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British sheep farmers were invited to complete a questionnaire about the impact of Schmallenberg virus (SBV) on animal health, welfare and their own emotional wellbeing during the 2011-2012 lambing season, through Defra and Farming Industry websites, letters to farmers who had requested SBV laboratory tests and advertisement at Sheep 2012. The 494 responders included SBV confirmed (positive by RT-PCR) (n=76), SBV suspected by farmer (n=140) or SBV not suspected (n=278). Percentage of barren ewes was similar across SBV groups, however, lamb and ewe losses were higher on responder farms where SBV was confirmed or suspected. The median percentages of all lambs born (and lambs born deformed ) that died within one week of birth was 10.4 per cent (5.5 per cent), 7.0 per cent (2.9 per cent) and 5.3 per cent (0 per cent), respectively, on SBV confirmed, suspected and not suspected farms (P<0.001). Eight to 16 per cent of SBV confirmed or suspected farms reported lamb mortality of ⩾40 per cent. Farmer perceived impact was greater where SBV was confirmed or suspected (P<0.001): 25 per cent reported a high impact on emotional wellbeing (4 per cent of SBV not suspected), 13 per cent reported a high impact on flock welfare and financial performance and 6 per cent were less likely to farm sheep next year because of SBV (<2 per cent in SBV not suspected). Overall, SBV impact has been large relative to reported sheep loss. [ABSTRACT FROM AUTHOR]

The article presents the prevention of the transfusion-transmitted malaria through the use of the malaria anti-body test. The test is used to detect the plasmodium antigens and the use of nucleic acid amplification testing (NAT) for the DNA of parasite. It mentions the criteria for the donors that are tested with the use of enzyme-linked immunosorbent assay (ELISA).

The article presents questions concerning the use of malaria antibody test to prevent transfusion-transmitted malaria. The questions which are being presented to several transfusion services include the consequences of the test on the donor and the most preferable technique to detect anti-malaria antibodies. The necessity of using pathogen-inactivation as a preventive measure is also being mentioned.

The incidence of BSE in Europe is in continued decline. At present, iatrogenic transmission from person to person is considered a serious threat to public health. This report of the International Society of Blood Transfusion Working Party on Transmissible Spongiform Encephalopathy will focus on the state of the art in relation to blood components and plasma safety. Latest information on the pathogenicity of the infectious agent, the frequency and dynamics of infection in blood and transfusion transmissibility will be documented. Preventive measures including donor deferral policies, technologies for prion removal from labile blood components and for prion detection in plasma, the absence of a sensitive and rapid reference assay able to confirm the positive results from any putative blood screening assay will be updated. At last, as many uncertainties remain and a number of assumptions await confirmation, the areas to continue to explore are listed. [ABSTRACT FROM AUTHOR]

