Outbreak of influenza A (H3N2) in a highly-vaccinated religious community: a retrospective cohort study

An outbreak of influenza occurred at the end of the 2001-2 winter season in a highly-vaccinated, semi-enclosed, religious community. On the basis of retrospective self reporting, 43% met the case definition (151/350) and 81% (25/31) of throat swabs from cases were polymerase chain reaction (PCR) -positive for influenza A (H3N2). The risk of developing influenza in people aged 65 or more was lower than that of children aged 2 years and under (odds ratio 0.1, 95% confidence interval 0.02 to 0.38). The risk of developing symptoms of influenza was not significantly different between people who had been vaccinated in the United Kingdom and those who had not been vaccinated (OR 1.14, CI 0.41 to 3.14). Chronic disease was an independent risk factor for developing symptoms of influenza (OR 1.9, CI 1 to 3.63). Timing of the outbreak, the age structure and mode of communal living may have influenced the efficacy of the influenza vaccine, which was well matched to circulating strains at the time of the outbreak. It is important to consider the diagnosis of influenza even in a highly-vaccinated community.

Measuring fast neutrons in Hiroshima at distances relevant to atomic-bomb survivors

Data from the survivors of the atomic bombs serve as the major basis for risk calculations of radiation-induced cancer in humans. A controversy has existed for almost two decades, however, concerning the possibility that neutron doses in Hiroshima may have been much larger than estimated. This controversy was based on measurements of radioisotopes activated by thermal neutrons that suggested much higher fluences at larger distances than expected. For fast neutrons, which contributed almost all the neutron dose, clear measurement validation has so far proved impossible at the large distances (900 to 1,500 m) most relevant to survivor locations. Here, the first results are reported for the detection of 63Ni produced predominantly by fast neutrons (above about 1 MeV) in copper samples from Hiroshima. This breakthrough was made possible by the development of chemical extraction methods and major improvements in the sensitivity of accelerator mass spectrometry for detection of 63Ni atoms (refs 8-11). When results are compared with 63Ni activation predicted by neutron doses for Hiroshima survivors, good agreement is observed at the distances most relevant to survivor data. These findings provide, for the first time, clear measurement validation of the neutron doses to survivors in Hiroshima.

Is there a role for antiandrogen monotherapy in patients with metastatic prostate cancer?

Castration is the most widely used form of androgen ablation employed in the treatment of metastatic (M1) prostate cancer. Non-steroidal antiandrogen monotherapy is a potential alternative treatment option for men for whom castration is unacceptable or not indicated. Of the three non-steroidal antiandrogens, bicalutamide ('Casodex'), flutamide and nilutamide, only bicalutamide has been compared with castration in large, controlled, randomised, Phase III trials in M1 patients. A post-hoc analysis of these studies indicated that bicalutamide 150 mg/day monotherapy may be of benefit to M1 patients with a prostate specific antigen (PSA) level </=400 ng/ml. Significant advantages for M1 patients treated with bicalutamide were observed in subjective response rate, maintenance of sexual interest and physical capacity. Patients with a higher disease burden (PSA >400 ng/ml) may decide that quality of life and symptomatic benefits outweigh the slight survival disadvantage seen in clinical trials and opt for bicalutamide monotherapy as an alternative to castration.Prostate Cancer and Prostatic Diseases (2001) 4, 196-203.

A randomised comparison of bicalutamide ('Casodex') 150 mg versus placebo as immediate therapy either alone or as adjuvant to standard care for early non-metastatic prostate cancer. First report from the Scandinavian Prostatic Cancer Group Study No. 6

OBJECTIVES

To assess the efficacy and tolerability of bicalutamide 150 mg ('Casodex'(1)) as immediate therapy, either alone or as adjuvant to treatment of curative intent, in patients with early (T1b-T4, any N, M0) prostate cancer.

METHODS

This randomised, double-blind study was conducted in the Nordic countries as part of the 'Casodex' Early Prostate Cancer programme. Patients received bicalutamide 150 mg (n=607) or placebo (n=611) in addition to standard care.

