Virus load during primary Human Immunodeficiency Virus (HIV) type 1 infection is related to the severity of acute HIV illness in Kenyan women

Primary headache disorders among people living with HIV in Lusaka, Zambia

OBJECTIVE

We completed a cross-sectional survey study to determine headache prevalence and its association with HIV characteristics among people living with HIV (PLHIV) in Lusaka, Zambia.

BACKGROUND

Headaches are common but their association with HIV status is unknown.

METHODS

The HARDSHIP survey, a headache epidemiology questionnaire previously validated in Zambia, was distributed during a 3-month period to 3666 consecutive adult PLHIV attending routine clinic appointments at the Adult Infectious Diseases Centre at the University Teaching Hospital in Lusaka, Zambia. HIV disease characteristics were abstracted from their charts.

RESULTS

1015 (27.7%) participants responded to the survey. Adjusted for age, 64% reported having a headache within the last year unrelated to another illness. Among participants, 201 met criteria for migraine (20%), 259 for tension-type headache (26%), 18 for probable medication-overuse headache (2%), and 121 for undetermined headache (12%). Prevalence for tension-type headache was significantly higher than that of migraine (P < 0.001). After adjusting for age and sex, higher CD4 counts were associated with migraine. No other associations were observed between overall headache or headache type with HIV disease characteristics including CD4 count, viral load, antiretroviral regimen, and time since HIV diagnosis.

CONCLUSIONS

Headaches are highly prevalent among this cohort of PLHIV in Zambia. Optimizing headache treatment and integrating it into routine HIV care may improve quality of life for a substantial proportion of PLHIV in Zambia.

HIV incidence among women engaging in sex work in sub-Saharan Africa: a systematic review and meta-analysis

Introduction

HIV incidence among women in sub-Saharan Africa (SSA) has declined steadily, but it is unknown whether new infections among women who engage in sex work (WESW) have declined at a similar rate. We synthesised estimates of HIV incidence among WESW in SSA and compared these to the wider female population to understand levels and trends in incidence over time.

Methods

We searched Medline, Embase, Global Health, Popline, Web of Science, and Google Scholar from January 1990 to October 2022, and grey literature for estimates of HIV incidence among WESW in SSA. We included studies reporting empirical estimates in any SSA country. We calculated incidence rate ratios (IRR) compared to age-district-year matched total female population incidence estimates. We conducted a meta-analysis of IRRs and used a continuous mixed-effects model to estimate changes in IRR over time.

Results

From 32 studies between 1985 and 2020, 2,194 new HIV infections were observed in WESW over 51,000 person-years (py). Median HIV incidence was 4.3/100py (IQR 2.8-7.0/100py), declining from a median of 5.96/100py between 1985 and 1995 to a median of 3.2/100py between 2010 and 2020. Incidence among WESW was nine times higher than in matched total population women (RR 8.6, 95%CI: 5.7-12.9), and greater in Western and Central Africa (RR 22.4, 95%CI: 11.3-44.3) than in Eastern and Southern Africa (RR 5.3, 95%CI: 3.7-7.6). Annual changes in log IRRs were minimal (-0.1% 95%CI: -6.9 to +6.8%).

Conclusions

Across SSA, HIV incidence among WESW remains disproportionately high compared to the total female population but showed similar rates of decline between 1990 and 2020. Improved surveillance and standardisation of approaches to obtain empirical estimates of sex worker incidence would enable a clearer understanding of whether we are on track to meet global targets for this population and better support data-driven HIV prevention programming.

Probabilistic HIV recency classification-a logistic regression without labeled individual level training data

Accurate HIV incidence estimation based on individual recent infection status (recent vs long-term infection) is important for monitoring the epidemic, targeting interventions to those at greatest risk of new infection, and evaluating existing programs of prevention and treatment. Starting from 2015, the Population-based HIV Impact Assessment (PHIA) individual-level surveys are implemented in the most-affected countries in sub-Saharan Africa. PHIA is a nationally-representative HIV-focused survey that combines household visits with key questions and cutting-edge technologies such as biomarker tests for HIV antibody and HIV viral load which offer the unique opportunity of distinguishing between recent infection and long-term infection, and providing relevant HIV information by age, gender, and location. In this article, we propose a semi-supervised logistic regression model for estimating individual level HIV recency status. It incorporates information from multiple data sources - the PHIA survey where the true HIV recency status is unknown, and the cohort studies provided in the literature where the relationship between HIV recency status and the covariates are presented in the form of a contingency table. It also utilizes the national level HIV incidence estimates from the epidemiology model. Applying the proposed model to Malawi PHIA data, we demonstrate that our approach is more accurate for the individual level estimation and more appropriate for estimating HIV recency rates at aggregated levels than the current practice - the binary classification tree (BCT).

Natural killer cells during acute HIV-1 infection: clues for HIV-1 prevention and therapy

Despite progress in preexposure prophylaxis, the number of newly diagnosed cases with HIV-1 remains high, highlighting the urgent need for preventive and therapeutic strategies to reduce HIV-1 acquisition and limit disease progression. Early immunological events, occurring during acute infection, are key determinants of the outcome and course of disease. Understanding early immune responses occurring before viral set-point is established, is critical to identify potential targets for prophylactic and therapeutic approaches. Natural killer (NK) cells represent a key cellular component of innate immunity and contribute to the early host defence against HIV-1 infection, modulating the pathogenesis of acute HIV-1 infection (AHI). Emerging studies have identified tools for harnessing NK cell responses and expanding specialized NK subpopulations with adaptive/memory features, paving the way for development of novel HIV-1 therapeutics. This review highlights the knowns and unknowns regarding the role of NK cell subsets in the containment of acute HIV-1 infection, and summarizes recent advances in selectively augmenting NK cell functions through prophylactic and therapeutic interventions.

A Stronger Innate Immune Response During Hyperacute Human Immunodeficiency Virus Type 1 (HIV-1) Infection Is Associated With Acute Retroviral Syndrome

BACKGROUND

Acute retroviral syndrome (ARS) is associated with human immunodeficiency virus type 1 (HIV-1) subtype and disease progression, but the underlying immunopathological pathways are poorly understood. We aimed to elucidate associations between innate immune responses during hyperacute HIV-1 infection (hAHI) and ARS.

METHODS

Plasma samples obtained from volunteers (≥18.0 years) before and during hAHI, defined as HIV-1 antibody negative and RNA or p24 antigen positive, from Kenya, Rwanda, Uganda, Zambia, and Sweden were analyzed. Forty soluble innate immune markers were measured using multiplexed assays. Immune responses were differentiated into volunteers with stronger and comparatively weaker responses using principal component analysis. Presence or absence of ARS was defined based on 11 symptoms using latent class analysis. Logistic regression was used to determine associations between immune responses and ARS.

