Plasma HIV viral load testing is the preferred means of monitoring antiretroviral treatment response. Dried blood spots (DBSs) hold considerable logistical advantages over EDTA samples, but they more frequently misclassify virological failure and have higher limits of detection (LoD). Plasma separation cards (PSCs) may overcome these limitations. Health workers collected EDTA whole blood by venipuncture and 140 μl of finger-prick blood by capillary tube from 53 HIV-infected adults. Capillary blood was immediately transferred to PSCs. Additionally, 432 EDTA samples from HIV-infected adults were spotted onto PSCs and analyzed together with the finger-prick samples. Specificity and sensitivity of PSC with paired EDTA-PSC samples tested on a cobas 6800/8800 system with the cobas HIV-1 test (cobas HIV) was determined. LoD (3rd HIV-1 WHO International Standard) and stability at a range of temperatures and storage durations was determined using cobas HIV and cobas AmpliPrep/cobas TaqMan HIV-1 test v2.0 (CAP/CTM). Of 132 specimens with quantitative values for paired EDTA-PSC samples, the mean log10difference between samples was 0.05 copies/ml (95% confidence interval [CI], −0.01 to 0.11). The LoD for cobas HIV was 790.2 copies/ml and for CAP/CTM was 737.9 copies/ml. At 1,000 copies/ml, PSC sensitivity was 97.0% (128/132) and specificity was 97.2% (343/353). Results correlated well with those from EDTA samples (DemingR2= 0.90). PSC results were unaffected by temperature and storage conditions. PSC samples correlate well with plasma viral load and have adequate sensitivity and specificity. The improved performance may be as a result of a reduction in contribution from cell-associated viral nucleic acids. The card provides an alternative sample collection technology to DBSs.

We compared the analytical and clinical performance of cobas® CT/NG for use on the Cobas® 6800/8800 Systems with the Cobas® 4800 CT/NG Test from urogenital and extragenital specimens in over 12,000 specimens from both male and female subjects in Germany and the United States. The analytical sensitivity was ≤40 EB/ml for Chlamydia trachomatis (CT) and ≤1 CFU/ml for Neisseria gonorrhoeae (NG). Using clinical specimens, the overall percent agreement with the Cobas® 4800 CT/NG Test was >98.5%. Across urogenital specimens, there were 93 discrepant specimens; 76 (93.8%) of 81 CT discrepant specimens were 6800+/4800– and 10 (83.3%) of 12 NG discrepant specimens were 6800+/4800–. Sequencing verified CT results for 45 (61.6%) of 73 samples positive by 6800 and 1 (20%) of 5 positive by 4800. Similarly, 7 (70.0%) of 10 NG samples positive by 6800 and 1 of 2 positive by 4800 were confirmed by sequencing. Among discrepant extragenital specimens (all 6800+/4800–), 7 (50%) of 14 oropharyngeal and 23 (76.7%) of 30 anorectal CT discordant samples were confirmed as CT positive by sequencing; all 8 anorectal and 20 (90.9%) of 22 oropharyngeal NG discordant results were also confirmed as NG positive. In conclusion, Cobas® CT/NG for use on the Cobas® 6800/8800 Systems provides high-throughput automated solutions for sexually transmitted infection (STI) screening programs.

