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Biomedical subjects

A E Williams

Publications and source records attributed to A E Williams.

At least 37 records · Page 2Linked to original sources
PubMed2001

Knowledge of HIV/AIDS transmission and screening in United States blood donors.

BACKGROUND: Increased knowledge of HIV transmission and behavioral and test screening may encourage high-risk blood donors to self-defer. STUDY DESIGN AND METHODS: Knowledge of HIV transmission and screening and the association with demographics, screening test reactivity, and unreported deferrable risks (UDRs) was assessed by a 1998 anonymous mail survey sent to 92,581 blood donors, of whom 57 percent responded. Groups were compared by using weighted chi-square tests and logistic regression analysis. RESULTS: Four percent of the donors thought that it was very likely or somewhat likely for a person to contract HIV from donating blood, and 20 percent perceived a similar risk from blood transfusion. Only 60 percent of the donors knew that the available screening tests may not detect a recent infection. Thirty-seven percent either did not know or felt it was acceptable to donate blood to obtain HIV testing. Those most likely to answer knowledge questions incorrectly were more likely to have a higher prevalence of test reactivity or UDRs and to be <or=25 years old, members of a minority, less educated, non-US-born, or first-time donors. CONCLUSION: Innovative ways to increase donor understanding of the implications of risk behaviors and the limitations of current screening procedures should be developed. They might prevent high-risk individuals from donating blood.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Aortic body chemodectoma causing pulmonary oedema in a cat.

A seven-year-old male domestic shorthaired cat was presented with persistent dyspnoea. Thoracic radiography and echocardiography revealed pulmonary oedema and a mass at the base of the heart. At necropsy the mass was found to be an aortic body chemodectoma that had metastasised to the sternal lymph node. This is a rare tumour in the cat, the third reported case where there was evidence of metastasis, and only the second reported case where there was evidence of lymphocytic infiltration of the primary tumour. Pulmonary oedema is an unusual presentation of this tumour in the cat.

Animals↗
PubMed2001

What do patients attending HIV and GUM outpatient clinics want from service providers? Results from a large-scale consultation exercise in west London.

Our objectives were to understand patient demographic profiles, experiences of care and opinions about services. A questionnaire survey of 202 HIV patients and 389 genitourinary medicine (GUM) outpatients attending clinics during one week in 1999 was undertaken at a clinical directorate of HIV/GUM in west London. HIV and GUM patients differed by age (over 30: 84% vs 39%), sex (male: 88% vs 51%), and attendance (attended 6+ times: 55% vs 14%). Most indicated that they were satisfied with the general standard of care (97% HIV patients vs 95% GUM patients). Several clinic features were rated essential. When indicating reasons they might leave in the future, HIV patients were more likely to select leading edge care factors, such as lack of up-to-date treatment (54%). More GUM patients selected factors relating to convenience, such as waiting times (58%). In conclusion, most HIV and GUM patients were satisfied with their care, but differing experiences and opinions need to be addressed when planning services.

Adult↗
PubMed2001

Unexpected deaths in young New Zealand white rabbits (Oryctolagus cuniculus).

Five weeks after the arrival of a batch of six New Zealand White rabbits for use in antisera production, four died unexpectedly within a 48-h period. Necropsy findings showed a consistent pattern of liver pathology in all animals, with multiple miliary abscesses in all liver lobes. Of the remaining two animals in the cohort, one showed weight loss, mild jaundice, and ascites, and the other rabbit had only weight loss. The differential diagnosis for these unexpected deaths included parasitic and bacterial infections. Histopathologic examination of the liver confirmed a diagnosis of hepatic coccidiosis. The possible origin of the coccidia responsible for this outbreak is discussed.