RESULTS

Of 55 volunteers, 31 (56%) had ARS. Volunteers with stronger immune responses (n = 36 [65%]) had increased odds of ARS which was independent of HIV-1 subtype, age, and risk group (adjusted odds ratio, 7.1 [95% confidence interval {CI}: 1.7-28.8], P = .003). Interferon gamma-induced protein (IP)-10 was 14-fold higher during hAHI, elevated in 7 of the 11 symptoms and independently associated with ARS. IP-10 threshold >466.0 pg/mL differentiated stronger immune responses with a sensitivity of 84.2% (95% CI: 60.4-96.6) and specificity of 100.0% (95% CI]: 90.3-100.0).

CONCLUSIONS

A stronger innate immune response during hAHI was associated with ARS. Plasma IP-10 may be a candidate biomarker of stronger innate immunity. Our findings provide further insights on innate immune responses in regulating ARS and may inform the design of vaccine candidates harnessing innate immunity.

Multisystem inflammation and susceptibility to viral infections in human ZNFX1 deficiency

BACKGROUND

Recognition of viral nucleic acids is one of the primary triggers for a type I interferon-mediated antiviral immune response. Inborn errors of type I interferon immunity can be associated with increased inflammation and/or increased susceptibility to viral infections as a result of dysbalanced interferon production. NFX1-type zinc finger-containing 1 (ZNFX1) is an interferon-stimulated double-stranded RNA sensor that restricts the replication of RNA viruses in mice. The role of ZNFX1 in the human immune response is not known.

OBJECTIVE

We studied 15 patients from 8 families with an autosomal recessive immunodeficiency characterized by severe infections by both RNA and DNA viruses and virally triggered inflammatory episodes with hemophagocytic lymphohistiocytosis-like disease, early-onset seizures, and renal and lung disease.

METHODS

Whole exome sequencing was performed on 13 patients from 8 families. We investigated the transcriptome, posttranscriptional regulation of interferon-stimulated genes (ISGs) and predisposition to viral infections in primary cells from patients and controls stimulated with synthetic double-stranded nucleic acids.

RESULTS

Deleterious homozygous and compound heterozygous ZNFX1 variants were identified in all 13 patients. Stimulation of patient-derived primary cells with synthetic double-stranded nucleic acids was associated with a deregulated pattern of expression of ISGs and alterations in the half-life of the mRNA of ISGs and also associated with poorer clearance of viral infections by monocytes.

CONCLUSION

ZNFX1 is an important regulator of the response to double-stranded nucleic acids stimuli following viral infections. ZNFX1 deficiency predisposes to severe viral infections and a multisystem inflammatory disease.

Development of antibody-dependent cell cytotoxicity function in HIV-1 antibodies

A prerequisite for the design of an HIV vaccine that elicits protective antibodies is understanding the developmental pathways that result in desirable antibody features. The development of antibodies that mediate antibody-dependent cellular cytotoxicity (ADCC) is particularly relevant because such antibodies have been associated with HIV protection in humans. We reconstructed the developmental pathways of six human HIV-specific ADCC antibodies using longitudinal antibody sequencing data. Most of the inferred naive antibodies did not mediate detectable ADCC. Gain of antigen binding and ADCC function typically required mutations in complementarity determining regions of one or both chains. Enhancement of ADCC potency often required additional mutations in framework regions. Antigen binding affinity and ADCC activity were correlated, but affinity alone was not sufficient to predict ADCC potency. Thus, elicitation of broadly active ADCC antibodies may require mutations that enable high-affinity antigen recognition along with mutations that optimize factors contributing to functional ADCC activity.

Dynamics in a simple evolutionary-epidemiological model for the evolution of an initial asymptomatic infection stage

Pathogens exhibit a rich variety of life history strategies, shaped by natural selection. An important pathogen life history characteristic is the propensity to induce an asymptomatic yet productive (transmissive) stage at the beginning of an infection. This characteristic is subject to complex trade-offs, ranging from immunological considerations to population-level social processes. We aim to classify the evolutionary dynamics of such asymptomatic behavior of pathogens (hereafter "latency") in order to unify epidemiology and evolution for this life history strategy. We focus on a simple epidemiological model with two infectious stages, where hosts in the first stage can be partially or fully asymptomatic. Immunologically, there is a trade-off between transmission and progression in this first stage. For arbitrary trade-offs, we derive different conditions that guarantee either at least one evolutionarily stable strategy (ESS) at zero, some, or maximal latency of the first stage or, perhaps surprisingly, at least one unstable evolutionarily singular strategy. In this latter case, there is bistability between zero and nonzero (possibly maximal) latency. We then prove the uniqueness of interior evolutionarily singular strategies for power-law and exponential trade-offs: Thus, bistability is always between zero and maximal latency. Overall, previous multistage infection models can be summarized with a single model that includes evolutionary processes acting on latency. Since small changes in parameter values can lead to abrupt transitions in evolutionary dynamics, appropriate disease control strategies could have a substantial impact on the evolution of first-stage latency.

Is symptom prevalence and burden associated with HIV treatment status and disease stage among adult HIV outpatients in Kenya? A cross-sectional self-report study

People with HIV experience a high prevalence and burden of physical and psychological symptoms throughout their disease trajectory. These have important public and clinical health implications. We aimed to measure: the seven-day period prevalence of symptoms, the most burdensome symptoms, and determine if self-reported symptom burden is associated with treatment status, clinical stage and physical performance. We conducted a cross-sectional study among adult (aged at least 18 years) patients with HIV, attending HIV outpatient care in Kenya. Data was gathered through self-report using the Memorial Symptom Assessment Scale-Short Form (MSAS-SF), file extraction (sociodemographic data, treatment status, CD4 count, clinical stage) and through observation using the Karnofsky Performance Scale (KPS). Multivariable ordinal logistic regression assessed the association of symptom burden (MSAS-SF) controlling for demographic and clinical variables. Of the 475 participants approached, 400 (84.2%) participated. Ordinal logistic regression showed that being on HIV treatment was associated lower global distress index (in quartiles) (odds ratio .45, 95% CI .23 to .88; p = 0.019). Pain and symptom burden still persist in the era of antiretroviral therapy. Routine clinical practice should incorporate assessment and management of pain and symptoms irrespective of disease stage and treatment status in order to achieve the proposed fourth ^"90" in the UNAIDS 90-90-90 targets (that is good quality of life).

Pilot testing of an online training module about screening for acute HIV infection in adult patients seeking urgent healthcare

BACKGROUND

Acute HIV infection (AHI) is the phase of HIV infection immediately after acquisition, during which many patients develop symptoms and often seek healthcare. However, clinicians in sub-Saharan Africa are not currently taught about AHI.

