Rapid HIV testing: a review of the literature and implications for the clinician

Isothermal nucleic acid amplification technology in HIV detection

Nucleic acid testing for HIV plays an important role in the early diagnosis and monitoring of antiretroviral therapy outcomes in HIV patients and HIV-infected infants. Currently, the main molecular diagnostic methods employed are complex, time-consuming, and expensive to operate in resource-limited areas. Isothermal nucleic acid amplification technology overcomes some of the shortcomings of traditional assays and makes it possible to use point-of-care tests for molecular HIV detection. Here, we summarize and discuss the latest technological advances in isothermal nucleic acid amplification for HIV detection, with the intent of providing guidance for the development of subsequent HIV assays with high sensitivity and specificity.

Diagnostic Performance of Competitive ELISA and Western Blot Methods for the Detection of Antibodies against Theileria equi and Babesia caballi

Theileria equi (T. equi) and Babesia caballi (B. caballi) are the causative pathogens of Equine piroplasmosis (EP), a disease that has brought huge economic losses and great restrictions to the global equine industry. Rapid and accurate diagnostic methods are critical for the effective monitoring of the disease. In this study, we developed novel competitive ELISA methods and western blot assays based on the EMA1 or Bc48 proteins to detect antibodies against T. equi or B. caballi, respectively. In the novel cELISA, horseradish peroxidase (HRP)-labeled monoclonal antibodies are used in place of enzyme-conjugated secondary antibodies, in order to speed up the entire procedure. These methods have high sensitivity and no cross-reactivity with antibodies against other equine diseases. In the newly developed western blot assays, we optimized the dilution of T. equi or B. caballi positive serum samples to 1:200. Compared with the commercially available kit, both the novel cELISA assay and the western blot assay showed high coincidence rates in detecting antibodies against T. equi and B. caballi. Taken together, the novel cELISA and the western blot assays for detecting antibodies against T. equi or B. caballi have the potential to rapidly test for T. equi or B. caballi and to contribute to the surveillance and control of this disease.

Evaluation of serological assays for the diagnosis of HIV infection in adults

Serological tests based on the enzyme immunoassay (EIA) are the primary tool for the diagnosis of human immunodeficiency virus (HIV) in adults and have rapidly evolved to quicker, affordable and more accurate test formats to detect early HIV infection. Second- and third-generation HIV rapid tests detect the immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to the HIV and are used at the point of care and in HIV self-testing. The tests are affordable and accessible in state and private diagnostic laboratories. The present-day fourth- and fifth-generation EIAs can detect both p24 antigen and IgG and IgM HIV antibodies and thereby diagnose early HIV infection at approximately 2 weeks. The fourth- and fifth-generation EIAs also report sensitivity and specificity of more than 99%. The correct interpretation of HIV diagnosis of false-positive and false-negative EIA test results requires collaborative scrutiny of patient factors and laboratory test methodologies.

Experiences Receiving HIV-Positive Results by Phone: Acceptability and Implications for Clinical and Behavioral Research

Improving HIV testing rates and increasing early detection among men who have sex with men (MSM) are critical strategies for enhancing overall health and decreasing HIV transmission. Remote testing and phone delivery of HIV test results may reduce barriers such as geographic isolation or HIV-related stigma. In 2018-19, 50 MSM completed qualitative interviews about their experience receiving a positive HIV test result via phone through their participation in a research study that included remote HIV testing. Interview topics included the acceptability of, and concerns about, phone delivery of HIV results, as well as suggestions for improvement. Interviews were transcribed, coded, and analysed using an inductive thematic approach. Overall, participants reported high acceptability of phone delivery of HIV-positive results. Participants praised the support and information provided by study staff. Benefits identified included increased convenience compared to in-person medical visits, allowing participants to emotionally process their test results privately, as well as receiving the results from supportive and responsive staff members. A few participants indicated drawbacks to phone-based HIV test result delivery, such as logistical concerns about receiving a phone call during the day (e.g., while at work), reduced confidentiality, and the lack of in-person emotional support. Overall, participants described phone delivery of positive HIV-results as acceptable. At-home testing with phone delivery has the potential to increase HIV testing access, especially to geographically isolated or medically underserved patients.

Molecular epidemiology in the HIV and SARS-CoV-2 pandemics

PURPOSE OF REVIEW

The aim of this review was to compare and contrast the application of molecular epidemiology approaches for the improved management and understanding of the HIV versus SARS-CoV-2 epidemics.

RECENT FINDINGS

Molecular biology approaches, including PCR and whole genome sequencing (WGS), have become powerful tools for epidemiological investigation. PCR approaches form the basis for many high-sensitivity diagnostic tests and can supplement traditional contact tracing and surveillance strategies to define risk networks and transmission patterns. WGS approaches can further define the causative agents of disease, trace the origins of the pathogen, and clarify routes of transmission. When coupled with clinical datasets, such as electronic medical record data, these approaches can investigate co-correlates of disease and pathogenesis. In the ongoing HIV epidemic, these approaches have been effectively deployed to identify treatment gaps, transmission clusters and risk factors, though significant barriers to rapid or real-time implementation remain critical to overcome. Likewise, these approaches have been successful in addressing some questions of SARS-CoV-2 transmission and pathogenesis, but the nature and rapid spread of the virus have posed additional challenges.

SUMMARY

Overall, molecular epidemiology approaches offer unique advantages and challenges that complement traditional epidemiological tools for the improved understanding and management of epidemics.

