Ultra HIV Research Articles

Prospective Laboratory Evaluation of the cobas Plasma Separation Card for HIV and Treponema pallidum Antibody Analysis.

The cobas Plasma Separation Card (PSC; Roche Diagnostics) was developed for HIV viral load testing. This study evaluates the performance of HIV and Treponema pallidum (Tp) antibody (Ab) detection on PSCs as an alternative to dried blood spots (DBSs). EDTA whole blood samples were collected from HIV-positive (n = 100), HIV-negative (n = 50), Tp-positive (n = 100), and Tp-negative patients (n = 50) and spotted on DBS and PSC. Antibody detection performance was evaluated for HIV Ab using the Genscreen ULTRA HIV Ag-Ab test (Bio-Rad) and for Tp Ab using the Syphilis Total Ab test (Bio-Rad). Plasma was used as a reference specimen. Receiver operating characteristic curve analysis for DBS and PSC generated areas under the curve (AUC + 95% confidence interval) of 0.985 (0.960-1.000) and 0.987 (0.973-1.000) for HIV Ab and 1.000 (1.000-1.000) and 0.996 (0.983-1.000) for Tp Ab, respectively. Receiver operating characteristic areas under the curve were not significantly different between DBS and PSC for HIV or TP Ab. At selected cutoff values rendering at least 99% sensitivity for HIV Ab detection, the specificity was 96% on DBS and 68% on PSC. For Tp Ab detection at 90% sensitivity, 100% specificity is reached on both DBS and PSC (exceeding the required 95%). However, the median quantitative HIV and Tp Ab signal of positive samples significantly decreased in PSC compared with DBS and plasma. Although receiver operating characteristic analysis does not seem to indicate significant differences in performance between DBS and PSC, the significant reduction in quantitative Ab detection signal dictates card composition optimization before its use for HIV and Tp Ab detection can be advised.

Assessment of the Accuracy, Usability and Acceptability of a Rapid Test for the Simultaneous Diagnosis of Syphilis and HIV Infection in a Real-Life Scenario in the Amazon Region, Brazil

We field-assessed the accuracy, acceptability, and feasibility of the SD BIOLINE HIV/Syphilis Duo rapid diagnostic test in three groups: pregnant women, female sex workers (FSW), and men who have sex with men (MSM). Venous blood samples collected in the field were compared with the respective gold standard methods: SD BIOLINE HIV/Syphilis Duo Treponemal Test versus FTA-abs (Wama brand) treponemal laboratory test for syphilis, and SD BIOLINE HIV/Syphilis Duo Test versus the fourth generation Genscreen Ultra HIV Ag-Ag (Bio-Rad brand) laboratory test for HIV. From a total of 529 participants, 397 (75.1%) were pregnant women, 76 (14.3%) FSW and 56 (10.6%) MSM. Sensitivity and specificity parameters of HIV were 100.0% (95% CI: 82.35-100.0%) and 100.0% (95% CI: 99.28-100.0%), respectively. Sensitivity and specificity parameters found for TP antibody detection were 95.00% (95% CI: 87.69-98.62%) and 100.0% (95% CI: 98.18-100.0%), respectively. The SD BIOLINE HIV/Syphilis Duo Test showed high acceptability among participants (85.87%) and health professionals (85.51%), as well as easy usability by professionals (91.06%). The usability of the SD BIOLINE HIV/Syphilis Duo Test kit would not be a barrier to accessing rapid testing, if the product were incorporated into the list of health service supplies.

Increased risk of false-positive HIV ELISA results after COVID-19.

From the first-generation options available in 1985, tests to detect HIV-1 specific antibodies have increased its sensitivity and specificity. HIV-1 and SARS-CoV-2 surface glycoproteins present a certain degree of homology and shared epitope motifs, which results of relevance as both pandemics coexist. Here, we aimed to evaluate the rate of false-positive HIV serology results among individuals with COVID-19 diagnosis and in vaccinated individuals. A retrospective analysis of the samples stored at the Infectious Disease Biobank in Argentina from donors with previous COVID-19 diagnosis or anti-SARS-CoV-2 vaccination. Plasma samples were analyzed using Genscreen Ultra HIV Ag-Ab. In those with a positive result, the following assays were also performed: ELISA lateral flow Determine Early Detect; RecomLine HIV-1 & HIV-2 IgG and Abbott m2000 RealTime PCR for HIV-1 viral load quantification. In all samples, the presence of anti-SARS-CoV-2 IgG antibodies was evaluated by ELISA using the COVIDAR kit. Statistical analysis was done using Pearson's and Fisher's exact chi-squared test; Mann-Whitney and Kruskal-Wallis tests. Globally, the false-positive HIV ELISA rate was 1.3% [95% confidence interval (95% CI) 0.66-2.22; χ2 = 4.68, P = 0.03, when compared with the expected 0.4% false-positive rate]. It increased to 1.4% (95% CI 0.70-2.24, χ2 = 5.16, P = 0.02) when only samples from individuals with previous COVID-19 diagnosis, and to 1.8% (95% CI 0.91-3.06, χ2 = 7.99, P = 0.005) when only individuals with detectable IgG SARS-CoV-2 antibodies were considered. This higher occurrence of HIV false-positive results among individuals with detectable antibodies against Spike SARS-CoV-2 protein should be dispersed among virology testing settings, health providers, and authorities.

