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Biomedical subjects

A R Gerber

Publications and source records attributed to A R Gerber.

At least 19 recordsLinked to original sources
PubMed1995

Performance of a rapid, on-site human immunodeficiency virus antibody assay in a public health setting.

Rapid, on-site human immunodeficiency virus (HIV) testing has the potential to improve the delivery of prevention services in publicly funded counseling and testing sites. The Single Use Diagnostic System (SUDS) HIV-1 is the only rapid enzyme immunoassay (EIA) approved for diagnostic use in the United States. To evaluate the feasibility of using SUDS in public clinics and to validate the test's performance in a public health laboratory, we conducted blinded SUDS testing on plasma sent for HIV testing. From 19 March through 30 June 1993, 1,923 consecutive samples from a sexually transmitted diseases clinic and an HIV counseling and testing clinic were tested on site with SUDS. Tests done in the first two weeks with a malfunctioning centrifuge n = 402) and those done when there were excessively high temperatures in the laboratory (n = 53) were analyzed separately. Of 1,466 tests, 39 were positive by both SUDS and EIA (with Western blot [immunoblot] confirmation) and 7 were SUDS positive and EIA negative. Western blotting was used as the "gold standard" to adjudicate these discrepancies. There were no SUDS-negative and EIA-positive tests. Compared with that of EIA (with Western blot confirmation), the sensitivity of SUDS was 100% (95% confidence interval, 88.8 to 100%) and the specificity was 99.5% (95% confidence interval, 98.9 to 99.8%). The positive predictive value of SUDS was 88% in the STD clinic and 81% in the HIV counseling and testing clinic. There was a 7.7-fold increase in false positives, from 0.48 to 3.7%, when there was inadequate centrifugation and when the temperature exceeded the manufacturer's recommendations. Rapid, on-site HIV testing by the SUDS assay is feasible and practical in public health settings. The test can be performed accurately, at reasonable cost, and within the time frame of a typical clinic visit. Caution should be used, however, as two conditions adversely affected the accuracy of this test: inadequate specimen preparation and elevated temperature.

AIDS Serodiagnosis↗
PubMed1993

Human immunodeficiency virus counseling, testing, referral, and partner notification services. A cost-benefit analysis.

BACKGROUND: The Centers for Disease Control and Prevention (Atlanta, Ga) annually provides more than +100 million in funding to states, territories, and cities for the provision of human immunodeficiency virus (HIV) counseling, testing, referral, and partner notification (CTRPN) services. Given the size of this expenditure, it is important to consider the net benefits of this program activity. We compared the economic costs and benefits of publicly funded HIV CTRPN services. METHODS: Standard methods for cost-benefit analysis were used. A societal perspective was employed. Major assumptions used in the base-case analysis included the following: (1) without public funding, the HIV CTRPN services would not be provided; (2) for every 100 HIV-seropositive persons identified and reached by CTRPN services, at least 20 new HIV infections are averted; and (3) for every +100 spent on direct and indirect costs of CTRPN services, approximately another +60 is spent on the ancillary costs of alerting people to HIV issues and CTRPN service availability. Sensitivity analyses were performed to explore the robustness of base-case results to these and other changes in model assumptions. RESULTS: Under base-case assumptions, the combined direct, indirect, and ancillary costs of the CTRPN program in 1990 dollars were +188,217,600. At a 6% discount rate, the estimated economic benefits of this expenditure are +3,781,918,000. The resultant benefit-cost ratio is 20.09. Sensitivity analyses showed that the benefit-cost ratio is greater than 1 for all considered cases. CONCLUSIONS: This cost-benefit analysis strongly suggests that publicly funded CTRPN services result in a net economic gain to society.

AIDS Serodiagnosis↗
PubMed1993

Preventive services guidelines for primary care clinicians caring for adults and adolescents infected with the human immunodeficiency virus.

Primary care clinicians caring for persons infected with the human immunodeficiency virus greatly contribute to public health efforts to combat the human immunodeficiency virus/acquired immunodeficiency disease epidemic in the United States. Primary care clinicians can assess the prevention needs of persons infected with the human immunodeficiency virus and ensure that needed prevention services are received.

AIDS Serodiagnosis↗
PubMed1993

Quality of laboratory performance in testing for human immunodeficiency virus type 1 antibody. Identification of variables associated with laboratory performance.