An immunoassay cassette with a handheld reader for HIV urine testing in point-of-care diagnostics

Currently, most HIV tests are performed with blood samples, or alternatively saliva samples are used for HIV testing. Simple HIV tests need to be performed in hospitals or other medical agencies instead of more invasive HIV blood tests. To enable point-of-care (POC) HIV diagnostics, based on a recently developed lateral flow strip for HIV urine testing, a microfluidic immunoassay cassette with a handheld optical reader is developed. Based on lateral flow strip with gold colloid reporter, the integrated immunoassay cassette can perform sample introduction, metering, discharging, applying and detection which simplifies HIV testing. An indicator is incorporated into the cassette to guide sample introduction based on color change, and further, the excess test sample is stored inside the sealed cassette to avoid any contamination. The low-cost handheld optical reader can provide a test result within a few seconds, which is useful for simple, sensitive and affordable HIV onsite detection. Instead of using normal white LEDs, a customized back light module embedded with green LEDs is adopted to illuminate the lateral flow strip with an appropriate working current to achieve optimal performance. Compared to the standard lateral flow strips using a benchtop reader, with the disposable immunoassay cassette assisted by the handheld optical reader, more convenient, easier-to-operate, and more affordable HIV urine testing can be achieved in POC diagnostics.

Diagnosis of Human Immunodeficiency Virus Infection

HIV diagnostics have played a central role in the remarkable progress in identifying, staging, initiating, and monitoring infected individuals on life-saving antiretroviral therapy. They are also useful in surveillance and outbreak responses, allowing for assessment of disease burden and identification of vulnerable populations and transmission "hot spots," thus enabling planning, appropriate interventions, and allocation of appropriate funding. HIV diagnostics are critical in achieving epidemic control and require a hybrid of conventional laboratory-based diagnostic tests and new technologies, including point-of-care (POC) testing, to expand coverage, increase access, and positively impact patient management. In this review, we provide (i) a historical perspective on the evolution of HIV diagnostics (serologic and molecular) and their interplay with WHO normative guidelines, (ii) a description of the role of conventional and POC testing within the tiered laboratory diagnostic network, (iii) information on the evaluations and selection of appropriate diagnostics, (iv) a description of the quality management systems needed to ensure reliability of testing, and (v) strategies to increase access while reducing the time to return results to patients. Maintaining the central role of HIV diagnostics in programs requires periodic monitoring and optimization with quality assurance in order to inform adjustments or alignment to achieve epidemic control.

Verification of post-chemotherapeutic clearance of Theileria equi through concordance of nested PCR and immunoblot

Certain countries including the United States remain non-endemic for particular infectious diseases such as equine piroplasmosis through import restrictions and surveillance. Endemic regions often employ premunition as the primary method to control disease, however in non-endemic countries, chemosterilization combined with methods to confirm parasite elimination are required to maintain disease-free status. The ability of imidocarb diproprionate (ID) to clear persistent Theileria equi infection from infected horses has been shown through the inability of treated horses to transmit via blood transfer. However, the common lengthy persistence of anti-T. equi antibody causes regulatory tests such as cELISA or IFA to remain positive for extended periods. Persistence of positive testing creates challenges for regulatory veterinary medicine and international trade. Concordance between nested polymerase chain reaction (nPCR) targeting the ema1 gene and immunoblotting (IB) measuring declination in anti-EMA1 and anti-EMA2 antibody were used to verify clearance of T. equi from 179 ID-treated horses. These data support the use of IB to demonstrate declining anti-EMA1 and EMA2 titers in T. equi-infected horses subsequent to successful ID treatment. Such data provide concordant support to a negative nPCR and allow for a more timely determination of effective ID clearance of T. equi. The post ID treatment results indicate that while nPCR was consistently negative by 14 days and cELISA generally remained positive after 1 year, immunoblot was on average negative after 4 months and 100% in agreement with nPCR.

Feasibility of supervised self-testing using an oral fluid-based HIV rapid testing method: a cross-sectional, mixed method study among pregnant women in rural India

INTRODUCTION

HIV self-testing can increase coverage of essential HIV services. This study aimed to establish the acceptability, concordance and feasibility of supervised HIV self-testing among pregnant women in rural India.

METHODS

A cross-sectional, mixed methods study was conducted among 202 consenting pregnant women in a rural Indian hospital between August 2014 and January 2015. Participants were provided with instructions on how to self-test using OraQuick(®) HIV antibody test, and subsequently asked to self-test under supervision of a community health worker. Test results were confirmed at a government-run integrated counselling and testing centre. A questionnaire was used to obtain information on patient demographics and the ease, acceptability and difficulties of self-testing. In-depth interviews were conducted with a sub-sample of 35 participants to understand their experiences.

RESULTS

In total, 202 participants performed the non-invasive, oral fluid-based, rapid test under supervision for HIV screening. Acceptance rate was 100%. Motivators for self-testing included: ease of testing (43.4%), quick results (27.3%) and non-invasive procedure (23.2%). Sensitivity and specificity were 100% for 201 tests, and one test was invalid. Concordance of test result interpretation between community health workers and participants was 98.5% with a Cohen's Kappa (k) value of k=0.566 with p<0.001 for inter-rater agreement. Although 92.6% participants reported that the instructions for the test were easy to understand, 18.7% required the assistance of a supervisor to self-test. Major themes that emerged from the qualitative interviews indicated the importance of the following factors in influencing acceptability of self-testing: clarity and accessibility of test instructions; time-efficiency and convenience of testing; non-invasiveness of the test; and fear of incorrect results. Overall, 96.5% of the participants recommended that the OraQuick(®) test kits should become publicly available.

