be as high as 67% among IDUs, and sharing of drugs from common ampules was found to be 35.5% of the studied subjects (n = 93). Most subjects (96%) were found to clean their injecting paraphernalia with plain water. Most IDUs (98%) were found to inject intravenously. About 52% of IDUs visited sex workers one or more times within the last 1 year, and 15% of the interviewed subjects (n = 93) reported to suffer from sexually transmitted diseases during the same period. All the IDUs knew about HIV/AIDS. About 69% of the subjects knew that apparently healthy looking person might have HIV infection. HIV was found to be associated significantly with age of the injectors and duration of injecting practices. The study revealed the epidemic of HIV and hepatitis C among IDU populations at this bordering district of West Bengal for the first time that requires urgent intervention at local, national, and international levels.

Adolescent↗
PubMed2005

Young age is a risk factor for HIV among female sex workers--an experience from India.

OBJECTIVE: A cross-sectional community-based study was conducted among brothel-based sex workers of West Bengal, eastern India, to study the prevalence of HIV and associated risk factors. METHODS: Unlinked anonymous HIV testing was performed on 2076 sex workers. Of these, 558 were interviewed using a pre-tested questionnaire to study their risk factors. RESULTS: Overall HIV sero-prevalence was 5.9%. All infections were HIV-1, except that four sex workers from Kolkata were infected with HIV-2. Surprisingly, HIV infection was much higher (12.5%) in younger sex workers (age < or =20 years) compared with older age groups (5.4%) (P=0.002; odds ratio 2.40, 95% CI: 1.29-4.38). CONCLUSIONS: This could be associated with larger areas of cervical ectopy of younger sex workers who are subjected to repeated trauma during sexual intercourse, facilitating higher HIV transmission. Behavioral factors may increase a young sex worker's risk of acquiring HIV infection, including professional immaturity with clients, which might lead to more unprotected sex. HIV status was associated with other sexually transmitted infection in the previous year but was not associated with literacy status, daily income, duration of sex work, number of clients entertained per day, entertaining clients outside a brothel (in a hotel), and reported condom use.

AIDS Serodiagnosis↗
PubMed2005

Determination of gag and env subtypes of HIV-1 detected among injecting drug users (IDUs) in Manipur, India: evidence for intersubtype recombination.

The majority of HIV-1 transmission in Manipur, one of the northeastern states of India, is through the sharing of needles and syringes among the injecting drug users (IDUs). A total of 28 HIV seropositive samples were used to determine the HIV-1 subtypes with respect to both gag and envelope genes. The specific regions within gag and envelope genes were amplified from PBMC DNA by nested PCR using appropriate primers. These amplicons were used in heteroduplex mobility assay followed by DNA sequencing. Phylogenetic analysis of the nucleotide sequences of respective regions showed that 89% of samples (25/28) were infected with subtype C with respect to both gag and envelope genes; however, 11% of the samples (3/28) showed subtype discordance with respect to the envelope (C2-V3) and gag (p24-p7) genomic regions. Simplot analysis of the discordant samples showed the presence of intersubtype recombination between subtype C and Thai B; two samples were found to be subtype C in envelope but Thai B in gag, whereas, one sample was found to be subtype Thai B in envelope and 'C' in gag region.

Adult↗
PubMed2005

Evaluation of sexually transmitted diseases/human immunodeficiency virus intervention programs for sex workers in Calcutta, India.

BACKGROUND AND OBJECTIVE: The Sonagachi Project in Calcutta, India, organized sex workers to improve working conditions. GOAL: To compare rates of sexually transmitted diseases between the Sonagachi Project and other areas in which only the National AIDS Control Organization (NACO) interventions were implemented. STUDY: A cross-sectional survey of randomly selected female sex workers. RESULTS: There was no difference in the prevalence of all STDs between the 2 areas; both were lower than reported in other surveys in 1992. Analysis using propensity scores also failed to demonstrate any difference. The number of preventive activities was similar in the Sonagachi and NACO-only areas but was more prevalent than in 1992. Sex workers in the Sonagachi area had better treatment-seeking behavior and attitudes. Both the Sonagachi and NACO strategies have resulted in lower STD rates, but the Sonagachi Project also increased the proportion who had an optimistic attitude and increased prevention and treatment-seeking behavior.

Adolescent↗
PubMed2005

Molecular tracking of the lineage of strains of Vibrio cholerae O1 biotype El Tor associated with a cholera outbreak in Andaman and Nicobar Islands, India.