METHODS

This study pilot-tested a self-directed AHI training module among clinical officers (COs) in coastal Kenya and assessed knowledge gained and challenges to instituting screening. The training module included four domains: AHI definition and importance of AHI recognition; symptoms and screening algorithms; diagnostic strategies; and management. AHI knowledge was assessed before and immediately after training. Participants' ability to utilize an AHI screening algorithm was evaluated with a case-based exercise.

RESULTS

Self-directed training was completed by 45 COs. Pre-test scores were low (median score 35% IQR 30-45%), but improved significantly after training (median post-test score 75%, IQR 70-85%, Wilcoxon signed-rank test p<0.0001). Participants had challenges in understanding the utility and application of a screening algorithm to identify patients for whom AHI testing would be indicated. Knowledge of AHI was poor at baseline, but improved with self-directed learning. Based on these findings, we revised and improved the AHI training module and pre- and post-assessments, which are now freely available online at www.marps-africa.org.

CONCLUSIONS

Guidelines on AHI screening and diagnosis are urgently needed in high HIV transmission areas.

Differences in acute retroviral syndrome by HIV-1 subtype in a multicentre cohort study in Africa

OBJECTIVE

Symptoms of acute retroviral syndrome (ARS) may be used to identify patients with acute HIV-1 infection who seek care. ARS symptoms in African adults differ by region. We assessed whether reporting of ARS was associated with HIV-1 subtype in a multicentre African cohort study representing countries with predominant HIV-1 subtypes A, C, and D.

METHODS

ARS symptoms were assessed in adults enrolling within 6 weeks after the estimated date of infection in an acute and early HIV-1 infection cohort study. HIV-1 subtype was determined by POL genotyping. We used log-binomial regression to compare ARS symptom prevalence among those with subtype A vs. C or D, adjusting for sex, time since enrolment, and enrolment viral load.

RESULTS

Among 183 volunteers ascertained within 6 weeks after estimated date of infection, 77 (42.0%) had subtype A, 83 (45.4%) subtype C, and 23 (12.6%) subtype D infection. Individuals with subtype A were 1.40 (95% confidence interval: 1.17, 1.68) times as likely as individuals with subtypes C or D to report any ARS symptoms; each individual symptom other than rash was also more prevalent in subtype A than in subtype C or D, with prevalence ratios ranging from 1.94 (1.40, 2.70) for headache to 4.92 (2.24, 10.78) for lymphadenopathy.

CONCLUSION

Individuals with subtype A were significantly more likely than individuals with subtypes C or D to report any ARS symptoms. HIV-1 subtypes may help explain differences in ARS that have been observed across regions in Africa, and may impact the yield of symptom-based screening strategies for acute HIV infection detection.

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.

HIV-specific CD4-induced Antibodies Mediate Broad and Potent Antibody-dependent Cellular Cytotoxicity Activity and Are Commonly Detected in Plasma From HIV-infected humans

HIV-specific antibodies (Abs) can reduce viral burden by blocking new rounds of infection or by destroying infected cells via activation of effector cells through Fc–FcR interaction. This latter process, referred to as antibody-dependent cellular cytotoxicity (ADCC), has been associated with viral control and improved clinical outcome following both HIV and SIV infections. Here we describe an HIV viral-like particle (VLP)-based sorting strategy that led to identification of HIV-specificmemory B cells encoding Abs that mediate ADCC froma subtype A-infected Kenyan woman at 914 days post-infection. Using this strategy, 12 HIV-envelope-specific monoclonal antibodies (mAbs) were isolated and three mediated potent ADCC activitywhen compared to well-characterized ADCC mAbs. The ADCC-mediating Abs also mediated antibody-dependent cell-mediated virus inhibition (ADCVI), which provides a net measure of Fc receptor-triggered effects against replicating virus. Two of the three ADCC-mediating Abs targeted a CD4-induced (CD4i) epitope also bound by the mAb C11; the third antibody targeted the N-terminus of V3. Both CD4i Abs identified here demonstrated strong cross-clade breadth with activity against 10 of 11 envelopes tested, including those from clades A, B, C, A/D and C/D, whereas the V3-specific antibody showed more limited breadth. Variants of these CD4i, C11-like mAbs engineered to interrupt binding to FcγRs inhibited a measurable percentage of the donor's ADCC activity starting as early as 189 days post-infection. C11-like antibodies also accounted for between 18–78% of ADCC activity in 9 chronically infected individuals from the same cohort study. Further, the two CD4i Abs originated from unique B cells, suggesting that antibodies targeting this epitope can be commonly produced. Taken together, these data provide strong evidence that CD4i, C11-like antibodies develop within the first 6 months of infection and they can arise fromunique B-cell lineages in the same individual. Further, thesemAbsmediate potent plasma IgG-specificADCC breadth and potency and contribute to ADCC activity in other HIV-infected individuals.

Physiological and Psychological Correlates of Fatigue in HIV Disease

Fatigue is a frequent symptom reported by persons living with HIV disease and one that affects all aspects of quality of life. To improve quality of care of persons with HIV disease, it is important to address all factors that contribute to fatigue. The purpose of this study was to determine the associations of physiological, psychological, and sociological factors with fatigue in an HIV-infected population. With Piper’s integrated fatigue model guiding selection, factors examined in this study were hemoglobin, hematocrit, CD4+ cell count, HIV-RNA viral load, total sleep time, sleep quality, daytime sleepiness, HIV-related symptoms, anxiety, depression, and perceived stress. The sample (N = 79) for this descriptive correlational study was recruited from a primary health care association in South Carolina and consisted of 42 (53.2%) HIV-infected women and 37 (46.8%) HIV-infected men between the ages of 24 and 63 years (x = 39.9, s = 7.9). Of the participants, 70 (90%) were African American, 5 (6%) were Caucasian, and 3 (4%) were Hispanic. Using Pearson’s r, significant relationships were observed between fatigue and sleep quality, daytime sleepiness, HIV-related symptoms, state anxiety, trait anxiety, depression, and perceived stress. Sleep quality (F5,65 = 12.02, P = 0.0009), state anxiety (F5,65 = 8.28, P = 0.0054), HIV-related symptoms (F5,65 = 4.87, P = 0.0308), and depression (F5,65 = 7.31, P = 0.0087) retained significance in a 3-step, backward stepwise elimination model and accounted for 67% of the variance in fatigue. These findings underscore the need for addressing psychosocial stressors and sleep quality in developing effective care for HIV-infected individuals who experience fatigue.