To identify factors that may affect the quality of laboratory performance of human immunodeficiency virus type 1 (HIV-1) antibody testing, the Centers for Disease Control and Prevention Model Performance Evaluation Program surveyed laboratories in 1989 that performed enzyme immunoassay (EIA) and Western blot tests for HIV-1 antibody. Panels of 10 HIV-1-antibody-positive and antibody-negative plasma samples, some of which were duplicates, were mailed to program-participating laboratories. Laboratories were also mailed survey questionnaires to ascertain their laboratory characteristics and testing practices. Using 1988 data, researchers previously found that the overall analytic performance of laboratories performing HIV-1 antibody testing was independently associated with the following: (1) requiring a minimum degree of testing personnel; (2) having written criteria for identifying unsatisfactory specimens; (3) requiring in-house training for testing personnel; (4) having tested more than 10,000 specimens; (5) being identified as an "other" laboratory type; (6) having more than 24 months of testing experience; (7) laboratory uses specific (Abbott) materials for EIA; and (8) testing specimens collected by family-planning clinics. To verify these findings, we performed multivariate analysis on 1989 performance data. For the 1989 EIA analytic sensitivity, significant positive (P < or = .05) associations were detected with having written criteria for identifying unsatisfactory specimens and with having tested more than 10,000 specimens. For the 1989 overall EIA analytic performance, a significant negative (P < or = .05) association was found with using specific (Abbott) EIA materials, and a significant positive (P < or = .05) association was found with having tested more than 10,000 specimens. For Western blot results, the only significant (P < or = .05) associations were for both analytic sensitivity and overall analytic performance and having tested more than 10,000 specimens.

Blotting, Western↗
PubMed1992

Content and design of laboratory report forms for human immunodeficiency virus type 1 antibody testing.

In a pilot study involving proficiency testing for human immunodeficiency virus, markedly diverse and potentially confusing test report forms were encountered among participating laboratories. Therefore, a comprehensive study of human immunodeficiency virus type 1 report forms was conducted from state-licensed testing laboratories in California. Participants analyzed three serum samples of known human immunodeficiency virus type 1 antibody reactivity and reported their results on forms that they would normally submit to clinicians. Report forms from 84 laboratories were evaluated for content, design, and clarity. Differences were found among commercial, hospital, and public health laboratories. The significance of these findings is discussed. This technique also may be applied to evaluate laboratory report form design and content for other diagnostic test results.

AIDS Serodiagnosis↗
PubMed1991

Capacity of US labs to provide TLI in support of early HIV-1 intervention.

We surveyed laboratories to assess their capacity to perform T-lymphocyte immunophenotyping. Of the 1026 respondents, 279 located in 41 states and the District of Columbia performed this type of testing. Most laboratories were located in hospitals, reported a low weekly test volume, and indicated that it took 6-24 weeks for flow cytometer operators to become proficient. Many laboratories appear to have the capacity to perform additional CD4+ cell testing, but training additional operators may be necessary. The paucity of laboratories performing T-lymphocyte immunophenotyping in the public sector may affect referral patterns from that setting.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Quality of laboratory performance in testing for human immunodeficiency virus type 1 antibody. Variables associated in multivariate analyses.

In May 1988, the Centers for Disease Control's Model Performance Evaluation Program (Atlanta, Ga) surveyed 1092 laboratories that performed enzyme immunoassays and Western blot tests for human immunodeficiency virus type 1 antibody on mailed plasma samples of known human immunodeficiency virus type 1 antibody reactivity and that described their laboratory characteristics and testing practices. The study objective was to evaluate the quality of laboratory performance in testing for human immunodeficiency virus type 1 antibody. After identifying relevant variables in univariate analyses, multivariate analyses were performed using stepwise logistic models. Human immunodeficiency virus type 1 antibody test performance was independently associated with analytic variables such as commercial test kit used and with nonanalytic variables such as experience, training, and degree requirements of laboratory personnel. These results validate the importance of nonanalytic variables to the quality of outcomes in laboratory testing.

AIDS Serodiagnosis↗
PubMed1990

An outbreak of non-A, non-B hepatitis associated with the infusion of a commercial factor IX complex during cardiovascular surgery.

