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N Shetty

Publications and source records attributed to N Shetty.

At least 19 recordsLinked to original sources
PubMed2006

Epidemiology of infections caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella spp.: a nested case-control study from a tertiary hospital in London.

Information on risk factors for acquisition of extended-spectrum ss-lactamase (ESBL)-producing organisms and their outcomes in patients with invasive infections is scant. The objectives of this study were to evaluate risk factors and all-cause mortality associated with infection due to ESBL-producing organisms using a nested case-control design, and to document transmission within a hospital employing molecular and conventional epidemiological methods. From December 2003 to April 2005, 50 patients with bloodstream infections (BSIs) due to ESBL-producing E. coli and Klebsiella spp. were recruited. Controls (N=50) were chosen, within the same period, from patients with non-ESBL-producing BSIs by simple random sampling; account was taken of potential confounding factors. Cases and controls were followed-up until November 2005, and outcomes were recorded as discharged or deceased. Molecular methods, supported by conventional epidemiology, were used to study the transmission of organisms. Logistic regression analyses showed prior ss-lactam antibiotics [odds ratio (OR) 11.57; 95% confidence intervals (CI) 2.31-51.15; P=0.003], hospital stay >15 days (OR 2.63; 95% CI 1.01-6.89; P=0.04) and prior admission to the intensive care unit (OR 13.98; 95% CI 1.88-19.15; P=0.006) to be independent risk factors for the acquisition of ESBL-producing organisms. In the first 15 days of follow-up, a significant proportion of patients with ESBL-producing organisms died; however, there was no difference in mortality between cases and controls at the end of the follow-up period. Molecular epidemiology identified five clusters amongst the ESBL-producing isolates. Conventional epidemiological analyses supported the evidence of transmission in three of these clusters.

Adolescent↗
PubMed2006

Laboratory diagnosis of bloodstream infections caused by extended-spectrum beta-lactamase-producing E. coli and Klebsiella species.

Extended-spectrum beta-lactamase (ESBL)-producing organisms are resistant to the third-generation cephalosporins commonly used as empirical therapy for a wide range of serious infections. It is therefore important for laboratories to offer reliable ESBL detection methods. This study compares two combination disc methods (Oxoid and Mast Diagnostics) containing cepodoxime with and without clavulanate with Vitek 2 for routine detection of ESBLs in Escherichia coli and Klebsiella spp. isolated from blood cultures. From December 2003 to April 2005, a total of 58 potential ESBL-producing isolates (resistant to cefotaxime and/or ceftazidime) by BSAC disc susceptibility were tested by the combination discs and Vitek 2. The Advanced Expert System, a feature of Vitek 2 reports possible mechanisms of resistance, based on interpretive reading of MICs. This study detected 7.4% more ESBL-producing isolates by Vitek 2 than by Oxoid disc testing (95% CI: 0.15-14.7%; P < 0.2) and 31.6% more ESBL-producing isolates were detected by Vitek 2 than by Mast disc testing, (95% CI: 16.2-46.96%; P < 0.001). Batch-to-batch variation was evident in disc performance for both disc types. Thus, use of appropriate controls is recommended when testing by the combination disc methods. Although no phenotypic test is 100% sensitive and specific, the Vitek 2 was a reliable system for ESBL detection; however, it is expensive and interpretation of results can be confusing to inexperienced users. Further studies to compare Vitek 2 with cefotaxime and ceftazidime combination discs may reveal disc methodology for ESBL detection to be a more reliable alternative than using cefpodoxime combination discs alone.

Anti-Bacterial Agents↗
PubMed2006

Clinical and radiological outcome of total hip replacement five years after pamidronate therapy. A trial extension.

Bisphosphonates reduce peri-prosthetic bone loss in the short term after total hip replacement but the mid- and longer term effects are not known. The aims of this randomised trial were to examine the effect of a single dose of 90 mg of pamidronate on the clinical and radiological outcome and peri-prosthetic bone mineral density in 50 patients (56 hips) over a five-year period, following total hip replacement. At five years, 37 patients (42 hips) returned for assessment. The Harris hip scores were similar in the pamidronate and placebo groups throughout the study. Also at five years, four patients, two from each group had osteolytic lesions on plain radiography. These were located around the acetabular component in three patients and in the femoral calcar in one. The femoral and acetabular peri-prosthetic bone mineral density in the pamidronate group and the control group was similar at five years. Pamidronate given as a single post-operative dose does not appear to influence the clinical outcome or prevent the development of osteolytic lesions at five years after total hip replacement.