Animals↗
PubMed2000

Trends in incidence and prevalence of major transfusion-transmissible viral infections in US blood donors, 1991 to 1996. Retrovirus Epidemiology Donor Study (REDS)

CONTEXT: Evaluating trends in blood donor infectious disease rates is essential for monitoring blood supply safety and donor screening effectiveness. OBJECTIVE: To determine changes over time in blood donor population infection rates of human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV), hepatitis C virus (HCV), and hepatitis B virus (HBV). DESIGN: Cross-sectional survey data from the National Heart, Lung, and Blood Institute-sponsored Retrovirus Epidemiology Donor Study. SETTING: Five blood centers in different regions of the United States. PARTICIPANTS: A total of 1.9 million volunteer blood donors with 1 or more nonautologous donations from January 1991 to December 1996. MAIN OUTCOME MEASURES: Changes in rates of HIV, HTLV, HCV, and HBV infections were evaluated by comparing yearly prevalence estimates (per 100,000 donations) for first-time allogeneic donors and period-specific incidence rates (IRs) (per 100,000 person-years) for repeat allogeneic donors between 1991 and 1996 (for HCV, from about March 1992 to June 1996). RESULTS: Prevalence of HIV decreased in first-time donors from 0.030% to 0.015% (P=.006) and HCV prevalence decreased from 0.63% to 0.40% (P<.001). Trends were not statistically significant for the proportion of first-time donors with hepatitis B surface antigen (HBsAg) or HTLV. For repeat donors, IRs did not change significantly, indicating a stable but low level of seroconversion. The overall IRs (95% confidence intervals) per 100,000 person-years were 2.92 (2.26-3.70) for HIV, 1.59 (1.12-2.19) for HTLV, 3.25 (2.36-4.36) for HCV, and an estimated 10.43 (7.99-13. 37) for HBV (based on an HBsAg rate of 2.66 [2.04-3.41] with presumed false-positive results considered negative). The HBV IR estimate with presumed false-positive results considered positive (for comparability to previous analyses) was 17.83 (14.60-21.56). CONCLUSION: The decrease in HIV and HCV prevalence rates, combined with the previously documented lower rates of infection in first-time donors compared with the general population, suggests the continued benefit of behavioral risk factor screening. JAMA. 2000;284:229-235

Blood Banks↗
PubMed2000

Risk factors for hepatitis C virus infection in United States blood donors. NHLBI Retrovirus Epidemiology Donor Study (REDS)

Injection drug use (IDU) is a known risk factor for hepatitis C virus (HCV) infection, but the strength of other parenteral and sexual risk factors is unclear. In 1997, we performed a case-control study of 2,316 HCV-seropositive blood donors and 2,316 seronegative donors matched on age, sex, race/ethnicity, blood center, and first-time versus repeat-donor status. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated using conditional logistic regression. Questionnaires were returned by 758 (33%) HCV(+) and 1,039 (45%) control subjects (P =.001). The final multivariate model included only the following independent HCV risk factors: IDU (OR = 49.6; 95% CI: 20.3-121.1), blood transfusion in non-IDU (OR = 10.9; 95% CI: 6.5-18.2), sex with an IDU (OR = 6.3; 95% CI: 3.3-12.0), having been in jail more than 3 days (OR = 2.9; 95% CI: 1.3-6.6), religious scarification (OR = 2.8; 95% CI: 1.2-7. 0), having been stuck or cut with a bloody object (OR = 2.1; 95% CI: 1.1-4.1), pierced ears or body parts (OR = 2.0; 95% CI: 1.1-3.7), and immunoglobulin injection (OR = 1.6; 95% CI: 1.0-2.6). Although drug inhalation and a high number of lifetime sex partners were significantly more common among HCV seropositives, they were not associated with HCV after controlling for IDU and other risk factors. IDU, blood transfusion among non-IDU, and sex with an IDU are strong risk factors for HCV among United States blood donors. Weaker associations with incarceration, religious scarification, being stuck or cut with a bloody object, pierced ears or body parts, and immunoglobulin injection must be interpreted with caution.

Adult↗
PubMed2000

Information provision to cancer patients: a practical example of identifying the need for changes in practice from the Dorset Cancer Centre.

The aim of this study was to produce a patient-centred information strategy based on the results of a local survey of cancer patients about the information they receive and their information needs. An anonymous patient survey was distributed at the Dorset Cancer Centre, Poole Hospital, the regional cancer centre for Dorset, in the South-west of England. All patients attending the Cancer Centre during 1 week in September 1999 were asked to complete a questionnaire on patient experience of the Cancer Centre, information sources, receipt and quality of Centre information, and perception of information requirements. Two hundred and eighty-two were returned. Most respondents had accessed information from a number of sources. Written Cancer Centre information had been given to most patients, and was generally perceived to be useful, understandable and timely. However, most patients had received information 'all at once', from a single professional group, and a notable proportion did not recall discussing it with staff. Furthermore, most patients indicated that information should also be provided to families and professionals. Seven items of information were selected as valuable by the majority of patients, with many others listed. There was a great deal of satisfaction with the current content of the patient information provided. However, the distribution system was shown to be in need of improvement. A new information strategy has been developed in the light of these findings.

