Accuracy of a history of blood donation from surrogate witnesses: data from the UK TMER study.

Look-back studies of blood transfusion in Creutzfeldt-Jakob disease commonly rely on reported history from surrogate witnesses. Data from the UK Transfusion Medicine Epidemiology Review have been analysed to determine the accuracy of the blood donation history provided by the relatives of cases. Our results show that only a small percentage of cases were found to be registered as donors on UK Blood Service (UKBS) databases when there was no family report of blood donation. In contrast, a history of reported donation was less accurate.

Risk factors for variant Creutzfeldt-Jakob disease in dental practice: a case-control study.

OBJECTIVE: To assess the risk of variant Creutzfeldt-Jakob Disease (vCJD) associated with dental treatment. DESIGN: Case-control study, investigation of links between cases. SETTING: National CJD surveillance, general dental practice and practice boards in Great Britain, 2008-2009. METHODS: Variant CJD cases were recruited from all those referred between May 1995 and August 2009 (n = 160); controls were recruited from the general population in 2003 using randomly selected geographic clusters and age-weighted sampling of individuals (n = 584). Risk factors were ascertained from dental records, with consent, using a structured questionnaire. RESULTS: Dental records were available for fewer cases (49%, 78 out of 160) than control subjects (78%, 457 out of 584). Variant CJD cases were no more or less likely than control subjects to have undergone dental treatment (p ≥0.05). Two cases had attended the same dental practice, but the type and timing of treatments did not provide strong evidence that this was linked to the route of transmission. CONCLUSION: There is no evidence of a vCJD risk associated with dental treatment, but because dental information is limited we cannot exclude this possibility. Improved methods for dental record keeping are recommended to aid future investigations of associations between infectious diseases and dental treatment.

The risk of variant Creutzfeldt-Jakob disease among UK patients with bleeding disorders, known to have received potentially contaminated plasma products.

The risk of variant Creutzfeldt-Jakob disease (vCJD) from potentially infected plasma products remains unquantified. This risk has been assessed for 787 UK patients with an inherited bleeding disorder prospectively followed-up for 10-20 years through the UK Haemophilia Centre Doctors' Organisation (UKHCDO) Surveillance Study. These patients had been treated with any of 25 'implicated' clotting factor batches from 1987 to 1999, which included in their manufacture, plasma from eight donors who subsequently developed clinical vCJD. Variant CJD infectivity of these batches was estimated using plasma fraction infectivity estimates and batch-manufacturing data. Total potential vCJD infectivity received by each patient has been estimated by cumulating estimated infectivity from all doses received during their lifetime. Of 787 patients, 604 (77%) were followed-up for over 13 years following exposure to an implicated batch. For these 604 patients, the estimated vCJD risk is ≥ 1% for 595, ≥ 50% for 164 and 100% for 51. This is additional to background UK population risk due to dietary exposure. Of 604 patients, 94 (16%) received implicated batches linked to donors who developed clinical vCJD within 6 months of their donations. One hundred and fifty-one (25%) had received their first dose when under 10 years of age. By 1st January 2009, none of these patients had developed clinical vCJD. The absence of clinical vCJD cases in this cohort to date suggests that either plasma fraction infectivity estimates are overly precautionary, or the incubation period is longer for this cohort than for implicated cellular blood product recipients. Further follow-up of this cohort is needed.

Evaluation of the meningitis epidemics risk model in Africa.

Meningitis epidemics have a strong environmental component in Africa with the most severe epidemics occurring in the Sahelian region known as the Meningitis Belt. The objective of this study is to evaluate an ecological model based on absolute humidity and land cover type to predict the location of these epidemics. The risk model is evaluated prospectively based on epidemics occurring in Africa from January 2000 to April 2004. Seventy-one epidemics occurred during this time period affecting 22% of continental African districts. The model predicted their location with a sensitivity of 88%. The evaluation also suggests that epidemics may be extending south of the Sahel, which is consistent with environmental changes in the region. This model could be used to select priority areas for the introduction of the newly developed conjugate meningococcal vaccines. Further studies are needed to enhance our understanding of the complex relationship between meningitis epidemics and the environment.