Laboratory-Based Evaluation of SD Bioline HIV/Syphilis Duo Rapid Test Kits in the Gambia, November 2019

Background: HIV and syphilis are mainly diagnosed using separate rapid test kits for the HIV counseling and testing (HCT), Prevention of Mother-to-Child Transmission of HIV (PMTCT) and other clinical requests in healthcare facilities in The Gambia, as recommended in the HIV testing management guidelines. The goal of this study was to evaluate the performance of SD Bioline HIV/ Syphilis Duo as a single test kit used for the simultaneous detection of HIV & Syphilis antibodies in the laboratory setting. Methods: We determined the sensitivity, specificity, positive and negative predictive values of SD Bioline HIV/Syphilis Duo kits in terms of HIV screening against the GenScreen Ultra HIV Ag-Ab ELISA (Lot 9D0126) using a total of 100 HIV negative and 150 HIV positive serum/plasma specimens that were stored at -20°C. Subtyping of the HIV positive specimens was previously performed using First Response HIV-1/2 test cards and Western Blot assays respectively. Moreover, the SD Bioline HIV/Syphilis Duo kit sensitivity, specificity, positive and negative predictive values in relation to Syphilis screening of 100 specimens was also determined against Treponema Pallidum Heamagglutination Assay (TPHA). Results: In terms of HIV screening (n=250), the sensitivity, specificity, positive and negative predictive values of the SD Bioline HIV/Syphilis Duo Test Kits were 100%, 100%, 100%, and 100% respectively when compared with the GenScreen Ultra HIV Ag-Ab ELISA results in the laboratory setting. Sensitivity for Syphilis screening (n=100) was 95.65%, whilst specificity was 100% when compared with TPHA. Positive predictive value was 100%, whilst the negative predictive value was 98.86%. Conclusions: These findings show that the SD Bioline HIV/Syphilis Duo kits have high sensitivity and specificity when used for the detection of HIV and Syphilis antibodies using human serum and/or plasma. Therefore, these kits could serve as a good alternative for the dual elimination of mother-to-child transmission (e-MTCT) HIV and Syphilis through a one-step timely diagnostic procedure, which is crucial in reducing the turnaround time of laboratory test results.

Laboratory-based Evaluation of Wondfo HIV1/2 Rapid Test Kits in the Gambia, December 2020

Background: HIV rapid diagnosis in The Gambia is mainly done using Determine HIV-1/2 and First Response HIV 1.2.0 or SD Bioline HIV-1/2 3.0 for screening and sero-typing of HIV respectively among children and adults. Polymerase Chain Reaction (PCR) is used for the detection of the HIV viral genome among infants born to HIV positive mothers. This is the HIV testing Algorithm recommended in the HIV testing guidelines of The Gambia for both HIV Counseling and Testing (HCT), Prevention of Mother-to-Child Transmission of HIV (PMTCT) as well as other clinical requests for HIV testing. At the National Public Health Reference Laboratories (NPHRL), ELISA is the first line of testing for HIV while First Response HIV 1.2.0 or SD Bioline HIV 1/2 3.0 is used for preliminary serotyping. MP Diagnostics HIV Blot 2.2 Western Assay, which is the gold standard for HIV testing in The Gambia, is used as the tie breaker (i.e., when there are discordant results). The aim of this study was to evaluate the sensitivity and specificity of the Wondfo HIV 1/2 rapid test kit for the detection of human antibodies to HIV in serum/plasma/whole blood and dried blood spots. Methods: The sensitivity, specificity, positive and negative predictive values of Wondfo HIV 1/2 kits were evaluated in terms of HIV screening against Determine HIV1/2, GenScreen Ultra HIV Ag-Ab ELISA and First Response HIV 1.2.0 using a total of 401 samples. Of these, 351 were sera/plasma samples {100 HIV negative, 250 HIV positive and 1 indeterminate that were stored at -20°C, 26 were whole blood samples (4 negative, 22 positive), and 24 were dried blood spot (DBS) specimens (16 negative and 8 positive) were used for this evaluation. HIV positive specimens were previously sero-typed using First Response HIV-1.2.0 test cards and MP Diagnostics HIV Blot 2.2 Western Assay. Results: The evaluation shows that the sensitivity, specificity, positive and negative predictive values of Wondfo HIV 1/2 Test Kits with regards to HIV Screening when compared with the GenScreen Ultra HIV Ag-Ab ELISA and First Response 1.2.O (n=401) were 100%, 100%, 100%, and 100% respectively. Similarly, the sensitivity, specificity, positive and negative predictive values of Wondfo HIV 1/2 Test Kits with regards to HIV Screening compared to Determine HIV1/2 (n=401) were 99.64%, 100%, 100%, and 99.17% respectively. Conclusions: This study demonstrates that Wondfo HIV 1/2 test kits have a high sensitivity and specificity when used for the detection of HIV antibodies using human serum/plasma, whole blood or DBS.