Attitude to Health↗
PubMed2000

Infectious disease markers in young blood donors. Retrovirus Epidemiology Donor Study.

BACKGROUND: To evaluate whether the active recruitment of young donors of high school and college age could affect the safety of the blood supply, prevalence and incidence rates of infectious disease markers among donors aged 17 to 18 and 19 to 22 were compared to those in donors 23 years of age and older. STUDY DESIGN AND METHODS: Over 15 percent of 4.97 million whole blood donations were collected from donors aged 17 to 18 and 19 to 22. Prevalence (per 100,000 first-time donors) and incidence (per 100,000 person-years) rates for confirmed infectious diseases were compared between age groups. RESULTS: The prevalence estimates for HIV, HCV, HTLV-I and -II, and serologic tests for syphilis (STS) were significantly lower among first-time donors aged 17 to 18 and 19 to 22 than among those 23 to 44 years of age. HBsAg prevalence was higher in the first-time donors in the younger groups than in first-time donors in the older group because of higher prevalences among Asians and blacks. The incidence rates of HIV, HCV, and HTLV were similar in the younger groups and the older group. Donors 19 to 22 years of age had a higher incidence rate of estimated HBV than did donors aged 23 to 44 and 45+ (p<0.001), but the incidence rate of STS was lower in donors aged 17 to 18 and 19 to 22 than in donors 23 to 44 and 45+ years of age (p<0.001). CONCLUSION: Aggressive recruitment of school-age donors should not result in an increased risk of transmission-transmitted infections, with the possible exception of HBV.

Adolescent↗
PubMed2000

Surveillance of HIV-1 genetic subtypesand diversity in the US blood supply.

BACKGROUND: Recent reports of variant (non-subtype B) HIV infections in US populations have raised concerns about the sensitivity of subtype B virus-based donor screening and diagnostic assays. This study was designed to determine the prevalence and genetic diversity of HIV subtypes in US blood donors over the last two decades. STUDY DESIGN AND METHODS: Three groups were studied: hemophiliacs infected by clotting factor concentrates in the early 1980s (n = 49), blood donors retrospectively identified as being seropositive in 1985 (n = 97), and blood donors identified as seropositive between 1993 and 1996 (n = 405). Subtype assignment was based primarily on heteroduplex mobility analysis (HMA) of HIV-1 env, with DNA sequence confirmation of selected specimens. HIV peptide-based EIA serotyping was used to rule out HIV-2 and group O infections and to serotype HMA-refractory specimens. RESULTS: Of 551 specimens, 535 (97%) were assigned subtypes; 532 (99%) of these were subtype B. Three postscreening donations (1%) were assigned non-B subtypes (2 A, 1 C). Two of these three donors were born in Africa; the third was born in the United States and reported no risk factors other than heterosexual activity. HMA distribution plots showed an increase in env diversity among HIV-1 group B strains over time. CONCLUSION: The results support the need for continued surveillance of HIV subtype diversity and ongoing validation of the sensitivity of HIV diagnostic assays to non-B subtype infections.

Blood Donors↗
PubMed2000

Validation of selected donor-screening questions: structure, content, and comprehension.

BACKGROUND: Donor questioning is an integral component of blood safety, designed to identify and interdict donors considered to be at elevated risk of transfusion-transmissible infection. Questions are frequently added to this screening procedure, but they are rarely evaluated for comprehension. STUDY DESIGN AND METHODS: Seven American Red Cross blood donor history questions were selected for evaluation. Focus groups were conducted using individuals from high school/college, church, business, and other sources, who had never donated blood. Both sexes and various age and racial groups were represented. The donation process and regulatory requirements or guidelines were explained. Participants were asked to consider 1) content, 2) clarity 3) likelihood of asking for more information, 4) suggestions for improvement, and 5) how a need for clarifying information would best be met. RESULTS: Constructive, helpful, and consistent comments obtained might be utilized in revising questions. CONCLUSION: Focus group discussions can be useful in providing guidance for developing screening questions that can be easily understood.