CONCLUSIONS

Self-testing for HIV status using an oral fluid-based rapid test under the supervision of a community health worker was acceptable and feasible among pregnant women in rural India. Participants were supportive of making self-testing publicly available. Policy guidelines and implementation research are required to advance HIV self-testing for larger populations at scale.

An analysis of socio-demographic and behavioural factors among immigrant MSM in Montreal from an HIV-testing site sample

Little Canadian research exists on immigrant men who have sex with men (MSM), who are internationally reported to use rapid HIV-testing sites. Our objective was to describe immigrant MSM in a sample of clients at an HIV testing site. From July 2012 to November 2013, clients at Actuel sur Rue (AsR), a Montreal-based HIV rapid-testing site, provided data for a staff- and a self-administered questionnaire. We compared immigrant and non-immigrant MSM's socio-demographics and risk practices. Among immigrants, we analyzed these variables by country of origin. We conducted regression analyses examining how immigrant status and socio-demographics were associated with risk practices. During the study, 1353 MSM visited AsR and 407 (30%) were immigrants, mostly from Europe, Latin America/Caribbean, and Africa/Middle-East. The same proportion (2%) of immigrant and non-immigrant MSM received a positive rapid HIV test result. Relative to non-immigrant MSM, significantly more immigrant MSM reported a post-secondary degree, a lower income, and being unemployed. Fewer reported receiving an HIV-positive/unknown-status partner's sperm/blood in their mouth, ever having unprotected sex with an HIV-positive partner, and ever selling sex. In comparisons between MSM immigrants by origin, fewer Asian and African/Middle-Eastern MSM reported ever testing for HIV. In the regression analyses, immigrant status was not independently associated with sexual risk. MSM who earned less, were unemployed, or had a high school degree or less were more likely to have sold sex. Socio-demographics like employment, education and income were associated with reported sexual risk in MSM clients, but not immigrant status alone.

On-site bundled rapid HIV/HCV testing in substance use disorder treatment programs: study protocol for a hybrid design randomized controlled trial

BACKGROUND

More than 1.2 million people in the United States are living with human immunodeficiency virus (HIV), and 3.2 million are living with hepatitis C virus (HCV). An estimated 25 % of persons living with HIV also have HCV. It is therefore of great public health importance to ensure the prompt diagnosis of both HIV and HCV in populations that have the highest prevalence of both infections, including individuals with substance use disorders (SUD).

METHODS/DESIGN

In this theory-driven, efficacy-effectiveness-implementation hybrid study, we will develop and test an on-site bundled rapid HIV/HCV testing intervention for SUD treatment programs. Its aim is to increase the receipt of HIV and HCV test results among SUD treatment patients. Using a rigorous process involving patients, providers, and program managers, we will incorporate rapid HCV testing into evidence-based HIV testing and linkage to care interventions. We will then test, in a randomized controlled trial, the extent to which this bundled rapid HIV/HCV testing approach increases receipt of HIV and HCV test results. Lastly, we will conduct formative research to understand the barriers to, and facilitators of, the adoption, implementation, and sustainability of the bundled rapid testing strategy in SUD treatment programs.

DISCUSSION

Novel approaches that effectively integrate on-site rapid HIV and rapid HCV testing are needed to address both the HIV and HCV epidemics. If feasible and efficacious, bundled rapid HIV/HCV testing may offer a scalable, potentially cost-effective approach to testing high-risk populations, such as patients of SUD treatment programs. It may ultimately lead to improved linkage to care and progress through the HIV and HCV care and treatment cascades.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02355080 . (30 January 2015).

Low Rates of Adoption and Implementation of Rapid HIV Testing in Substance Use Disorder Treatment Programs

INTRODUCTION

Rapid HIV testing (RHT) greatly increases the proportion of clients who learn their test results. However, existing studies have not examined the adoption and implementation of RHT in programs treating persons with substance use disorders, one of the population groups at higher risk for HIV infection.

METHODS

We examined 196 opioid treatment programs (OTPs) using data from the 2011 National Drug Abuse Treatment System Survey (NDATSS). We used logistic regressions to identify client and organizational characteristics of OTPs associated with availability of on-site RHT. We then used zero-inflated negative binomial regressions to measure the association between the availability of RHT on-site and the number of clients tested for HIV.

RESULTS

Only 31.6% of OTPs offered on-site rapid HIV testing to their clients. Rapid HIV testing was more commonly available on-site in larger, publicly owned and better-staffed OTPs. On the other hand, on-site rapid HIV testing was less common in OTPs that prescribed only buprenorphine as a method of opioid dependence treatment. The availability of rapid HIV testing on-site reduced the likelihood that an OTP did not test any of its clients during the prior year. But on-site availability rapid HIV testing was not otherwise associated with an increased number of clients tested for HIV at an OTP.

CONCLUSIONS

New strategies are needed to a) promote the adoption of rapid HIV testing on-site in substance use disorder treatment programs and b) encourage substance use disorder treatment providers to offer rapid HIV testing to their clients when it is available.