RESULTS

More than 80% of patients had not received therapy of primary curative intent. Median follow-up in both groups was 3 years. Median exposure to study treatment in the bicalutamide and standard care alone groups was 2.5 and 2.3 years, respectively. Bicalutamide reduced the risk of objective disease progression by 57% compared with standard care alone (HR 0.43; 95% CI 0.34, 0.55; p<<0.0001). Survival data were immature (11.4% deaths) with no difference between the two treatment groups.

CONCLUSIONS

Bicalutamide 150 mg as immediate therapy, either alone or as adjuvant to treatment of curative intent, significantly reduces the risk of disease progression in patients with early prostate cancer. The trial is ongoing to assess whether the reduction in risk of objective progression translates into an overall survival benefit.

Differences in the use of health services among people with and without epilepsy in the United Kingdom: socio-economic and disease-specific determinants

We aim to examine the socio-economic, demographic and disease-specific determinants in the use of health services by patients with epilepsy, compared to people without epilepsy. We used data from the fourth national survey of morbidity in general practice, carried out in 1991-1992. Overall mean annual number of consultations with general practitioners, home visits and referrals to secondary care per person were calculated for people with epilepsy, stratified by age, sex and socio-economic status. The proportion of patients consulting for certain diseases or disease groups were also calculated for patients with epilepsy. Results were compared to these in people without epilepsy, and rate ratios were calculated. Patients with epilepsy consulted twice as often, required three to four times more home visits, and were referred to secondary care three times more often than people without epilepsy, irrespective of age, sex and social class. Among patients with epilepsy, consultation rates and home visits were higher in females, older people and people from the manual social classes. A higher proportion of patients with epilepsy consulted for neoplasms, haematological and mental health disorders, dementia, stroke and gastrointestinal bleeding. Older age and low social class were less strongly associated with health service utilisation than in people without epilepsy, indicating that people with epilepsy lose much of the protective effect of young age and high social class on health. Factors contributing to the higher utilisation of health services in people with epilepsy need to be studied further and their effects taken into account in the organisation of health services for people with epilepsy.

Toxicity of 17alpha-ethinylestradiol and bisphenol A to the freshwater Cnidarian Hydra vulgaris

Estrogens and estrogen mimics that enter the environment are known to present a serious threat to the development and reproduction of vertebrates by disrupting their normal endocrine function. There is also concern that such chemicals may be damaging to invertebrates. In this study, Hydra vulgaris, a member of the Cnidaria, an evolutionarily primitive group of invertebrates present before the divergence of the protostomes and deuterostomes, was exposed to the synthetic estrogen 17alpha-ethinylestradiol (EE2) and bisphenol A (BPA), both of which are known to be estrogenic in fish. Effects on polyp survival, structure, and regeneration (and sexual reproduction for EE2) were examined and mortality was recorded at high concentrations, with 96-h LC(50)s of 3.8 mg/L and 6.9 mg/L for EE2 and BPA, respectively. The structure and physiology of polyps was adversely affected at concentrations greater than 58 microg/L EE2 and 42 microg/L BPA. There was a concentration-related inhibition of regeneration above 150 microg/L EE2 and 460 microg/L BPA. Sexual reproduction was only impaired at 500 microg/L EE2. These results clearly suggest that the signaling processes necessary for the control and regulation of cell movement and differentiation during normal development, regeneration, and sexual reproduction in H. vulgaris are not disrupted by estrogenic pollutants at low environmentally relevant concentrations.