Adult↗
PubMed1999

'Putting the pressure on': a study of compression sleeves used in breast cancer-related lymphoedema.

Breast cancer-related lymphoedema is a chronic, progressive condition characterized by swelling in the arm and adjacent trunk, with changes to the skin and underlying tissues. The application of compression garments is an essential component in the long-term management of lymphoedema. A wide range of garments is available in the UK; however, there is limited literature to guide therapists in their appropriate selection. This paper reviews the effects of compression therapy, outlines the components of lymphoedema treatment, and discusses features of lymphoedema compression sleeves. A small study of nine women with breast cancer-related lymphoedema is reported. The study investigates the interface pressure profiles of a selection of commonly used compression sleeves as measured by the Oxford Pressure Monitor. The results showed a wide variation in the interface pressures for all sleeves. A graduated profile along the length of the arm was not always present, Two layers of garments led to markedly increased pressures at the top of the arm but the pressures along the arm did not double. The possible implications for clinical practice are discussed.

Aged↗
PubMed1999

Absence of human T-lymphotropic virus type I tax sequences in a population of normal blood donors in the Baltimore, MD/Washington, DC, area: results from a multicenter study.

BACKGROUND: It was reported recently that sequences corresponding to the human T-lymphotropic virus type I (HTLV-I) tax gene were detected in peripheral blood mononuclear cells from 8 to 11 percent of healthy blood donors without detectable antibodies to HTLV-I. A multicenter blind study was conducted to determine if these results could be independently confirmed. STUDY DESIGN AND METHODS: Specimens were collected from 100 anti-HTLV-I-negative healthy blood donors and from 11 anti-HTLV-I- or anti-HTLV-II-positive individuals. All samples were coded and distributed to each of four independent testing laboratories for polymerase chain reaction analysis to detect sequences of the HTLV-I or HTLV-II tax gene, using detailed procedures specified by the laboratory reporting the original observation. Each laboratory also tested a dilution panel of a plasmid containing HTLV-I tax to determine the analytical sensitivity of the procedure. RESULTS: The analytical sensitivity of the screening methods permitted detection of as few as 1 to 10 copies of the tax gene. However, HTLV-I tax sequences could not be detected in any of the anti-HTLV-I-negative blood donors at more than one test site. CONCLUSION: HTLV-I tax sequences appear not to be present in this population of 100 blood donors negative for anti-HTLV-I.

Adult↗
PubMed1999

Predictive value of past and current screening tests for syphilis in blood donors: changing from a rapid plasma reagin test to an automated specific treponemal test for screening.

BACKGROUND: This study evaluated the change from a rapid plasma reagin (RPR) test to an automated specific treponemal test (PK-TP) in screening for syphilis in blood donors. STUDY DESIGN AND METHODS: A cross-sectional seroprevalence analysis was performed on 4,878,215 allogeneic blood donations from 19 American Red Cross Blood Services regions from May 1993 through September 1995. Positive predictive values relative to the confirmatory fluorescent treponemal antibody absorption test (FTA-ABS) were calculated. Differences in seroprevalence were compared in RPR and PK-TP tests for 1) unconfirmed and confirmed tests, 2) first-time and repeat donors, and 3) "recent" versus "past" infections. Donation data from three additional Red Cross regions were evaluated for repeat donation patterns of blood donors who had a donation that was positive in a serologic screening test for syphilis. The value of RPR and PK-TP tests as surrogate markers for HIV infection was compared. RESULTS: Reactive rates were lower but the positive predictive values was higher for the PK-TP test than for the RPR test. Initially, donors screened by PK-TP were more likely to be confirmed as positive than were donors screened by RPR, but these rates became comparable. It is estimated that a single HIV window-period donation was removed by serologic testing for syphilis each year of this study period. CONCLUSIONS: The change to the PK-TP test resulted in a lower repeatedly reactive rate, better prediction that a confirmed-positive test for syphilis would occur in testing in the FTA-ABS, fewer donations lost, and comparable deferral rates. Because of the high rate of reactivity to serologic testing for syphilis among donors previously confirmed positive for syphilis, indefinite deferral after a confirmed-positive index donation may be warranted. Serologic testing for syphilis is ineffective as a marker of HIV-infectious window-period donations.