The objectives of the study were to describe the introduction of testing blood donations for antibodies to human T-cell lymphotropic virus (anti-HTLV) and to determine the risk of HTLV potentially infectious donations entering the UK blood supply. The rationale for testing was based on (i) evidence of transmission through transfusion in the UK, (ii) the serious nature of HTLV I-associated morbidity and (iii) evidence of infection in UK blood donors. From mid-2002, all blood donations made at UK blood centres were tested in pooled samples using Abbott-Murex HTLV I/II GE 80/81 enzyme immunoassay (EIA). Surveillance data were used to calculate the incidence and prevalence of anti-HTLV and derive estimates of risk. Between August 2002 and December 2006, 106 donations were confirmed positive for anti-HTLV (95 anti-HTLV I and 11 anti-HTLV II). Prevalence was 10-fold higher among donations from new donors than repeat (4·0 and 0·42 per 100 000 donations), and only one repeat donor had evidence of seroconversion. The risk of an HTLV I potentially infectious donation entering the UK blood supply was estimated at 0·11 per million donations (95% confidence interval 0·06 to 0·18). The current very low observed incidence and prevalence among blood donors reflect the very low estimated risk of an HTLV I-positive donation entering the UK blood supply. A change in either the epidemiology of HTLV in UK blood donors or the length of the window period of the test should prompt further review of the risk and a reassessment of anti-HTLV testing in the UK. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the performance of HIV screening kits introduced over a 12-year period. HIV kits used by the National Blood Service (NBS) were assessed in the context of other HIV kits employed by diagnostic and reference laboratories. Thirty-three HIV screening kits were assessed and 13 had the potential to be used by the NBS. Specimens applied to NBS evaluations included 2000 HIV-negative specimens collected from blood donors, 200 HIV-positive specimens and 21 seroconversion panels, with larger numbers applied to the latter two categories prior to implementation of Communauté Européennes (CE) marking. The 33 HIV kits gave repeat reactive rates, based on HIV-negative specimens, of between 0% and 0·8% (and between 0% and 0·2% for kits relevant to the NBS). When examined for diagnostic sensitivity, the 33 kits gave sensitivities between 99·78% and 100%. Kits relevant to NBS gave sensitivities of 100% except one kit, which failed to detect one anti-HIV-2-positive specimen. Twenty-six kits were compared for detection of primary HIV infection. Of these, the 10 combined HIV antigen/antibody kits examined were more sensitive than other formats and have been exclusively adopted by NBS where operational considerations allow. Their added seroconversion sensitivity makes them the screening method of choice for populations at increased risk, e.g. in sexually transmitted infection (STI) clinics. The regular review of evaluation results has demonstrated a continuing improvement over time in the performance of HIV screening kits and contributed to advances in blood safety. [ABSTRACT FROM AUTHOR]

In February 2003, a postal survey of 1279 sheep farmers in the Shetland Islands yielded 586 responses (46 per cent response rate). The principal aim of the survey was to gather information on the history and control of scrapie. Overall, 28.5 per cent of the respondents thought they had had a case of scrapie in their flock at some time. There was a slow increase in the proportion of affected flocks during the 1970s, followed by a more rapid increase during the 1980s and early 1990s, and a decline from the mid-1990s onwards. The peak proportion of affected flocks was approximately 6 per cent in 1994. Of the farmers who had ever had scrapie in their flock, 97.1 per cent had attempted to control the disease. The most common method of control was breeding from non-susceptible tups, used by 90.6 per cent of the affected flocks and 75.1 per cent of the flocks that had never been affected. A comparison of the characteristics of the affected and unaffected flocks indicated that an increased risk of scrapie was associated with the larger flocks, the open flocks and the flocks that bought in lambs. The basic reproduction ratio for the spread of scrapie between flocks was estimated to be 1.47, and the mean duration of an outbreak within a flock was estimated to be approximately two years. [ABSTRACT FROM AUTHOR]

Discusses the results of a survey on the implementation of Hepatitis C virus (HCV) nucleic acid amplification technology (NAT) in testing of blood donations in eighteen countries. Number of countries who have implemented HCV NAT; Alternatives used by countries whose HCV NAT are yet to be approved; Characteristics of NAT assays.

Between October 2001 and January 2003 the prion protein (PrP) genotypes of over 250,000 sheep were determined through the operation of the National Scrapie Plan (NSP); the results for 38 breeds were analysed to provide an estimate of the underlying PrP genotype distribution of the British sheep population. Although there was marked variability among the genotype profiles of the different breeds, several trends emerged. A comparison of the allele frequencies demonstrated that the breeds could be grouped into three categories: breeds dominated by ARR and ARQ in which the frequency of ARR exceeded the frequency of ARQ; breeds dominated by ARR and ARQ in which the frequency of ARQ exceeded the frequency of ARR; and breeds with significant levels of either AHQ, ARH or VRQ. Hill breeds were more likely to have a lower proportion of animals at low risk of scrapie (NSP type 1) and a higher proportion of animals at an intermediate risk of scrapie (NSP type 3) than other breeds. Most breeds had a small proportion of animals at high risk of scrapie (NSP type 5). The frequency of ARR/VRQ (NSP type 4) was variable. [ABSTRACT FROM AUTHOR]

Discusses the implementation of genome amplification technology for hepatitis V virus (HCV) RNA detection by the English National Blood Service. Strategy for handling the blood donations; Requirements of the assay; Development of a performance-monitoring system of the process.