Blood Safety: On-Site Verification Of The Screening Of HIV, HBV And HCV By Enzyme Linked Immuno-Sorbent Assay (ELISA) Kits From Bio-Rad Laboratories At The “Centre National De Transfusion Sanguine” (CNTS) Of Lomé In Togo

Background: Blood transfusion improves health and saves lives. Safe blood must be ensured for our populations. Quality assurance is a process that includes a set of coordinated activities in order to achieve the quality objective. Compliance with the quality management rules of medical biology laboratories requires verification of methods prior to their use. This study aimed to verify the on-site verification of the performance of the Enzyme Linked Immuno-Sorbent Assay (ELISA) method performed at the serology laboratory of the CNTS of Lomé. Methods: The performance of ELISA method performed at the serology laboratory of CNTS for the diagnosis of HIV, Hepatitis B and C with Bio-Rad Genscreen ULTRA-HIV Ag-Ac, Bio-Rad Monolisa-HBs Ag ULTRA and Bio-Rad Monolisa HCV Ag-Ac ULTRA V2 kits respectively was evaluated on repeatability, reproducibility, sensitivity and specificity according to COFRAC's SH GTA 04 reference. Results: The evaluation of the repeatability and reproducibility of each kit used in the laboratory resulted in compliant Coefficients of Variation (CV) with manufacturers’ ones. Sensitivities obtained with Bio-Rad Monolisa HCV Ag-Ac ULTRA V2, Bio-Rad Monolisa HBs Ag ULTRA and Bio-Rad Genscreen ULTRA HIV Ag-Ac kits were 94.59%, 98.08% and 100% respectively. For specificity tests, we found 86.49% with BIO-Rad Genscreen ULTRA-HIV Ag-Ac kit, 94.34% with Bio-Rad Monolisa HCV Ag-Ac ULTRA V2 kit and 97.37% with Bio-Rad Monolisa-HBs Ag ULTRA. Conclusion: In general, results were compliant except HIV diagnosis specificity. This study appears as a contribution to the establishment of a verification file for ELISA method used at the serology laboratory of CNTS of Lomé.

Detection of HIV-1 and -2 Antibodies among Children and Knowledge, Attitude, Perceptions and Practices (KAPP) of Their Parents in Port Harcourt, Nigeria

Aim: Paediatric testing for HIV in low-income and middle-income countries is poor and must be raved up as this is important for treatment and survival among this disease-prone demographic area. This study was carried out to detect the presence of HIV-1 and -2 antibodies among children receiving health care service in the University of Port Harcourt Teaching Hospital (UPTH), Port Harcourt, Rivers State, Nigeria. It also aimed to assess the knowledge, attitude, perceptions and practices of their parents on HIV/AIDS in Port Harcourt, Nigeria.
 Study Design: Cross-sectional study.
 Place and Duration of Study: University of Port Harcourt Teaching Hospital (UPTH) in Port Harcourt, Nigeria, between August 2012 and July 2015.
 Methods: One hundred subjects (58 males and 42 females) were used in this study. Blood samples were collected randomly from children in the outpatient department of the hospital. HIV-1/2 was detected using Gen ScreenTM ULTRA HIV Ag-Ab Kit (BIO-RAD), an ELISA based test kit following the manufacturer's instructions.
 Results: The overall prevalence was found to be 5.0%. The gender-specific infection rate shows that males had a higher infection rate (5.2%) for HIV infection than their female counterparts (4.8%). The age-specific prevalence showed that the children in age groups 8-10 years had a higher prevalence (6.7%) than those 2-4 years (4.5%) and 5-7 years (4.2%). None appeared to be significantly associated (P>0.05) with HIV-1/2 antibodies prevalence among the children population. The knowledge, attitude, perceptions and practices of parents of the children indicate that 100.0% of them believed HIV/AIDS is real and children live with it; 62.0% have been screened for HIV before while 38.0% have not; 77.0% believe HIV cannot be cured while 19.0% believe it can; 66.0% know that it can be transmitted from mother to child whereas 16.0% believe it cannot and 70.0% confirmed they share sharp objects.
 Conclusion: This study however further confirmed the presence of HIV-1 and 2 antibodies among Children in Port Harcourt, Nigeria. HIV can affect all age groups, both males and females. Health education campaigns and training on HIV prevention and control is recommended.