eThe use of nucleic acid detection for HIV type 1 (HIV-1) detection is strongly recommended in infants <18 months of age, in whom serology is unreliable. This study evaluated the Cobas AmpliPrep/Cobas TaqMan HIV-1 Qualitative Test v2.0 (TaqMan HIV-1 Qual Test, v2.0), a dual-target total nucleic acid real-time PCR assay. The limit of detection (LOD) of the new test in plasma and dried blood spots (DBS) was determined with the 2nd International HIV-1 RNA WHO standard. The specificity of the assay was tested with EDTA plasma (n ‫؍‬ 1,301) and DBS from HIV-negative adults (n ‫؍‬ 1,000). The sensitivity was determined using HIV-1-positive samples (n ‫؍‬ 169 adult EDTA plasma, n ‫؍‬ 172 adult DBS, and n ‫؍‬ 100 infant DBS) that included group M, subtypes A to H, CRF01_AE, CRF02_AG, and groups O and N. All positive specimens and a subset of the negative specimens were also tested with the Abbott RealTime HIV-1 Qual assay (RealTime). The LOD of the TaqMan assay was 20 copies/ml in plasma and 300 copies/ml in DBS, with specificities of 99.8% in plasma and 99.9% in DBS. The TaqMan . Although access to early infant diagnosis of HIV is improving, in 2011 only 35% of infants born to HIV-positive mothers were tested within 2 months of birth (1). The Joint United Nations Programme on HIV/AIDS (UNAIDS) call for action has set new targets for 2020, the first of which is for 90% of those infected with HIV to know their status. Improved assays like the one evaluated in this study should assist in increasing access to HIV diagnosis, particularly in a vulnerable pediatric population that requires nucleic acid-based testing (2). Transmission of HIV occurs through sexual contact, exposure to infected blood products (3), and vertical mother-to-child transmission (4). For many infected infants, the progression of AIDS is rapid, and thus, early antiretroviral therapy is crucial for survival. In a randomized, controlled clinical trial in South Africa, it was demonstrated that early HIV diagnosis and early antiretroviral therapy could reduce early infant mortality by 76% and slow HIV progression by 75% (5). Access to HIV testing and early confirmation of a pediatric infection are thus critical for immediate access to treatment and care programs. Nucleic acid testing is particularly important for early diagnosis of infants Յ18 months of age. In this population, serologic tests are unreliable for the identification of true virologic status, because passively transferred maternal HIV type 1 (HIV-1) antibodies may be detectable in the HIV-exposed infant for up to 18 months of life (6) or longer in some instances (7). Thus, the World Health Organization (WHO) strongly recommends that HIV virological testing be used to diagnose HIV infections in infants and children below 18 months of age (8). The regions that are most severely affected by the HIV epidemic, such as sub-Saharan Africa, are often faced with severe resource constraints limiting access to virological testing. The difficulties of cold-chain transfer of collected blood samples from ...

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Background: Nucleic acid amplification tests (NATs) minimize the time from HIV infection to diagnosis, reducing transmission during acute HIV. NATs are especially useful for diagnosing HIV in children younger than 18 months and discriminating between HIV-1 and HIV-2. Methods: We evaluated the performance of the cobas HIV-1/HIV-2 qualitative (cobas HIV-1/2 Qual) test for use on cobas 6800/8800 Systems. The results of adult plasma and serum samples and pediatric dried blood spots were compared with those of the recomLine HIV-1 & HIV-2 Immunoglobulin G serological test and COBAS AmpliPrep/COBAS TaqMan HIV-1 qualitative test, v2.0. Genotype inclusivity and limits of detection were determined, and sensitivity on seroconversion panels was compared with that in the Bio-Rad Geenius HIV 1/2 Confirmatory Assay, Abbott ARCHITECT HIV Ag/Ab Combo serological test, and cobas TaqScreen MPX, v2.0. Results: Concordance of cobas HIV-1/2 Qual test with the comparator serological test and COBAS AmpliPrep/COBAS TaqMan test was ≥99.6% with all sample types. Reactivity with all HIV genotypes was 100%. LOD in plasma samples was 14.8, 12.6, and 27.9 copies/mL for HIV-1 group M, HIV-1 group O, and HIV-2, respectively, with similar results for serum samples. LOD in dried blood spots was 255 copies/mL for HIV-1 and 984 copies/mL for HIV-2. HIV infection was detected 18.9 days and 8.5 days earlier than the confirmatory and serological assays, respectively, and at a similar time to the NAT. Conclusions: The cobas HIV-1/2 Qual test enables early and accurate diagnoses of HIV-1 and HIV-2 in adults and children across sample types. The assay could help avert transmission during acute HIV, simplify HIV diagnostic algorithms, and promote the survival of HIV-infected children.