A large outbreak of acute watery diarrhoea involving all age groups of mongoloid tribal aborigines occurred during October-November, 2002 in the Nancowry group of Andaman and Nicobar Islands in the Indian Ocean. Twenty-one of the 67 stool samples from 67 patients were positive for toxigenic Vibrio cholerae O1, serotype Ogawa biotype El Tor, which showed striking similarity in its antibiogram with some of the strains of V. cholerae O1 Serotype Ogawa biotype El Tor isolated in Kolkata. The Nancowry and Kolkata isolates were compared with molecular tools involving random amplified polymorphic DNA (RAPD) fingerprinting, ribotyping and pulsed-field gel electrophoresis (PFGE). RAPD fingerprinting and ribotyping techniques revealed that all the V. cholerae strains associated with the outbreak in these islands were clonal in nature and identical to a population of isolates obtained from Kolkata since 1993. PFGE could discriminate within these Kolkata isolates further and established that a particular subtype of this population reached the remote Nancowry islands and was responsible for the outbreak.

Adolescent↗
PubMed2005

A multi-country cluster randomized controlled effectiveness evaluation to accelerate the introduction of Vi polysaccharide typhoid vaccine in developing countries in Asia: rationale and design.

Phase-III vaccine efficacy trials typically employ individually randomized designs intended to ensure that measurements of vaccine protective efficacy reflect only direct vaccine effects. As a result, decisions about introducing newly licensed vaccines into public health programmes often fail to consider the substantially greater protection that may occur when a vaccine is deployed in public health programmes, due to the combination of direct plus indirect vaccine protective effects. Vaccine total protection can be better evaluated with cluster randomized trials. Such a design was considered to generate policy relevant data to accelerate the rationale introduction of the licensed typhoid fever Vi polysaccharide (PS) vaccine in Asia by the Diseases of the Most Impoverished (DOMI) typhoid fever programme. The DOMI's programme multi-country study is one of the largest cluster randomized vaccine trials ever mounted in Asia, which includes approximately 200,000 individuals. Its main objective is to determine the effectiveness of a licensed Vi PS vaccine. The rationale and design of this study are discussed. Preliminary results are presented that determined the final planning of the trial before immunization. Important methodological and practical issues regarding vaccine cluster randomized designs are illustrated.

Adolescent↗
PubMed2005

Diagnosis and genotyping of Helicobacter pylori by polymerase chain reaction of bacterial DNA from gastric juice.

BACKGROUND: Efficient and accurate detection of Helicobacter pylori infection as well as identification of virulence-associated alleles are important for the treatment of gastroduodenal diseases caused by this gastric pathogen. The present study was performed to test the efficiency of gastric juice polymerase chain reaction (PCR) method for the rapid detection of H. pylori infection and to determine the bacterial genotypes without the need for culture, which is often not feasible especially in developing countries. METHODS: DNA was extracted from gastric juice samples collected from 45 subjects and was used to amplify urease B gene (ureB) for H. pylori. Results obtained from this method were further confirmed by rapid urease test (RUT), histology and culture. Genotypes of the infected strains predicted from gastric juice PCR were compared to the genotype data obtained from the isolated strains. RESULTS: Among 45 cases, 32 were positive by RUT, 37 by histological examination, 25 by gastric juice PCR method, while culture yielded positive results for 19 samples. Except for one case, all the 19 culture-positive strains gave the same genotype with the gastric juice PCR result. It was found that the gastric juice PCR is more efficient for detection of multiple-strain infection as compared to genotype data obtained from strains isolated as pooled culture. CONCLUSIONS: This moderately sensitive technique could be employed with good efficiency, particularly in cases where it is difficult to obtain biopsy. Moreover, with this method bacterial genotype could be obtained.

Bangladesh↗
PubMed2005

Nucleic acid sequence analysis of basal core promoter/precore/core region of hepatitis B virus isolated from chronic carriers of the virus from Kolkata, eastern India: low frequency of mutation in the precore region.