COMPARATIVE EVALUATION OF THE 4TH GENERATION ELISA/CLIA ASSAYS USED FOR THE DIAGNOSIS OF HIV INFECTION IN THE RUSSIAN FEDERATION

The aim of the work was to compare the five most widely used ELISA diagnostic kits on the territory of the Russian Federation, which are used for screening for HIV infection.Materials and methods. 5442 samples from visitors of diagnostic centers who came for blood donation for non-infectious analyses, cohorts with a high risk of HIV infection, as well as patients with potentially interfering conditions were used as a material for the study. Additionally, seroconversion panels and a panel of viral diversity were used to evaluate the analytical characteristics. The following test systems were compared: Architect HIV Ag/Ab Combo (Abbott), Genscreen Ultra HIV Ag-Ab (Bio-Rad), CombiBest HIV-1,2 AG/AT (Vector-Best), DS-ELISA-HIVAGAT-SCREEN (Diagnostic Systems), HIV-1,2-AG/AT (Medical-Biological Union).Conclusion. The diagnostic sensitivity of all tests was 100% with the exception of one (Medical-Biological Union), in which it turned out to be 99,54%. Diagnostic specificity ranged from 99,58% to 99,89%, but unexpectedly strongly depended on the test population, decreasing on a group with a high risk of HIV infection to 93,26% (Vector-Best). The convergence between initial and repeat reactive samples ranged from 100% (Abbott) to 89,51% (Vector-Best). The results of the analysis of seroconversion panels showed that the tests differed slightly from each other, receiving positive results from 22,12% (Diagnostic Systems) to 27,88% (Abbott) samples. When testing the panel of viral diversity, diagnostic tests from foreign manufacturers showed better results, revealing 100% (Abbott) and 85,9% (Bio-Rad). The smallest number of panel samples was detected by the kit of the Medical-Biological Union (52,1%). This work is the only study where the 4th generation ELISA kits, widely used in the Russian Federation for screening for HIV infection, were compared in an extensive sampling. The results obtained make it possible to evaluate the effectiveness of the use of the listed kits in routine diagnostic practice.

Prevalence of HIV in a Cohort of Pregnant Women Attending a Tertiary Hospital in Ibadan, Nigeria

HIV/AIDS is one of the major barriers to community development. It is a global pandemic with high prevalence rates worldwide. This research was carried out to determine the prevalence of HIV among pregnant women attending the antenatal clinic at the University College Hospital, Ibadan using Enzyme Linked Immunosorbent Assay (ELISA) Gen Screen TM ULTRA HIV Ag-Ab Kit. HIV prevalence was found to be 26.4%. A total of 91 samples were tested, 24 (26.4%) were found to be positive and 67 (73.6%) negative. Women between the ages 25 – 31 had the highest prevalence rate of 16.5% while those between the ages of 39 – 45 years had the least prevalence rate of 1.1%. The results revealed a relatively high prevalence rate for HIV among pregnant women which suggests the need for active surveillance and implementation of preventive measures to avoid further spread of the virus. Pregnant women need to be continually tested for HIV and those infected monitored closely to prevent mother to child transmission.

Diagnostic accuracy of HIV test kits, Genscreen Ultra and Bioelisa.

PurposeGenetic diversities in different countries affect the performance of HIV test kits. Therefore, WHO recommends evaluation of every HIV test kit in countries’ context before its use. Therefore, this study aimed to evaluate the performance of Genscreen ULTRA HIV Ag–Ab and Bioelisa.Materials and methodsThe study had used 400 characterized plasma samples obtained from CDC Atlanta bio-bank derived from Africa, USA, and Thailand.ResultsDiagnostic performance of both test kits under evaluation was assessed at 95% CI. Genscreen ULTRA HIV Ag–Ab had sensitivity and negative predictive value of 99.5% [95% CI, 97.2–99.9] and the specificity and positive predictive value of 98.5% [95% CI, 95.7–99.7]. Bioelisa HIV test kit had exhibited sensitivity and negative predictive value of 99% [95% CI, 96.4–99.7] and specificity and positive predictive value of 98.5% [95% CI, 95.7–99.7]. Both test kits were able to detect almost all samples with HIV-2, dual infections, and seroconversion.ConclusionBoth the test kits were highly sensitive and specific in detecting HIV. However, there are still few samples containing HIV antibody which were not identified by both kits. Therefore, additional screening measures should be done in using these assays for blood transfusion and organ transplantation. In addition, the study can be used as a reference by other African countries.

