Evaluation of dried blood spot protocols with the Bio-Rad GS HIV Combo Ag/Ab EIA and Geenius™ HIV 1/2 Supplemental Assay

Validation of mailed via postal service dried blood spot cards on commercially available HIV testing systems

The demand for HIV testing using dried blood spots (DBS) has increased recently. However, DBS is not an approved sample for HIV testing in Japan. This study examined the validation of HIV testing with DBS, prepared at the laboratory or remotely and mailed via postal service to the laboratory. DBS were punched out from a 5.5 mm diameter circle on filter paper, then eluted with 600 μL of phosphate buffered saline overnight at 4℃, and analyzed by Lumipulse S HIVAg/Ab (LUM). The mean LUM count of DBS was 237.4-times diluted compared to titrated plasma. Repeated sample testing showed that although LUM count of DBS decreased slightly with increase in sample storage time (up to one month), it did not affect the result of HIV testing with DBS. Based on testing of 50 HIV+ confirmed cases and 50 HIV- persons, the estimated sensitivity was 98% (49/50) with a specificity of 100% when the cut-off value is 0.5. The single false negative case was a patient with undetectable viral load over the last 10 years, resulting in a decrease of antibody titer below the cut-off level. In conclusion, although DBS cannot completely replace plasma in HIV testing because the sensitivity was a little lower than that of plasma, it can be potentially useful for a screening test by self-finger-prick and postal service use. This will allow people to receive HIV testing without visiting public health centers.

HIV testing in COVID-19 pandemic and beyond in Japan

In Japan, HIV testing has been offered anonymously and free-of-charge at local public health centers, together with pre- and post-test counseling since 1993. Since then, the number of HIV tests increased steadily to reach a peak in 2008 but has since decreased by 30% during the last decade. The number of tests further decreased in 2020 during the COVID-19 pandemic and steeply by 50% this year compared with the previous year, mostly due to a shift in the workload at these centers to COVID-19-related services. To deal with this decline and thinking beyond the current pandemic, more options for HIV testing are needed, such as self-testing/postal delivery of dried blood spot specimen, a method that is yet to be approved in Japan, in addition to the conventional plasma/serum-based HIV testing.

The feasibility of modified HIV and antiretroviral drug testing using self-collected dried blood spots from men who have sex with men

BACKGROUND

In the US, one in six men who have sex with men (MSM) with HIV are unaware of their HIV infection. In certain circumstances, access to HIV testing and viral load (VL) monitoring is challenging. The objective of this study was to evaluate the feasibility of conducting laboratory-based HIV and antiretroviral (ARV) drug testing, and VL monitoring as part of two studies on self-collected dried blood spots (DBS).

METHODS

Participants were instructed to collect DBS by self-fingerstick in studies that enrolled MSM online. DBS from the first study (N = 1444) were tested with HIV serological assays approved by the Food and Drug Administration (FDA). A subset was further tested with laboratory-modified serological and VL assays, and ARV levels were measured by mass spectrometry. DBS from the second study (N = 74) were only tested to assess VL monitoring.

RESULTS

In the first study, the mail back rate of self-collected DBS cards was 62.9%. Ninety percent of DBS cards were received at the laboratory within 2 weeks from the day of collection, and 98% of the cards had sufficient spots for one assay. Concordance between FDA-approved and laboratory-modified protocols was high. The samples with undetectable ARV had higher VL than samples with at least one ARV drug. In the second study, 70.3% participants returned self-collected DBS cards, and all had sufficient spots for VL assay. High VL was observed in samples from participants who reported low ARV adherence.

CONCLUSIONS

In these studies, MSM were able to collect and provide adequate DBS for HIV testing. The FDA-approved and laboratory-modified testing algorithms performed similarly. DBS collected at home may be feasible for HIV testing, ARV measurement, and monitoring viral suppression.

Evaluation of Rapid Testing Algorithms for Venue-based Anonymous HIV Testing among Non-HIV-Positive Men Who Have Sex with Men, National HIV Behavioral Surveillance (NHBS), 2017