Absorptiometry, Photon↗
PubMed2006

An epidemiological evaluation of risk factors for tuberculosis in South India: a matched case control study.

SETTING: There are limited data on risk factors associated with tuberculosis (TB) in India. OBJECTIVES: To evaluate potential socio-demographic risk factors for TB. DESIGN: Matched case-control. Cases were all new diagnoses of pulmonary TB attending as out-patients at St John's Medical College Hospital, Bangalore, India, from October 2001 to October 2003. Age- and sex-matched controls, one for each case (n = 189), were recruited among relatives accompanying non-TB in-patients in the hospital. RESULTS: Significant risk factors were low education level (OR 0.30; 95%CI 0.11-0.82), not having a separate kitchen (OR 3.26; 95%CI 1.25-8.46) and chronic disease, mainly diabetes (OR 2.44; 95%CI 1.17-5.09). High income, cooking with biomass fuels, history of smoking and alcohol consumption were not significant on multivariate analysis. Patients were respectively 11 and seven times more likely to have a BMI <18.5 (95%CI 5.62-21.98) and mid-arm circumference <24 cm (95%CI 3.87-11.89). CONCLUSIONS: In our study, TB was associated with low education level, kitchen type and diabetes, reflecting the complex interaction between non-communicable disease, urbanisation and a changing economic climate in Bangalore. The relationship between TB, the use of biomass cooking fuels and gender differentials related to fuel exposure merit further exploration. The study underscores the poor nutritional status of patients.

Adolescent↗
PubMed2005

Infections with Corynebacterium diphtheriae: six years' experience at an inner London teaching hospital.

Recently, a preponderance of non-toxigenic strains of Corynebacterium diphtheriae has been reported, as has the broadening spectrum of disease caused by these strains. This study presents data on 85 isolates of C. diphtheriae over a six year period (1998-2003). Eighty were non-toxigenic isolates from patients with sore throat, and five (one toxigenic) were from cutaneous ulcers in travellers returning from endemic areas. When examined in relation to denominator data provided by the Health Protection Agency (HPA) for the whole of England and Wales, 1998-2002, 75% of all notifications of C. diphtheriae for England and Wales originated from the laboratories at University College London Hospitals (UCLH). In some years (1999 and 2001) 95-100% of isolates came from UCLH. We believe that national data do not reflect true incidence, as universal screening for these organisms is not routine policy in many laboratories. The results presented suggest the need for increased clinical and laboratory awareness of this important pathogen.

Adolescent↗
PubMed2005

Hyperammonemia: an unusual presenting feature of multiple myeloma.

A 76 year old lady presented with altered sensorium and was found to have hyperammonemia on evaluation. She had no evidence of liver disease. For her symptomatology of backache, evaluation by bone marrow study showed evidence of multiple myeloma. She was given chemotherapy for multiple myeloma, which resulted in improvement in her sensorium, along with this there was also a rapid decline in serum ammonia levels. Hyperviscosity and hypercalcemia are common causes of altered sensorium in a patient with myeloma but in this case hyperammonemia was the likely cause.

Aged↗
PubMed2004

The public health response to a case of Lassa fever in London in 2000.

OBJECTIVES: Evaluation of the Department of Health 1996 guidance, the Memorandum on the Management and Control of Viral Haemorrhagic Fevers. METHODS: Description of the public health management in 2000 of the fifth UK patient confirmed to have Lassa fever. RESULTS: Delayed risk categorisation of the patient occurred for a variety of reasons. DH Guidance was followed once infection control advice was sought. Active surveillance of 125 contacts was extremely resource intense, involving over 3000 communications. Self-monitoring by healthcare workers should be considered in future. Advice on use of ribavirin prophylaxis is not included in the Memorandum, nor advice or templates for information sheets for contacts. Information sheets are now available from the Health Protection Agency in the event of future cases. International aspects not adequately addressed include the need for reliable risk assessment to be carried out before patients are medically evacuated from the country of origin, and the steps required to repatriate UK nationals. Effective and efficient communication is required between national and international organisations involved in such incidents. CONCLUSIONS: If guidelines are unclear or impracticable they will not be followed. It is important that lessons are learned and documented and that national guidance be regularly reviewed.