Field accuracy of HIV rapid diagnostic tests for blood donors screening, Bukavu, Eastern Democratic Republic of the Congo.

Rapid diagnostic tests (RDTs) are widely used for point-of-care. point-of-care diagnosis of HIV infection in resource-limited settings. However, there are no data about their field diagnostic performance in Eastern Democratic Republic of the Congo (DRC), especially in the context of blood banks screening for transfusion safety purpose. Blood specimens were collected from blood donors in Bukavu, Eastern DRC, from May the 1st to June the 30th, 2015, to evaluate the accuracy of Alere Determine HIV-1/2, Trinity Biotech Uni-Gold HIV, and DoubleCheckGold Ultra HIV 1 and 2 compared to the laboratory-based 4th generation ELISA apDia HIV Ag/Ab assay. Sensitivity, specificity, positive and negative predictive values, and related 95% confidence intervals were calculated using MedCalc statistical software version 15.1. Reliability was evaluated using Cohen's Kappa Statistic, K. Among 312 participants who provided blood bags, 96/312 (30.7%) were female and the mean age (SD) was 31.7 years (±8.1 years). Sensitivity for the three tests was 57.1% (95% CI: 18.4-90.1). The specificity was 99.7% (95% CI: 18.4-90.1) for Alere Determine HIV 1/2, 100% (95% CI: 98.8-100.0) for Uni-Gold HIV, and (100% (95% CI: 98.8-100.0) for DoubleCheckGold Ultra HIV 1 and 2. Cohen's Kappa Statistic showed moderate agreement between the 4th generation ELISA apDia HIV Ag/Ab and RDTs Alere Determine HIV 1/2 and Uni-Gold HIV (K = 0.66; 95% CI: 0.55-0.76) but good agreement for DoubleCheckGold Ultra HIV 1 and 2 (K = 0.72; 95% CI: 0.61-0.82). Compared to the laboratory-based ELISA apDia HIV Ag/Ab assay, the currently used 3rd generation HIV RDTs showed poor field accuracy results in a context of blood donors screening. These data support the need for 4th generation Ag-Ab RDTs in transfusion blood qualification.

HIV rapid diagnostic testing by lay providers in a key population-led health service programme in Thailand

Introduction: Rapid diagnostic testing (RDT) for HIV has a quick turn-around time, which increases the proportion of people testing who receive their result. HIV RDT in Thailand has traditionally been performed only by medical technologists (MTs), which is a barrier to its being scaled up. We evaluated the performance of HIV RDT conducted by trained lay providers who were members of, or worked closely with, a group of men who have sex with men (MSM) and with transgender women (TG) communities, and compared it to tests conducted by MTs.Methods: Lay providers received a 3-day intensive training course on how to perform a finger-prick blood collection and an HIV RDT as part of the Key Population-led Health Services (KPLHS) programme among MSM and TG. All the samples were tested by lay providers using Alere Determine HIV 1/2. HIV-reactive samples were confirmed by DoubleCheckGold Ultra HIV 1&2 and SD Bioline HIV 1/2. All HIV-positive and 10% of HIV-negative samples were re-tested by MTs using Serodia HIV 1/2.Results: Of 1680 finger-prick blood samples collected and tested using HIV RDT by lay providers in six drop-in centres in Bangkok, Chiang Mai, Chonburi and Songkhla, 252 (15%) were HIV-positive. MTs re-tested these HIV-positive samples and 143 randomly selected HIV-negative samples with 100% concordant test results.Conclusion: Lay providers in Thailand can be trained and empowered to perform HIV RDT as they were found to achieve comparable results in sample testing with MTs. Based on the task-shifting concept, this rapid HIV testing performed by lay providers as part of the KPLHS programme has great potential to enhance HIV prevention and treatment programmes among key at-risk populations.

Syphilis and HIV infections among pregnant women attending antenatal clinics in Republic of Congo.

