Rapid, real-time detection of acute HIV infection in patients in Africa

“Facilitating HIV status adjustment: Qualitative insights from the Tambua Mapema proof-of-concept study in Kenya”

Systematic efforts are needed to prepare persons newly diagnosed with acute or chronic HIV infection to cope. We examined how patients dealt with this news, looking at how readiness to accept an HIV diagnosis impacted treatment outcomes, prevention of transmission, and HIV status disclosure. We examined vulnerability and agency over time and considered implications for policy and practice. A qualitative sub-study was embedded in the Tambua Mapema (“Discover Early”) Plus (TMP) study (NCT03508908), conducted in coastal Kenya between 2017 and 2020, which was a stepped wedge trial to evaluate an opt-out HIV-1 nucleic acid testing intervention diagnosing acute and chronic HIV infections. Diagnosed participants were offered antiretroviral therapy (ART), viral load monitoring, HIV partner notification services, and provision of pre-exposure prophylaxis (PrEP) to their uninfected partners. Data were analyzed using thematic approaches. Participants included 24 individuals who completed interviews at four time points (2 weeks and 3, 6, and 9 months after diagnosis), including 18 patients (11 women and 7 men) and 6 partners (1 woman, 5 men, of whom 4 men started PrEP). Acceptance of HIV status was often a long, individualized, and complex process, whereby participants’ coping strategies affected day-to-day issues and health over time. Relationship status strongly impacted coping. In some instances, couples supported each other, but in others, couples separated. Four main themes impacted participants’ sense of agency: acceptance of diagnosis and commitment to ART; positive feedback after attaining viral load suppression; recognition of partner supportive role and focus on sustained healthcare support whereby religious meaning was often key to successful transition. To support patients with acute or newly diagnosed chronic HIV, healthcare and social systems must be more responsive to the needs of the individual, while also improving quality of care, strengthening continuity of care across facilities, and promoting community support.

Effect of an opt-out point-of-care HIV-1 nucleic acid testing intervention to detect acute and prevalent HIV infection in symptomatic adult outpatients and reduce HIV transmission in Kenya: a randomized controlled trial

BACKGROUND

In sub-Saharan Africa, adult outpatients with symptoms of acute infectious illness are not routinely tested for prevalent or acute HIV infection (AHI) when seeking healthcare.

METHODS

Adult symptomatic outpatients aged 18-39 years were evaluated by a consensus AHI risk score. Patients with a risk score ≥ 2 and no previous HIV diagnosis were enrolled in a stepped-wedge trial of opt-out delivery of point-of-care (POC) HIV-1 nucleic acid testing (NAAT), compared with standard provider-initiated HIV testing using rapid tests in the observation period. The primary outcome was the number of new diagnoses in each study period. Generalized estimating equations with a log-binomial link and robust variance estimates were used to account for clustering by health facility. The trial is registered with ClinicalTrials.gov NCT03508908.

RESULTS

Between 2017 and 2020, 13 (0.9%) out of 1374 participants in the observation period and 37 (2.5%) out of 1500 participants in the intervention period were diagnosed with HIV infection. Of the 37 newly diagnosed cases in the intervention period, two (5.4%) had AHI. Participants in the opt-out intervention had a two-fold greater odds of being diagnosed with HIV (odds ratio = 2.2, 95% confidence interval: 1.39-3.51) after adjustment for factors imbalanced across study periods.

CONCLUSIONS

Among symptomatic adults aged 18-39 years targeted by our POC NAAT intervention, we identified one chronic HIV infection for every 40 patients and one AHI patient for every 750 patients tested. Although AHI yield was low in this population, routinely offered opt-out testing could diagnose twice as many patients as an approach relying on provider discretion.

HIV infection in Eastern and Southern Africa: Highest burden, largest challenges, greatest potential

BACKGROUND

The burden of HIV is especially concerning for Eastern and Southern Africa (ESA), as despite expansion of test-and-treat programmes, this region continues to experience significant challenges resulting from high rates of morbidity, mortality and new infections. Hard-won lessons from programmes on the ground in ESA should be shared.

OBJECTIVES

This report summarises relevant evidence and regional experts' recommendations regarding challenges specific to ESA.

METHOD

This commentary includes an in-depth review of relevant literature, progress against global goals and consensus opinion from experts.

RESULTS

Recommendations include priorities for essential research (surveillance data collection, key and vulnerable population education and testing, in-country testing trials and evidence-based support services to improve retention in care) as well as research that can accelerate progress towards the prevention of new infections and achieving ambitious global goals in ESA.

CONCLUSION

The elimination of HIV in ESA will require continued investment, commitment to evidence-based programmes and persistence. Local research is critical to ensuring that responses in ESA are targeted, efficient and evaluated.

Human Immunodeficiency Virus (HIV)-1 Transmission Among Persons With Acute HIV-1 Infection in Malawi: Demographic, Behavioral, and Phylogenetic Relationships

BACKGROUND

Understanding sexual networks involving acute human immunodeficiency virus (HIV)-1 infections (AHI) may lead to prevention opportunities to mitigate high rates of onward transmission. We evaluated HIV-1 phylogenetic and behavioral characteristics among persons with AHI and their referred partners.

METHODS

Between 2012 and 2014, 46 persons with AHI in Malawi participated in a combined behavioral and biomedical intervention. Participants referred sexual partners by passive referral. Demographics and sexual behaviors were collected through interviews and HIV-1 genetic relationships were assessed with phylogenetics.

RESULTS

Among 45 AHI participants with HIV-1 sequences, none was phylogenetically-linked with another AHI index. There were 19 (42%) AHI participants who referred a single partner that returned for testing. Most partners (n = 17) were HIV-infected, with 15 (88%) presenting with an established infection. There were 14 index-partner pairs that had sequences available; 13 (93%) pairs were phylogenetically-linked dyads. The AHI index was female in 7/13 (54%) dyads. Age-disparate relationships among dyads were common (≥5-year age difference in 67% of dyads), including 3/6 dyads involving a male index and a younger woman. Index participants with a referred partner were more likely to report no casual partners and to be living with their current partner than participants not in dyads.

CONCLUSIONS

Passive-partner referral successfully identified partners with genetically-similar HIV infections-the likely source of infection-but only 40% of index cases referred partners who presented for HIV-1 testing. Future work evaluating assisted partner notification may help reach susceptible partners or more people with untreated HIV-1 infections connected to acute transmission.

CLINICAL TRIALS REGISTRATION

NCT01450189.

A Novel HIV-1 RNA Testing Intervention to Detect Acute and Prevalent HIV Infection in Young Adults and Reduce HIV Transmission in Kenya: Protocol for a Randomized Controlled Trial

Background

Detection and management of acute HIV infection (AHI) is a clinical and public health priority, and HIV infections diagnosed among young adults aged 18 to 39 years are usually recent. Young adults with recent HIV acquisition frequently seek care for symptoms and could potentially be diagnosed through the health care system. Early recognition of HIV infection provides considerable individual and public health benefits, including linkage to treatment as prevention, access to risk reduction counseling and treatment, and notification of partners in need of HIV testing.

Objective

The Tambua Mapema Plus study aims to (1) test 1500 young adults (aged 18-39 years) identified by an AHI screening algorithm for acute and prevalent (ie, seropositive) HIV, linking all newly diagnosed HIV-infected patients to care and offering immediate treatment; (2) offer assisted HIV partner notification services to all patients with HIV, testing partners for acute and prevalent HIV infection and identifying local sexual networks; and (3) model the potential impact of these two interventions on the Kenyan HIV epidemic, estimating incremental costs per HIV infection averted, death averted, and disability-adjusted life year averted using data on study outcomes.

Methods

A modified stepped-wedge design is evaluating the yield of this HIV testing intervention at 4 public and 2 private health facilities in coastal Kenya before and after intervention delivery. The intervention uses point-of-care HIV-1 RNA testing combined with standard rapid antibody tests to diagnose AHI and prevalent HIV among young adults presenting for care, employs HIV partner notification services to identify linked acute and prevalent infections, and follows all newly diagnosed patients and their partners for 12 months to ascertain clinical outcomes, including linkage to care, antiretroviral therapy (ART) initiation and virologic suppression in HIV-infected patients, and pre-exposure prophylaxis uptake in uninfected individuals in discordant partnerships.

