Performance of an alternative HIV diagnostic algorithm using the ARCHITECT HIV Ag/Ab Combo assay and potential utility of sample-to-cutoff ratio to discriminate primary from established infection

BACKGROUND

The ARCHITECT HIV Ag/Ab Combo assay has a wide dynamic range for determining the sample-to-cutoff ratio (S/CO) values compared to other diagnostic HIV antibody assays.

OBJECTIVES

Determine the performance of an HIV testing algorithm that uses the ARCHITECT combo assay in the clinical setting and explore the utility of the signal-to-cutoff (S/CO) ratio to predict acute HIV-1 infection status.

STUDY DESIGN

A retrospective analysis of clinical samples from a hospital and referral population screened for HIV-1 infection between May 2011 and March 2013. Repeatedly reactive samples were tested using the Multispot HIV-1/HIV-2 rapid test and depending on that result, confirmatory orthogonal testing used the Western blot (WB) for HIV-1, Immunoblot for HIV-2 and nucleic acid amplification testing (NAAT) for HIV RNA.

RESULTS

A total of 21,317 test results were evaluated of which 509 were ARCHITECT repeatedly reactive; of these, 422 were Multispot-reactive only for HIV-1 (413 WB-positive; 9 indeterminate), 4 were Multispot-reactive for both HIV-1 and HIV-2 (one HIV-2 immunoblot-positive with 17 HIV-2 RNA copies/mL) and 83 were Multispot-non-reactive of which 15 were HIV-1 RNA positive and represented acute HIV-1 infection. There was an association among the ARCHITECT S/CO (median; IQR) values for antibody-negative (0.14; 0.11-0.16), acute infection (33; 2.1-76) and established HIV-1 infection (794; 494-1,029) (Kruskal-Wallis, p<0.0001).

CONCLUSIONS

The ARCHITECT combo assay with Multispot confirmation and reserved use of HIV-1 WB, HIV-2 Immunoblot and HIV NAAT for Multispot dual HIV-1/2 infection, and NAAT alone for Multispot-negative specimens, had a suitable test performance for detecting acute and established HIV infection.

ru2hot?: A public health education campaign for men who have sex with men to increase awareness of symptoms of acute HIV infection

OBJECTIVES

Teach HIV-negative men who have sex with men (MSM) symptoms of acute HIV infection (AHI) and direct them to nucleic acid amplification testing (NAAT) though Public Health--Seattle & King County (PHSKC).

DESIGN

Cross-sectional surveys, retrospective database analysis and chart review.

METHODS

Beginning in June 2009, the ru2hot? campaign described AHI symptoms and NAAT. Two preintervention and two postintervention surveys assessed campaign visibility, symptom knowledge, and healthcare-seeking behaviour. Regression analyses evaluated secular trends in case-finding.

RESULTS

366 MSM completed surveys. In survey 4, 23% of 100 men reported seeing the campaign, and 25% knew 'ru2hot?' referred to AHI. From survey 1 to survey 4, the proportion of subjects who knew ≥2 symptoms or that AHI was a 'flu-like' illness was unchanged (61% vs 57%, p=0.6). However, in survey 4, 13 (72%) of 18 subjects who saw the campaign named fever as a symptom of AHI compared with 19 (35%) of 55 subjects who had not seen the campaign (p=0.005). From 9/2003 to 12/2010, 622 (2.2%) of 27 661 MSM tested HIV-positive, and 111 (18%) were identified by the Public Health--Seattle & King County NAAT programme. In terms of the impact of the campaign on case-finding, diagnosis of EIA-negative/NAAT-positive and OraQuick-negative/EIA-positive cases increased from six in 2004 to 20 in 2010 (p=0.01), but postcampaign numbers were unchanged. 23 (51%) of 45 cases identified before and 8 (44%) of 18 cases identified after the campaign reported symptoms at initial testing (p=0.6).

CONCLUSIONS

Although a quarter of MSM surveyed saw the campaign and knowledge of fever (the symptom of emphasis) was high, case-finding was unchanged. Increasing campaign visibility could have had greater impact.

Understanding barriers to routine HIV screening: knowledge, attitudes, and practices of healthcare providers in King County, Washington

OBJECTIVE

In 2006, the Centers for Disease Control and Prevention (CDC) recommended routine HIV screening in healthcare settings for persons between 13 and 64 years old. In 2010, the Washington Administrative Code (WAC) was changed to align testing rules with these recommendations. We designed this survey to ascertain the current state of HIV testing and barriers to routine screening in King County, Washington.