HIV rapid testing algorithms (RTAs) using any two orthogonal rapid tests (RTs) allow for on-site confirmation of infection. RTs vary in performance characteristics therefore the selection of RTs in an algorithm may affect identification of infection, particularly if acute. National HIV Behavioral Surveillance (NHBS) assessed RTAs among men who have sex with men recruited using anonymous venue-based sampling. Different algorithms were evaluated among participants who self-reported never having received a positive HIV test result prior to the interview. NHBS project areas performed sequential or parallel RTs using whole blood. Participants with at least one reactive RT were offered anonymous linkage to care and provided a dried blood spot (DBS) for testing at CDC. Discordant results (RT-1 reactive/RT-2 non-reactive) were tested at CDC with lab protocols modified for DBS. DBS were also tested for HIV-1 RNA (VL) and antiretroviral (ARV) drug levels. Of 6500 RTAs, 238 were RT-1 reactive; of those, 97.1% (231/238) had concordant results (RT-1/RT-2 reactive) and 2.9% (7/238) had discordant results. Five DBS associated with discordant results were available for confirmation at CDC. Four had non-reactive confirmatory test results that implied RT-1 false reactivity; one had ambiguous confirmatory test results which was non-reactive in further testing. Regardless of order and type of RT used, RTAs demonstrated high concordant results in the population surveyed. Additional laboratory testing on DBS following discordant results confirmed no infection. Implementing RTAs in the context of anonymous venue-based HIV testing could be an option when laboratory follow-up is not practicable.

Screening for Human Immunodeficiency Virus Infection by Use of a Fourth-Generation Antigen/Antibody Assay and Dried Blood Spots: In-Depth Analysis of Sensitivity and Performance Assessment in a Cross-Sectional Study

We evaluated the performance of a fourth-generation antigen/antibody (Ag/Ab) assay for detecting HIV-1 infection on dried blood spots (DBS) both in a conventional laboratory environment and in an epidemiological survey corresponding to a real-life situation. Although a 2-log loss of sensitivity compared to that with plasma was observed when using DBS in an analytical analysis, the median delay of positivity between DBS and crude serum during the early phase postacute infection was 7 days. The performance of the fourth-generation assay on DBS was approximately similar to that of a third-generation (antibody only) assay using crude serum samples. Among 2,646 participants of a cross-sectional study in a population of men having sex with men, 428 DBS were found reactive, but negative results were obtained from 5 DBS collected from individuals who self-reported a positive HIV status, confirmed by detection of antiretroviral (ARV) drugs in their DBS. The data generated allowed us to estimate a sensitivity of 98.8% of the fourth-generation assay/DBS strategy in a high-risk population, even including a broad majority of individuals on ARV treatment among those HIV positive. Our study brings additional proofs that DBS testing using a fourth-generation immunoassay is a reliable strategy able to provide alternative approaches for both individual HIV testing and surveillance of various populations.

HIV Testing With and Without a Clinical Consultation Among Men Who Have Sex With Men: A Randomized Controlled Trial

BACKGROUND

Increasing the frequency of HIV testing among men who have sex with men (MSM) maximizes the preventive effect of antiretroviral therapy, by reducing time to diagnosis and treatment.

SETTING

Melbourne Sexual Health Centre, Australia.

METHODS

This randomized controlled trial evaluated whether access to testing, without seeing a clinician would increase testing frequency. MSM attending for HIV testing between July 2014 and April 2015 were randomized in 1:1 ratio to the intervention arm (access to HIV and syphilis testing at 300 pathology centers, without requiring consultations) or the control arm (consultation at every test), without blinding. The primary outcome was the incidence of HIV testing over 12 months.

RESULTS

Of 443 men referred, 422 were randomized, 3 HIV positives at baseline were excluded, and 419 were analyzed. Of 208 control, 202 (97.1%) and 200 (94.8%) of 211 intervention group members were followed to 12 months. The intervention group had 453 tests in 205.6 person-years, incidence rate was 2.2 (95% confidence interval [CI]: 2.0 to 2.4) tests per year. The control group had 432 tests during 204.0 person-years, incidence rate was 2.1 (95% CI: 1.9 to 2.3) tests per year, and incidence rate ratio was 1.04 (95% CI: 0.89 to 1.2; P = 0.63). The annual rate of consultations was as follows: intervention, 1.61 (95% CI: 1.44 to 1.79); controls, 2.12 (95% CI: 1.92 to 2.33); rate ratio, 0.76 (95% CI: 0.65 to 0.88; P = 0.0001). There was no difference in quality of life scores (P = 0.61).

CONCLUSIONS

MSM permitted HIV and syphilis testing outside of clinical consultations did not test more frequently than controls but had 24% fewer consultations, reducing service demand.

TRIAL REGISTRATION

ACTRN12614000760673.

Evaluation of the Bio-Rad Geenius HIV 1/2 Assay as Part of a Confirmatory HIV Testing Strategy for Quebec, Canada: Comparison with Western Blot and Inno-Lia Assays

The rapid confirmatory Bio-Rad Geenius HIV 1/2 assay was evaluated as an alternative to the HIV-1 Western blot (WB) confirmatory assay. A total of 370 retrospective samples collected from 356 patients were tested.