IntroductionHIV and syphilis during pregnancy remain a public health concern especially in developing countries. Pregnant women attending antenatal clinics sites for the first time between September and December 2011 and who accepted to participate in the study were enrolled. The objective was to estimate the syphilis and HIV infection rate in this population.MethodsA study was conducted in 44 selected ANCs from 12 departments (5 urban and 7 rural). Pregnant women who accepted to participate in the study, attending selected sentinel ANCs sites for the first time between September and December 2011 were enrolled. To detect HIV antibodies, two consecutive ELISA assays were used (Genscreen Ultra HIV Ag/Ac, (BioRad, France) and Enzygnostic Intergral II (Siemens, GMBH, Marbug-Germany). In case of discordant results, the Western blot test II, HIV1 and 2 (Bio-Rad, Marne la Coquette, France) was used as the reference method. The RPR (Bio-Scan, Karnataka, India) test was performed to detect syphilis infection. The RPR positive results were confirmed using the TPHA test (Biotech, Cambridge, UK). Data were analyzed using SPSS 17.0 software.ResultsA total of 2979 pregnant women attending ANCs were enrolled. The global HIV infection rate was estimated to be 3.6% (CI: 95%; 3.0-4.4). As expected, HIV prevalence was significantly higher in women aged above 25 years (4.4% (3.4-5.6), p = 0.026) and those attending urban ANCs (5.04%, p < 0.01). Also, women living in the urban area are more at risk to be infected (5.04 VS 2.38, p < 0.01). The RPR test was positive in 117 pregnant women (3.92%). The risk for syphilis occurrence was significantly higher among the single women compared to the married ones (4.4% VS 2.7%; p < 0.01). It was also estimated that the HIV and syphilis coinfection occurred in 22 cases (0.73%).ConclusionThe prevalence's of syphilis and HIV were relatively low. Marital status and sentinel site location were a risk factor associated with HIV and syphilis infections respectively. Therefore, substantial effort is needed to reinforce prevention strategies in this population to prevent mother-to-child and further horizontal transmissions of these infections.

The validation and evaluation of anti-HIV testing algorithm used in mobile clinic setting for men who have sex with men in metropolitan Bangkok, Thailand

Same-day anti-HIV testing algorithm is recommended by Thai National Guidelines. We compared performance characteristics of algorithms used in a mobile clinic and a facility-based clinic for men who have sex with men (MSM) in Bangkok. Mobile clinic samples collected from 4 saunas and 2 spa venues were tested by Alere DetermineTM HIV 1/2, followed by DoubleCheck GoldTM Ultra HIV 1/2 and SD Bioline HIV 1/2 3.0. All samples were re-tested at the Thai Red Cross Anonymous Clinic (TRCAC) by Architect HIV Ag/Ab or Elecsys HIV combi PT, followed by Alere DetermineTM HIV 1/2 and Serodia HIV 1/2. Non-reactive samples were tested by Aptima nucleic acid amplification test (NAAT) and reactive/inconclusive samples were tested by less-sensitive immunoassays (IA) and HIV-1 RNA to detect acute HIV infection (positive NAAT or non-reactive IA/positive HIV-1 RNA). Of 233 MSM, 36 (15.5%) had HIV infection diagnosed using mobile clinic algorithm. Two additional acute HIV cases (1 positive NAAT and 1 reactive Architect with detectable HIV-1 RNA) were diagnosed using TRCAC algorithm. The mobile clinic algorithm had a sensitivity of 94.9% (95% CI: 82.7, 99.4) and a specificity of 100% (95% CI: 98.1, 100). Use of whole blood on rapid test kits demonstrated satisfactory performance and allowed same-day HIV test result through a mobile clinic model. For populations with high HIV incidence, careful history taking to define the window period is crucial and repeat testing must be encouraged if the testing algorithm does not include 4th generation anti-HIV assay or NAAT.

HIV P24 antigen among HIV antibody seronegative blood donors in Osogbo Osun State, South Western Nigeria

Background: Efforts to curb the spread of HIV transmission through transfusion of blood and its products is still a problem because of challenge in countries using antibody-based rapid methods to detect infection during window period. Transmission of HIV through infected blood and its products accounts for approximately 10% in African region.Methods: This study analyzed true negativity of HIV infection in blood donors screened by ELISA test based on p24 core antigen detection. Four hundred and eighty (480) blood donors initially negative for HIV antibody by rapid screening kit, Determine™ HIV-1/2 (Abbott Laboratory, IL, USA) and re-screened with Immuno Comb® II HIV 1 and 2 (Bispot kit PBS Organics and Israel 2005). The samples were further tested for the presence of HIV antibody and p24 HIV core antigen using ELISA kits (Genscreen TM ULTRA HIV Ag–Ab) following manufacturer’s instructions. All donors initially tested negative for Hepatitis B virus, Hepatitis C virus.Result: Two (0.42%) of 480 blood donors tested positive for the p24 HIV core antigen. The two positive donors for the p24 antigen had multiple sexual partners and recent sexually transmitted infections.Conclusion: The association of the HIV p24 antigen with blood donation was highly significant (p = 0.000) and pose a great risk to recipients if screening of blood donor is only carried out by HIV antibody detection.