Deaths from variant Creutzfeldt-Jakob disease in the UK.

In 2002, 17 people died from variant CJD (vCJD) in the UK, compared with 20 in 2001 and 28 in 2000. We analysed data for deaths from vCJD since 1995 and estimated the underlying trend in mortality. The trend had a quadratic component (p=0.005), suggesting that the increase was not exponential, and that the previously increasing trend is slowing down. The death rate peaked in 2000. These findings are encouraging, but mortality might increase again in the future.

Survival after diagnosis of AIDS among adults resident in the United Kingdom in the era of multiple therapies.

The epidemiology of HIV and AIDS in the United Kingdom (UK) has changed markedly since highly active antiretroviral therapy (HAART) was introduced in 1996. HAART including protease inhibitors has considerably improved survival from AIDS diagnosis. The number of deaths of individuals with HIV infection in the UK, reported within 12 months of the end of the year of death, have decreased between 1995 and 1998. Concurrently AIDS diagnoses, reported within 12 months of the end of the year of diagnosis, have declined whilst diagnoses of HIV infection, similarly reported, have risen. Data from 13,689 adult AIDS cases diagnosed up to the end of 1996 were analysed. The overall median survival from AIDS diagnosis to death was 19.3 months. Over 50% of the cases diagnosed in 1996 were alive at the end of the survey therefore median survival exceeds 24 months, the maximum follow up time for the cohort. The opportunity for receiving HAART was modelled in three time periods: pre-multiple therapies (before September 1995), multiple reverse-transcriptase inhibitor therapy available (September 1995 to March 1996), and multiple therapy including protease inhibitors available (April 1996 onwards). Survival rates improved significantly among female heterosexuals and men who have sex with men when multiple therapy including protease inhibitors became available.

Results of a survey of diagnosed HIV infections prevalent in 1996 in England and Wales.

This paper describes a survey undertaken to assess the caseload of HIV infected patients who received medical care from statutory service providers in England and Wales in 1996 in order to inform health authorities about the size and composition of their resident population of such patients. A total of 13,670 HIV infected patients were identified as living in England and Wales, 70% of whom lived in the Thames NHS executive regions. Over half the total caseload received care within their health authority of residence. Regional care centres attracted patients from wider areas, however, particularly in the North West and Thames regions. This survey of prevalent diagnosed HIV infections, one of a series conducted annually, provides public health specialists with information relevant to their localities without compromising patient confidentiality. Along with other data from the surveillance of AIDS cases and HIV infections it contributes to the assessment and projection of demands on health and social services and provides evidence on which to develop and direct national and local health campaigns.

Results from the 1995 survey of prevalent clinically diagnosed HIV infection in England, Wales, and Northern Ireland.

Health districts in England, Wales, and Northern Ireland were surveyed in 1996 to collect summary information about people with diagnosed HIV infection who received care under the statutory services in 1995. The survey provided demographic and epidemiological information about the prevalent caseload by area of residence, and the extent to which patients with diagnosed HIV infection travelled to obtain care related to it. A total of 13362 people with diagnosed HIV infection were reported to be resident and treated in England, Wales, or Northern Ireland in 1995. Forty-four per cent of these were treated outside the health district where they lived, with regional specialist centres attracting patients from wider areas. At least 13% received care from more than one treatment centre. This national survey of prevalent diagnosed HIV infections provided public health specialists with information relevant to their own localities without compromising confidentiality. This information complements surveillance data from confidential AIDS case diagnosis reports, laboratory reports of HIV infections, and the unlinked anonymous HIV prevalence monitoring programme, all of which contribute to the assessment and projection of demands on health and social services, and provide evidence on which to develop and direct national and local health campaigns.