METHODS

Between March 23 and April 16, 2010, a convenience sample of healthcare providers completed an online survey. Providers answered true-false and multiple choice questions about national recommendations and the WAC, policies in their primary clinical settings, and their personal HIV testing practices. Providers were asked to agree or disagree whether commonly reported barriers limited their implementation of routine HIV screening.

RESULTS

Although 76% of the 221 respondents knew that the CDC recommended routine HIV screening for persons regardless of their risk, 99 (45%) providers reported that their primary clinical setting had a policy to target testing based on patient risk factors. Forty-four (20%) providers reported that their primary clinical setting had a policy of routine HIV screening, 54 (25%) reported no official policy, and 15 (7%) did not know whether a policy existed. Only 11 (5%) providers offer HIV testing to all patients at initial visits. When asked about barriers to routine screening, 57% of providers agreed that perception that their patient population is low risk limits the number of HIV tests they perform. Only 26 (13%) providers agreed that concern about reimbursement posed a barrier to testing.

CONCLUSIONS

Most providers participating in this survey continue to target HIV testing, despite knowledge of national recommendations. Efforts are still needed to educate providers and policymakers, clarify the recent WAC revisions, and implement structural changes in order to increase HIV testing in Washington State.

Are there benefits to starting antiretroviral therapy during primary HIV infection? Conclusions from the Seattle Primary Infection Cohort vary by control group

It is controversial whether starting combination antiretroviral therapy (cART) during primary HIV infection (PHI) is beneficial. Subjects in this observational cohort began cART <30 days (group 1: acute treatment, n = 40), 31-180 days (group 2: early treatment, n = 82) or >180 days (group 3: delayed treatment, n = 35) after HIV infection, and were compared with 27 historical and 60 contemporary controls. Time to HIV-related diagnoses did not differ for group 1 (adjusted hazard ratio [aHR] 1.44, P = 0.3) or group 2 (aHR 1.17, P = 0.5) compared with contemporary controls, but it was delayed for both treated groups (aHR 0.38 for group 1, P = 0.01; and aHR 0.28 for group 2, P < 0.0001) compared with historical controls. Although rates of HIV-related diagnoses were similar in acutely treated subjects and contemporary controls, results were confounded by associations between higher CD4 counts, lower HIV RNA levels and delayed disease progression as reasons for deferring treatment. Randomized trials are needed to address benefits of cART during PHI.

Use of a home-use test to diagnose HIV infection in a sex partner: a case report

Background

Home-use HIV tests have the potential to increase testing and may be used by sex partners to inform sexual decision-making. To our knowledge, this is the first report of an individual diagnosed with HIV using a home-use test with a sex partner.

Case presentation

We are conducting a randomized controlled trial of home self-testing for HIV using the OraQuick ADVANCE^® HIV-1/2 Antibody Test on oral fluids. In 2011, a 27-year-old, homeless, Latino man who has sex with men not enrolled in the trial (the case) reported receiving a reactive result from a diverted study kit. When interviewed by study staff, the case reported that, 11 months prior, he had unprotected anal sex with a trial subject without discussing HIV status. Afterwards, the subject asked the case if he would like to test, performed the test, and disclosed the reactive result. The case reported altering his behavior to decrease the risk of HIV transmission to subsequent partners and sought care two months later.

Conclusions

This case demonstrates that home-use HIV tests will be used by sex partners to learn and disclose HIV status and inform sexual decision-making. It also highlights concerns regarding the absence of counseling and the potential for delayed entry into HIV care. Additional research must be done to determine under what circumstances home-use tests can be used to increase awareness of HIV status, how they impact linkage to care among persons newly diagnosed with HIV, and whether they can be safely used to increase the accuracy of serosorting.

HIV intertest interval among MSM in King County, Washington

OBJECTIVES

The authors examined temporal trends and correlates of HIV testing frequency among men who have sex with men (MSM) in King County, Washington.

METHODS

The authors evaluated data from MSM testing for HIV at the Public Health-Seattle & King County (PHSKC) STD Clinic and Gay City Health Project (GCHP) and testing history data from MSM in PHSKC HIV surveillance. The intertest interval (ITI) was defined as the number of days between the last negative HIV test and the current testing visit or first positive test. Correlates of the log(10)-transformed ITI were determined using generalised estimating equations linear regression.