ERK1/2 mediates PDGF-BB stimulated vascular smooth muscle cell proliferation and migration on laminin-5

During restenosis following arterial injury, vascular smooth muscle cells (VSMCs) form a neointimal layer in arteries by changing from a differentiated, contractile phenotype to a dedifferentiated, migratory, and proliferative phenotype. Several growth factors, cytokines, and extracellular matrix components released following injury have been implicated in these phenotypic changes. We have recently detected the expression of laminin-5, an ECM protein found predominantly in epithelial tissues, in the arterial vasculature. Here we report that ln-5 expression by VSMC is upregulated by platelet-derived growth factor (PDGF-BB), epidermal growth factor, basic fibroblast growth factor, and transforming growth factor-beta1. Adhesion to ln-5 specifically enhances PDGF-BB-stimulated VSMC proliferation and migration. PD98059, a specific inhibitor of the ERK1/2 members of the Mitogen Activated Protein kinase family, increases both VSMC adhesion to ln-5 and blocks PDGF-BB-stimulated VSMC migration on ln-5. These results suggest that adhesion to ln-5 mediates a PDGF-BB-stimulated VSMC response to vascular injury via an ERK1/2 signaling pathway.

Comorbidity associated with atrial fibrillation: a general practice-based study

BACKGROUND

[corrected] Atrial fibrillation is an important risk factor for ischaemic stroke. Anticoagulation treatment with warfarin can substantially reduce the risk of stroke in people with atrial fibrillation but concerns about their side-effects have limited their use in clinical practice. However there has been little population-based research on the comorbidity associated with atrial fibrillation and on the prevalence of potential contraindications to anticoagulantion treatment among these patients.

AIM

To determine the prevalence of known risk factors for ischaemic stroke and possible contraindications to anticoagulant treatment among patients with atrial fibrillation.

METHOD

One-year prospective cohort study in 60 general practices in England and Wales with a total population of 502,493 people. Age and sex specific prevalence rates and relative risks of risk factors for ischaemic stroke and possible contraindications to antithrombotic treatment were calculated.

RESULTS

The number of patients who had a diagnosis of atrial fibrillation during the year was 1,414 (0.3%) patients. The prevalence of other nsk factors for ischaemic stroke in patients with atrial fibrillation increased with age in men, from 48% (relative risk [RR] = 3.78, 95% confidence interval [95% CI] = 3.23-4.41) at 45 to 64 years to 64% (RR = 2.21, 95% CI = 2.00-2.44) at 75years and over A similar increase of 50% (RR = 4.36, 95% CI = 3.54-5.38) to 60% (RR = 2.07, 95% CI = 1.91-2.23) was seen in women. The percentage of men with atrial fibrillation with at least one contraindication to antithrombotic treatment was 5% at 45 to 64 years and 14% at 75 years and over. Among women with atrial fibrillation, 7% had a contraindication at 45 to 64 years and 16% at 75 years and over. The all-ages relative risk of a contraindication was 1.17 (95% CI = 0.92-1.48) in men and 1.53 (95% CI = 1.28-1.83) in women. Forty per cent (575) of patients with atrial fibrillation had at least one risk factor for ischaemic stroke and no contraindications to antithrombotic treatment.

CONCLUSION

Atrial fibrillation is associated with a substantial increase in the prevalence of risk factors for ischaemic stroke. By contrast, potential contraindications for antithrombotic treatment are more evenly distributed among patients with and without atrial fibrillation. Around 40% of patients with atrial fibrillation in primary care are at high risk of stroke and have no contraindicationsfor antithrombotic treatment.

Chronic exposure to 17 alpha-ethinylestradiol and bisphenol A-effects on development and reproduction in the freshwater invertebrate Chironomus riparius (Diptera: Chironomidae)

The effect of 17 alpha-ethinylestradiol (EE) and bisphenol A (BPA) on development and reproduction in Chironomus riparius was determined over two generations in chronic sediment exposure assays. A number of response criteria were examined in order to identify any chemical-related effects including median emergence times (EmT50), the number and sex ratio of emerged adults, egg production and egg viability. The results showed that emergence time and percentage adult emergence were affected by EE and BPA exposure. These effects were primarily associated with the second generation of test animals, most notably in the BPA study, where the emergence of male and female adults was significantly (P<0.05) delayed at concentrations ranging from 78 ng/l to 0.75 mg/l. At very low concentrations (1 ng/l) of EE, both the first and second generation of adults emerged significantly earlier than control animals. No effect on the percentage emergence of first generation adults was evident with either chemical or in the second generation with BPA. The number of egg-ropes produced by the first generation females varied between treatments but no dose-response pattern was evident. Although certain responses were significantly affected, results in general do not suggest that the criteria examined, although validated as indicators of general sediment toxicity, could be used to detect the oestrogenic effects of EE and BPA on C. riparius.