Short communication: Fc gamma receptors IIa and IIIa genetic polymorphisms do not predict HIV-1 disease progression in Kenyan women

Genetic polymorphisms of the Fc gamma receptors (FcγR) IIa and IIIa have been implicated in the rate of HIV-1 disease progression, but results are inconsistent. We aimed to determine the association between these polymorphisms and disease progression in a cohort of HIV-1 seroconverters from Mombasa, Kenya. Neither FcγRIIa nor FcγRIIIa genotypes were predictive of set point viral load, viral load increase, CD4 decline, or HIV-1 disease progression (time to CD4 count <200 cells/mm(3), death, or treatment initiation). Our results suggest that FcγR polymorphisms might not be an important indicator of viral control and disease progression in this population.

Analysis of HIV/AIDS epidemiology in Japan from 1985-2011-infection detection pattern for male homosexuals different from that for male heterosexuals but similar to that for females

This article reviews Japanese HIV/AIDS surveillance data from 1985 to 2011. It revealed that heterosexual males are more prone to be detected as "AIDS cases," whereas male homosexuals and females are more prone to be detected as "HIV cases," irrespective of the gender, age, infection route, residential area, and nationality. The probability of being detected as an "AIDS case" increased with advanced age, irrespective of the gender and infection route. Interpretation of the data requires further information on the clinical latency of AIDS that could differ depending on differences in infection routes, gender, age, nature of the acute-phase syndrome and factors enhancing it, e.g., route and dose of infection, and mucosal immunity involved in sexually transmitted HIV/AIDS infection and the influence of age and gender on it.

Challenges of diagnosing acute HIV-1 subtype C infection in African women: performance of a clinical algorithm and the need for point-of-care nucleic-acid based testing

Background

Prompt diagnosis of acute HIV infection (AHI) benefits the individual and provides opportunities for public health intervention. The aim of this study was to describe most common signs and symptoms of AHI, correlate these with early disease progression and develop a clinical algorithm to identify acute HIV cases in resource limited setting.

Methods

245 South African women at high-risk of HIV-1 were assessed for AHI and received monthly HIV-1 antibody and RNA testing. Signs and symptoms at first HIV-positive visit were compared to HIV-negative visits. Logistic regression identified clinical predictors of AHI. A model-based score was assigned to each predictor to create a risk score for every woman.

Results

Twenty-eight women seroconverted after a total of 390 person-years of follow-up with an HIV incidence of 7.2/100 person-years (95%CI 4.5–9.8). Fifty-seven percent reported ≥1 sign or symptom at the AHI visit. Factors predictive of AHI included age <25 years (OR = 3.2; 1.4–7.1), rash (OR = 6.1; 2.4–15.4), sore throat (OR = 2.7; 1.0–7.6), weight loss (OR = 4.4; 1.5–13.4), genital ulcers (OR = 8.0; 1.6–39.5) and vaginal discharge (OR = 5.4; 1.6–18.4). A risk score of 2 correctly predicted AHI in 50.0% of cases. The number of signs and symptoms correlated with higher HIV-1 RNA at diagnosis (r = 0.63; p<0.001).

Conclusions

Accurate recognition of signs and symptoms of AHI is critical for early diagnosis of HIV infection. Our algorithm may assist in risk-stratifying individuals for AHI, especially in resource-limited settings where there is no routine testing for AHI. Independent validation of the algorithm on another cohort is needed to assess its utility further. Point-of-care antigen or viral load technology is required, however, to detect asymptomatic, antibody negative cases enabling early interventions and prevention of transmission.

Loss to follow-up as a competing risk in an observational study of HIV-1 incidence

OBJECTIVE

Conventional survival estimates may be biased if loss to follow-up (LTF) is associated with the outcome of interest. Our goal was to assess whether the association between sexual risk behavior and HIV-1 acquisition changed after accounting for LTF with competing risks regression.

METHODS

HIV-1-seronegative women who enrolled in a Kenyan sex worker cohort from 1993-2007 were followed prospectively and tested for HIV at monthly clinic visits. Our primary predictor was self-reported sexual risk behavior in the past week, analyzed as a time-dependent covariate. Outcomes included HIV-1 acquisition and LTF. We analyzed the data using Cox proportional hazards regression and competing risks regression, in which LTF was treated as a competing event.

RESULTS

A total of 1,513 women contributed 4,150 person-years (py), during which 198 (13.1%) acquired HIV-1 infection (incidence, 4.5 per 100 py) and 969 (64.0%) were LTF (incidence, 23.4 per 100 py). After adjusting for potential confounders, women reporting unprotected sex with multiple partners were less likely to be lost to follow-up (adjusted sub-hazard ratio (aSHR) 0.50, 95% confidence interval (CI) 0.32-0.76, relative to no sexual activity). The risk of HIV-1 acquisition after reporting unprotected sex with multiple partners was similar with Cox regression (adjusted hazard ratio (aHR) 2.41, 95% CI 1.36-4.27) and competing risks regression (aSHR 2.47, 95% CI 1.33-4.58).

CONCLUSIONS

Unprotected sex with multiple partners was associated with higher HIV-1 acquisition risk, but lower attrition. This differential attrition did not substantially bias Cox regression estimates when compared to competing risks regression results.

A model of HIV drug resistance driven by heterogeneities in host immunity and adherence patterns

Background

Population transmission models of antiretroviral therapy (ART) and pre-exposure prophylaxis (PrEP) use simplistic assumptions – typically constant, homogeneous rates – to represent the short-term risk and long-term effects of drug resistance. In contrast, within-host models of drug resistance allow for more detailed dynamics of host immunity, latent reservoirs of virus, and drug PK/PD. Bridging these two levels of modeling detail requires an understanding of the “levers” – model parameters or combinations thereof – that change only one independent observable at a time. Using the example of accidental tenofovir-based pre-exposure prophyaxis (PrEP) use during HIV infection, we will explore methods of implementing host heterogeneities and their long-term effects on drug resistance.

Results

We combined and extended existing models of virus dynamics by incorporating pharmacokinetics, pharmacodynamics, and adherence behavior. We identified two “levers” associated with the host immune pressure against the virus, which can be used to independently modify the setpoint viral load and the shape of the acute phase viral load peak. We propose parameter relationships that can explain differences in acute and setpoint viral load among hosts, and demonstrate their influence on the rates of emergence and reversion of drug resistance. The importance of these dynamics is illustrated by modeling long-lived latent reservoirs of virus, through which past intervals of drug resistance can lead to failure of suppressive drug regimens. Finally, we analyze assumptions about temporal patterns of drug adherence and their impact on resistance dynamics, finding that with the same overall level of adherence, the dwell times in drug-adherent versus not-adherent states can alter the levels of drug-resistant virus incorporated into latent reservoirs.