The rapid confirmatory Bio-Rad Geenius HIV 1/2 assay was evaluated as an alternative to the HIV-1 Western blot (WB) confirmatory assay. A total of 370 retrospective samples collected from 356 patients were tested. Sensitivity of the Geenius assay to detect HIV-1 and HIV-2 infections was 100% and 97%, respectively, and that of the WB assay was 86% and 39%, respectively. Geenius reduced the number of indeterminate results by 85% and exhibited a differentiation capacity for HIV-1 and HIV-2 of 100% and 89%, respectively. Three of 10 patients presenting with an early HIV infection (1 to 2 weeks before seroconversion by WB) were positive using Geenius. None of the HIV-negative samples were positive using Geenius or WB. However, 7% and 10% of them were indeterminate with Geenius and WB, respectively, leading to a specificity rate of 93% for Geenius and 90% for WB. Ninety cadaveric samples (54 negative, 23 HIV-1 positive, and 3 HIV-1 indeterminate) were tested with Geenius, leading to a sensitivity of 100%, a specificity of 96%, and an indeterminate rate of 4%. Our results indicate that the Bio-Rad Geenius HIV 1/2 rapid test exhibits better sensitivity to detect HIV-1 infections and better performance than WB to confirm and differentiate between HIV-1 and HIV-2 infections. The performance of this new confirmatory assay to detect early infections, to reduce the rate of indeterminate status, and to confirm HIV-1 infection in cadaveric blood samples makes Geenius a potent reliable alternative to the WB.

Assessment of HIV prevalence among MSM in Tokyo using self-collected dried blood spots delivered through the postal service

BACKGROUND

Men who have sex with men (MSM) are at high risk of HIV infection. However, there are only few data on HIV prevalence in MSM in Japan. The objective of this study was to explore the HIV prevalence in MSM at Shinjuku 2-chome, a well known gay quarter in Tokyo.

METHODS

MSM directly collected the dried blood spot (DBS) self-collection HIV test kit from a drop-in center in Shinjuku 2-chome between August 2015 and December 2016. The participants collected their own blood by finger-prick and anonymously posted the kit to the laboratory. The participants accessed the study website and checked the results of their tests using unique ID and password. DBS was soaked in phosphate buffered saline overnight and the eluted sample was examined by the fourth generation HIV Ag/Ab test of LUMIPULSE (FUJIREBIO INC.), and followed by HISCL (Sysmex Corp.) when the first assay was positive. The result was defined provisionally positive if both were positive.

RESULTS

A total of 1702 HIV test kits were distributed and 1403 DBS were returned (return rate: 82.4%). Since 20.2% of participants collected the test kit more than once, the estimated number of actual test kit users was 1120. Based on the results of the test kit, 34 cases were provisionally diagnosed with HIV. The estimated prevalence was 3.04% (95% confidence interval: 2.03-4.04). Of these 34, 24 (70.6%) were later confirmed to be HIV-positive in the hospital, while the remaining 10 were lost to follow-up. Among the participants, 34.5% received HIV test for the first time. Especially in those aged 20-29, 46.0% were first time HIV testers.

CONCLUSIONS

The prevalence of HIV infection in the study population was 3.04%. The high collection suggested a demand for this type of testing in MSM. The test should be expanded further to difficult-to-reach or hidden populations.

TRIAL REGISTRATION

This study was registered with the University Hospital Medical Information Network Clinical Trial Registry in August 20th, 2015 (Registry number: UMIN000018699 ).

Stability of Human Immunodeficiency Virus Serological Markers in Samples Collected as HemaSpot and Whatman 903 Dried Blood Spots

Dried blood spots (DBS) are frequently used in clinical testing for biosurveillance, infectious disease and confirmatory testing, and clinical trials, particularly for populations in remote areas. The HemaSpot-HF blood collection device (HS) provides an alternative format to the Whatman 903 cards (903) to simplify sample collection and processing. In this study, the performance of the HS was compared to that of the 903 using previously characterized clinical specimens and HIV seroconversion panels known to exhibit markers of early human immunodeficiency virus (HIV) infection. HS and 903 samples were prepared and tested by Bio-Rad GS HIV Combo Ag/Ab enzyme immunoassay (EIA), GS HIV-1/-2 Plus O EIA, GS HIV-1 Western blot, and HIV-1 Geenius assays. Both HS and 903 performed well for up to 6 months at room temperature, but a marked loss of Western blot and low titer antibody signals from early infection samples was observed in samples stored for 180 days at elevated (37 to 45°C) temperatures and high humidity (95%). HemaSpot samples placed in sealed bags with additional desiccant were protected from degradation and showed improved signal recovery relative to that of the 903. HS was easier to use than the 903 and showed higher sensitivity and reproducibility for early infection samples and improved stability.