Evaluation of nine HIV rapid test kits to develop a national HIV testing algorithm in Nigeria

Background: Non-cold chain-dependent HIV rapid testing has been adopted in many resource-constrained nations as a strategy for reaching out to populations. HIV rapid test kits (RTKs) have the advantage of ease of use, low operational cost and short turnaround times. Before 2005, different RTKs had been used in Nigeria without formal evaluation. Between 2005 and 2007, a study was conducted to formally evaluate a number of RTKs and construct HIV testing algorithms. Objectives: The objectives of this study were to assess and select HIV RTKs and develop national testing algorithms. Method: Nine RTKs were evaluated using 528 well-characterised plasma samples. These comprised 198 HIV-positive specimens (37.5%) and 330 HIV-negative specimens (62.5%), collected nationally. Sensitivity and specificity were calculated with 95% confidence intervals for all nine RTKs singly and for serial and parallel combinations of six RTKs; and relative costs were estimated. Results: Six of the nine RTKs met the selection criteria, including minimum sensitivity and specificity (both ≥ 99.0%) requirements. There were no significant differences in sensitivities or specificities of RTKs in the serial and parallel algorithms, but the cost of RTKs in parallel algorithms was twice that in serial algorithms. Consequently, three serial algorithms, comprising four test kits (BundiTM, DetermineTM, Stat-Pak® and Uni-GoldTM) with 100.0% sensitivity and 99.1% - 100.0% specificity, were recommended and adopted as national interim testing algorithms in 2007. Conclusion: This evaluation provides the first evidence for reliable combinations of RTKs for HIV testing in Nigeria. However, these RTKs need further evaluation in the field (Phase II) to re-validate their performance.

Explaining the appeal for immigrant men who have sex with men of a community-based rapid HIV-testing site in Montreal (Actuel sur Rue)

Immigrant men who have sex with men (MSM) are vulnerable to HIV. In the last decade, several rapid HIV-testing facilities targeting MSM have been established around the world and seem popular among immigrants. This study analyzes factors contributing to immigrant MSM's use of Actuel sur Rue (AsR), a community-based rapid HIV-testing site in Montreal's gay village, where 31% of clients are immigrants. From October 2013 to January 2014, AsR staff compiled a list of new clients born outside of Canada. With their consent, 40 immigrant MSM were reached among these new clients for a 15-minute phone survey entailing open-ended and multiple-choice questions. The survey sought immigrant MSM's reasons for visiting AsR; satisfaction with service and staff; and open comments. An inductive thematic analysis was conducted with the qualitative data, and descriptive statistics were produced with the quantitative data. The qualitative findings indicate that the main reasons for seeking an HIV test were a recent risk, routine testing, or being in a new relationship. Clients chose AsR mainly because it is easily accessible, service is fast or they heard about it from a friend. The quantitative findings indicate that rates of satisfaction were high (over 90% were satisfied about all aspects except for openings hours) and more than 80% felt comfortable while receiving services at AsR. Nevertheless, this study's findings have implications for improving services. They stress the importance of offering rapid yet comprehensive service and of taking into account immigrant MSM's concerns for confidentiality.

Emerging technologies for point-of-care management of HIV infection

The global HIV/AIDS pandemic has resulted in 39 million deaths to date, and there are currently more than 35 million people living with HIV worldwide. Prevention, screening, and treatment strategies have led to major progress in addressing this disease globally. Diagnostics is critical for HIV prevention, screening and disease staging, and monitoring antiretroviral therapy (ART). Currently available diagnostic assays, which include polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and western blot (WB), are complex, expensive, and time consuming. These diagnostic technologies are ill suited for use in low- and middle-income countries, where the challenge of the HIV/AIDS pandemic is most severe. Therefore, innovative, inexpensive, disposable, and rapid diagnostic platform technologies are urgently needed. In this review, we discuss challenges associated with HIV management in resource-constrained settings and review the state-of-the-art HIV diagnostic technologies for CD4(+) T lymphocyte count, viral load measurement, and drug resistance testing.

Pharmacist Testers in Multidisciplinary Health care Team Expand HIV Point-of-Care Testing Program

Knowledge of HIV serostatus is the first step to accessing treatment, reducing transmission, and mitigating public health challenges. We describe the expansion of an HIV point-of-care testing (POCT) program within a health care system utilizing pharmacists as testers. The testing program’s expansion is detailed and its impact assessed. The POCT program was evaluated by comparing the number of traditional HIV venipuncture tests to the number of POCTs performed across the health system as well as comparing the number of POCTs performed by clinical pharmacists to the number of tests at other POCT locations. Although pharmacists’ contributions to HIV prevention are well documented, pharmacists’ involvement in HIV testing initiatives is still nascent. Our POCT program demonstrates an effective HIV testing initiative driven by pharmacists and other health care providers.

Improving survival of children with severe acute malnutrition in HIV-prevalent settings

The care of severely malnourished children in sub-Saharan Africa is challenging, especially in HIV-prevalent settings. Recent improvements to facility-based individual case management, and increased community-based management focusing on early identification and high programme coverage have led to reductions in mortality. Further interventions are urgently needed to address resistant mortality, mostly attributable to HIV. This paper explores strategies in three main areas to improve survival for children with severe acute malnutrition (SAM): identifying HIV and improving case management for HIV-infected children; strengthening existing strategies to improve outcomes for all children with SAM, regardless of HIV status; and improving early identification and increasing programme coverage. Although interventions to further improve survival among children with SAM in sub-Saharan Africa must firstly ensure best care for all children, HIV-infected children are at particular risks for mortality. Integration of specific interventions for HIV testing and treatment into SAM care is essential. International guidelines should reflect best evidence, and are in urgent need of updating and adapting to local country context. Effective interventions already exist that can improve survival in children with SAM in HIV-prevalent settings. The challenge is to implement what we know and to research what we do not.

