Multilaboratory Evaluation of Real-Time PCR Tests for Hepatitis B Virus DNA Quantification

The performance characteristics of four different assays for hepatitis B virus (HBV) quantification were assessed: the Abbott RealTime HBV IUO, the Roche Cobas AmpliPrep/Cobas TaqMan HBV test, the Roche Cobas TaqMan HBV test with HighPure system, and the Qiagen artus HBV TM ASR. Limit of detection (LOD), linear range, reproducibility, and agreement were determined using a serially diluted plasma sample from a single chronically infected subject. Each assay was tested by at least three laboratories. The LOD of the RealTime and two TaqMan assays was approximately 1.0 log10 IU/ml; for artus HBV (which used the lowest volume of extracted DNA), it was approximately 1.5 log10 IU/ml. The linear range spanned 1.0 to at least 7.0 log10 IU/ml for all assays. Median values were consistently lowest for artus HBV and highest for Cobas AmpliPrep/Cobas TaqMan HBV. Assays incorporating automated nucleic acid extraction were the most reproducible; however, the overall variability was minor since the standard deviations for the means of all tested concentrations were ≤0.32 log10 IU/ml for all assays. False-positive results were observed with all assays; the highest rates occurred with tests using manual nucleic acid extraction. The performance characteristics of these assays suggest that they are useful for management and therapeutic monitoring of chronic HBV infection

Detection of Fastidious Vaginal Bacteria in Women with HIV Infection and Bacterial Vaginosis

Background. Fastidious bacteria have been associated with bacterial vaginosis (BV) using PCR methods. We assessed the prevalence of these bacteria in HIV-1 infected women and their relationship with vaginal pH and shedding of HIV-1 RNA. Methods. 64 cervicovaginal lavage (CVL) samples were collected from 51 women. Vaginal microbiota were characterized using 8 bacterium-specific quantitative PCR assays. Results. Women with the fastidious bacteria Bacterial Vaginosis Associated Bacterium (BVAB) 1, 2, and 3 showed a trend to increased HIV-1 shedding (OR 2.59–3.07, P = .14–.17). Absence of Lactobacillus crispatus (P < .005) and presence of BVAB2 (P < .001) were associated with elevated vaginal pH. BVAB1, 2, and 3 were highly specific indicators of BV in HIV-infected women, with specificities of 89%–93%. Conclusions. Fastidious bacteria (BVAB 1, 2, and 3) remain specific indicators of BV in HIV-infected women, and BVAB2 may contribute to the elevated vaginal pH that is a hallmark of this syndrome

Maintaining Life-saving Testing for Patients With Infectious Diseases: Infectious Diseases Society of America, American Society for Microbiology, and Pan American Society for Clinical Virology Recommendations on the Regulation of Laboratory-developed Tests

In 2014, the US Food and Drug Administration (FDA) proposed to regulate laboratory-developed tests (LDTs)-diagnostics designed, manufactured, and used within a single laboratory. The Infectious Diseases Society of America, the American Society for Microbiology, and the Pan American Society for Clinical Virology recognize that the FDA is committed to protecting patients. However, our societies are concerned that the proposed regulations will limit access to testing and negatively impact infectious diseases (ID) LDTs. In this joint commentary, our societies discuss why LDTs are critical for ID patient care, hospital infection control, and public health responses. We also highlight how the FDA's proposed regulation of LDTs could impair patient access to life-saving tests and stifle innovation in ID diagnostics. Finally, our societies make specific recommendations for the FDA's consideration to reduce the burden of the proposed new rules on clinical laboratories and protect patients' access to state-of-the art, quality LDTs

Use of dietary supplements among people living with HIV/AIDS is associated with vulnerability to medical misinformation on the internet

<p>Abstract</p> <p>Background</p> <p>Use of dietary supplements is common among people living with HIV/AIDS. Because dietary supplements are used in the context of other health behaviors, they may have direct and indirect health benefits. However, supplements may also be associated with vulnerability to medical misinformation and unfounded health claims. We examined use of dietary supplements among people living with HIV/AIDS (PLWH) and the association between use of dietary supplements and believing medical misinformation.</p> <p>Methods</p> <p>A convenience sample of 268 men and 76 women living with HIV was recruited from AIDS services and clinics in Atlanta, GA. Participants completed measures of demographic and health characteristics, dietary supplement use, beliefs about dietary supplements, internet use, and an internet evaluation task designed to assess vulnerability to medical misinformation.</p> <p>Results</p> <p>One out of four PLWH currently used at least one dietary supplement product excluding vitamins. Dietary supplement use was associated with higher education and greater use of the internet for health-related information. Dietary supplement users also endorsed greater believability and trust in unfounded claims for HIV cures.</p> <p>Conclusions</p> <p>Dietary supplement use is common among PLWH and is associated with a broad array of health information seeking behaviors. Interventions are needed to reduce the vulnerability of PLWH, particularly dietary supplement users, to medical misinformation propagated on the internet.</p

Indeterminate and discrepant rapid HIV test results in couples' HIV testing and counselling centres in Africa