OBJECTIVE: The aim of the present study was to characterize the predominant hepatitis B virus (HBV) strains and their molecular variants present in the HBV isolates of the different genotypes found among the chronic carriers of the virus in our community. METHODS: Precore/core and core promoter regions of HBV DNA were amplified by polymerase chain reaction and then subjected to direct sequencing. Of the 64 hepatitis B surface antigen (HBsAg)-positive chronic HBV carriers investigated, 44 were HBeAg negative and 20 were HBeAg positive. RESULTS: In addition to genotype D, which was the predominant genotype, 12 genotype C (18.7%) and 6 genotype A (9.4%) were also detected. Presence of T at nt 1858 has often been related to the development of precore stop mutation at nt 1896, while that of C has been related to the development of 1762-1764 double mutation. In our study group, 39 of the 44 HBeAg-negative samples have T1858. The precore stop codon mutation was found in only 8 (18%) of the HBeAg-negative samples. More than half of the HBeAg-negative samples had wild-type sequence in the precore region. The core promoter region could be sequenced from 40 samples, and 1762-1764 double mutation was detected in 13 (32.5%) of them. No significant changes could be detected in the core amino acid sequence of these isolates. CONCLUSION: The pattern of core promoter and precore mutation of HBV isolates in the present study is atypical and not in accordance with reports from other parts of the world, where genotype D and genotype C with T at codon 1858 are common.

Adolescent↗
PubMed2003

Hepatitis C virus infection in the general population: a community-based study in West Bengal, India.

Limited information is available about the prevalence and genotype distribution of hepatitis C virus (HCV) in the general population of India. A community-based epidemiologic study was carried out in a district in West Bengal, India. By a 1:3 sampling method, 3,579 individuals were preselected from 10,737 inhabitants of 9 villages of the district, of whom 2,973 (83.1%) agreed to participate. Twenty-six subjects (0.87%) were HCV antibody positive. The prevalence increased from 0.31% in subjects <10 years of age to 1.85% in those >or=60 years. No difference in prevalence between men and women was observed. Serum alanine aminotransferase (ALT) levels were elevated in 30.8% (8 of 26) of anti-HCV-positive subjects compared with 3.2% (94 of 2,947) anti-HCV-negative subjects (P <.001). HCV RNA was detectable in 80.8% (95% CI, 65.6%-95.91%) of the anti-HCV-positive subjects by reverse transcription-primed polymerase chain reaction (RT-PCR). The participants were HCV types 1b in 2 (9.5%), 3a in 8 (38.1%), 3b in 6 (28.6%), and unclassified in 5 (23.8%). Nucleotide sequencing and phylogenetic analysis assigned the unclassified type to genotype 3e. In conclusion, this study provides general population-based estimates of HCV prevalence, including genotypes, from a South Asian country. Although the prevalence of HCV infection in this population was lower than that reported from industrialized countries of the west, the total reservoir of infection is significant and calls for public health measures, including health education to limit the magnitude of the problem.

Adolescent↗
PubMed2003

An evaluation of current cholera treatment.

Cholera, caused by Vibrio cholerae O1 and O139, is characterised by profuse purging of watery stools, and vomiting and dehydration. The mainstay of therapy of cholera patients is rehydration with oral rehydration salt solution or intravenous Ringer's lactate depending upon the degree of dehydration. Antibiotics such as tetracycline, doxycycline, norfloxacin, ciprofloxacin and furazolidone may be used as an adjunct to rehydration therapy for severely purging cholera patients to reduce the rate of stool output. This shortens the duration of hospital stay, stops excretion of vibrios in the stool and minimises the requirement of fluids. Resistance to many of these drugs has been observed and is a matter of concern. Other antidiarrhoeals are not recommended. Many antisecretory drugs have been tried as an adjunct therapy, unfortunately, until today, none has been found useful in the treatment of cholera. Feeding during and after cholera is emphasised.

Anti-Infective Agents↗
PubMed2003

An evaluation of current shigellosis treatment.

Shigellosis or bacillary dysentery, characterised by the passage of frequent loose stools mixed with blood and mucous, is caused by Shigella spp. which can be subdivided into four serotypes, namely, S. sonnei, S. boydii, S. flexneri and S. dysenteriae. S. dysenteriae type 1 produces severe dysentery and may be associated with many complications like leukaemoid reaction and haemolytic-ureamic syndrome. It is known to produce protracted epidemics and pandemics and is usually multi-drug resistant. Antibiotics are the mainstay of therapy of all cases of shigellosis. Antibiotics such as tetracycline, ampicillin and co-trimoxazole, were previously highly effective. Newer fluoroquinolones such as norfloxacin, ciprofloxacin, ofloxacin, azithromycin and ceftriaxone are effective. Although single dose of norfloxacin 800 mg and ciprofloxacin 1 g have been shown to be effective, they are currently less effective against S. dysenteriae type 1 infection. Oral rehydration salt should be given concurrently to prevent or correct dehydration. Antimotility agents are contraindicated. Feeding during and after shigellosis is emphasised. Hand-washing practices with plenty of water and soap help to prevent the transmission of infection from person to person. A search is on for an effective vaccine against shigella.

Anti-Bacterial Agents↗