Conclusions

We have shown how a diverse range of observable viral load trajectories can be produced from a basic model of virus dynamics using immunity-related “levers”. Immune pressure, in turn, influences the dynamics of drug resistance, with increased immune activity delaying drug resistance and driving more rapid return to dominance of drug-susceptible virus after drug cessation. Both immune pressure and patterns of drug adherence influence the long-term risk of drug resistance. In the case of accidental PrEP use during infection, rapid transitions between adherence states and/or weak immunity fortifies the “memory” of previous PrEP exposure, increasing the risk of future drug resistance. This model framework provides a means for analyzing individual-level risks of drug resistance and implementing heterogeneities among hosts, thereby achieving a crucial prerequisite for improving population-level models of drug resistance.

Using HIV viral load to guide treatment-for-prevention interventions

PURPOSE OF REVIEW

To provide evidence that HIV-1 RNA load can guide treatment-for-prevention interventions to mitigate the HIV epidemic.

RECENT FINDINGS

Some HIV-infected individuals maintain increased levels of HIV-1 RNA load after acute infection for an extended period of time, and can disproportionately contribute to the spread of HIV in the community. The recent HIV Prevention Trials Network 052 study has demonstrated 96% efficacy for initiation of early antiretroviral treatment (ART) in HIV-1 serodiscordant couples.

SUMMARY

The level of HIV-1 RNA load in plasma is the major biological predictor of virus transmission. HIV-infected individuals who maintain increased levels of HIV-1 RNA load, extended high viremics, can transmit virus at higher rates. Combinatorial ART decreases HIV replication, thus reducing rates of virus transmission. Identifying high viremics and placing them on ART seems an attractive strategy that has the potential to achieve both individual benefits by lowering risk for early onset of clinical AIDS and public health benefits by reducing HIV transmission. A key logistical challenge is to screen for high viremics among HIV-positive individuals. Efficacy of the modified treatment-for-prevention approach focused on high viremics is being evaluated in ongoing and upcoming clinical trials. If efficacious, such an approach could be used widely to mitigate and control the HIV epidemic.

Prevalence of seroconversion symptoms and relationship to set-point viral load: findings from a subtype C epidemic, 1995-2009

OBJECTIVE

To describe symptoms, physical examination findings, and set-point viral load associated with acute HIV seroconversion in a heterosexual cohort of HIV-discordant couples in Zambia.

DESIGN

We followed HIV serodiscordant couples in Lusaka, Zambia from 1995 to 2009 with HIV testing of negative partners and symptom inventories 3 monthly, and physical examinations annually.

METHODS

We compared prevalence of self-reported or treated symptoms (malaria syndrome, chronic diarrhea, asthenia, night sweats, and oral candidiasis) and annual physical examination findings (unilateral or bilateral neck, axillary, or inguinal adenopathy; and dermatosis) in seroconverting vs. HIV-negative or HIV-positive intervals, controlling for repeated observations, age, and sex. A composite score comprised of significant symptoms and physical examination findings predictive of seroconversion vs. HIV-negative intervals was constructed. We modeled the relationship between number of symptoms and physical examination findings at seroconversion and log set-point viral load using linear regression.

RESULTS

Two thousand, three hundred and eighty-eight HIV-negative partners were followed for a median of 18 months; 429 seroconversions occurred. Neither symptoms nor physical examination findings were reported for most seroconverters. Seroconversion was significantly associated with malaria syndrome among nondiarrheic patients [adjusted odds ratio (aOR) = 4.0], night sweats (aOR = 1.4), and bilateral axillary (aOR = 1.6), inguinal (aOR = 2.2), and neck (aOR = 2.2) adenopathy relative to HIV-negative intervals. Median number of symptoms and findings was positively associated with set-point viral load (P < 0.001).

CONCLUSION

Although most acute and early infections were asymptomatic, malaria syndrome was more common and more severe during seroconversion. When present, symptoms and physical examination findings were nonspecific and associated with higher set-point viremia.

Acute retroviral syndrome and high baseline viral load are predictors of rapid HIV progression among untreated Argentinean seroconverters

Background

Diagnosis of primary HIV infection (PHI) has important clinical and public health implications. HAART initiation at this stage remains controversial.

Methods

Our objective was to identify predictors of disease progression among Argentinean seroconverters during the first year of infection, within a multicentre registry of PHI-patients diagnosed between 1997 and 2008. Cox regression was used to analyze predictors of progression (LT-CD4 < 350 cells/mm³, B, C events or death) at 12 months among untreated patients.

Results

Among 134 subjects, 74% presented with acute retroviral syndrome (ARS). Seven opportunistic infections (one death), nine B events, and 10 non-AIDS defining serious events were observed. Among the 92 untreated patients, 24 (26%) progressed at 12 months versus three (7%) in the treated group (p = 0.01). The 12-month progression rate among untreated patients with ARS was 34% (95% CI 22.5-46.3) versus 13% (95% CI 1.1-24.7) in asymptomatic patients (p = 0.04). In univariate analysis, ARS, baseline LT-CD4 < 350 cells/mm³, and baseline and six-month viral load (VL) > 100,000 copies/mL were associated with progression. In multivariate analysis, only ARS and baseline VL > 100,000 copies/mL remained independently associated; HR: 8.44 (95% CI 0.97-73.42) and 9.44 (95% CI 1.38-64.68), respectively.

Conclusions

In Argentina, PHI is associated with significant morbidity. HAART should be considered in PHI patients with ARS and high baseline VL to prevent disease progression.

Extended high viremics: a substantial fraction of individuals maintain high plasma viral RNA levels after acute HIV-1 subtype C infection

OBJECTIVE

The present study addressed two questions: what fraction of individuals maintain a sustained high HIV-1 RNA load after the acute HIV-1C infection peak and how long is a high HIV-1 RNA load maintained after acute HIV-1C infection in this subpopulation?

DESIGN/METHODS

Plasma HIV-1 RNA dynamics were studied in 77 participants with primary HIV-1C infection from African cohorts in Gaborone, Botswana, and Durban, South Africa. HIV-infected individuals who maintained mean viral load of at least 100,000 (5.0 log(10)) copies/ml after 100 days postseroconversion (p/s) were termed extended high viremics. Individuals were followed longitudinally for a median [interquartile range (IQR)] of 573 (226-986) days p/s.

RESULTS

The proportion of extended high viremics was 34% [95% confidence interval (CI) 23-44%] during the period 100-300 days p/s and 19% (95% CI 9-29%) over the period of 200-400 days p/s. The median (IQR) duration of HIV-1 RNA load at least 100,000 copies/ml among extended high viremics was 271 (188-340) days p/s. For the subset with average viral load at least 100,000 copies/ml during 200-400 days p/s, the median (IQR) duration was 318 (282-459) days. The extended high viremics had a significantly shorter time to CD4 cell decline to 350 cells/μl (median: 88 vs. 691 days p/s for those not designated as extended high viremics; P < 0.0001, Gehan-Wilcoxon test).