Seroprevalence of &amp;lt;i&amp;gt;Toxoplasma gondii&amp;lt;/i&amp;gt; among AIDS Patients in Saudi Arabia

Background: Toxoplasma gondii (T. gondii) is an intracellular parasite mainly found in the central nervous system CNS, however, it can persist in multiple tissues in the body. Moreover, T. gondii is the commonest protozoans causing infections among individuals with acquired immunodeficiency syndrome (AIDS). Thus, the aim of this study was to investigate the frequency of T. gondii infection among AIDS patients in Makkah at Saudi Arabia. Methods: Fifty patients with AIDS proved to be positive by ULTRA HIV Ag-Ab Enzyme Immunoassay, and thirty healthy volunteers negative for AIDS by ULTRA HIV Ag-Ab Enzyme Immunoassay were subjected to determination of anti T. gondii immunoglobulin M (IgM) antibody seropositivity and anti T. gondii immunoglobulin G (IgG) antibody seropositivity using commercially available enzyme-linked immunosorbent assay kits. Results: The results showed that the seropositivity rate of anti T. gondii IgM antibodies among AIDS patients (18%) was significantly higher than in the healthy volunteers group (3.33%). Regarding the serum level of anti T. gondii IgG antibodies among AIDS patients, it was 30% significantly higher compared with those of the seropositive healthy volunteers (6.67%). Conclusions: These statistically significant results support the association between T. gondii infection and AIDS and suggest the usefulness of providing data for an educational program that will be designed to prevent T. gondii infection among AIDS patients.

P07.13 Detection oftreponema pallidumdna from whole blood and earlobe specimens in patients from two sti clinics in lima, peru

Background Prior studies have reported PCR detection of Treponema pallidum DNA from whole blood and earlobe scrapings. Factors affecting efficiency such as PCR target gene and clinical stage of syphilis have been studied. We aimed to determine other factors associated with detection of T.pallidum DNA from whole blood and earlobe samples. Methods Data were obtained from baseline samples collected for a prospective cohort study of 401 men who have sex with men (MSM) and transgender women (TW) in Lima, Peru. Participants were assessed for HIV using rapid HIV testing (Alere Determine, USA), a combined Antigen/Antibody HIV EIA, and Western blot confirmation (Genscreen ULTRA HIV Ag-Ab and Genetic Systems HIV-1 Western Blot, Bio Rad, USA). Syphilis infection was assessed with RPR (BD Macro-Vue, USA) and TPPA (Fujirebio, Japan). Whole blood samples and earlobe capillary blood was collected from patients with a positive RPR and TPPA. DNA extraction was performed using the QIAamp mini kit (Qiagen, Valencia, CA), and samples were then concentrated. Ujchowsing specific primers for the TpN47 gene, an aliquot of the DNA sample was amplified using conventional PCR for participants with high RPR titers (≥1:16). Positivity was determined by visual detection of PCR product on 1% agarose gel. Results 56 participants had RPR titer ≥1:16 (1:16(n = 18), 1:32(n = 16), 1:64(n = 17), 1:128(n = 3), and 1:256(n = 2)). A total of 7 (12.5%) participants had T.pallidum DNA detected from whole blood, and 6 (10.7%) from earlobe capillary blood (10 participants total). Of these 10 participants, 5 were HIV positive, and 5 were HIV negative. Conclusion Our relatively low efficiency of detection from both whole blood and earlobe samples suggest that neither HIV status nor high RPR titer (≥1:16) seem to predict high likelihood of DNA detection. Further study is ongoing to determine if these or other characteristics are associated with positive detection of T.pallidum DNA. Disclosure of interest statement The Picasso study is funded by a grant from the United States NIAID and was implemented by the Universidad Peruana Cayetano Heredia in collaboration with the University of California, Los Angeles. The molecular part of the study was implemented under the supervision of the University of Washington. No pharmaceutical grants were received during the development of this study.

Automatic oral fluid‐based HIV testing in HIV screening programmes: automatic for the people

UK guidelines recommend routine HIV testing in general clinical settings when the local HIV prevalence is > 0.2%. During pilot programmes evaluating the guidelines, we used laboratory-based testing of oral fluid from patients accepting tests. Samples (n = 3721) were tested manually using the Bio-Rad Genscreen Ultra HIV Ag-Ab test (Bio-Rad Laboratories Ltd, Hemel Hempstead, UK). This was a methodologically robust method, but handling of samples was labour intensive. We performed a validation study to ascertain whether automation of oral fluid HIV testing using the fourth-generation HIV test on the Abbott Architect (Abbott Diagnostics, Maidenhead, UK) platform was possible. Oral fluid was collected from 143 patients (56 known HIV-positive volunteers and 87 others having contemporaneous HIV serological tests) using the Oracol+ device (Malvern Medicals, Worcester, UK). Samples were tested concurrently: manually using the Genscreen Ultra test and automatically on the Abbott Architect. For oral fluid, the level of agreement of results between the platforms was 100%. All results agreed with HIV serology. The use of the Oracol+ device produced high-quality samples. Subsequent field use of the test has shown a specificity of 99.97% after nearly 3000 tests. Laboratory-based HIV testing of oral fluid requires less training of local staff, with fewer demands on clinical time and space than near-patient testing. It is acceptable to patients. The validation exercise and subsequent clinical experience support automation, with test performance preserved. Automation reduces laboratory workload and speeds up the release of results. Automated oral fluid testing is thus a viable option for large-scale HIV screening programmes.