Background and Objectives In order to reduce the potential for transmission of hepatitis C virus (HCV) from an RNA-positive, anti-HCV-negative blood donation, the National Blood Service (NBS) introduced nucleic acid amplification technology (NAT) testing for HCV in England and Wales. The objective of this study was to develop an automated assay using commercial components for the detection of HCV RNA in blood donations for transfusion. Materials and Methods The Qiagen QIAamp 96 ‘Viral RNA’ and ‘Virus’ BioRobot kits for HCV RNA extraction, and the Roche COBAS HCV Amplicor v2·0 and AmpliScreen v2·0 assays for polymerase chain reaction (PCR) amplification and detection, were investigated. Results QIAamp technology and the BioRobot 9604 allow automation of the viral RNA extraction process. By combining the automated silica-membrane based QIAamp 96 Virus extraction and automated reverse transcription–polymerase chain reaction (RT–PCR) set-up with COBAS HCV AmpliScreen v2·0 amplification and detection it is possible to achieve a 95% detection level for HCV of 12·8 IU/ml. Cross-contamination studies have shown that use of the BioRobot 9604 does not pose a detectable contamination risk. Between 1999 and 2001, ≈ 6·8 × 106 donations were tested in England and Wales, of which only four were found to contain RNA without anti-HCV. Conclusions This combination of methods results in an assay with a high sample throughput, little ‘hands-on’ time and fast turnaround time that is also sufficiently sensitive to allow testing of pools of up to 96 samples at a time. These methods have been successfully introduced into routine use within the NBS for release of blood components with a shelf-life of longer than 24 h. [ABSTRACT FROM AUTHOR]

Objective: To evaluate short and long term effects of giving nebulised budesonide early in respiratory syncytial viral (RSV) bronchiolitis.Design: A multicentre randomised double blind placebo controlled trial.Subjects: Infants admitted to hospital with their first episode of RSV positive bronchiolitis.Intervention: Randomisation to receive either 1 mg of nebulised budesonide (Bud) or placebo (Pla) twice daily from admission until 2 weeks after discharge. Follow up was for 12 months.Main Outcome Measures: Duration of hospital admission, time taken to become symptom free, re-admission rates, general practitioner consultation rates, and use of anti-wheeze medication during follow up.Results: 161 infants were studied. Both arms were similar with respect to initial clinical severity, age, sex, socioeconomic class, and tobacco exposure. Median time from first nebulisation to discharge: Bud and Pla, 2 days. Median number of days for 50% of infants to be symptom free for 48 hours: Bud, 10 days; Pla, 12 days. Respiratory re-admission rates in the 12 month follow up: Bud, 16%; Pla, 18%; median difference (95% confidence interval (CI)), -2 (-14 to 10). Median respiratory related general practitioner attendances: Bud, 4.0; Pla, 4.5; median difference (95% CI), -1 (-2 to 0). Percentage of infants receiving at least one prescription for anti-wheeze medication during follow up, corticosteroids: Bud, 50%; Pla, 60%; difference (95% CI), -10 (-26 to 6); bronchodilators: Bud, 60%; Pla, 67%; difference (95% CI), -7 (-22 to 8).Conclusions: There are no short or long term clinical benefits from the administration of nebulised corticosteroids in the acute phase of RSV bronchiolitis. [ABSTRACT FROM AUTHOR]

Penicillium chrysogenum spores have been immobilized by adsorption on two grades of wet or dry diatomaceous earth particles, Chromosorb-W and Celite R-633. Almost 90% of the spores were adsorbed within 2 h and those remaining in suspension were removed by washing to minimise the growth of free mycelia. After germination the immobilized biomass was almost independent of the spore loading on the particles and whether or not the spore suspension was added to wet or dry particles. The free biomass obtained was less than 5% of the immobilized biomass. [ABSTRACT FROM AUTHOR]