CONCLUSION

A high proportion of extended high viremics - individuals maintaining high plasma HIV-1 RNA load after acute infection - have been identified during primary HIV-1 subtype C infection. These extended high viremics likely contribute disproportionately to HIV-1 incidence.

Most adults seek urgent healthcare when acquiring HIV-1 and are frequently treated for malaria in coastal Kenya

BACKGROUND

Acute HIV-1 infection (AHI) may present with symptoms for which urgent healthcare is sought. However, little is known about healthcare seeking around the time of HIV-1 seroconversion in sub-Saharan Africa.

METHODS

Review of clinical, counselling, treatment and laboratory records of previously HIV-1 seronegative at-risk adults, followed at monthly or 3-monthly visits, who seroconverted and enrolled in an AHI cohort. All HIV-seronegative plasma samples were tested for p24 antigen (p24) and stored preseroconversion samples for HIV-1 RNA (RNA). Factors associated with malaria treatment while acquiring HIV-1 were evaluated in multiple logistic regression.

RESULTS

Sixty men and 12 women (95% of 75 seroconverters) were evaluated, including 43 (60%) with either p24-positive or RNA-positive or HIV-1 discordant rapid antibodies prior to seroconversion. Prior to diagnosis, 54 patients (75%) reported fever and 50 (69%) sought urgent care for symptomatic illness, including 23 (32%) who sought care in a nonresearch setting. Twenty-nine patients (40%) received presumptive malaria treatment. Only 24% of febrile patients were tested for malaria parasites. All documented smear results were negative. Malaria treatment was strongly associated with fever [adjusted odds ratio (aOR): 46, 95% confidence interval (CI): 3-725] and nonresearch setting (aOR: 5, 95% CI: 3-64). AHI was suspected in six (12%) patients who presented for urgent care during research evaluation.

CONCLUSIONS

The majority of adults with AHI seek urgent healthcare. These individuals are often presumptively treated for malaria. Improved recognition of AHI in adults presenting for care may offer opportunities for optimizing HIV prevention strategies.

HIV RNA level in early infection is predicted by viral load in the transmission source

OBJECTIVE

HIV-1 viral load in early infection predicts the risk of subsequent disease progression but the factors responsible for the differences between individuals in viral load during this period have not been fully identified. We sought to determine the relationship between HIV-1 RNA levels in the source partner and recently infected recipient partners within transmission pairs.

METHODS

We recruited donor partners of persons who presented with acute or recent (<6 months) HIV infection. Transmission was confirmed by phylogenetic comparison of virus sequence in the donor and recipient partners. We compared viral load in the donor partner and the recipient in the first 6 months of HIV infection.

RESULTS

We identified 24 transmission pairs. The median estimated time from infection to evaluation in acutely/recently infected recipient individuals was 72 days. The viral load in the donor was closely associated with viral load at presentation in the recipient case (r = 0.55, P = 0.006).

CONCLUSION

The strong correlation between HIV-1 RNA levels within HIV transmission pairs indicates that virus characteristics are an important determinant of viral load in early HIV infection.

Clinical presentation and diagnosis of primary HIV-1 infection

PURPOSE OF REVIEW

To describe current findings concerning the clinical manifestations and diagnosis of primary HIV-1 infection.

RECENT FINDINGS

HIV-1 seroconversion can occur with a variety of clinical manifestations or without symptoms. More severe and numerous symptoms during primary HIV-1 infection predict a higher plasma HIV-1 RNA set-point and faster disease progression. While detection of primary HIV-1 infection is potentially very important for HIV-1 prevention and may offer clinical benefits, the diagnosis is often missed. Diagnosis of symptomatic individuals with antibody-negative HIV-1 infection requires recognition of the diverse signs and symptoms of this syndrome. Diagnostic tests for primary HIV-1 infection include assays for HIV-1 RNA, p24 antigen, and third generation enzyme immunoassay antibody tests capable of detecting IgM antibodies. Targeting these tests using clinical presentation alone will probably miss the diagnosis in many individuals. Consequently, increasing effort has gone into developing strategies to incorporate the use of these assays into routine HIV-1 testing algorithms.

SUMMARY

More numerous and severe primary HIV-1 infection symptoms predict more rapid disease progression. Pooled HIV-1 RNA screening and fourth generation HIV-1 enzyme immunoassay antibody tests with sensitive p24 antigen detection are beginning to be implemented in routine HIV-1 testing algorithms, but further research is needed to define optimal strategies for increasing detection of primary HIV-1 infection.

Viral load and CD4+ T-cell dynamics in primary HIV-1 subtype C infection

BACKGROUND

Most knowledge of primary HIV-1 infection is based on subtype B studies, whereas the evolution of viral parameters in the early phase of HIV-1 subtype C infection is not well characterized.

METHODS

The kinetics of viral RNA, proviral DNA, CD4+ T-cell count, and subsets of CD4+ T cells expressing CCR5 or CXCR4 were characterized in 8 acute and 62 recent subtype C infections over the first year postseroconversion.

RESULTS

The viral RNA peak was 6.25 +/- 0.92 log10 copies per milliliter. After seroconversion, heterogeneity among acute cases was evident by patterns of change in viral load and CD4+ T-cell count over time. The patterns were supported by the rate of viral RNA decline from peak (P = 0.022), viral RNA means (P = 0.005), CD4 levels (P < 0.001), and CD4 decline to 350 (P = 0.011) or 200 (P = 0.046). Proviral DNA had no apparent peak and its mean was 2.59 +/- 0.69 log10 per 106 peripheral blood mononuclear cell. In recent infections, viral RNA set point was 4.00 +/- 0.97 log10 and viral RNA correlated inversely with CD4+ T cells (P < 0.001) and directly with proviral DNA (P < 0.001).

CONCLUSIONS

Distinct patterns of viral RNA evolution may exist shortly after seroconversion in HIV-1 subtype C infection. The study provides better understanding of the early phase of subtype C infection.

Human immunodeficiency virus type 1 superinfection occurs despite relatively robust neutralizing antibody responses

Superinfection by a second human immunodeficiency virus type 1 (HIV-1) strain indicates that gaps in protective immunity occur during natural infection. To define the role of HIV-1-specific neutralizing antibodies (NAbs) in this setting, we examined NAb responses in 6 women who became superinfected between approximately 1 to 5 years following initial infection compared to 18 women with similar risk factors who did not. Although superinfected individuals had less NAb breadth than matched controls at approximately 1 year postinfection, no significant differences in the breadth or potency of NAb responses were observed just prior to the second infection. In fact, four of the six subjects had relatively broad and potent NAb responses prior to infection by the second strain. To more specifically examine the specificity of the NAbs against the superinfecting virus, these variants were cloned from five of the six individuals. The superinfecting variants did not appear to be inherently neutralization resistant, as measured against a pool of plasma from unrelated HIV-infected individuals. Moreover, the superinfected individuals were able to mount autologous NAb responses to these variants following reinfection. In addition, most superinfected individuals had NAbs that could neutralize their second viral strains prior to their reinfection, suggesting that the level of NAbs elicited during natural infection was not sufficient to block infection. These data indicate that preventing infection by vaccination will likely require broader and more potent NAb responses than those found in HIV-1-infected individuals.