Communicable Disease Control↗
PubMed2004

Knowledge, attitudes and practices regarding tuberculosis among immigrants of Somalian ethnic origin in London: a cross-sectional study.

The objectives were to study knowledge, attitudes, and practices (KAP) regarding tuberculosis (TB) among Somalian subjects in inner London. We administered structured, fixed response KAP questionnaires to 23 patients (culture proved TB), and two groups of controls: 25 contacts (family members) and 27 lay controls (general Somali immigrant population). Responses were summed on a five-point scale. Most were aware of the infectious nature of TB but uncertain of other risk factors. Many were uncertain about coping with the disease and its effect on lifestyle. Belief in biomedicine for TB was unequivocal with men having a significantly higher belief score than women (p = 0.02); the need to comply with TB medication was unambiguously understood. Somalians interviewed were educated, multilingual, and aware of important health issues. Uncertainties in core TB knowledge need to be addressed with direct educational input, especially in women and recent entrants into the country. Volunteers from the established Somalian community could play a valuable part as links in the community to fight TB.

Black People↗
PubMed2004

Molecular epidemiology of Mycobacterium tuberculosis in patients of Somalian and white ethnic origin attending an inner London clinic.

BACKGROUND: In 2002, 6891 and 2850 tuberculosis (TB) notifications were received respectively for England and Wales and London. TB is an important public health problem in the Somalian population of inner London. SETTING: An inner London TB clinic. OBJECTIVE: To study the epidemiology, genetic diversity and clustering of tuberculosis in Somalian and white patients. MAIN OUTCOME METHODS: In a cross sectional study from June 1998 to June 2001, IS6110 restriction fragment length polymorphism (RFLP) and secondary spoligotyping was performed on 57 M. tuberculosis isolates from 40 Somalian and 17 white patients. Contact tracing of patients provided epidemiological information. RESULTS: In the Somalian group, using RFLP and spoligotyping, there were three clusters. Routine contact tracing confirmed one household cluster (two siblings). Spoligotyping yielded one cluster of two white patients who were patrons of a local pub. The rates of recent transmission were respectively 10.0% and 5.9% in the Somalian and white groups. CONCLUSIONS: Heterogeneous RFLP patterns in both groups showed a predominance of reactivation disease. Clustering as evidence of recent transmission has public health implications for enhanced contact tracing and active intervention.

Adolescent↗
PubMed2002

Strain relatedness of endemic MRSA isolates in a burns unit in South India--a five year study.

Methicillin-resistant Staphylococcus aureus (MRSA) is an important hospital-acquired pathogen in healthcare centres worldwide. The strain characteristics vary widely from country to country, although some strains have the propensity to spread globally. E-MRSA 15 and 16 have been established as epidemic strains in the UK and Europe. MRSA is widely prevalent in the Indian sub-continent and is endemic in the Burns Unit of St Johns Medical College Hospital, Bangalore, India. The purpose of the study was to investigate the predominance of one or more epidemic strains within an endemic situation. A representative selection of 65 isolates of MRSA over a period spanning five years (1994-1998) was subjected to antibiogram comparison, phage-typing and pulsed field gel electrophoresis (PFGE) using SmaI. The antibiogram comparison was not a discerning method of strain discrimination. At least 11 different phage-types were seen among these 65 isolates; 35.4% belonged to phage-types A and SM-A. PFGE studies showed 12 distinct patterns, with a single pattern accounting for over half of the isolates. The study showed that the isolates from India were diverse and distinct from strains of MRSA such as E-MRSA reported from many studies in the UK. Molecular characterization of isolates is a source of valuable information that could enhance global surveillance; more work is needed across the Indian sub-continent to establish the nature of MRSA strain diversity.

Bacteriophage Typing↗
PubMed2002

Detection of methicillin and mupirocin resistance in Staphylococcus aureus isolates using conventional and molecular methods: a descriptive study from a burns unit with high prevalence of MRSA.