Results

Enrollment started in December 2017. As of April 2020, 1374 participants have been enrolled in the observation period and 1500 participants have been enrolled in the intervention period, with 13 new diagnoses (0.95%) in the observation period and 37 new diagnoses (2.47%), including 2 AHI diagnoses, in the intervention period. Analysis is ongoing and will include adjusted comparisons of the odds of the following outcomes in the observation and intervention periods: being tested for HIV infection, newly diagnosed with prevalent or acute HIV infection, linked to care, and starting ART by week 6 following HIV diagnosis. Participants newly diagnosed with acute or prevalent HIV infection in the intervention period are being followed for outcomes, including viral suppression by month 6 and month 12 following ART initiation and partner testing outcomes.

Conclusions

The Tambua Mapema Plus study will provide foundational data on the potential of this novel combination HIV prevention intervention to reduce ongoing HIV transmission in Kenya and other high-prevalence African settings.

Trial Registration

ClinicalTrials.gov NCT03508908; https://clinicaltrials.gov/ct2/show/NCT03508908

International Registered Report Identifier (IRRID)

DERR1-10.2196/16198

Spectrophotometric ellipsometry based Tat-protein RNA-aptasensor for HIV-1 diagnosis

Rapid and reliable diagnosis of Human Immunodeficiency Virus (HIV) Type I that causes autoimmune deficiency syndrome (AIDS) is still important today. In this study, the HIV-I Tat (trans-activator of transcription) protein-specific RNA-aptamer (antiTat) and spectroscopic ellipsometer were preferred to increase specificity and sensitivity in the diagnosis. The ellipsometry is a well-known characterization tool for the ultra-thin films, where polarization state changes show surface deposition in terms of the ellipsometric angles, psi (Ψ) and delta (Δ). Here, we reported the HIV-Tat protein detection performance of antiTat aptamers both for the spectroscopic ellipsometry (SE) and for the surface plasmon resonance enhanced total internal reflection ellipsometry (SPReTIRE), first time. Detection limits for antiTat aptamers with various configurations were in the range of nM-pM protein in the buffer solution. For instance, SPRe-TIRE configuration revealed a detection limit of 1 pM (or about 1.5 pg/mL) for HIV-Tat protein in the range of 1.0-500 nM.

Sustained Sexual Behavior Change After Acute HIV Diagnosis in Malawi

BACKGROUND

Identification of acute HIV infection (AHI) allows for important opportunities for HIV prevention through behavior change and biomedical intervention. Here, we evaluate changes in sexual risk behaviors among persons with AHI enrolled in a combined behavioral and biomedical intervention designed to reduce onward transmission of HIV.

METHODS

Participants were randomized to standard HIV counseling, a multisession behavioral intervention, or a multisession behavioral intervention plus antiretrovirals. Sexual behaviors were assessed periodically over 1 year.

RESULTS

Four weeks after diagnosis, the predicted probability of reporting multiple sexual partners decreased from 24% to 9%, and the probability of reporting unprotected sex decreased from 71% to 27%. These declines in sexual risk behaviors were sustained over follow-up irrespective of study arm.

CONCLUSIONS

Diagnosis of AHI alone may be sufficient to achieve immediate and sustained behavior change during this highly infectious period.

Randomized Controlled Pilot Study of Antiretrovirals and a Behavioral Intervention for Persons With Acute HIV Infection: Opportunity for Interrupting Transmission

Background

Persons with acute HIV infection (AHI) have heightened transmission risk. We evaluated potential transmission reduction using behavioral and biomedical interventions in a randomized controlled pilot study in Malawi.

Methods

Persons were randomized 1:2:2 to standard counseling (SC), 5-session behavioral intervention (BI), or behavioral intervention plus 12 weeks of antiretrovirals (ARVs; BIA). All were followed for 26–52 weeks and, regardless of arm, referred for treatment according to Malawi-ARV guidelines. Participants were asked to refer partners for testing.

Results

Among 46 persons (9 SC, 18 BI, 19 BIA), the average age was 28; 61% were male. The median viral load (VL) was 5.9 log copies/mL at enrollment. 67% (10/15) of BIA participants were suppressed (<1000 copies/mL) at week 12 vs 25% BI and 50% SC (P = .07). Although the mean number of reported condomless sexual acts in the past week decreased from baseline across all arms (1.5 vs 0.3 acts), 36% experienced incident sexually transmitted infection by 52 weeks (12% SC, 28% BI, 18% BIA). Forty-one percent (19/46) of participants referred partners (44% SC, 44% BI, 37% BIA); 15 of the partners were HIV-infected.

Conclusions

Diagnosis of AHI facilitates behavioral and biomedical risk reduction strategies during a high-transmission period that begins years before people are typically identified and started on ARVs. Sexually transmitted infection incidence in this cohort suggests ongoing risk behaviors, reinforcing the importance of early intervention with ARVs to reduce transmission. Early diagnosis coupled with standard AHI counseling and early ARV referral quickly suppresses viremia, may effectively change behavior, and could have tremendous public health benefit in reducing onward transmission.

A Cohort Approach to Real-Time Detection of Acute HIV Infections Among People Who Inject Drugs in St. Petersburg, Russia

To detect acute HIV infections (AHIs) in real time among people who inject drugs (PWID) in St. Petersburg, Russia and to test the feasibility of this approach. Prospective cohort study. One hundred seronegative or acutely HIV-infected at screening PWID were enrolled and followed until the end of the 12-month pilot period. Each participant was evaluated, tested, and counseled for HIV monthly. Two HIV tests were used: HIV antibody and HIV RNA PCR. If diagnosed with AHI, participants were followed weekly for a month; then, monthly for 3 months; and then, quarterly for the duration of the follow-up period. HIV risk behavior was assessed at each study visit. Most enrolled PWID were 30-39 years old, male, completed high school or more, not employed full-time, heroin users, and frequently shared injection paraphernalia. AHI prevalence at screening was 1.8% [95% confidence interval (CI): 0.4, 5.5]. Three participants with AHI at enrollment represented 3% (95% CI: 0.6, 8.5) of the 100 participants who consented to enroll. Among the HIV-uninfected participants (n = 97), the AHI incidence over time was 9.3 per 100 person-years. Persons with AHI were more likely to report alcohol intoxication within the prior 30 days. This was the first study to detect AHI using a cohort approach. The approach proved to be feasible: recruitment, retention, AHI detection, and virological endpoints were successfully reached. A cost analysis in a real-world setting would be required to determine if this strategy could be brought to scale. The study revealed continued high HIV incidence rate among PWID in St. Petersburg, Russia and the importance of prevention and treatment programs for this group.

IP-10 Levels as an Accurate Screening Tool to Detect Acute HIV Infection in Resource-Limited Settings

Acute HIV infection (AHI) is the period prior to seroconversion characterized by high viral replication, hyper-transmission potential and commonly, non-specific febrile illness. AHI detection requires HIV-RNA viral load (VL) determination, which has very limited access in low-income countries due to restrictive costs and implementation constraints. We sought to identify a biomarker that could enable AHI diagnosis in scarce-resource settings, and to evaluate the feasibility of its implementation. HIV-seronegative adults presenting at the Manhiça District Hospital, Mozambique, with reported-fever were tested for VL. Plasma levels of 49 inflammatory biomarkers from AHI (n = 61) and non-HIV infected outpatients (n = 65) were determined by Luminex and ELISA. IP-10 demonstrated the best predictive power for AHI detection (AUC = 0.88 [95%CI 0.80-0.96]). A cut-off value of IP-10 ≥ 161.6 pg/mL provided a sensitivity of 95.5% (95%CI 85.5-99.5) and a specificity of 76.5% (95%CI 62.5-87.2). The implementation of an IP-10 screening test could avert from 21 to 84 new infections and save from US$176,609 to US$533,467 to the health system per 1,000 tested patients. We conclude that IP-10 is an accurate biomarker to screen febrile HIV-seronegative individuals for subsequent AHI diagnosis with VL. Such an algorithm is a cost-effective strategy to prevent disease progression and a substantial number of further HIV infections.