Hepatitis B virus (HBV) infection occurred despite full passive-active immunoprophylaxis in 20 of 321 infants born to mothers seropositive for hepatitis B e antigen. In 2 (12%) of 17 infected infants, mother-infant DNA sequence mismatches were found in a segment of the HBV S gene coding for antigenic determinants of the HBV surface antigen (HBsAg) amplified from sera by polymerase chain reaction (PCR). Point substitutions occurred in codons 120, 134, and 144 of the HBsAg polypeptide in the variant sequence of 1 infant and in codon 126 in the other; all were missense mutations. Mutant sequences could not be recovered from maternal sera by PCR cloning but were selectively generated using an amplification refractory mutation system. The frequency of potential vaccine escape mutants is therefore low, and these preexist maternally as minor variants. [ABSTRACT FROM PUBLISHER]

A method for inactivating viruses in tissues is reported that does not impair the antigenicity of the Coxsackie virus or of some common tissue antigens, a common problem with standard tissue fixation methods. Tissues can be placed briefly in Betapropiolactone before cryostat sectioning without any adverse effect on preservation or antigen expression. It is suggested that use of Betapropiolactone is applicable to tissues harbouring or exposed to the human immunodeficiency virus (HIV). As betapropiolactone has been reported to be carcinogenic in rodents any potential danger can be avoided by basic simple precautions. [ABSTRACT FROM PUBLISHER]

The small-plaque effect occurs with a wide range of herpesviruses following irradiation with ultraviolet light. The 37 per cent survival (D37) values, or dose required for one lethal hit (e), for herpes simplex, pseudorabies and pigeon herpesviruses in different cells indicate a broad spectrum of host-cell repair capacity. Other DNA-containing viruses such as SV40 and adenoviruses, which also replicate in the cell nucleus, show the small-plaque effect. Ionizing irradiation of herpes simplex virus type 1 (HSV-1) showed but little reduction in plaque-size. [ABSTRACT FROM AUTHOR]

A 9 year old boy developed acute monoarthritis of the left knee concurrent with the appearance of a varicella zoster virus (VZV) rash. Repeated VZV DNA hybridisation of the cells within the synovial fluid and synovial membrane failed to show any evidence of intracellular virus. Virus was isolated from synovial fluid 24 hours after the start of clinical infection but not later. These findings suggest that the mechanism of the arthritis is not due to viral replication inside the swollen joint. [ABSTRACT FROM PUBLISHER]

Over a period of three weeks about 9000 full blood counts were analysed on the Technicon H6000 automated haematology machine. From these, 62 patients were identified who had abnormally high numbers of large unstained white cells; these patients were followed up for evidence of viral infection. Seventeen were either lost to follow up or in chronic renal failure; of the remaining 45 patients, 40 had viral infections, 26 of which were due to Epstein-Barr virus. In the presence of a raised number of large unstained white cells, an IgM test for Epstein-Barr virus is recommended, followed by routine serology when necessary. [ABSTRACT FROM PUBLISHER]

Editorial. Describes the developing role of polymerase chain reaction (PCR) and of other techniques for amplifying nucleic acid sequences. Approaches in different countries to genome detection of established and recently described viruses; Future of microbial screening in blood transfusion.

The current position will be discussed regarding the stage of development of the leading blood screening assays for the detection of vCJD and their relative progress towards production of test with the required sensitivity and specificity. The regulatory process to be introduced for the control and standardisation of the use of these assays is in development, with the associated key step of assigning them to Annex II A classification. The application of commercial Western Blot format assays to the detection of PrPsc in tissue samples is underway in NBS and HPA. The validation and implementation of these methods for human tissues demonstrates the paucity of human material available for use as standards and controls. It is appropriate to use animal material for these validation exercises. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor about an article on viraemia in a primarily isolated anti-HBc donor who seroconverted to anti-HBs following vaccination.

Discusses the progress made in two methods of screening blood supplies. Nucleic acid testing; Pathogen inactivation of blood components.

Responds to inquiries on the serological screening of post-transfusion cytomegalovirus (CMV) infections. Prevention of CMV infections; Leucodepletion for blood components; Patients ar risk of post-transfusion CMV infections.