Viral load, clinical disease severity and cellular immune responses in primary varicella zoster virus infection in Sri Lanka

BACKGROUND

In Sri Lanka, varicella zoster virus (VZV) is typically acquired during adulthood with significant associated disease morbidity and mortality. T cells are believed to be important in the control of VZV replication and in the prevention of reactivation. The relationship between viral load, disease severity and cellular immune responses in primary VZV infection has not been well studied.

METHODOLOGY

We used IFNgamma ELISpot assays and MHC class II tetramers based on VZV gE and IE63 epitopes, together with quantitative real time PCR assays to compare the frequency and phenotype of specific T cells with virological and clinical outcomes in 34 adult Sri Lankan individuals with primary VZV infection.

PRINCIPAL FINDINGS

Viral loads were found to be significantly higher in patients with moderate to severe infection compared to those with mild infection (p<0.001) and were significantly higher in those over 25 years of age (P<0.01). A significant inverse correlation was seen between the viral loads and the ex vivo IFNgamma ELISpot responses of patients (P<0.001, r = -0.85). VZV-specific CD4+ T cells expressed markers of intermediate differentiation and activation.

CONCLUSIONS

Overall, these data show that increased clinical severity in Sri Lankan adults with primary VZV infection associates with higher viral load and reduced viral specific T cell responses.

Chronic HIV-1 infection frequently fails to protect against superinfection

Reports of HIV-1 superinfection (re-infection) have demonstrated that the immune response generated against one strain of HIV-1 does not always protect against other strains. However, studies to determine the incidence of HIV-1 superinfection have yielded conflicting results. Furthermore, few studies have attempted to identify superinfection cases occurring more than a year after initial infection, a time when HIV-1-specific immune responses would be most likely to have developed. We screened a cohort of high-risk Kenyan women for HIV-1 superinfection by comparing partial gag and envelope sequences over a 5-y period beginning at primary infection. Among 36 individuals, we detected seven cases of superinfection, including cases in which both viruses belonged to the same HIV-1 subtype, subtype A. In five of these cases, the superinfecting strain was detected in only one of the two genome regions examined, suggesting that recombination frequently occurs following HIV-1 superinfection. In addition, we found that superinfection occurred throughout the course of the first infection: during acute infection in two cases, between 1-2 y after infection in three cases, and as late as 5 y after infection in two cases. Our results indicate that superinfection commonly occurs after the immune response against the initial infection has had time to develop and mature. Implications from HIV-1 superinfection cases, in which natural re-exposure leads to re-infection, will need to be considered in developing strategies for eliciting protective immunity to HIV-1.

The Relation Between Symptoms, Viral Load, and Viral Load Set Point in Primary HIV Infection

OBJECTIVES

To examine the relation between symptoms, initial viral load, and viral load set point in primary HIV infection (PHI).

DESIGN

Prospective cohort of patients with preseroconversion or recent seroconversion HIV infection (typically <60 days) in San Francisco.

METHODS

Subjects were questioned about 21 potential PHI symptoms at enrollment and were subsequently followed with viral load measures.

RESULTS

The analysis included 57 subjects with preseroconversion HIV infection and 120 with recent seroconversion. In univariate analysis, most symptoms and the total number of symptoms were each associated with a significantly higher initial viral load. In stepwise multiple linear regression, however, only the number of symptoms was independently associated with a higher initial viral load, with an increase in the initial viral load of 0.08 log10 per additional symptom (P < 0.001). In univariate analysis, more PHI symptoms were associated with a higher viral load set point, but in a multivariable mixed-effects model, this association was accounted for by the initial viral load, which was strongly correlated with viral load set point (R = 0.44, P < 0.001).

CONCLUSIONS

A high initial viral load was associated with more symptoms during PHI. The strong correlation between initial HIV-1 RNA viral load levels and viral load set point suggests that early interactions between the HIV-1 virus and a new host, even before fully developed adaptive immune responses, are important in establishing viral load set point.

Inverse relationship between viral load and genotypic resistance mutations in Korean patients with primary HIV type 1 infections

The transmission of antiretroviral-resistant HIV-1 strains is associated with suboptimal virological responses to initial antiretroviral therapy. However, certain types of resistance mutations are known to be associated with decreased viral fitness, which confers a lower replication capacity than that of the wild-type virus in the absence of antiretroviral drugs. Therefore, we evaluated the relationship between antiretroviral resistance mutations and viral replication in the primary HIV-1 infection (PHI) period. From January 2002 to March 2005, 52 PHI patients were identified in the Republic of Korea. HIV-1 RNA genotyping was performed, and the resistance mutation score was obtained from the HIV Drug Resistance Database of Stanford University. We defined the sum of the average resistance mutation scores (SARMS) for each antiretroviral drug class as a measure of the degree of resistance of any specific strain. The overall mean SARMS was 2.00 +/- 2.74, and the annual mean did not change significantly during the study period. No critical resistance mutation gene was identified in the study group. The SARMS showed a weak negative correlation with the viral load log10 during PHI, but without statistical significance (r = -0.274, p = 0.051). But the mean SARMS of patients with a viral load exceeding 100,000 copies/ml was significantly lower than that of patients with a viral load of less than 100,000 copies/ml (p = 0.03). Evaluation of the potency of antiretroviral resistance revealed a weak negative correlation with viral replication in the PHI period. This could be one reason why the transmission of resistant strains in PHI patients is not increasing significantly despite the widespread use of highly active antiretroviral therapy (HAART).

Primary human immunodeficiency virus type 1 infection: clinical, virological and immunological characteristics of 75 patients (1997-2003)

OBJECTIVES

To describe the epidemiological and clinical characteristics and the evolution of a cohort of patients with primary HIV-1 infection from the Barcelona area.

METHODS

Prospective cohort study of HIV-infected patients diagnosed with primary HIV infection in a tertiary hospital in Barcelona (Spain) from 1997 through 2003. Descriptive analysis of epidemiological and clinical characteristics and effect of highly active antiretroviral treatment (HAART) on outcome.