Nucleic acid testing for blood banks: An experience from a tertiary care centre in New Delhi, India

IntroductionBlood safety is a challenging task in India; with a population of around 1.23 billion and a high prevalence rate of HIV (0.29%), HBV (2–8%) and HCV (∼2%) in general population. Nucleic acid testing (NAT) in blood donor screening has been implemented in many developed countries to reduce the risk of transfusion-transmitted viral infections (TTIs). NAT shortens this window period, thereby offering blood centers a much higher sensitivity for detecting viral infections. Materials and methodsRoutine ID-NAT for HIV-1, HCV and HBV was started from June 2010 at AIIMS blood bank by the Procleix® Ultrio® Assay (Novartis Diagnostics, USA) a multiplex NAT, which allows the simultaneous detection of HIV-1, HCV, and HBV in a single tube. During the period of 27months from June 2010 to August 2012, around 73,898 samples were tested for all the three viruses using both ELISA (by Genscreen Ultra HIV Ag–Ab(BIO-RAD), Hepanostika HCV Ultra & HBsAg Ultra(Biomerieux) and Nucleic acid testing. The comparative results of both the assays are being presented here in this study. ResultsOut of 73,898 samples, 1104 samples (1.49%) were reactive by NAT. out of these 1104 samples, 73 were reactive for HIV-1 (0.09%), 186 were reactive for HCV only (0.25%), 779 (1.05%) were reactive for HBV only, and around 66 (0.08%) were HBV-HCV co-infections. There was one HIV, 37 HCV, 73 HBV and 10 HBV–HCV co-infection cases that were not detected by serology but reactive on NAT testing, with a combined yield of 1 in 610 donations (total 121 NAT yields). ConclusionNAT could detect HIV, HBV and HCV cases in blood donor samples that were undetected by serological tests. NAT can interdict a large number of infected unit transfusions and thus help in providing safe blood to the patients.

HIV-1 p24 抗原検出感度が向上した改良型 HIV 抗原抗体同時検出試薬の検討

The performance of a new version of the HIV p24 antigen and antibody combination assays (Genscreen Ultra HIV Ag-Ab) was evaluated by comparing it with three other fourth-generation enzyme immunoassays (Architect HIV Ag/Ab Combo assay, VIDAS HIV DUO Quick and Genscreen Plus HIV Ag-Ab). The assays were examined with 200 HIV positive samples, 1,000 HIV negative samples, 30 samples (28 positives including 24 samples of subtype A, B, B', C, D, F, G, B/D, CRF01_AE in HIV-1 group M, one sample of HIV-1 group O, three samples of HIV-2 and two negatives) of one worldwide HIV performance panel, 59 samples of ten HIV-1 seroconversion panels and the WHO international standard HIV-1 p24 antigen. Both the sensitivity and specificity of Genscreen Ultra HIV Ag-Ab were 100%. All of the 28 positive samples in the worldwide HIV performance panel were positive. The days of the earliest detection in the ten seroconversion panels were the same in three assays (Genscreen Ultra HIV Ag-Ab, Architect HIV Ag/Ab combo assay and VIDAS HIV DUO Quick). Genscreen Plus HIV Ag-Ab which is a former version of the Genscreen Ultra HIV Ag-Ab detected the earliest positive sample one bleed slower than the other three assays in 5 of 10 seroconversion panels. The p24 antigen limit of detection was determined in two ways, using the WHO international standard and three samples from HIV-1 antigen panels; the values obtained were 1IU/mL and 3.5-9.9 pg/mL for Genscreen Ultra HIV Ag-Ab, 1U/mL and 7.1-9.9 pg/mL for Architect HIV Ag/Ab combo assay, 0.5IU/mL and 4.0-7.1 pg/mL for VIDAS HIV DUO Quick, and 32.0-56.5 pg/mL for Genscreen Plus HIV Ag-Ab. In this study, we have shown that Genscreen Ultra HIV Ag-Ab has the sensitivity, specificity and p24 antigen limit of detection that is equal to those of two typical fourth-generation assays. This assay can be considered useful and reliable for HIV screening.