Discordant rapid HIV tests: lessons from a low-resource community

OBJECTIVES

HIV rapid antibody tests are widely used in Africa, but dual testing sometimes produces discordant results. It is not clear if discordant rapid HIV tests should always heighten suspicion by frontline health workers that early HIV infection is present. Some studies have reported that discordant rapid tests have value for identifying early HIV infection in high HIV prevalence populations. It is not known if rapid test performance influenced this conclusion, or if this observation will hold true for low HIV prevalence populations. We therefore explored the occurrence of discordant rapid HIV tests in a low-resource community.

METHODS

A cross-sectional sample of HIV status-unaware adults with recent exposure to unsafe sex was assessed using a validated risk-based tool (University of North Carolina (UNC)-Malawi Risk Screening Score) for acute HIV infection. Participants received rapid testing with Determine™ HIV 1/2 and Uni-Gold™ HIV assays, plus plasma HIV-1 antigen testing with the COBAS^® Ampliprep/COBAS^® Taqman^® HIV-1 assay, followed by western blot in those with detected HIV-1 antigen.

RESULTS

Of 408 participants, 1.0% were confirmed to have established HIV infection. The discordance between rapid tests at initial screening was 2.45 and 2.94% when the two assays were used sequentially and simultaneously, respectively. Discordant rapid tests were strongly associated with risk scores > 2 [odds ratio (OR) 10.88; 95% confidence interval (CI) 2.35-50.43], and with detected HIV-1 RNA (OR 26.06; 95% CI 3.91-173.60).

CONCLUSIONS

When the sample occurrence of discordance between the first and second tests is below 5%, discordant rapid tests in an adult with sexual risk behaviour should trigger strong suspicion of early HIV infection in low HIV prevalence populations.

Clinical and public health implications of acute and early HIV detection and treatment: a scoping review

INTRODUCTION

The unchanged global HIV incidence may be related to ignoring acute HIV infection (AHI). This scoping review examines diagnostic, clinical, and public health implications of identifying and treating persons with AHI.

METHODS

We searched PubMed, in addition to hand-review of key journals identifying research pertaining to AHI detection and treatment. We focused on the relative contribution of AHI to transmission and the diagnostic, clinical, and public health implications. We prioritized research from low- and middle-income countries (LMICs) published in the last fifteen years.

RESULTS AND DISCUSSION

Extensive AHI research and limited routine AHI detection and treatment have begun in LMIC. Diagnostic challenges include ease-of-use, suitability for application and distribution in LMIC, and throughput for high-volume testing. Risk score algorithms have been used in LMIC to screen for AHI among individuals with behavioural and clinical characteristics more often associated with AHI. However, algorithms have not been implemented outside research settings. From a clinical perspective, there are substantial immunological and virological benefits to identifying and treating persons with AHI - evading the irreversible damage to host immune systems and seeding of viral reservoirs that occurs during untreated acute infection. The therapeutic benefits require rapid initiation of antiretrovirals, a logistical challenge in the absence of point-of-care testing. From a public health perspective, AHI diagnosis and treatment is critical to: decrease transmission via viral load reduction and behavioural interventions; improve pre-exposure prophylaxis outcomes by avoiding treatment initiation for HIV-seronegative persons with AHI; and, enhance partner services via notification for persons recently exposed or likely transmitting.

CONCLUSIONS

There are undeniable clinical and public health benefits to AHI detection and treatment, but also substantial diagnostic and logistical barriers to implementation and scale-up. Effective early ART initiation may be critical for HIV eradication efforts, but widespread use in LMIC requires simple and accurate diagnostic tools. Implementation research is critical to facilitate sustainable integration of AHI detection and treatment into existing health systems and will be essential for prospective evaluation of testing algorithms, point-of-care diagnostics, and efficacious and effective first-line regimens.

Performance of HIV Rapid Tests Among Breastfeeding, Malawian Infants

INTRODUCTION

Timely, accurate and affordable testing algorithms at point-of-care are critical for early infant HIV diagnosis and initiation of antiretroviral therapy in the postpartum period. We aimed to assess the utility of HIV rapid tests for young, breast-fed HIV-exposed infants in resource limited, high HIV burden settings.

MATERIALS AND METHODS

We collected data on the performance of 2 commonly used rapid tests (Determine and Unigold) in Malawi between 2008 and 2012 or at the University of North Carolina between 2014 and 2015. For each 3-month interval between ages 3 and 18 months, we calculated the sensitivity, specificity, positive and negative predictive values of each test compared with the HIV DNA/RNA PCR gold standard. We also assessed the utility of each rapid test to diagnose incident HIV infection during the breastfeeding period.

RESULTS

Among 121 HIV-exposed infants who were negative at age 6 weeks, 21 (17.2%) became infected by 18 months. At 3 months of age, both rapid tests had minimal clinical value with specificity values of 7.0% [95% confidence interval (CI): 2.3-15.7] for Determine and 19.4% (95% CI: 11.1-30.5) for Unigold. Starting at age 6 and 9 months, the Unigold test could be used as a screening tool in the follow-up of HIV-exposed infants with specificity values of 83.7% (95% CI: 74.4-89.9) and 97.7% (95% CI: 94.6-99.7), respectively. Starting at age 12 months, the type of test became less important as both tests performed well in identifying HIV-free children, although both tests failed to detect some incident HIV infections.

CONCLUSIONS

Updated guidelines for the use of rapid tests in young HIV-exposed children that explicitly take type of test and infant age into account are urgently needed to ensure optimal care for the 1.5 million HIV-exposed infants born annually.

Gender asymmetry in concurrent partnerships and HIV prevalence

The structure of the sexual network of a population plays an essential role in the transmission of HIV. Concurrent partnerships, i.e. partnerships that overlap in time, are important in determining this network structure. Men and women may differ in their concurrent behavior, e.g. in the case of polygyny where women are monogamous while men may have concurrent partnerships. Polygyny has been shown empirically to be negatively associated with HIV prevalence, but the epidemiological impacts of other forms of gender-asymmetric concurrency have not been formally explored. Here we investigate how gender asymmetry in concurrency, including polygyny, can affect the disease dynamics. We use a model for a dynamic network where individuals may have concurrent partners. The maximum possible number of simultaneous partnerships can differ for men and women, e.g. in the case of polygyny. We control for mean partnership duration, mean lifetime number of partners, mean degree, and sexually active lifespan. We assess the effects of gender asymmetry in concurrency on two epidemic phase quantities (R₀ and the contribution of the acute HIV stage to R₀) and on the endemic HIV prevalence. We find that gender asymmetry in concurrent partnerships is associated with lower levels of all three epidemiological quantities, especially in the polygynous case. This effect on disease transmission can be attributed to changes in network structure, where increasing asymmetry leads to decreasing network connectivity.

Sensitivity of HIV rapid tests compared with fourth-generation enzyme immunoassays or HIV RNA tests

OBJECTIVE

Determine the sensitivity of HIV rapid tests compared with fourth-generation enzyme immunoassays (EIA) or nucleic acid amplification tests (NAAT) in clinical settings.

DESIGN

Systematic review and meta-analysis.

METHODS

Medline, PubMed, Embase, Cochrane Controlled Trials Register, Cochrane reviews and Cumulative Index to Nursing and Allied Health Literature were searched until 14 July 2015 for studies of adults comparing point-of-care HIV rapid tests to fourth-generation HIV EIA antibody/p24 antigen or HIV NAAT.