RESULTS

A total of 75 patients were diagnosed, accounting for 2.9% of the total of newly diagnosed HIV patients during the same time period. Eighty-one percent of the patients were males and the median age was 30 years (IQR 26-38). The most frequent transmission route was homosexual (72%), followed by heterosexual (17%) and intravenous drug abuse (11%). Seventy-seven percent of patients presented symptoms, the most frequent being fever (98%), asthenia (86%), arthralgia-myalgia (65%), lymphadenopathy (55%), night sweats (48%) and rash. Sixty-five percent started HAART, although the proportion of patients that received HAART decreased from 79% during the period 1997-2000 to 49% during the period 2001-2003 (p < 0.01). After a median follow-up of 37 months (IQR 26-66), one patient died and eight cases were lost to follow-up. The patients who did not receive HAART had a higher probability of immunological or clinical deterioration during the follow-up when compared to the group that received HAART (42.3% versus 12.3%; p < 0.001). In treated patients, dyslipidemia and lipodystrophy were diagnosed in 58% and 37% of cases, respectively.

CONCLUSIONS

Primary HIV-1 infection was diagnosed more frequently in homosexual males, and its clinical characteristics were similar to those observed in previous studies. HAART given during primary HIV infection was effective, but was associated with a high percentage of adverse effects.

Higher set point plasma viral load and more-severe acute HIV type 1 (HIV-1) illness predict mortality among high-risk HIV-1-infected African women

BACKGROUND

There is limited information on the natural history of human immunodeficiency virus type 1 (HIV-1) infection in Africa, especially from individuals with well-defined dates of infection. We used data from a prospective cohort study of female sex workers in Mombasa, Kenya, who were followed up monthly from before the date of HIV-1 infection.

METHODS

Antiretroviral-naive women who had a well-defined date of HIV-1 infection were included in this analysis. The effects of set point plasma viral load (measured 4-24 months after infection), early CD4+ cell count, and symptoms of acute HIV-1 infection on mortality were assessed using Cox proportional hazards analysis.

RESULTS

Among 218 women, the median duration of follow-up after HIV-1 infection was 4.6 years. Forty women died, and at 8.7 years (the time of the last death), the cumulative survival rate was 51% by Kaplan-Meier analysis. Higher set point viral load, lower early CD4+ cell count, and more-symptomatic acute HIV-1 illness each predicted death. In multivariate analysis, set point viral load (hazard ratio [HR], 2.28 per 1 log10 copies/mL increase; P=.001) and acute HIV-1 illness (HR, 1.14 per each additional symptom; P=.05) were independently associated with higher mortality.

CONCLUSION

Among this group of African women, the survival rate was similar to that for HIV-1-infected individuals in industrialized nations before the introduction of combination antiretroviral therapy. Higher set point viral load and more-severe acute HIV-1 illness predicted faster progression to death. Early identification of individuals at risk for rapid disease progression may allow closer clinical monitoring, including timely initiation of antiretroviral treatment.

[Advances in the diagnosis and treatment of acute human immunodeficiency virus type 1 (HIV-1) infection]

According the WHO there are about 14,000 new HIV infections a day. However, in a few cases the diagnosis will be made in the acute phase of the disease. Acute HIV infection is the period between infection with the virus and complete seroconversion, defined by a positive Western blot test. This period lasts approximately 30 days and most patients (40-90%) have mild clinical manifestations (fever, rash, pharyngitis, mucosal ulcers, among others) for 2 weeks which, because they are nonspecific, can be confused with other community-acquired infections. Microbiological diagnosis is based on the absence of serum antibodies (negative ELISA test) together with a positive HIV viral load in plasma (> 10,000 copies/ml). Diagnosis of acute HIV infection is important for several reasons: firstly, from the epidemiological point of view, this is the period with the highest rates of HIV transmission and identification of new HIV infections reveals the growth of the epidemic and the transmission rates of resistant HIV strains, which in Spain is about 10%; secondly, from the immunopathological point of view, this period provides a unique opportunity to study the virological, immunological and genetic mechanisms that play a role in the transmission and pathogenesis of this disease; and thirdly, therapeutically, starting antiretroviral therapy during this phase could alter the natural history of the disease. However, this is a controversial issue and currently most guidelines recommend treatment only if these patients can be included in clinical trials or if they show lasting or severe clinical manifestations.

Evidence for frequent reinfection with human immunodeficiency virus type 1 of a different subtype

A major premise underlying current human immunodeficiency virus type 1 (HIV-1) vaccine approaches is that preexisting HIV-1-specific immunity will block or reduce infection. However, the recent identification of several cases of HIV-1 reinfection suggests that the specific immune response generated for chronic HIV-1 infection may not be adequate to protect against infection by a second HIV-1 strain. It has been unclear, though, whether these individuals are representative of the global epidemic or are rare cases. Here we show that in a population of high-risk women, HIV-1 reinfection occurs almost as commonly as first infections. The study was designed to detect cases of reinfection by HIV-1 of a different subtype and thus captured cases where there was considerable diversity between the first and second strain. In each case, the second virus emerged approximately 1 year after the first infection, and in two cases, it emerged when viral levels were high, suggesting that a well-established HIV-1 infection may provide little benefit in terms of immunizing against reinfection, at least by more-divergent HIV-1 variants. Our findings indicate an urgent need for studies of larger cohorts to determine the incidence and timing of both intersubtype and intrasubtype reinfection.

Human immunodeficiency virus type 1 genetic diversity in the nervous system: Evolutionary epiphenomenon or disease determinant?

Over the past decade there has been a revolution in the understanding and care of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS)-associated disease. Much of this progress stems from a broader recognition of the importance of differences in viral types, including receptor preference(s), replication properties, and reservoirs, as contributing factors to immunosuppresion and disease progression. In contrast, there is limited conceptualizatin of viral diversity and turnover in the brain and circulation in relation to neurocognitive impairments. Herein, the authors review current concepts regarding viral molecular diversity and phenotypes together with features of HIV-1 neuroinvasion, neurotropism, neurovirulence and neurosusceptiblity. Viral genetic and antigenic diversity is reduced within the brain compared to blood or other systemic organs within individuals. Conversely, viral molecular heterogeneity is greater in patients with HIV-associated dementia compared to nondemented patients, depending on the viral gene examined. Individual viral proteins exert multiple neuropathogenic effects, although the neurological consequences of different viral polymorphisms remain uncertain. Nonetheless, host genetic polymorphisms clearly influence neurological disease outcomes and likely dictate both acquired and innate immune responses, which in turn shape viral evolution within the host. Emerging issues include widespread antiretroviral therapy resistance and increasing awareness of viral superinfections together with viral recombination, all of which are likely to impact on both HIV genetic variation and neuropathogenesis. With the persisting prevalence of HIV-induced neurocognitive disabilities, despite marked improvements in managing immunosuppression, it remains imperative to fully define and understand the mechanisms by which viral dynamics and diversity contribute to neurological disease, permitting the development of new therapeutic strategies.