<p>Abstract</p> <p>Background</p> <p>Many HIV voluntary testing and counselling centres in Africa use rapid antibody tests, in parallel or in sequence, to establish same-day HIV status. The interpretation of indeterminate or discrepant results between different rapid tests on one sample poses a challenge. We investigated the use of an algorithm using three serial rapid HIV tests in cohabiting couples to resolve unclear serostatuses.</p> <p>Methods</p> <p>Heterosexual couples visited the Rwanda Zambia HIV Research Group testing centres in Kigali, Rwanda, and Lusaka, Zambia, to assess HIV infection status. Individuals with unclear HIV rapid antibody test results (indeterminate) or discrepant results were asked to return for repeat testing to resolve HIV status. If either partner of a couple tested positive or indeterminate with the screening test, both partners were tested with a confirmatory test. Individuals with indeterminate or discrepant results were further tested with a tie-breaker and monthly retesting. HIV-RNA viral load was determined when HIV status was not resolved by follow-up rapid testing. Individuals were classified based on two of three initial tests as "Positive", "Negative" or "Other". Follow-up testing and/or HIV-RNA viral load testing determined them as "Infected", "Uninfected" or "Unresolved".</p> <p>Results</p> <p>Of 45,820 individuals tested as couples, 2.3% (4.1% of couples) had at least one discrepant or indeterminate rapid result. A total of 65% of those individuals had follow-up testing and of those individuals initially classified as "Negative" by three initial rapid tests, less than 1% were resolved as "Infected". In contrast, of those individuals with at least one discrepant or indeterminate result who were initially classified as "Positive", only 46% were resolved as "Infected", while the remainder was resolved as "Uninfected" (46%) or "Unresolved" (8%). A positive HIV serostatus of one of the partners was a strong predictor of infection in the other partner as 48% of individuals who resolved as "Infected" had an HIV-infected spouse.</p> <p>Conclusions</p> <p>In more than 45,000 individuals counselled and tested as couples, only 5% of individuals with indeterminate or discrepant rapid HIV test results were HIV infected. This represented only 0.1% of all individuals tested. Thus, algorithms using screening, confirmatory and tie-breaker rapid tests are reliable with two of three tests negative, but not when two of three tests are positive. False positive antibody tests may persist. HIV-positive partner serostatus should prompt repeat testing.</p

The Third International Consensus Guidelines on the Management of Cytomegalovirus in Solid-organ Transplantation

Despite recent advances, cytomegalovirus (CMV) infections remain one of the most common complications affecting solid organ transplant recipients, conveying higher risks of complications, graft loss, morbidity, and mortality. Research in the field and development of prior consensus guidelines supported by The Transplantation Society has allowed a more standardized approach to CMV management. An international multidisciplinary panel of experts was convened to expand and revise evidence and expert opinion-based consensus guidelines on CMV management including prevention, treatment, diagnostics, immunology, drug resistance, and pediatric issues. Highlights include advances in molecular and immunologic diagnostics, improved understanding of diagnostic thresholds, optimized methods of prevention, advances in the use of novel antiviral therapies and certain immunosuppressive agents, and more savvy approaches to treatment resistant/refractory disease. The following report summarizes the updated recommendations

First reported case of vertebral osteomyelitis due to Erysipelothrix rhusiopathiae

We describe a case of acute vertebral osteomyelitis with associated prevertebral abscess due to Erysipelothrix rhusiopathiae in an immunocompetent adult with recent known traumatic inoculation from the barb of a fish

Reproducibility of Positive Test Results in the BDProbeTec ET System for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

Nucleic acid amplification tests such as the BDProbeTec ET (BDPT) system are more prone to reproducibility problems than are antigen detection tests and culture. A repeat testing algorithm for all samples with method other than acceleration (MOTA) scores greater than or equal to the cutoff value (2,000) was developed for the BDPT system and applied in a clinical laboratory setting. All positive samples were retested, and if the result of the second test was below the cutoff value, a third test was performed to resolve the discrepancy. Overall, 11 (5.3%) of 207 samples initially positive for Chlamydia trachomatis and 11 (10.7%) of 103 samples initially positive for Neisseria gonorrhoeae were not confirmed by repeat testing of the original sample. Poor reproducibility was associated with low-positive MOTA scores (2,000 to 9,999) for both analytes. Only 21 (80.8%) of 26 low-positive samples in the C. trachomatis test and 4 (33.3%) of 12 low-positive samples in the N. gonorrhoeae test retested as positive. The reproducibility of both tests with samples with initial MOTA scores of ≥10,000 increased to 96.7%. The data suggest that retesting of low-positive samples is warranted and could reduce the number of potentially false-positive test results

Performance Characteristics of a Quantitative TaqMan Hepatitis C Virus RNA Analyte-Specific Reagent

We determined the dynamic range, reproducibility, accuracy, genotype bias, and sensitivity of the TaqMan hepatitis C virus (HCV) analyte-specific reagent (ASR). Serum samples were processed using the MagNA Pure LC instrument and run on the COBAS TaqMan 48 analyzer. The performance characteristics of the ASR were also compared with those of the qualitative AMPLICOR and quantitative AMPLICOR MONITOR HCV tests. The ASR exhibited a ≥6-log(10) linear dynamic range and excellent reproducibility, with a mean coefficient of variation of 14%. HCV RNA concentration measured with the ASR agreed within an average of 0.42 log(10) (2.6-fold) of the labeled concentration with members of a standard reference panel. HCV genotypes 1 to 4 were amplified with similar efficiencies with the ASR. The ASR and AMPLICOR MONITOR viral load results were significantly correlated (r = 0.8898; P < 0.01), but the agreement was poor (mean difference, 0.45 ± 0.35 log(10)) for 72 HCV RNA-positive clinical samples. However, 98.9% agreement between the ASR and qualitative AMPLICOR test results was found with 60 positive and 29 negative samples. Limiting-dilution experiments demonstrated that the limits of detection for ASR and AMPLICOR tests were 84 and 26 IU/ml, respectively. The performance characteristics of the TaqMan HCV ASR are appropriate for all clinical applications of HCV RNA testing