RESULTS

From 953 titles, 18 studies were included, involving 110 122 HIV rapid test results. Compared with EIA, the estimated sensitivity (random effects) of HIV rapid tests was 94.5% [95% confidence interval (CI): 87.4-97.7]. Compared with NAAT, the sensitivity of HIV rapid tests was 93.7% (95% CI: 88.7-96.5). The sensitivity of HIV rapid tests in high-income countries was 85.7% (95% CI: 81.9-88.9) and in low-income countries was 97.7% (95% CI: 95.2-98.9) compared with either EIA or NAAT (P < 0.01 for difference between settings). Proportions of antibody negative acute infections were 13.6 (95% CI: 10.1-18.0) and 4.7% (95% CI: 2.8-7.7) in studies from high-income and low-income countries, respectively (P < 0.01).

CONCLUSION

In clinical settings, HIV rapid tests were less sensitive in high-income countries compared with low-income countries, missing about one in seven infections, possibly because of the larger proportion of acute infections in targeted populations. This suggests that in high-income countries, HIV rapid tests should be used in combination with fourth-generation EIA or NAAT tests, except in special circumstances. Prospective Registration of Systematic Reviews registration number CRD42015020154.Supplementary video link: http://links.lww.com/QAD/A924.

Incorporating Acute HIV Screening into Routine HIV Testing at Sexually Transmitted Infection Clinics, and HIV Testing and Counseling Centers in Lilongwe, Malawi

Background and Objectives:

Integrating acute HIV-infection (AHI) testing into clinical settings is critical to prevent transmission, and realize potential treatment-as-prevention benefits. We evaluated acceptability of AHI testing and compared AHI prevalence at sexually transmitted infection (STI) clinics and HIV testing and counseling (HTC) clinics in Lilongwe, Malawi.

Methods:

We conducted HIV RNA testing for HIV-seronegative patients visiting STI and HTC clinics. AHI was defined as positive RNA and negative/discordant rapid antibody tests. We evaluated demographic, behavioral, and transmission-risk differences between STI and HTC patients and assessed performance of a risk-score for targeted screening.

Results:

Nearly two-thirds (62.8%, 9280/14,755) of eligible patients consented to AHI testing. We identified 59 persons with AHI (prevalence = 0.64%)–a 0.9% case-identification increase. Prevalence was higher at STI [1.03% (44/4255)] than at HTC clinics [0.3% (15/5025), P < 0.01], accounting for 2.3% of new diagnoses vs 0.3% at HTC clinic. Median viral load (VL) was 758,050 copies per milliliter; 25% (15/59) had VL ≥10,000,000 copies per milliliter. Median VL was higher at STI (1,000,000 copies/mL) compared with HTC (153,125 copies/mL, P = 0.2). Among persons with AHI, those tested at STI clinics were more likely to report genital sores compared with those tested at HTC clinics (54.6% vs 6.7%, P < 0.01). The risk score algorithm performed well in identifying persons with AHI at HTC clinics (sensitivity = 73%, specificity = 89%).

Conclusions:

The majority of patients consented to AHI testing. AHI prevalence was substantially higher in STI clinics than HTC clinics. Remarkably high VLs and concomitant genital scores demonstrate the potential for transmission. Universal AHI screening at STI clinics, and targeted screening at HTC centers, should be considered.

Ten Years of Screening and Testing for Acute HIV Infection in North Carolina

OBJECTIVE

To describe demographic and behavioral characteristics of persons with acute HIV infection (AHI) over time.

METHODS

We conducted a retrospective assessment of AHI identified through the Screening and Tracing Active Transmission (STAT) program from 2003 to 2012 in North Carolina (NC). AHI was identified using pooled nucleic acid amplification for antibody negative samples and individual HIV-1 RNA for antibody indeterminate samples. The STAT program provides rapid notification and evaluation. We compared STAT-collected demographic and risk characteristics with all persons requesting tests and all non-AHI diagnoses from the NC State Laboratory of Public Health.

RESULTS

The STAT Program identified 236 AHI cases representing 3.4% (95% confidence interval: 3.0% to 3.9%) of all HIV diagnoses. AHI cases were similar to those diagnosed during established HIV. On pretest risk-assessments, AHI cases were predominately black (69.1%), male (80.1%), young (46.8% < 25 years), and men who have sex with men (MSM) (51.7%). Per postdiagnosis interviews, the median age decreased from 35 (interquartile range 25-42) to 27 (interquartile range 22-37) years, and the proportion <25 years increased from 23.8% to 45.2% (trend P = 0.04) between 2003 and 2012. AHI men were more likely to report MSM risk post-diagnosis than on pretest risk-assessments (64%-82.9%; P < 0.0001). Post-diagnosis report of MSM risk in men with AHI increased from 71.4% to 96.2%.

CONCLUSIONS

In NC, 3.4% of individuals diagnosed with HIV infection have AHI. AHI screening provides a real-time source of incidence trends, improves the diagnostic yield of HIV testing, and offers an opportunity to limit onward transmission.

Systematic review and meta-analysis of community and facility-based HIV testing to address linkage to care gaps in sub-Saharan Africa

HIV testing and counselling is the first crucial step for linkage to HIV treatment and prevention. However, despite high HIV burden in sub-Saharan Africa, testing coverage is low, particularly among young adults and men. Community-based HIV testing and counselling (testing outside of health facilities) has the potential to reduce coverage gaps, but the relative impact of different modalities is not well assessed. We conducted a systematic review of HIV testing modalities, characterizing community (home, mobile, index, key populations, campaign, workplace and self-testing) and facility approaches by population reached, HIV positivity, CD4 count at diagnosis and linkage. Of 2,520 abstracts screened, 126 met eligibility criteria. Community HIV testing and counselling had high coverage and uptake and identified HIV-positive people at higher CD4 counts than facility testing. Mobile HIV testing reached the highest proportion of men of all modalities examined (50%, 95% confidence interval (CI) = 47-54%) and home with self-testing reached the highest proportion of young adults (66%, 95% CI = 65-67%). Few studies evaluated HIV testing for key populations (commercial sex workers and men who have sex with men), but these interventions yielded high HIV positivity (38%, 95% CI = 19-62%) combined with the highest proportion of first-time testers (78%, 95% CI = 63-88%), indicating service gaps. Community testing with facilitated linkage (for example, counsellor follow-up to support linkage) achieved high linkage to care (95%, 95% CI = 87-98%) and antiretroviral initiation (75%, 95% CI = 68-82%). Expanding home and mobile testing, self-testing and outreach to key populations with facilitated linkage can increase the proportion of men, young adults and high-risk individuals linked to HIV treatment and prevention, and decrease HIV burden.

The HIV treatment cascade in acutely infected people: informing global guidelines

PURPOSE OF REVIEW

Acute and early HIV (AHI) is a pivotal time during HIV infection, yet there remain major shortfalls in diagnosis, linkage to care, and antiretroviral therapy (ART) initiation during AHI. We introduce an AHI-specific cascade, review recent evidence pertaining to the unique challenges of AHI, and discuss strategies for improving individual and public health outcomes.

RECENT FINDINGS

Presentation during AHI is common. Expanding use of fourth-generation testing and pooled nucleic acid amplification testing has led to improved AHI detection in resource-wealthy settings. Technologies capable of AHI diagnosis are rare in resource-limited settings; further development of point-of-care devices and utilization of targeted screening is needed. Rapid ART initiation during AHI limits reservoir seeding, preserves immunity, and prevents transmission. Reporting of AHI cascade outcomes is limited, but new evidence suggests that impressive rates of diagnosis, linkage to care, rapid ART initiation, and viral suppression can be achieved.

SUMMARY

With advancements in AHI diagnostics and strong evidence for the therapeutic and prevention benefits of ART initiated during AHI, improving AHI cascade outcomes is both crucial and feasible. HIV guidelines should recommend diagnostic algorithms capable of detecting AHI and prescribe rapid, universal ART initiation during AHI.

Determination of HIV Status in African Adults With Discordant HIV Rapid Tests

BACKGROUND

In resource-limited settings, HIV infection is often diagnosed using 2 rapid tests. If the results are discordant, a third tie-breaker test is often used to determine HIV status. This study characterized samples with discordant rapid tests and compared different testing strategies for determining HIV status in these cases.