Laboratory support of global health research

Laboratory generated data are used in support of several types of global health research. Routinely obtained clinical diagnostic data are used for disease surveillance, epidemiologic analysis of frequencies and trends, health outcomes research, and sponsored research projects. Clinical data from research laboratories is also collected in support of sponsored research projects. Whether the initial purpose of the testing is in support of research protocols or the data are retrospectively reviewed, the quality of the laboratory data is essential to drawing correct conclusions. The types and use of data generated by on-site, routine diagnostic, research diagnostic and basic science laboratories will be described, with a focus on quality-related issues. Full integration of laboratory management as a partner is essential to successful research planning and execution.

Piloting HIV rapid testing in community-based settings in Estonia

BACKGROUND

In the European Union it is estimated that up to 30% of HIV-infected people are not aware of their status. Community-based testing (CBT) models are implemented to increase the uptake of HIV testing.

AIMS

The aim of this project was to assess the feasibility and acceptance of HIV rapid testing in CBT settings in Estonia to identify non-clinical recruitment venues for people more likely to engage in high-risk behaviours.

METHODS

Participants for this anonymous, cross-sectional study were recruited from a syringe exchange programme and gay-oriented locations using convenience sampling. Socio-demographic and HIV testing preferences data were collected using a semi-structured questionnaire. HIV rapid testing was performed using Determine HIV-1/2 (Abbott) rapid test system.

RESULTS

With a participation rate of 88.3%, this project enrolled 308 persons and identified 58 preliminary positive cases. Out of them, 52 reported injecting drug use in last 12 months and 30 reported no previous HIV test. Approximately 45% of all participants preferred rapid testing while 25% reported a preference for a full blood test.

CONCLUSIONS

This project demonstrates that HIV rapid testing in community-based settings in Eastern Europe can be an effective approach for reaching people who engage in high-risk behaviours and increasing the number of HIV-infected people who are aware of their status.

A surveillance report of HIV status and high risk behaviors among rapid testing participants in Tallinn, Estonia

Estonia has the second highest adult HIV prevalence in Europe of 1.3%. The primary transmission is among injecting drug users (IDU), who account for 56-90% of HIV infections (Report on the Global AIDS Epidemic: UNAIDS/WHO, July 2008 and Platt et al. AIDS 20(16):2120-2123, 2006). Of those persons newly diagnosed, 50.4% reported injecting drugs in the last 12 months, 16.3% of these reported IDU as the sole risk factor and 31.2% reported IDU among other risk factors. In this sample (n = 790) 170 persons reported a high risk behavior and 51 persons received a positive result through rapid testing. The largest proportion (35.29%) was among persons reporting high risk heterosexual intercourse and second (33.33%) among persons sharing injecting equipment. Covariates in a logistic regression model indicate that male sex (OR = 2.57, 95% CI 1.00-6.59), non-Estonian ethnicity (OR = 2.68, 95% CI 1.46-4.93), higher education (OR = 0.56, 95% CI 0.40-0.80), and high risk heterosexual intercourse (OR = 2.68, 95% CI 1.19-6.02) are statistically significant in predicting a positive HIV status.

Biosensors as rapid diagnostic tests for tropical diseases

Effective diagnosis of infectious pathogens is essential for disease identification and subsequent adequate treatment, to prevent drug resistance and to adopt suitable public health interventions for the prevention and control of epidemic outbreaks. Particular situations under which medical diagnostics operate in tropical environments make the use of new easy-to-use diagnostic tools the preferred (or even unique) option. These diagnostic tests and devices, usually based on biosensing methods, are being increasingly exploited as promising alternatives to classical, "heavy" lab instrumentation for clinical diagnosis, allowing simple, inexpensive and point-of-care testing. However, in many developing countries the lack of accessibility and affordability for many commercial diagnostic tests remains a major cause of high disease burden in such regions. We present a comprehensive overview about the problems of conventional medical diagnosis of infectious pathologies in tropical regions, while pointing out new methods and analytical tools for in-the-field and decentralized diagnosis of current major infectious tropical diseases. The review includes not only biosensor-based rapid diagnostic tests approved by regulatory entities and already commercialized, but also those at the early stages of research.

Unprotected sex in heterosexual partnerships of injecting drug users in st. Petersburg, Russia

We examined the association of individual demographic and behavioral attributes, partnership (dyad) and social network characteristics with unprotected sex in the heterosexual dyads of IDUs in St. Petersburg, Russia. Of the individual-level characteristics female gender and younger age; and of the dyad-level characteristics sharing injecting equipment, social exposure to the sex partner ("hanging out with" or seeing each other daily), and both partners self-reporting being HIV infected were associated with unprotected sex. Although self-reported HIV discordant couples were less likely to engage in unprotected sex, it was reported in over half of self-reported HIV discordant relationships. This study highlights the intertwining of sexual risk and injecting risk, and the importance of sero-sorting based on perceived HIV status among IDU sexual partnerships in St. Petersburg, Russia. A combination of social network and dyad interventions may be appropriate for this population of IDUs, especially for IDUs who are both injecting and sex partners, supported by free and confidential rapid HIV testing and counseling services to provide a comprehensive response to the wide-spread HIV epidemic among IDUs in St. Petersburg.