Antibody Specificity↗
PubMed1998

Assessment of motivations for return donation among deferred blood donors. American Red Cross ARCNET Study Group.

BACKGROUND: The recent addition of a computerized donor deferral registry to American Red Cross blood donation procedures has enabled blood center staffs to identify, before donation, persons who attempt to donate despite previous deferral. The current study investigated reasons that deferred donors return to donate, despite having been notified that they are ineligible. STUDY DESIGN AND METHOD: Anonymous mail surveys requesting demographic information, details of last donation or attempted donation, and assessments of incentives for donating were sent to 311 donors presenting inappropriately at blood drives and 849 matched controls in three American Red Cross regions between April and July 1996. RESULTS: Responses were received from a total of 113 deferred donors and 388 matched controls. Analysis of the 49 permanently deferred donors indicated that they were more likely than controls to donate blood to receive test results or to be awarded community service credit. Responses also revealed that some deferred donors may return to donate blood because of a misunderstanding of the deferral message or erroneous recruitment by blood center staff. CONCLUSION: There is a need before donation for the provision of educational materials regarding the window period of infection and for careful consideration of the use of incentives to attract donors to blood centers. It is also important to provide to donors a clear and consistent message regarding their test results and deferral status.

Altruism↗
PubMed1998

Identification and characterization of an HIV-2 antibody-positive blood donor in the United States.

BACKGROUND: As of June 1, 1992, the Food and Drug Administration recommended that all donated blood be screened for antibodies specific to HIV-2. Despite broad serologic surveillance, only two cases of HIV-2 infection had been detected among potential blood and plasma donors since the implementation of the test. CASE REPORT: The identification of a third HIV-2 antibody-positive blood donor is reported. The first-time donor was identified by routine screening procedures as anti-HIV-1/HIV-2-reactive, and that status was confirmed by licensed HIV-1 Western blot. Concurrent whole-virus lysate enzyme immunoassay and Western blot for HIV-2 were strongly positive, but the possibility of HIV-1 cross-reactivity could not be eliminated. The donor was notified, counseled, and deferred from future donation. He subsequently enrolled in a Centers for Disease Control and Prevention-sponsored epidemiologic study of HIV-positive former donors. When it was revealed during the standardized interview that he was a native of an HIV-2-endemic region, follow-up samples were submitted to the Centers for Disease Control and Prevention. Investigational HIV-1 and HIV-2 peptide enzyme immunoassays indicated that this infection was due to HIV-2 only. CONCLUSION: Enzyme immunoassays for antibodies to synthetic peptides of HIV-1 and HIV-2 may be useful in differentiating the two viruses in individuals with ambiguous Western blot results and risk factors for HIV-2 infection.

Adult↗
PubMed1998

Demographic characteristics, unreported risk behaviors, and the prevalence and incidence of viral infections: a comparison of apheresis and whole-blood donors. The Retrovirus Epidemiology Donor Study.

BACKGROUND: The demographics, deferrable risk behaviors, and the prevalence and incidence of viral infections of apheresis (PH) and whole-blood (WB) donors were compared, to characterize these two populations and to evaluate the relative safety of PH and WB donors in terms of transfusion-transmitted viral infections. STUDY DESIGN AND METHODS: A comparison was made of 36,119 PH donors (> or = 1 PH donation) and 1.38 million WB donors (> or = 1 WB donation) in terms of demographics and the prevalence (/100,000 donors) and incidence (/100,000 person-years) of viral infections, by using data collected at five United States blood collection centers between 1991 and 1994. Deferrable risk behaviors were defined as those risk behaviors that would have resulted in donor deferral, had they been reported. The prevalence of deferrable risk behaviors was estimated by using data collected through an anonymous mail survey. RESULTS: PH donors were older and more likely than repeat (2+ donations) WB donors to be female, white, and United States-born and to have a higher degree of education (p < or = 0.001). The prevalence of any viral infection was 50 percent higher in WB donors than in PH donors (p = 0.04), whereas the incidence of HIV, human T-lymphotropic virus, and hepatitis B surface antigen was nonsignificantly higher in WB donors. The prevalence of deferrable risk behaviors did not differ in the two groups. CONCLUSION: Further studies will be needed to evaluate whether the difference in the prevalence of viral infections observed in this study can be explained by demographic characteristics and patterns of donation frequency.

Blood Component Removal↗