METHODS

Samples were previously collected from 173 African adults in a population-based survey who had discordant rapid test results. Samples were classified as HIV positive or HIV negative using a rigorous testing algorithm that included two fourth-generation tests, a discriminatory test, and 2 HIV RNA tests. Tie-breaker tests were evaluated, including rapid tests (1 performed in-country), a third-generation enzyme immunoassay, and two fourth-generation tests. Selected samples were further characterized using additional assays.

RESULTS

Twenty-nine samples (16.8%) were classified as HIV positive and 24 of those samples (82.8%) had undetectable HIV RNA. Antiretroviral drugs were detected in 1 sample. Sensitivity was 8.3%-43% for the rapid tests; 24.1% for the third-generation enzyme immunoassay; 95.8% and 96.6% for the fourth-generation tests. Specificity was lower for the fourth-generation tests than the other tests. Accuracy ranged from 79.5% to 91.3%.

CONCLUSIONS

In this population-based survey, most HIV-infected adults with discordant rapid tests were virally suppressed without antiretroviral drugs. Use of individual assays as tie-breaker tests was not a reliable method for determining HIV status in these individuals. More extensive testing algorithms that use a fourth-generation screening test with a discriminatory test and HIV RNA test are preferable for determining HIV status in these cases.

Evaluation of the clinical effectiveness of HIV antigen/antibody screening using a chemiluminescence microparticle immunoassay

Human immunodeficiency virus (HIV) screening assays have improved from single-antigen detection to detection of antigen-antibody combinations. However, concerns have been raised over the potential for false-positive results in antigen-antibody combination assays. The present study investigated the clinical effectiveness of HIV antigen/antibody (HIV Ag/Ab) combination screening by chemiluminescence microparticle immunoassay (CMIA) in over 88,000 samples from an HIV low-prevalence area of Beijing, China. The HIV Ag/Ab CMIA screening results were consistent with those obtained by Western blot and HIV-RNA testing, and had an accuracy of 99.74% (Kappa index=0.98). False-positive results were more common for women affected by clinical interfering factors (e.g., kidney disease, tumors) than for men (80.95% vs. 15.09%, P<0.001). When CMIA signal-to-cutoff ratio (S/CO) was 11.26, the sensitivity and specificity were highest (100%, 99.43%), and the area under the ROC curve (AUC) was 0.998. Specimens that were negative by CMIA (S/CO <1) were all negative by HIV-RNA testing. These results indicate that HIV Ag/Ab CMIA has a good clinical performance; however, some clinical interfering factors should be considered in HIV low-prevalence areas for their potential to skew testing results.

Acute HIV-1 infection is as common as malaria in young febrile adults seeking care in coastal Kenya

Background:

Febrile adults are usually not tested for acute HIV-1 infection (AHI) in Africa. We assessed a strategy to diagnose AHI among young adult patients seeking care.

Methods:

Young adults (<30 years) who met predefined AHI criteria at care seeking, including fever, sexually transmitted disease symptoms, diarrhoea, body pains or multiple partners were referred from five pharmacies and screened at five health facilities. Prevalent HIV-1 was diagnosed by nationally recommended serial rapid HIV-1 testing. Willing HIV-1-negative patients were evaluated for AHI, defined as a positive p24 antigen test, and subsequent seroconversion or RNA detection. Febrile patients evaluated for AHI were also screened for malaria using a rapid test, with PCR confirmation of positives.

Results:

In 3602 adults seeking care, overall HIV-1 prevalence was 3.9%: 7.6% (68/897) among patients meeting AHI criteria vs. 2.6% (71/2705) among those who did not (P < 0.001). AHI was diagnosed in five of 506 HIV-1-negative or discordant patients who met AHI risk criteria and were completely evaluated [prevalence 1.0%, 95% confidence interval (CI) 0.3–2.3%]. Of these five AHI cases, four were diagnosed among the 241 patients with fever (prevalence 1.7%, 95% CI 0.5–4.2%), vs. one among 265 non-febrile patients (prevalence 0.4%, 95% CI 0.0–2.0%, P = 0.1). Malaria was confirmed by PCR in four (1.7%) of the 241 febrile patients.

Conclusion:

AHI was as common as confirmed malaria in young febrile adults seeking care. An AHI detection strategy targeting young febrile adults seeking care at pharmacies and health facilities is feasible and should be considered as an HIV-prevention strategy in high-transmission settings.

Diagnosing acute and prevalent HIV-1 infection in young African adults seeking care for fever: a systematic review and audit of current practice

Fever is a common complaint in HIV-1 infected adults and may be a presenting sign of acute HIV-1 infection (AHI). We investigated the extent to which HIV-1 infection was considered in the diagnostic evaluation of febrile adults in sub-Saharan Africa (SSA) through a systematic review of published literature and guidelines in the period 2003–2014. We also performed a detailed audit of current practice for the evaluation of febrile young adults in coastal Kenya. Our review identified 43 studies investigating the aetiology of fever in adult outpatients in SSA. While the guidelines identified recommend testing for HIV-1 infection, none mentioned AHI. In our audit of current practice at nine health facilities, only 189 out of 1173 (16.1%) patients, aged 18–29 years, were tested for HIV-1. In a detailed record review, only 2 out of 39 (5.1%) young adults seeking care for fever were tested for HIV-1, and the possibility of AHI was not mentioned. Available literature on adult outpatients presenting with fever is heavily focused on diagnosing malaria and guidelines are poorly defined in terms of evaluating aetiologies other than malaria. Current practice in coastal Kenya shows poor uptake of provider-initiated HIV-1 testing and AHI is not currently considered in the differential diagnosis.

Transcription elongation regulator 1 (TCERG1) regulates competent RNA polymerase II-mediated elongation of HIV-1 transcription and facilitates efficient viral replication

Background

Control of RNA polymerase II (RNAPII) release from pausing has been proposed as a checkpoint mechanism to ensure optimal RNAPII activity, especially in large, highly regulated genes. HIV-1 gene expression is highly regulated at the level of elongation, which includes transcriptional pausing that is mediated by both viral and cellular factors. Here, we present evidence for a specific role of the elongation-related factor TCERG1 in regulating the extent of HIV-1 elongation and viral replication in vivo.

Results

We show that TCERG1 depletion diminishes the basal and viral Tat-activated transcription from the HIV-1 LTR. In support of a role for an elongation mechanism in the transcriptional control of HIV-1, we found that TCERG1 modifies the levels of pre-mRNAs generated at distal regions of HIV-1. Most importantly, TCERG1 directly affects the elongation rate of RNAPII transcription in vivo. Furthermore, our data demonstrate that TCERG1 regulates HIV-1 transcription by increasing the rate of RNAPII elongation through the phosphorylation of serine 2 within the carboxyl-terminal domain (CTD) of RNAPII and suggest a mechanism for the involvement of TCERG1 in relieving pausing. Finally, we show that TCERG1 is required for HIV-1 replication.

Conclusions

Our study reveals that TCERG1 regulates HIV-1 transcriptional elongation by increasing the elongation rate of RNAPII and phosphorylation of Ser 2 within the CTD. Based on our data, we propose a general mechanism for TCERG1 acting on genes that are regulated at the level of elongation by increasing the rate of RNAPII transcription through the phosphorylation of Ser2. In the case of HIV-1, our evidence provides the basis for further investigation of TCERG1 as a potential therapeutic target for the inhibition of HIV-1 replication

Evaluation of an empiric risk screening score to identify acute and early HIV-1 infection among MSM in Coastal Kenya

We evaluated the University of North Carolina-Malawi Risk Screening Score (UMRSS) for detection of acute and early HIV-1 infection (AEHI) in a cohort of Kenyan MSM with approximately 8% annual HIV-1 incidence. Three components of the UMRSS (fever, diarrhea, and discordant rapid HIV tests) were also independent predictors of AEHI in our cohort. The predictive ability (area under the receiver operating characteristic curve, AUC) of the UMRSS was 0.79. A cohort-derived risk score consisting of six characteristics (fever, diarrhea, discordant rapid HIV tests, fatigue, age <30 years, and symptomatic sexually transmitted disease) had a higher AUC of 0.85. Screening for AEHI will have substantial transmission prevention benefits.