Opportunities to diagnose, treat, and prevent HIV in the criminal justice system

Persons involved with the criminal justice system are at risk for HIV and other transmissible diseases due to substance use and related risk behaviors. Incarceration provides a public health opportunity to test for HIV, viral hepatitis, and other sexually transmitted infections, provide treatment such as highly active antiretroviral therapy, and link infected persons to longitudinal comprehensive HIV care upon their release for such comorbidities as addiction and mental illness. Delivering health interventions inside prisons and jails can be challenging, yet the challenges pale in comparison to the benefits of interventions for inmates and their communities. This article reviews the current state of delivering HIV testing, prevention, treatment, and transition services to incarcerated populations in the United States. It concludes with summary recommendations for research and practice to improve the health of inmates and their communities.

Who Chooses a Rapid Test for HIV in Los Angeles County, California?

The purpose of this study was to determine who chooses a rapid test for HIV when given a choice in a community-based or mobile van setting in Long Beach, California. Individuals were given a choice of either rapid or standard HIV testing either alone or in conjunction with testing for sexually transmitted diseases (STD). Of the 2,752 HIV tests performed between March 2005 and March 2009, 917 (33%) were rapid tests. Preference for rapid HIV testing was among men who have sex with men (MSM), who reported using alcohol in the last 48 hr but who did not endorse the use of illicit drugs; individuals reporting sex trading were also more likely to choose the rapid HIV test. African Americans, regardless of sexual identification, were significantly less likely to choose an HIV rapid test. Strategies are needed to encourage HIV rapid testing among both noninjection and injection drug users, and other at-risk groups.

Rapid detection and differentiation of antibodies to HIV-1 and HIV-2 using multivalent antigens and magnetic immunochromatography testing

A simplified lateral-flow assay for the detection of antibodies to HIV using magnetic-bead conjugates and multibranched peptides from both HIV-1 and HIV-2 was developed. Magnetic immunochromatography testing (MICT) uses a standard lateral-flow platform that incorporates magnetic-bead conjugates for quantitative measurement of the magnetic field distortion associated with the bound magnetic conjugate (reported as adjusted relative magnetic units [MAR]). The results of the optimized MICT assay were compared to standard enzyme immunoassay (EIA) and Western blotting (WB) results using a blinded 649-member panel of specimens from the United States, Cameroon, and West Africa. The panel was comprised of samples from individuals infected with various HIV-1 subtypes (n = 234) or HIV-2 (n = 65) and HIV-seronegative specimens (n = 350). Additionally, 13 HIV-1 seroconversion panels (total specimens = 85), a worldwide panel containing seven of the major circulating HIV-1 subtypes (n = 18), an HIV-2 panel, an HIV-1/HIV-2 mixed panel, and 100 prospective specimens were tested with completely concordant results. Assay reproducibility (observed MAR) for both intra- and interrun testing was excellent, with coefficients of variation of <12%. MICT can provide a rapid, low-cost method of determining HIV antibody status requiring no subjective interpretations.

Immunoassays for the diagnosis of HIV: meeting future needs by enhancing the quality of testing

Immunoassays for detecting HIV infection perform better than other serological assays. HIV immunoassays are presented in a number of different formats: instrument-based, plate, rapid assays and as immunoblots. HIV immunoassays for screening and diagnosis are now in their fourth generation; an assay generation meaning that significant modifications to the assay format have led to a significant enhancement in quality. Although still not perfect, they are now of exceptionally high quality if conducted properly. Most problems relate to how the assays are performed. Many laboratories, especially in high human development index (HDI) countries, manage testing within functioning quality-management systems, but this is not true of laboratories in low HDI countries or in many medium HDI countries. Simple rapid tests for HIV are being used increasingly, and create special challenges for assuring quality. Users of HIV immunoassays are learning that a poorer assay used well has better outcomes than a splendid assay performed poorly. Experience highlights the importance of conducting HIV testing within quality-managed systems and according to international standards, but testing quality and laboratory quality management must be funded adequately.

Emergency medicine resident attitudes and perceptions of HIV testing before and after a focused training program and testing implementation

OBJECTIVES

The objectives were to determine attitudes and perceptions (A&P) of emergency medicine (EM) residents toward emergency department (ED) routine provider-driven rapid HIV testing services and the impact of both a focused training program (FTP) and implementation of HIV testing on A&P.

METHODS

A three-phase, consecutive, anonymous, identity-unlinked survey was conducted pre-FTP, post-FTP, and 6 months postimplementation. The survey was designed to assess residents' A&P using a five-point Likert scale. A preimplementation FTP provided both the rationale for the HIV testing program and the planned operational details of the intervention. The HIV testing program used only indigenous ED staff to deliver HIV testing as part of standard-of-care in an academic ED. The impact of the FTP and implementation on A&P were analyzed by multivariate regression analysis using generalized estimating equations to control for repeated measurements in the same individuals. A "favorable" A&P was operationally defined as a mean score of >3.5, "neutral" as mean score of 2.5 to 3.5, and "unfavorable" as mean score of <2.5.