RESULTS

Between 2003 and 2010, the median ITI among MSM seeking HIV testing at the STD Clinic and GCHP were 215 (IQR: 124-409) and 257 (IQR: 148-503) days, respectively. In multivariate analyses, younger age, having only male partners and reporting ≥10 male sex partners in the last year were associated with shorter ITIs at both testing sites (p<0.05). Among GCHP attendees, having a regular healthcare provider, seeking a test as part of a regular schedule and inhaled nitrite use in the last year were also associated with shorter ITIs (p<0.001). Compared with MSM testing HIV negative, MSM newly diagnosed with HIV had longer ITIs at the STD Clinic (median of 278 vs 213 days, p=0.01) and GCHP (median 359 vs 255 days, p=0.02).

CONCLUSIONS

Although MSM in King County appear to be testing at frequent intervals, further efforts are needed to reduce the time that HIV-infected persons are unaware of their status.

Prevalence and impact of minority variant drug resistance mutations in primary HIV-1 infection

Objective

To evaluate minority variant drug resistance mutations detected by the oligonucleotide ligation assay (OLA) but not consensus sequencing among subjects with primary HIV-1 infection.

Design/Methods

Observational, longitudinal cohort study. Consensus sequencing and OLA were performed on the first available specimens from 99 subjects enrolled after 1996. Survival analyses, adjusted for HIV-1 RNA levels at the start of antiretroviral (ARV) therapy, evaluated the time to virologic suppression (HIV-1 RNA<50 copies/mL) among subjects with minority variants conferring intermediate or high-level resistance.

Results

Consensus sequencing and OLA detected resistance mutations in 5% and 27% of subjects, respectively, in specimens obtained a median of 30 days after infection. Median time to virologic suppression was 110 (IQR 62–147) days for 63 treated subjects without detectable mutations, 84 (IQR 56–109) days for ten subjects with minority variant mutations treated with ≥3 active ARVs, and 104 (IQR 60–162) days for nine subjects with minority variant mutations treated with <3 active ARVs (p = .9). Compared to subjects without mutations, time to virologic suppression was similar for subjects with minority variant mutations treated with ≥3 active ARVs (aHR 1.2, 95% CI 0.6–2.4, p = .6) and subjects with minority variant mutations treated with <3 active ARVs (aHR 1.0, 95% CI 0.4–2.4, p = .9). Two subjects with drug resistance and two subjects without detectable resistance experienced virologic failure.

Conclusions

Consensus sequencing significantly underestimated the prevalence of drug resistance mutations in ARV-naïve subjects with primary HIV-1 infection. Minority variants were not associated with impaired ARV response, possibly due to the small sample size. It is also possible that, with highly-potent ARVs, minority variant mutations may be relevant only at certain critical codons.

Demographic processes affect HIV-1 evolution in primary infection before the onset of selective processes

HIV-1 transmission and viral evolution in the first year of infection were studied in 11 individuals representing four transmitter-recipient pairs and three independent seroconverters. Nine of these individuals were enrolled during acute infection; all were men who have sex with men (MSM) infected with HIV-1 subtype B. A total of 475 nearly full-length HIV-1 genome sequences were generated, representing on average 10 genomes per specimen at 2 to 12 visits over the first year of infection. Single founding variants with nearly homogeneous viral populations were detected in eight of the nine individuals who were enrolled during acute HIV-1 infection. Restriction to a single founder variant was not due to a lack of diversity in the transmitter as homogeneous populations were found in recipients from transmitters with chronic infection. Mutational patterns indicative of rapid viral population growth dominated during the first 5 weeks of infection and included a slight contraction of viral genetic diversity over the first 20 to 40 days. Subsequently, selection dominated, most markedly in env and nef. Mutants were detected in the first week and became consensus as early as day 21 after the onset of symptoms of primary HIV infection. We found multiple indications of cytotoxic T lymphocyte (CTL) escape mutations while reversions appeared limited. Putative escape mutations were often rapidly replaced with mutually exclusive mutations nearby, indicating the existence of a maturational escape process, possibly in adaptation to viral fitness constraints or to immune responses against new variants. We showed that establishment of HIV-1 infection is likely due to a biological mechanism that restricts transmission rather than to early adaptive evolution during acute infection. Furthermore, the diversity of HIV strains coupled with complex and individual-specific patterns of CTL escape did not reveal shared sequence characteristics of acute infection that could be harnessed for vaccine design.