The detection and management of early HIV infection: a clinical and public health emergency

This review considers the detection and management of early HIV infection (EHI), defined here as the first 6 months of infection. This phase is clinically important because a reservoir of infected cells formed in the individual renders HIV incurable, and the magnitude of viremia at the end of this period predicts the natural history of disease. Epidemiologically, it is critical because the very high viral load that typically accompanies early infection also makes infected individuals maximally contagious to their sexual partners. Future efforts to prevent HIV transmission with expanded testing and treatment may be compromised by elevated transmission risk earlier in the course of HIV infection, although the extent of this impact is yet unknown. Treatment as prevention efforts will nevertheless need to develop strategies to address testing, linkage to care, and treatment of EHI. Cost-effective and efficient identification of more persons with early HIV will depend on advancements in diagnostic technology and strengthened symptom-based screening strategies. Treatment for persons with EHI must balance individual health benefits and reduction of the risk of onward viral transmission. An increasing body of evidence supports the use of immediate antiretroviral therapy to treat EHI to maintain CD4 count and functionality, limit the size of the HIV reservoir, and reduce the risk of onward viral transmission. Although we can anticipate considerable challenges in identifying and linking to care persons in the earliest phases of HIV infection, there are many reasons to pursue this strategy.

Community viral load as a measure for assessment of HIV treatment as prevention

Community viral load, defined as an aggregation of individual viral loads of people infected with HIV in a specific community, has been proposed as a useful measure to monitor HIV treatment uptake and quantify its effect on transmission. The first reports of community viral load were published in 2009, and the measure was subsequently incorporated into the US National HIV/AIDS Strategy. Although intuitively an appealing strategy, measurement of community viral load has several theoretical limitations and biases that need further assessment, which can be grouped into four categories: issues of selection and measurement, the importance of HIV prevalence in determining the potential for ongoing HIV transmission, interpretation of community viral load and its effect on ongoing HIV transmission in a community, and the ecological fallacy (ie, ecological bias). These issues need careful assessment as community viral load is being considered as a public health measurement to assess the effect of HIV care on prevention.

Antiviral activity of retrocyclin RC-101, a candidate microbicide against cell-associated HIV-1

Microbicides have been evaluated mostly against cell-free HIV-1. Because semen contains both cell-free and cell-associated HIV-1, HIV-1 transmission could occur via either or both sources. Therefore, it is important to examine the antiviral activity of microbicides against cell-associated HIV-1. The cyclic antimicrobial peptide retrocyclin RC-101 has been shown previously to have antiviral activity against cell-free HIV-1, with no associated cellular toxicity. In this article we have examined the antiviral activity of RC-101 against cell-associated HIV-1. The results demonstrate potent antiviral activity of RC-101 against cell-cell HIV-1 transmission in both CD4-dependent and CD4-independent assays against CCR5- and CXCR4-tropic HIV-1, with no cellular toxicity. Furthermore, this antiviral activity was retained in the presence of human seminal plasma. The potent antiviral activity of RC-101 against cell-associated HIV-1 reported here, and the previously reported antiviral activity in cervical tissues, suggest that RC-101 is an excellent and promising microbicide candidate against HIV-1.

Diagnosing acute HIV infection

Individuals with acute HIV infection (AHI) pose a greater transmission risk than most chronically HIV-infected patients and prevention efforts targeting these individuals are important for reducing the spread of HIV infection. Rapid and accurate diagnosis of AHI is crucial. Since symptoms of AHI are nonspecific, its diagnosis requires a high index of suspicion and appropriate HIV laboratory tests. However, even 30 years after the start of the HIV epidemic, laboratory tools remain imperfect and only a few individuals with AHI are identified. We review the clinical presentation of the acute retroviral syndrome, the laboratory markers and their detection methods, and propose an algorithm for the laboratory diagnosis of AHI.

Testing for acute HIV infection: implications for treatment as prevention

PURPOSE OF REVIEW

The aim of this study is to give an overview of the recent literature related to HIV testing with an emphasis on detecting acute HIV infection. Testing technology as well as implications for treatment as prevention will be discussed.

RECENT FINDINGS

HIV testing technology continues to evolve. Advances include updated immunologic formats that detect both HIV antibody and antigen (4th generation assays), new nucleic acid amplification tests, and continued development of rapid assays that can be used in either clinical or nonclinical settings. Because of these advances there are proposed changes for HIV diagnostic algorithms to encourage detection of acute infection. These technologic advances have implications for HIV prevention as testing is a cornerstone for all HIV prevention strategies. There is considerable new research indicating that treatment may be an important aspect of HIV prevention. Data also suggest that detection of acute infection will be important for the success of these prevention strategies.

SUMMARY

Continued improvements in technology and testing practice are vital for the success of HIV prevention. Detection of acute or early HIV infection will likely play a key role in the success of treatment as prevention, as well as play an important role in ongoing behavioral prevention strategies.

Detection of acute HIV infection: a field evaluation of the determine® HIV-1/2 Ag/Ab combo test

BACKGROUND

Most human immunodeficiency virus (HIV) point-of-care tests detect antibodies (Ab) but not p24 antigen (Ag) or RNA. In the absence of antibodies, p24 antigen and RNA typically indicate acute HIV infection. We conducted a field evaluation of the Determine® HIV-1/2 Ag/Ab Combo rapid test (Combo RT).

METHODS

The antigen portion of the Combo RT (for acute HIV infection) was compared with a Roche Monitor HIV RNA polymerase chain reaction assay. The antibody portion of Combo RT (for established HIV infection) was compared with rapid test algorithms. Participants were enrolled at a sexually transmitted infection clinic and HIV testing and counseling center in Lilongwe, Malawi. Rapid testing was conducted with parallel testing in the clinic and serial testing in the center. The Combo RT was performed in clinic participants with negative or discordant antibody results and in all center participants.

RESULTS

Of the participants 838 were HIV negative, 163 had established HIV infection, and 8 had acute HIV infection. For detecting acute HIV infection, the antigen portion had a sensitivity of 0.000 and a specificity of 0.983. For detecting established HIV infection, the antibody portion had a sensitivity of 0.994 and a specificity of 0.992.

CONCLUSIONS

Combo RT displayed excellent performance for detecting established HIV infection and poor performance for detecting acute HIV infection. In this setting, Combo RT is no more useful than current algorithms.

Sexual partnership patterns in malawi: implications for HIV/STI transmission

BACKGROUND

Concurrent sexual partnerships are believed to play an important role in HIV transmission in sub-Saharan Africa, but the contributions of concurrency to HIV and sexually transmitted infection (STI) spread depend on the details of infectious periods and relationship patterns. To contribute to the understanding of sexual partnership patterns in this region, we estimated partnership lengths, temporal gaps between partners, and periods of overlap across partners at an STI clinic in Lilongwe, Malawi.

METHODS

Participants underwent physical examinations and HIV tests, and responded to questionnaires about demographics and risk behaviors, including detailed questions about a maximum of 3 sexual partners in the previous 2 months. We calculated partnership length as the time between the first and most recent sexual contact with a partner, and gap length as the time between the most recent contact with 1 partner and the first contact with the next. We defined concurrent and consecutive partnerships as gap length ≤0 days and gap length >0 days, respectively.

RESULTS

In the study population (n = 183), 86% reported 0 or 1 partner, 5% reported multiple consecutive partnerships, and 9% reported concurrency. The mean partnership length was 858 days (median = 176 days). Gaps between consecutive partnerships were short (mean = 21 days), and overlaps across concurrent partners tended to be long (mean = 246 days).