AIMS: To compare conventional phenotypic methods for the detection of methicillin and mupirocin resistance in Staphylococcus aureus in routine laboratory practice with reference to an established molecular method. METHODS: This study was conducted on a selection of 65 isolates of methicillin resistant Staphylococcus aureus (MRSA) from a burns unit in India which is endemic for MRSA. The Kirby-Bauer and modified Stokes disc diffusion tests and the Vitek breakpoint minimum inhibitory concentration (MIC) were performed on all isolates using the presence of the mecA gene as the reference standard. Gel based and colorimetric polymerase chain reaction (PCR) assays were evaluated as molecular methods for the diagnosis of MRSA. A commercial latex agglutination test, the Mastalex, was assessed for the detection of penicillin binding protein 2a (PBP2a), the mecA gene product. Conventional disc diffusion and molecular methods were investigated for the detection of mupirocin resistance. RESULTS: Fifty one of 65 isolates were positive for the mecA gene. All three phenotypic methods showed high sensitivity (> 96.2%), whereas the specificity varied: 50% for Kirby-Bauer, 87.5% for modified Stokes, and 93.3% for Vitek. The colorimetric PCR was less cumbersome than the gel based PCR; there was complete concordance between both systems. The Mastalex kit showed good correlation with PCR. One isolate was found to be mupirocin resistant and harboured the mupA gene. CONCLUSIONS: The specificity of routine laboratory tests for MRSA detection was variable. mecA gene detection, the "gold standard" to confirm ambiguous results, is difficult to perform in routine diagnostic laboratories. The Mastalex kit for the detection of PBP2a is an alternative that could be used in most laboratories. High level mupirocin resistance can be confirmed with genotypic methods.

Anti-Bacterial Agents↗
PubMed2002

Sclerosing mediastinitis: a case report.

A rare case of sclerosing mediastinitis in a 38 year old male is described. This interesting case illustrates how a seemingly benign fibrosing condition may lead to disastrous and fatal complications.

Adult↗
PubMed2001

Permanent cerebellar toxicity of cytosine arabinoside (Ara C) in a young woman.

This report provides the first videotape example of a patient with permanent cerebellar ataxia from high dose cytosine arabinoside. This case was unusual in that the patient was young, the effects are seemingly permanent and severe, and corticospinal tract damage also occurred. Early recognition to stop drug administration remains the only method to reduce risk.

Adult↗
PubMed2001

Tuberculosis of the craniocervical junction.

Tuberculosis of the craniocervical junction is rare even where the condition is endemic. It poses problems in both diagnosis and management. We describe 25 cases followed over a period of 12 years, and relate the presentation, diagnosis and management. Of our 25 patients 16 were managed conservatively and nine by surgery. In order to diagnose this condition a high index of suspicion and advanced imaging techniques are necessary. Early diagnosis and adequate treatment led to good results without fatal complications.

Adolescent↗
PubMed2000

Sitafloxacin in the treatment of patients with infections caused by vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus.

Sitafloxacin is a new quinolone active against multi-resistant Gram-positive pathogens. An open study was conducted in patients with serious systemic infections with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococcus (VRE). Patients with MRSA were recruited if treatment with glycopeptides had failed. Of 11 patients with MRSA infection, four were cured, six failed treatment and one was indeterminate. Of nine patients with VRE infection (one patient had both pathogens), five were cured and four failed. Fifteen adverse events in 12 patients were potentially related to the study drug. Sitafloxacin was effective in VRE and some recalcitrant MRSA infections.

Adolescent↗
PubMed2000

Is the detection of Mycobacterium tuberculosis DNA by ligase chain reaction worth the cost: experiences from an inner London teaching hospital.

AIMS: To evaluate the clinical usefulness and the costs of using a rapid, commercial ligase chain reaction test (LCx) to detect Mycobacterium tuberculosis directly from clinical samples. METHODS: A prospective study of 2120 routine clinical specimens from 1161 patients over a 13 month period. Investigations for mycobacterial disease by microscopy, culture, and the Abbott LCx assay were performed. Sequential LCx assays were monitored in a cohort of patients undergoing treatment. The costs of the assay were calculated using the WELCAN system. Sensitivity, specificity, and positive and negative predictive values of the LCx assay were compared with conventional tests. The performance of the assay in patients undergoing treatment and cost in terms of WELCAN units converted to pounds/annum was studied. RESULTS: The assay was 85%/88% sensitive and 98%/100% specific in culture confirmed/clinically confirmed cases of tuberculosis, respectively. The assay was not useful for the measurement of treatment outcomes. The test cost approximately 42,500 Pounds/annum. CONCLUSIONS: The assay is a rapid, sensitive, and specific adjunct to clinical diagnosis, especially in differentiating non-tuberculous mycobacteria. However, it does not differentiate old and treated tuberculosis from reactivated disease, it is not useful to monitor adherence to treatment, and it is expensive.

Costs and Cost Analysis↗