Atypical variants of bovine spongiform encephalopathy: rare diseases with consequences for BSE surveillance and control

Occurring for the first time in 1986 in the United Kingdom, bovine spongiform encephalopathy (BSE), the so-called “mad-cow disease”, has had unprecedented consequences in veterinary public health. The implementation of drastic measures, including the ban of meat-and-bone-meal from livestock feed and the removal of specified risk materials from the food chain has eventually resulted in a significant decline of the epidemic. The disease was long thought to be caused by a single agent, but since the introduction of immunochemical diagnostic techniques, evidence of a phenotypic variation of BSE has emerged. Reviewing the literature available on the subject, this paper briefly summarizes the current knowledge about these atypical forms of BSE and discusses the consequences of their occurrence for disease control measures.

Late presentation for HIV care across Europe: update from the Collaboration of Observational HIV Epidemiological Research Europe (COHERE) study, 2010 to 2013.

Late presentation (LP) for HIV care across Europe remains a significant issue. We provide a cross-European update from 34 countries on the prevalence and risk factors of LP for 2010-2013. People aged ≥ 16 presenting for HIV care (earliest of HIV-diagnosis, first clinic visit or cohort enrollment) after 1 January 2010 with available CD4 count within six months of presentation were included. LP was defined as presentation with a CD4 count < 350/mm(3) or an AIDS defining event (at any CD4), in the six months following HIV diagnosis. Logistic regression investigated changes in LP over time. A total of 30,454 people were included. The median CD4 count at presentation was 368/mm(3) (interquartile range (IQR) 193-555/mm(3)), with no change over time (p = 0.70). In 2010, 4,775/10,766 (47.5%) were LP whereas in 2013, 1,642/3,375 (48.7%) were LP (p = 0.63). LP was most common in central Europe (4,791/9,625, 49.8%), followed by northern (5,704/11,692; 48.8%), southern (3,550/7,760; 45.8%) and eastern Europe (541/1,377; 38.3%; p < 0.0001). There was a significant increase in LP in male and female people who inject drugs (PWID) (adjusted odds ratio (aOR)/year later 1.16; 95% confidence interval (CI): 1.02-1.32), and a significant decline in LP in northern Europe (aOR/year later 0.89; 95% CI: 0.85-0.94). Further improvements in effective HIV testing strategies, with a focus on vulnerable groups, are required across the European continent.

Record linkage to correct under-ascertainment of cancers in HIV cohorts: the Sinikithemba HIV clinic linkage project.

The surveillance of HIV-related cancers in South Africa is hampered by the lack of systematic collection of cancer diagnoses in HIV cohorts and the absence of HIV status in cancer registries. To improve cancer ascertainment and estimate cancer incidence, we linked records of adults (aged ≥ 16 years) on antiretroviral treatment (ART) enrolled at Sinikithemba HIV clinic, McCord Hospital in KwaZulu-Natal (KZN) with the cancer records of public laboratories in KZN province using probabilistic record linkage methods. We calculated incidence rates for all cancers, Kaposi sarcoma (KS), cervix, non-Hodgkin's lymphoma and non-AIDS defining cancers (NADCs) before and after inclusion of linkage-identified cancers with 95% confidence intervals (CI). A total of 8,721 records of HIV-positive patients were linked with 35,536 cancer records. Between 2004 and 2010 we identified 448 cancers, 82% (n=367) were recorded in the cancer registry only, 10% (n=43) in the HIV cohort only and 8% (n=38) both in the HIV cohort and the cancer registry. The overall cancer incidence rate in patients starting ART increased from 134 (95% CI 91-212) to 877 (95% CI 744-1,041) after inclusion of linkage-identified cancers. Incidence rates were highest for KS (432, 95% CI 341-555), followed by cervix (259, 95% CI 179-390) and NADCs (294, 95% CI 223-395) per 100,000 person-years. Ascertainment of cancer in HIV cohorts is incomplete, probabilistic record linkage is both feasible and essential for cancer ascertainment. This article is protected by copyright. All rights reserved.

When to Monitor CD4 Cell Count and HIV RNA to Reduce Mortality and AIDS-Defining Illness in Virologically Suppressed HIV-Positive Persons on Antiretroviral Therapy in High-Income Countries: A Prospective Observational Study.

OBJECTIVE To illustrate an approach to compare CD4 cell count and HIV-RNA monitoring strategies in HIV-positive individuals on antiretroviral therapy (ART). DESIGN Prospective studies of HIV-positive individuals in Europe and the USA in the HIV-CAUSAL Collaboration and The Center for AIDS Research Network of Integrated Clinical Systems. METHODS Antiretroviral-naive individuals who initiated ART and became virologically suppressed within 12 months were followed from the date of suppression. We compared 3 CD4 cell count and HIV-RNA monitoring strategies: once every (1) 3 ± 1 months, (2) 6 ± 1 months, and (3) 9-12 ± 1 months. We used inverse-probability weighted models to compare these strategies with respect to clinical, immunologic, and virologic outcomes. RESULTS In 39,029 eligible individuals, there were 265 deaths and 690 AIDS-defining illnesses or deaths. Compared with the 3-month strategy, the mortality hazard ratios (95% CIs) were 0.86 (0.42 to 1.78) for the 6 months and 0.82 (0.46 to 1.47) for the 9-12 month strategy. The respective 18-month risk ratios (95% CIs) of virologic failure (RNA >200) were 0.74 (0.46 to 1.19) and 2.35 (1.56 to 3.54) and 18-month mean CD4 differences (95% CIs) were -5.3 (-18.6 to 7.9) and -31.7 (-52.0 to -11.3). The estimates for the 2-year risk of AIDS-defining illness or death were similar across strategies. CONCLUSIONS Our findings suggest that monitoring frequency of virologically suppressed individuals can be decreased from every 3 months to every 6, 9, or 12 months with respect to clinical outcomes. Because effects of different monitoring strategies could take years to materialize, longer follow-up is needed to fully evaluate this question.