CONCLUSIONS

Multiple sexual partnerships were uncommon, and partnerships were long on average. Among those reporting multiple recent partners, both long-term concurrency and narrowly spaced consecutive partnerships could present substantial risk for efficient transmission of HIV and classical STIs.

Performance of an alternative laboratory-based algorithm for HIV diagnosis in a high-risk population

BACKGROUND

An immunoassay (IA) followed by Western blot (WB) or immunofluorescence assay has been the primary algorithm used to provide laboratory confirmation of the diagnosis of HIV infection in the US for more than 20 years. Recently, an alternative diagnostic algorithm was proposed to more accurately identify early HIV-1 infection and differentiate between HIV-1 and HIV-2 infection.

OBJECTIVES

Evaluate a sequential alternative algorithm in which reactive IAs are followed by a rapid HIV test and, if negative, a nucleic acid amplification test (NAAT).

STUDY DESIGN

Specimens from high-risk persons were tested with 4 HIV IAs, 6 rapid HIV tests and NAAT (APTIMA(®)), which are approved by the United States Food and Drug Administration. IAs were repeated in duplicate if specimen volumes were sufficient. The performance of the alternative algorithm was compared to HIV WB and NAAT.

RESULTS

The original study classified 377 specimens as HIV-positive and 3070 as HIV-negative. All 4 IAs correctly identified >99.5% of HIV-positive specimens and, on initial screening, >95.8% of HIV-negative specimens. When repeated, specificity of IAs improved to >99%. Between 6.7% and 12.4% of IA-repeatedly reactive specimens required APTIMA for resolution. The alternative algorithm led to the correct classification of all IA-reactive specimens.

CONCLUSIONS

Regardless of screening IA and rapid test used, the alternative algorithm correctly classified the infection status of all persons with reactive screening IA results. Few specimens required NAAT for resolution, and the proportion requiring NAAT was lower when repeat IA test results were considered.

The role of acute and early HIV infection in the spread of HIV and implications for transmission prevention strategies in Lilongwe, Malawi: a modelling study

BACKGROUND

HIV transmission risk is higher during acute and early HIV infection than it is during chronic infection, but the contribution of early infection to the spread of HIV is controversial. We estimated the contribution of early infection to HIV incidence in Lilongwe, Malawi, and predict the future effect of hypothetical prevention interventions targeted at early infection only, chronic infection only, or both stages.

METHODS

We developed a deterministic mathematical model describing heterosexual HIV transmission, informed by detailed behavioural and viral-load data collected in Lilongwe. We included sexual contact within and outside of steady pairs and divided the infectious period into intervals to allow for changes in transmissibility by infection stage. We used a Bayesian melding approach to fit the model to HIV prevalence data collected between 1987 and 2005 at Lilongwe antenatal clinics. We assessed interventions that reduced the per-contact transmission probability to 0.00003 in people receiving them, and varied the proportion of individuals receiving the intervention in each stage.

FINDINGS

We estimated that 38.4% (95% credible interval 18.6-52.3) of HIV transmissions in Lilongwe are attributable to sexual contact with individuals with early infection. Interventions targeted at only early infection substantially reduced HIV prevalence, but did not lead to elimination, even with 100% coverage. Interventions targeted at only chronic infections also reduced HIV prevalence, but coverage levels of 95-99% were needed for the elimination of HIV. In scenarios with less than 95% coverage of interventions targeted at chronic infections, additional interventions reaching 25-75% of individuals with early infection reduced HIV prevalence substantially.

INTERPRETATION

Our results suggest that early infection plays an important part in HIV transmission in this sub-Saharan African setting. Without near-complete coverage, interventions during chronic infection will probably have incomplete effectiveness unless complemented by strategies targeting individuals with early HIV infection.

FUNDING

National Institutes of Health, University of North Carolina Center for AIDS Research.

Diagnostic accuracy of ultrasensitive heat-denatured HIV-1 p24 antigen in non-B subtypes in Kampala, Uganda

We evaluated the accuracy of heat-denatured, amplification-boosted ultrasensitive p24 assay (Up24) compared with reverse transcriptase polymerase chain reaction (RT-PCR). We tested 394 samples from Ugandans infected with HIV-1 non-B subtypes. We compared Up24 levels (HIV-1 p24 Core Profile enzyme-linked immunosorbent assay (ELISA), NEN Life Science Products) to RNA viral loads (Amplicor HIV-1 Monitor 1.5, Roche) by linear regression, and calculated sensitivity, specificity, positive and negative predictive values. Median viral load was 4.9 log10 copies/mL (interquartile range [IQR], 2.6-5.5); 114 samples (29%) were undetectable (<400 copies/mL). Sensitivity of the Up24 assay to detect viral load ≥400 copies/mL was 69%, specificity was 67%, and positive and negative predictive values were 84% and 47%, respectively. Sensitivity of Up24 was 90%, 80%, 68%, 62% and 45% to detect viral loads of >500,000, 250,000-500,000, 100,000-250,000, 50,000-100,000 and 400-50,000 copies/mL, respectively. In conclusion, when compared with RT-PCR for patients infected with non-B subtypes, the Up24 demonstrated limited sensitivity especially at low viral loads. Moreover, the Up24 was positive in 33% of samples deemed undetectable by RT-PCR, which may limit the use of the Up24 to detect viral suppression.

Concurrent sexual partnerships and primary HIV infection: a critical interaction

The combination of long-term concurrent sexual partnerships and high infectiousness early in HIV infection has been suggested as a key driver of the extensive spread of HIV in general populations in sub-Saharan Africa, but this has never been scientifically investigated. We use a mathematical model to simulate HIV spreading on sexual networks with different amounts of concurrency. The models show that if HIV infectiousness is constant over the duration of infection, the amount of concurrency has much less influence on HIV spread compared to when infectiousness varies over three stages of infection with high infectiousness in the first months. The proportion of transmissions during primary infection is sensitive to the amount of concurrency and, in this model, is estimated to be between 16 and 28% in spreading epidemics with increasing concurrency. The sensitivity of epidemic spread to the amount of concurrency is greater than predicted by models that do not include primary HIV infection.

Screening for acute HIV infection in South Africa: finding acute and chronic disease

BACKGROUND

The yield of screening for acute HIV infection among general medical patients in resource-scarce settings remains unclear. Our objective was to evaluate the strategy of using pooled HIV plasma RNA to diagnose acute HIV infection in patients with negative or discordant rapid HIV antibody tests in Durban, South Africa.

METHODS

We prospectively enrolled patients with negative or discordant rapid HIV antibody tests from a routine HIV screening programme in an out-patient department in Durban with an HIV prevalence of 48%. Study participants underwent venipuncture for pooled qualitative HIV RNA, and, if this was positive, quantitative RNA, enzyme immunoassay and Western blot (WB). Patients with negative or indeterminate WB and positive quantitative HIV RNA were considered acutely infected. Those with chronic infection (positive RNA and WB) despite negative or discordant rapid HIV tests were considered to have had false negative rapid antibody tests.

RESULTS

Nine hundred and ninety-four participants were enrolled with either negative (n=976) or discordant (n=18) rapid test results. Eleven [1.1%; 95% confidence interval (CI) 0.6-2.0%] had acute HIV infection, and an additional 20 (2.0%; 95% CI 1.3-3.1%) had chronic HIV infection (false negative rapid test).

CONCLUSIONS

One per cent of out-patients with negative or discordant rapid HIV tests in Durban, South Africa had acute HIV infection readily detectable through pooled serum HIV RNA screening. Pooled RNA testing also identified an additional 2% of patients with chronic HIV infection. HIV RNA screening has the potential to identify both acute and chronic HIV infections that are otherwise missed by standard HIV testing algorithms.

Screening for 'window-period' acute HIV infection among pregnant women in rural South Africa

OBJECTIVES

The aim of this study was to evaluate the HIV-1 RNA pooled nucleic acid amplification testing (NAAT) strategy to screen pregnant women in the 'window period' of acute HIV infection (AHI) in rural South Africa.