RESULTS

Thirty of 36 residents (83.3%) participated in all three phases. Areas of favorable A&P found in phase I and sustained through phases II and III included "ED serving as a testing venue" (score range = 3.7-4.1) and "emergency medicine physicians offering the test" (score range = 3.9-4.1). Areas of unfavorable and neutral A&P identified in phase I were all operational barriers and included required paperwork (score = 3.2), inadequate staff support (score = 2.2), counseling and referral requirements (score range = 2.2-3.1), and time requirements (score = 2.9). Following the FTP, significant increases in favorable A&P were observed with regard to impact of the intervention on modification of patient risk behaviors, decrease in rates of HIV transmission, availability of support staff, and self-confidence in counseling and referral (p < 0.05). At 6 months postimplementation, all A&P except for time requirements and lack of support staff scored favorably or neutral. During the study period, 388 patients were consented for and received HIV testing; six (1.5%) were newly confirmed HIV positive.

CONCLUSIONS

Emergency medicine residents conceptually supported HIV testing services. Most A&P were favorably influenced by both the FTP and the implementation. All areas of negative A&P involved operational requirements, which may have influenced the low overall uptake of HIV testing during the study period.

The potential role of biomarkers in HIV preventive vaccine trials

BACKGROUND

Successful conduct of HIV vaccine efficacy trials entails identification and enrollment of at-risk populations, assessment of appropriate end points as measures of vaccine efficacy for prevention of HIV acquisition, and amelioration of disease course among infected vaccinees, as well as identification of potential confounders or effect modifiers. Although not invariably useful and bringing their own cost in terms of measurement and validation, a variety of biomarkers may aid at each stage of trial conduct.

METHODS

A review of selected articles, chosen based on quality, relevance of the biomarker to HIV vaccine trials, and availability of the publication, was conducted. The authors also drew experience from current trials and other planned or ongoing trials.

CONCLUSIONS

Biomarkers are available to assess HIV incidence in potential study populations, but care is needed in interpreting results of these assays. During trial conduct, sexually transmitted infections such as herpes simplex virus type 2 may act as effect modifiers on primary and secondary end points, including HIV incidence and set point viral load. The utility of sexually transmitted infection biomarkers will likely depend heavily on local epidemiology at clinical trial sites. Analyses from recent large HIV vaccine efficacy trials point to the complexities in interpreting trial results and underscore the potential utility of biomarkers in evaluating confounding and effect modification.

Rapid human immunodeficiency virus testing in obstetric outpatient settings: the MIRIAD study

OBJECTIVE

To evaluate the acceptability and feasibility of rapid human immunodeficiency virus testing in obstetric outpatient settings.

STUDY DESIGN

The Mother-Infant Rapid Intervention at Delivery (MIRIAD) study was a prospective, multicenter study. Women were offered rapid and conventional human immunodeficiency virus testing if they presented to outpatient settings late in pregnancy with undocumented human immunodeficiency virus status. We compared median times between conventional and rapid testing and between rapid point-of-care and rapid laboratory-based testing.

RESULTS

Among eligible women who were offered participation, 90% accepted testing. The median time from blood draw to result available was faster for rapid testing (25 minutes) than conventional testing (23 hours; P < .0001). For rapid tests, point-of-care testing was faster than laboratory-based testing (24 minutes vs 35 minutes; P < .0001). Almost 96% of rapid test results were available within 1 hour.

CONCLUSION

Rapid human immunodeficiency virus testing is acceptable, feasible, and provides results far sooner than conventional testing in obstetric outpatient settings.

Would offering rapid point-of-care testing or non-invasive methods improve uptake of HIV testing among high-risk genitourinary medicine clinic attendees? A patient perspective

While most genitourinary (GU) medicine clinics achieve a high uptake for testing HIV in new patients, they may still miss testing those at highest risk. Point-of-care testing (POCT) and salivary samples are acceptable and feasible but have not yet been shown to increase uptake among high-risk patients (HRP). This study aimed to describe reasons why HRP decline HIV testing and whether offering POCT along with standard testing would increase the uptake of testing HIV in two London GU medicine clinics. Anonymous self-administered questionnaires were offered to all new and rebooked patients. Eight hundred and ninety-nine questionnaires were analysed of which 598 were HRP. Uptake of HIV testing was 77.1 % among HRP and 65.8% among the rest. A total of 51.1 % of HRP who declined HIV testing said they would be more likely to accept a POCT and 32.8% a salivary test. Introduction of rapid POCT for HIV would increase patient's choice and may increase the likelihood of HRP accepting an HIV test.

Implications and impact of the new US Centers for Disease Control and prevention HIV testing guidelines

Of the 1.2 million Americans estimated to be living with HIV in the United States, approximately 250,000 are unaware of their diagnosis and therefore unable to access clinical care and life-sustaining treatment. The revised 2006 US Centers for Disease Control and Prevention's guidelines for HIV testing recommend universal, routine, and voluntary HIV screening in public and private health care settings for all adults and adolescents between 13 and 64 years old. These major revisions present new challenges for health care providers, hospitals, government agencies, and community advocacy groups. In this review, we discuss the important issues in diverse care venues such as opt-out testing, consent and confidentiality, barriers to treatment, and financial impact. The implications of the revised recommendations for HIV testing are addressed in the context of a fragmented, overstressed, underfunded US health care system.

Assessment of rapid tests for detection of human immunodeficiency virus-specific antibodies in recently infected individuals

We have evaluated four current Food and Drug Administration-cleared rapid tests for human immunodeficiency virus (HIV)-specific antibodies with a panel of specimens from recently infected individuals. Recent infection was detected by RNA-based screening coupled with enzyme immunoassay-based testing. We found that the sensitivities of the various rapid tests vary greatly with regard to their ability to detect HIV-specific antibodies in recently infected individuals.