High rates of multiple antibiotic resistance in Streptococcus pneumoniae from healthy children living in isolated rural communities: association with cephalosporin use and intrafamilial transmission

OBJECTIVE

Streptococcus pneumoniae is one of the most clinically significant pathogens with emerging antibiotic resistance. We performed a surveillance study in isolated rural populations of healthy children to estimate the prevalence of pneumococcal resistance and to contrast factors that predict pneumococcal carriage with those that specifically predict resistant pneumococcal carriage.

METHODS

The study was conducted in 1998 in 2 rural communities in Utah. Families were recruited directly for participation through community canvassing. Surveillance nasopharyngeal cultures were obtained from children who were younger than 8 years. Antibiotic usage and information on other potential risk factors were obtained from questionnaires and local pharmacy records. Resistance was determined by testing isolates for susceptibility to penicillin, cefaclor, trimethoprim-sulfamethoxazole, erythromycin, ceftriaxone, and trovafloxacin. Selected resistant isolates were characterized further by serotyping, pulsed field gel electrophoresis, and Southern blot with DNA probes specific for the pneumococcal lytA gene and for antibiotic resistance genes.

RESULTS

In April 1998, surveillance nasopharyngeal cultures were obtained from 368 children aged </=8 years in community A and 369 children in community B. The number of antibiotic courses per child within 1 year before culture was higher in community B than A (mean: 2.2 vs 1.7). Conversely, oral cephalosporins were more frequently used in community A than B (community A: 22% received cephalosporins within 4 months; community B: 12%). Colonization with S pneumoniae was detected in 24% of children in community A and 14% in community B; 36% of isolates from community A and 28% of isolates from community B were resistant or intermediately susceptible to at least 1 antibiotic tested. Reduced susceptibility was most common to trimethoprim-sulfamethoxazole and cefaclor (28% and 26%, respectively). Pneumococcal carriage (susceptible or resistant) was independently associated with age <5 years (odds ratio [OR]: 2.2), child care exposure (OR: 2.4), presence of a sibling with a positive culture (OR: 3.3), and residence in community A (OR: 1.7). Among carriers, age <2 years (OR: 2.6), use of cephalosporins within the preceding 4 months (OR: 2.7), and having a sibling colonized with resistant S pneumoniae (OR: 5.5) were independent predictors of reduced susceptibility or resistance. Each pair of resistant isolates from siblings was indistinguishable by pulsed field gel electrophoresis and other molecular typing techniques. Several pneumococcal isolates from these isolated rural areas had the molecular characteristics of international clones of multiple-drug-resistant pneumococci that have been associated with worldwide spread.

CONCLUSIONS

Young age and intrafamilial transmission were important risk factors for carriage of both susceptible and resistant S pneumoniae. In contrast, previous cephalosporin use was linked specifically to resistant pneumococcal carriage, which suggests that modifications in antibiotic usage patterns may have salutary effects on antimicrobial resistance. These results extend previous observations in large cities regarding the penetration of multiple-drug-resistant clones of pneumococci into community populations.

Trends in the prevalence and management of atrial fibrillation in general practice in England and Wales, 1994-1998: analysis of data from the general practice research database

OBJECTIVE

To determine the prevalence of atrial fibrillation in England and Wales, and examine trends in its treatment with warfarin and aspirin between 1994 and 1998.

DESIGN

Analysis of data from the general practice research database.

SETTING

England and Wales.

PATIENTS

1.4 million patients registered with 211 general practices.