METHODS

In 2007 and 2008, 750 consecutive pregnant women on their first antenatal care visit to a primary health care clinic were tested anonymously for HIV infection. HIV-1 RNA pooled NAAT was performed on HIV antibody-negative samples. All positive pools were tested individually and positive samples were classified as incident cases to calculate HIV incidence.

RESULTS

The overall HIV prevalence was 37.3% [95% confidence interval (CI) 34.3–41.3]. Of the 467 HIV antibody-negative samples, four (0.9%) were HIV-1 RNA-positive. The mean viral load in the four samples was 386 260 HIV-1 RNA copies/mL (range 64 200–1 228130). The HIV incidence was 11.2%per year (95% CI 0.3–22.1) and all women with AHI were 21 years of age.

CONCLUSIONS

Identifying AHI in pregnancy is important for health interventions to reduce perinatal and heterosexual transmission of HIV, and to estimate HIV incidence for epidemiological surveillance.

Role of acute and early HIV infection in the sexual transmission of HIV

PURPOSE OF REVIEW

Acute HIV infection (AHI), the earliest period after HIV acquisition, is only a few weeks in duration. In this brief period, the concentration of HIV in blood and genital secretions is extremely high, increasing the probability of HIV transmission. Although a substantial role of AHI in the sexual transmission of HIV is biologically plausible, the significance of AHI in the epidemiological spread of HIV remains uncertain.

RECENT FINDINGS

AHI is diagnosed by detecting viral RNA or antigen in the blood of persons who are HIV seronegative. Depending on the setting, persons with AHI represent between 1 and 10% of persons with newly diagnosed HIV infection. The high concentration of virus during AHI leads to increased infectiousness, possibly as much as 26 times greater than during chronic infection. In mathematical models, the estimated proportion of transmission attributed to AHI has varied considerably, depending on model structure, model parameters, and the population. Key determinants include the stage of the HIV epidemic and the sexual risk profile of the population.

SUMMARY

Despite its brief duration, AHI plays a disproportionate role in the sexual transmission of HIV infection. Detection of persons with AHI may provide an important opportunity for transmission prevention.

Should South Africa be performing nucleic acid testing on HIV enzyme-linked immunosorbent assay-negative samples?

The frequency of acute HIV infection (AHI) among HIV-1 enzyme-linked immunosorbent assay (ELISA)-negative samples received from general hospital patient admissions was assessed. Of 3,005 samples pooled for nucleic acid testing, a prevalence of 0.13% was found. Pooled nucleic acid testing may be feasible for low-cost identification of AHI in high-prevalence settings.

Evaluation of an HIV nucleic acid testing program with automated Internet and voicemail systems to deliver results

BACKGROUND

Nucleic acid testing (NAT) in routine HIV testing programs can increase the detection of infected individuals, but the most effective implementation of NAT remains unclear.

OBJECTIVE

To determine how many HIV cases can be identified with NAT and how many persons can be contacted, to identify predictors of acute and early HIV infection cases, and to test reporting of negative results by automated Internet and voicemail systems.

DESIGN

Prospective study.

SETTING

San Diego County, California.

PARTICIPANTS

Persons seeking HIV testing.

MEASUREMENTS

Rates and predictors of HIV infection by stage, notification of positive NAT results, use of automated Internet or voicemail systems to access negative NAT results, and estimated HIV infections prevented.

RESULTS

Of 3151 persons tested, 79 had newly diagnosed cases of HIV: 64 had positive results from rapid HIV test, and 15 had positive results only by NAT (that is, NAT increased the HIV detection yield by 23%). Of all HIV infections, 44% (in 35 persons) were in the acute and early stages. Most participants (56%) and persons with HIV (91%) were men who have sex with men (MSM). All persons with NAT-positive results were notified within 1 week. Of all 3070 uninfected patients, 2105 (69%) retrieved their negative NAT results, with 1358 using the Internet system. After adjustment for covariates, persons reporting MSM behavior, higher incomes, younger ages, no testing at substance abuse rehabilitation centers, no recent syphilis, and no methamphetamine use were more likely to access negative NAT results by either Internet or voicemail systems.

LIMITATION

Findings may not be generalizable to other populations and testing programs.

CONCLUSION

Nucleic acid testing programs that include automated systems for result reporting can increase case yield, especially in settings that cater to MSM.

Antiretrovirals to prevent HIV infection: pre- and postexposure prophylaxis

More than 3 million people are now receiving antiretroviral therapy (ART) worldwide. Currently, the indications for ART depend primarily on CD4 count, blood viral burden, and clinical signs and symptoms suggesting advanced HIV disease. However, interest is increasing in ART's preventive potential. Postexposure prophylaxis following both occupational and nonoccupational exposure to HIV is the standard-of-care in many settings. Observational and ecologic studies suggest that ART administered to HIV-infected people reduces transmission within serodiscordant couples. Pre-exposure prophylaxis to prevent HIV infection is a potentially safe and intermittent intervention for very high-risk people, and clinical trials to evaluate this preventive strategy are underway. The prevention benefits of ART may begin to affect the decision of when to start therapy and add a much-needed strategy to current HIV prevention efforts.

Current antibody-based immunoassay algorithm failed to confirm three late-stage AIDS cases in China: case report

Background

Immunoassays composed of screening and confirmation are the established algorithm to confirm HIV infection in China, with a Western blot result as the final diagnosis.

Case presentation

In this report, three late-stage AIDS patients were initially tested HIV antibody positive using multiple screening kits, but tested indeterminate using Western blot. HIV infection diagnosis was confirmed based on nucleic acid assays, clinic manifestations and epidemiological history. Case A was identified positive at 30 months, using Western blot, Case B at 8 months, and case C remained indeterminate until he died of Kaposi's sarcoma 4 months after HAART.

Conclusion

The report indicates that current antibody-based testing algorithms may miss late-stage AIDS patients and therefore miss the opportunity for preventing these cases from further transmission. The report also implies that viral load assays is not easy to be universely applicated in developing country like China although it is helpful in diagnosing complicated cases of HIV infection, so the counselling before and after testing is imperative to the diagnosis of HIV infection and risk behavior survey on the examinee should be as detailed as possible.

High prevalence of symptomatic acute HIV infection in an outpatient ward in southern Mozambique: identification and follow-up

OBJECTIVES

To determine the prevalence of acute HIV infection (AHI) within the HIV-seronegative adult population presenting with reported fever in a district hospital in southern Mozambique and evaluate clinical, immunological and virological parameters of AHI.

DESIGN

This is a prospective observational study.

METHODS

Three hundred and forty-six adults presenting with reported fever at an outpatient ward at the Manhiça District Hospital in Mozambique were screened for AHI by HIV rapid serology testing, followed by HIV-RNA testing in HIV-seronegative individuals. Plasma from HIV-seronegative patients was pooled in the ratio of 1: 5 for HIV-RNA testing. Whole blood was used for Plasmodium falciparum rapid test determination at screening visit. Follow-up visits at day 7, 4 and 10 months included clinical examination, HIV serotesting and assessment of HIV-RNA, CD4 cell counts and percentage of activated CD8 T cells.

RESULTS

HIV serotesting revealed that 37.8% (95% confidence interval 32.7-43.2) of the adults had previously undiagnosed established HIV infection. Among the HIV-seronegative patients, 3.3% (95% confidence interval 1.3-6.7) were found to have AHI as demonstrated by positive HIV-1 RNA testing. Median HIV-1 RNA levels at diagnosis of AHI were 6.21 log10 copies/ml (interquartile range 5.92-6.41) and significantly higher than median HIV-RNA load at 4 months. At day 7 after screening, patients showed a median CD4 cell count of 384 cells/microl (interquartile range 239-441) and a median percentage of activated CD8 T cells of 68.4% (interquartile range 59.6-87.8).

CONCLUSION

Of patients reporting with fever, 3.3% were shown to be potentially due to AHI. High prevalence of AHI in southern African populations may warrant investigation of tools and target populations for AHI screening as a novel way to address HIV prevention.