The proteomes of human parotid and submandibular/sublingual gland salivas collected as the ductal secretions

Saliva is a body fluid with important functions in oral and general health. A consortium of three research groups catalogued the proteins in human saliva collected as the ductal secretions: 1166 identifications--914 in parotid and 917 in submandibular/sublingual saliva--were made. The results showed that a high proportion of proteins that are found in plasma and/or tears are also present in saliva along with unique components. The proteins identified are involved in numerous molecular processes ranging from structural functions to enzymatic/catalytic activities. As expected, the majority mapped to the extracellular and secretory compartments. An immunoblot approach was used to validate the presence in saliva of a subset of the proteins identified by mass spectrometric approaches. These experiments focused on novel constituents and proteins for which the peptide evidence was relatively weak. Ultimately, information derived from the work reported here and related published studies can be used to translate blood-based clinical laboratory tests into a format that utilizes saliva. Additionally, a catalogue of the salivary proteome of healthy individuals allows future analyses of salivary samples from individuals with oral and systemic diseases, with the goal of identifying biomarkers with diagnostic and/or prognostic value for these conditions; another possibility is the discovery of therapeutic targets.

Population prevalence of reported and unreported HIV and related behaviors among the household adult population in New York City, 2004

BACKGROUND

Surveillance for HIV likely underestimates infection among the general population: 25% of US residents are estimated to be unaware of their HIV infection.

OBJECTIVE

To determine the prevalence of HIV infection and risk behaviors among New York City (NYC) adults and compare these with surveillance findings.

METHODS

The NYC Health and Nutrition Examination Survey (HANES) provided the first opportunity to estimate population-based HIV prevalence among NYC adults. It was conducted in 2004 among a representative sample of adults > 20 years. Previously reported HIV infection was identified from the NYC HIV/AIDS Surveillance Registry. A blinded HIV serosurvey was conducted on archived blood samples of 1626 NYC HANES participants. Data were used to estimate prevalence for HIV infection, unreported infections, high-risk activities, and self-perceived risk.

RESULTS

Overall, 18.1% engaged in one or more risky sexual/needle-use behaviors, of which 92.2% considered themselves at low or no risk of HIV or another sexually transmitted disease. HIV occurred in 21 individuals (prevalence 1.4%; 95% confidence interval (CI), 0.8-2.5]; one infection (5%; 95% CI, 0.7-29.9) was not reported previously and possibly undiagnosed. HIV infection was significantly elevated in those with herpes simplex virus 2 (4%), men who have sex with men (14%), and needle-users (21%) (P < 0.01).

CONCLUSIONS

Among NYC adults, HIV prevalence was consistent with surveillance findings overall. The proportion of unreported HIV was less than estimated nationally, but findings were limited by sample size. Most adults with risky behaviors perceived themselves to be at minimal risk, highlighting the need for risk reduction and routine HIV screening.

Outcomes of blood and oral fluid rapid HIV testing: a literature review, 2000-2006

Rapid HIV antibody testing is a new technology whose implementation promises to facilitate the early detection of persons with HIV/AIDS. The goal of this study was to review and summarize the literature from 2000-2006 regarding four outcomes of rapid (including both blood and oral fluid) HIV testing: rates of client acceptance; rates of clients' receiving their test results; rates of entry into medical care for those found to be HIV positive; and the efficacy of prevention counseling after testing. A total of 116 studies in peer-reviewed journals were screened. Twenty-six met the screening criteria (published in peer-reviewed journals and focused on at least one of the outcomes of interest) and were selected for review. Considerable variation was found in client acceptance rates with the highest rates among pregnant women in labor and delivery units and the lowest rates in needle exchange and bath-house settings. The evidence shows that most persons tested with a rapid test receive their test result. Three studies on entry into medical care among those who were newly identified HIV positive found rates of 47%, 82%, and 97% of clients adhering to their first medical appointment. No long-term medical follow-up studies were found. Only one study examined the efficacy of prevention counseling after rapid testing and found no statistically significant differences in the number of sexually transmitted diseases (STDs) conventional versus rapid HIV testers contracted following testing.

Article Commentary: Occupational Risks of Blood Exposure in the Operating Room

Bloodborne pathogens continue to be a source of occupational infection for healthcare workers, but particularly for surgeons. Over 1 per cent of the U.S. population has one or more chronic viral infections. Hepatitis B is the infection that has the longest known role as an occupational pathogen, but infection with this virus is largely preventable with the use of the effective hepatitis B vaccine. Hepatitis C affects the largest number of people in the United States, and there is no vaccine available for the prevention of this infection. HIV infection still has not been associated with a documented transmission in the operating room environment, but six cases of probable occupational transmission have been reported. A total of 57 healthcare workers have had documented occupational infection since the epidemic of HIV infection began. Infection of blood-borne pathogens to patients from infected surgeons remains a concern. Surgeons who are e-antigen-positive for hepatitis B have been well documented to be an infection risk to patients in the operating room. Only four surgeons have been documented to transmit hepatitis C, although other transmissions have occurred in the care of patients when practices of infection control have been violated. No surgical transmission of HIV to a patient has been identified at this time. Prevention of occupational infection requires use of protective barriers, avoidance of exposure risk by modification of techniques, and a constant awareness of sharp instruments in the operating room. Blood exposure in the operating room carries risk of infection and should be avoided. It is likely that other infectious agents will emerge as operating room threats. Surgeons must maintain vigilance in avoiding blood exposure and percutaneous injury.