MAIN OUTCOME MEASURES

Age and sex specific prevalence rates of atrial fibrillation; percentage of patients with atrial fibrillation treated with oral anticoagulants or aspirin.

RESULTS

The prevalence of atrial fibrillation in 1998 was 12.1/1000 in men and 12.7/1000 in women. Prevalence increased from less than 1/1000 in under 35 year olds to over 100/1000 in those aged 85 years and over. There was a 22% increase in the age standardised prevalence of atrial fibrillation in men and a 14% increase in women between 1994 and 1998. The percentage of patients prescribed oral anticoagulants increased from 20% to 34% in men and from 17% to 25% in women. The percentage of men with atrial fibrillation prescribed aspirin increased from 26% to 36%, and the percentage of women increased from 24% to 36%. Applying the age and sex specific prevalence and treatment rates to the population gives an estimate of around 650 000 cases of atrial fibrillation in England and Wales. The greatest number of cases occurs in the 75-84 year old age group.

CONCLUSIONS

The number of patients in the community with identified atrial fibrillation is increasing. There has also been a pronounced increase in the percentage of patients with atrial fibrillation prescribed oral anticoagulants or aspirin.

Invasive serotype a Haemophilus influenzae infections with a virulence genotype resembling Haemophilus influenzae type b: emerging pathogen in the vaccine era?

OBJECTIVE

Haemophilus influenzae type b causes severe disease in nonimmune infants and young children; other serotypes are uncommon pathogens and thought to have low virulence. Some have hypothesized that with the virtual elimination of H influenzae type b, other serotypes might acquire virulence traits and emerge as important pathogens of children. We describe the clinical, epidemiologic, and molecular biologic features of 5 cases of severe disease attributable to Haemophilus influenzae type a.

METHODS

After observing 4 cases of invasive disease caused by H influenzae type a, we reviewed microbiology records at 3 reference laboratories that perform all serotyping in Utah and surveillance databases. Strains of H influenzae type a and control strains were examined by Southern blotting with the use of the cap probe pUO38 and by pulsed-field gel electrophoresis. The putative virulence mutation, the IS1016-bexA deletion, was detected by polymerase chain reaction amplification and sequencing.

RESULTS

During a 10-month period, we observed 5 children with severe invasive disease caused by H influenzae type a. No isolates of H influenzae type a had been submitted to the reference laboratories between 1992 and 1998. The median age of patients was 12 months (range: 6-48 months). Four of 5 had meningitis and bacteremia; 1 had purpura fulminans. Three isolates, representing 1 of 2 pulsed-field gel electrophoresis patterns, contained the IS1016-bexA deletion and were associated with particularly severe disease.

CONCLUSIONS

We describe an unusual cluster of severe disease caused by H influenzae type a that resembles the clinical and epidemiologic features of H influenzae type b disease. Our data support the hypothesis that the IS1016-bexA deletion may identify more virulent strains of H influenzae. Haemophilus influenzae, epidemiology, virulence, serotyping, pathogenicity.

Survival and precopulatory behaviour of Gammarus pulex (L.) exposed to two xenoestrogens

The effects of the xenoestrogens ethinylestradiol (EE) and bisphenol A (BPA) on the survival and reproductive behaviour of the amphipod Gammarus pulex were determined in a series of bioassays. Acute toxicity of the test chemicals was determined under static conditions, revealing 10 d median lethal concentrations (LC50s) of 0.84 and 1.49 mg/L for EE and BPA, respectively. Several aspects of the reproductive behaviour including the ability of males and females to detect each other, form precopulatory guarding pairs and to continue the guarding behaviour, were examined during a 24 h exposure period over a wide range of concentrations. However, reproductive behaviour was only disrupted at relatively high concentrations where it would be unrealistic to attribute the effects to an endocrine mediated process. Consequently, changes in precopulatory guarding resulting from acute exposure. do not seem to be suitable for detecting the presence in water of xenoestrogens known to cause endocrine disruption in vertebrates.