An outbreak of non-A, non-B hepatitis was recognized among cardiovascular surgical patients from one hospital in June 1985. Illness was found to be significantly associated with a commercial brand of factor IX complex given to patients because of intraoperative bleeding. A change in the commercial brand of factor IX stocked by the hospital pharmacy had occurred in October 1984 and coincided with the onset of the outbreak. A retrospective study of cardiovascular surgery patients identified 23 cases and 7 probable cases of non-A, non-B hepatitis among patients who had received infusions of brands A and B factor IX complex. Three cases were in brand A recipients and 27 were in brand B recipients. Respective brand-specific attack rates were 5 and 42% (relative risk = 7.7; p less than 2 x 10(-5); chi 2 test). Nineteen of 30 case patients (63%) were jaundiced, including 2 brand A recipients and 17 brand B recipients. Median peak serum aminotransferase was 690.5 IU (range 27-2,824). The incubation period for cases in brand B recipients was a median of 7 weeks (range 2-17 weeks). Prevention of non-A, non-B hepatitis in this population requires adhering to strict indications for the use of clotting factor preparations and avoiding these products when at all possible. Heat treatment of clotting factor products may reduce the risk of viral disease transmission, but certain methods may not inactivate the causative agents of non-A, non-B hepatitis.

Arizona↗
PubMed1989

Shigella dysenteriae type 1 infections in US travellers to Mexico, 1988.

In 1988, the number of Shigella dysenteriae type 1 (Sd1) infections reported in the USA increased five-fold over the annual mean from the previous decade. 44 (94%) of 47 interviewed patients reported recent travel to Mexico; 33 (75%) of these had been tourists to the Yucatan peninsula. 27 patients who had travelled to Mexico were admitted to hospital, of whom 2 had a haemolytic uraemic syndrome; none died. The antimicrobial resistance pattern and plasmid profile of the Yucatan strain were similar to those of the 1969-72 pandemic strain. Antimicrobial resistances and plasmid profiles were different in sporadic Western hemisphere strains. This is the first outbreak of Sd1 among US tourists and it is the largest known outbreak in the Western hemisphere since the early 1970s. The dominant Sd1 strain is similar to that which caused the catastrophic 1969-72 pandemic. Surveillance and control measures have been instituted in the Yucatan peninsula.

Acute Disease↗
PubMed1989

An outbreak of syphilis on an Indian reservation: descriptive epidemiology and disease-control measures.

From January 1983 through January 1985, 88 cases of early adult syphilis and five cases of congenital syphilis were identified among residents of a southwestern Indian reservation. The male-to-female ratio of primary and secondary syphilis cases was 1.7: 1; over 90 per cent of women were of childbearing age. Using community health workers to determine the social circles of infected persons was effective in identifying persons at risk; treatment of partners of infected persons prior to development of seroreactivity contributed to the successful control of this outbreak.

Adolescent↗
PubMed1988

Prior herpes simplex virus type 2 infection as a risk factor for HIV infection.

Antibodies to cytomegalovirus (CMV), Epstein-Barr virus (EBV), and herpes simplex viruses types 1 and 2 (HSV-1, HSV-2) in three sequential serum samples from 62 men who did and 61 men who did not develop human immunodeficiency virus (HIV) infection at the time of the final (third) serum specimen were studied. Antibody titers to CMV, EBV, and HSV-1 did not significantly rise in or differ between men who did or did not get HIV infection. However, we found that 32 (68%) of 47 HIV seroconverters had antibodies to HSV-2 at the time the third specimen was drawn, whereas only 26 (46%) of 57 men who remained HIV seronegative had HSV-2 antibody positivity. Seroconversion to HSV-2 between any two serum specimens was found in 11 (42%) of the 26 HIV seroconverters but in only five (14%) of 35 men who remained HIV seronegative. The association between HSV-2 seropositivity (or seroconversion) and subsequent or concurrent HIV seroconversion remained when we controlled for factors known to influence HIV infection, including age, number of sexual partners, and percentage of sexual acts involving receptive anal intercourse. These serologic studies do not support the role of CMV, EBV, or HSV-1 in HIV infection but do suggest that HSV-2 infection is a risk factor for subsequent or concurrent HIV infection.

Acquired Immunodeficiency Syndrome↗