Patient acceptance of universal screening for hepatitis C virus infection

BACKGROUND

In the United States, about 70% of 2.9-3.7 million people with hepatitis C (HCV) are unaware of their infection. Although universal screening might be a cost-effective way to identify infections, prevent morbidity, and reduce transmission, few efforts have been made to determine patient opinions about new approaches to screening.

METHODS

We surveyed 200 patients in August 2010 at five outpatient clinics of a major public urban medical center in Seattle, WA, with an 85.8% response rate.

RESULTS

The sample was 55.3% women, median 47 years of age, and 56.3% white and 32.7% African or African-American; 9.5% and 2.5% reported testing positive for HCV and HIV, respectively. The vast majority of patients supported universal screening for HCV. When presented with three options for screening, 48% preferred universal testing without being informed that they were being tested or provided with negative results, 37% preferred testing with the chance to "opt-out" of being tested and without being provided with negative results, and 15% preferred testing based on clinician judgment. Results were similar for HIV screening.

CONCLUSIONS

Patients support universal screening for HCV, even if that screening involves testing without prior consent or the routine provision of negative test results. Current screening guidelines and procedures should be reconsidered in light of patient priorities.

HIV testing in a high-incidence population: is antibody testing alone good enough?

BACKGROUND

The Centers for Disease Control and Prevention recently recommended the expansion of human immunodeficiency virus (HIV) antibody testing. However, antibody tests have longer "window periods" after HIV acquisition than do nucleic acid amplification tests (NAATs).

METHODS

Public Health-Seattle & King County offered HIV antibody testing to men who have sex with men (MSM) using the OraQuick Advance Rapid HIV-1/2 Antibody Test (OraQuick; OraSure Technologies) on oral fluid or finger-stick blood specimens or using a first- or second-generation enzyme immunoassay. The enzyme immunoassay was also used to confirm reactive rapid test results and to screen specimens from OraQuick-negative MSM prior to pooling for HIV NAAT. Serum specimens obtained from subsets of HIV-infected persons were retrospectively evaluated by use of other HIV tests, including a fourth-generation antigen-antibody combination assay.

RESULTS

From September 2003 through June 2008, a total of 328 (2.3%) of 14,005 specimens were HIV antibody positive, and 36 (0.3%) of 13,677 antibody-negative specimens were NAAT positive (indicating acute HIV infection). Among 6811 specimens obtained from MSM who were initially screened by rapid testing, OraQuick detected only 153 (91%) of 169 antibody-positive MSM and 80% of the 192 HIV-infected MSM detected by the HIV NAAT program. HIV was detected in serum samples obtained from 15 of 16 MSM with acute HIV infection that were retrospectively tested using the antigen-antibody combination assay.

CONCLUSIONS

OraQuick may be less sensitive than enzyme immunoassays during early HIV infection. NAAT should be integrated into HIV testing programs that serve populations that undergo frequent testing and that have high rates of HIV acquisition, particularly if rapid HIV antibody testing is employed. Antigen-antibody combination assays may be a reasonably sensitive alternative to HIV NAAT.

Spatial learning of adult rats with fetal alcohol exposure: deficits are sex-dependent

The effects of prenatal alcohol exposure on learning in adult offspring were studied in a spatial task in a T-maze. Male and female Long-Evans rats were selected from litters whose dams had received one of three treatments: alcohol in a liquid diet (35% ethanol-derived calories, 35% EDC), pair-fed nutritional control (0% ethanol-derived calories, 0% EDC) or standard control (lab chow, LC). The task included trial-independent (reference memory) and trial-dependent (working memory) components: subjects were required to make a fixed left-right discrimination, and then to alternate left and right choices to escape water. Prenatal alcohol exposure was associated with a greater number of reference errors for both sexes; only males from the alcohol prenatal treatment group, however, were impaired on the working memory component. These results suggest that prenatal exposure to alcohol can cause behavioral dysfunctions that persist into adulthood. Secondly, the pattern of memory impairments suggests that both sexes may be equivalently damaged in neural areas subserving reference memory, but that males are selectively more vulnerable in neural areas subserving working memory.