Cross infection control measures and the treatment of patients at risk of Creutzfeldt Jakob disease in UK general dental practice

AIMS: To determine the suitability of key infection control measures currently employed in UK dental practice for delivery of dental care to patients at risk of prion diseases. MATERIALS AND METHODS: Subjects: Five hundred dental surgeons currently registered with the General Dental Council of the UK. Data collection: Structured postal questionnaire. Analysis: Frequencies, cross-tabulations and chi-squared analysis. RESULTS: The valid response rate to the questionnaire was 69%. 33% of practices had no policy on general disinfection and sterilisation procedures. Only 10 of the 327 responding practices (3%) possessed a vacuum autoclave. 49% of dentists reported using the BDA medical history form but less than 25% asked the specific questions recommended by the BDA to identify patients at risk of iatrogenic or familial CJD. However, 63% of practitioners would refer such patients, if identified, to a secondary care facility. Of the 107 practitioners who were prepared to provide dental treatment, 75 (70%) would do so using routine infection control procedures. CONCLUSIONS: Most of the dental practices surveyed were not actively seeking to identify patients at risk of prion diseases. In many cases, recommended procedures for providing safe dental care for such patients were not in place

Human Prion Diseases in the United States

BACKGROUND: Prion diseases are a family of rare, progressive, neurodegenerative disorders that affect humans and animals. The most common form of human prion disease, Creutzfeldt-Jakob disease (CJD), occurs worldwide. Variant CJD (vCJD), a recently emerged human prion disease, is a zoonotic foodborne disorder that occurs almost exclusively in countries with outbreaks of bovine spongiform encephalopathy. This study describes the occurrence and epidemiology of CJD and vCJD in the United States. METHODOLOGY/PRINCIPAL FINDINGS: Analysis of CJD and vCJD deaths using death certificates of US residents for 1979-2006, and those identified through other surveillance mechanisms during 1996-2008. Since CJD is invariably fatal and illness duration is usually less than one year, the CJD incidence is estimated as the death rate. During 1979 through 2006, an estimated 6,917 deaths with CJD as a cause of death were reported in the United States, an annual average of approximately 247 deaths (range 172-304 deaths). The average annual age-adjusted incidence for CJD was 0.97 per 1,000,000 persons. Most (61.8%) of the CJD deaths occurred among persons >or=65 years of age for an average annual incidence of 4.8 per 1,000,000 persons in this population. Most deaths were among whites (94.6%); the age-adjusted incidence for whites was 2.7 times higher than that for blacks (1.04 and 0.40, respectively). Three patients who died since 2004 were reported with vCJD; epidemiologic evidence indicated that their infection was acquired outside of the United States. CONCLUSION/SIGNIFICANCE: Surveillance continues to show an annual CJD incidence rate of about 1 case per 1,000,000 persons and marked differences in CJD rates by age and race in the United States. Ongoing surveillance remains important for monitoring the stability of the CJD incidence rates, and detecting occurrences of vCJD and possibly other novel prion diseases in the United States

Stroke in the Lehigh Valley: combined risk factors for recurrent ischemic stroke.

We used the Lehigh Valley Stroke Register and a logistic regression model for the odds ratio to study the relative contribution of several factors, considered jointly, to the risk of recurrent ischemic stroke. The factors were hypertension (HT), transient ischemic attack (TIA), myocardial infarction (MI), other heart diseases (OHD), diabetes mellitus (DM), age, and sex. Among these factors MI, OHD, and TIA constituted significantly greater risk than HTN, DM, age, or sex for ischemic stroke recurrence

Risk factors for Creutzfeldt-Jakob disease: a reanalysis of case-control studies.

To review the evidence for risk factors of Creutzfeldt-Jakob disease (CJD), we pooled and reanalyzed the raw data of three case-control studies. The pooled data set comprised 178 patients and 333 control subjects. The strength of association between CJD and putative risk factors was assessed by computing the odds ratio as estimate of the relative risk. The risk of CJD was statistically significantly increased for subjects with a family history of CJD (odds ratio = 19.1; 95% CI 1.1 to 348.0). Further, there was a significant association between the risk of CJD and a history of psychotic disease (odds ratio = 9.9; 95% CI 1.1 to 86.1). Although not significantly increased, there was an elevated risk of CJD for subjects with a family history of dementia, a history of poliomyelitis, subjects employed as health professionals, and subjects ever exposed to cows and sheep. No association could be shown with organ meat consumption, including brain. The negative results of this reanalysis reassures the absence of a common risk factor in all CJD patients. However, the ongoing epidemiologic surveillance of CJD in several European countries may provide more evidence to exclude any environmental exposure early in childhood

Melatonin Levels and Low-Frequency Magnetic Fields in Humans and Rats: Reconciling Opposite Results with a Bayesian Regression

International audienceBackground: The present analysis revisit the impact of extremely low-frequency magnetic fields (ELF MF) on melatonin (MLT) levels in human and rat subjects using both a parametric and non-parametric approach. Method: In this analysis, we use 62 studies from review articles. The parametric approach consists in a Bayesian Logistic Regression (LR) analysis and the non-parametric approach consists of a Support Vector analysis which are designed to be robust against spurious/false results. Results: Both approach reveal a unique well ordered pattern, and show that humans and rat studies are consistent with each other once the MF strength is restricted to cover the same range (with B 50µT). In addition, the data reveal that chronic exposure (longer than ∼ 22 days) to ELF MF appears to decrease MLT levels only when the MF strength is below a threshold of 30µT (log B thr /µT= 1.4 +0.7 −0.5), i.e. when the man-made ELF MF intensity is below that of the static geomagnetic field. Conclusions: Studies reporting an association between ELF MF and changes to MLT levels and some the opposite (no association with ELF MF) can be reconciled under a single framework

A case-control study of sporadic Creutzfeldt-Jakob disease in Switzerland: analysis of potential risk factors with regard to an increased CJD incidence in the years 2001-2004

BACKGROUND: In 2001, the observed annual mortality from Creutzfeldt-Jakob disease (CJD) in Switzerland increased from less than 1.5 to 2.6 per million inhabitants. An underlying cause could not be identified. METHODS: To analyse potential risk factors for sCJD in Switzerland, close relatives of 69 sCJD-patients and 224 frequency age-matched controls were interviewed in a case-control study using a standardised questionnaire. 135 potential risk factors including socio-demographics, medical history, occupation and diet were analysed by logistic regression adjusting for age, sex and education. RESULTS: sCJD patients were more likely to have travelled abroad, worked at an animal laboratory, undergone invasive dental treatment, orthopaedic surgery, ophthalmologic surgery after 1980, regular GP visits, taken medication regularly, and consumed kidney. No differences between patients and controls were found for residency, family history, and exposure to environmental and other dietary factors. CONCLUSION: Although some factors were significantly more frequent among sCJD-cases, this study did not reveal specific explanations for the increased incidence of deaths due to sporadic CJD observed in Switzerland since 2001. Results have to be interpreted with caution due to multiple testing and possible recall bias in association with a long incubation period. The most plausible reason for the increase in Swiss sCJD cases after 2000 is an improved case ascertainment. Therefore, underreporting of cases might well have occurred before the year 2001, and the "real" yearly incidence of sCJD might not be lower than, but rather above 2 per million inhabitants