Scope of the AIDS epidemic in the United States

Estimating age-specific COVID-19 fatality risk and time to death by comparing population diagnosis and death patterns: Australian data

Background

Mortality is a key component of the natural history of COVID-19 infection. Surveillance data on COVID-19 deaths and case diagnoses are widely available in the public domain, but they are not used to model time to death because they typically do not link diagnosis and death at an individual level. This paper demonstrates that by comparing the unlinked patterns of new diagnoses and deaths over age and time, age-specific mortality and time to death may be estimated using a statistical method called deconvolution.

Methods

Age-specific data were analysed on 816 deaths among 6235 cases over age 50 years in Victoria, Australia, from the period January through December 2020. Deconvolution was applied assuming logistic dependence of case fatality risk (CFR) on age and a gamma time to death distribution. Non-parametric deconvolution analyses stratified into separate age groups were used to assess the model assumptions.

Results

It was found that age-specific CFR rose from 2.9% at age 65 years (95% CI:2.2 – 3.5) to 40.0% at age 95 years (CI: 36.6 – 43.6). The estimated mean time between diagnosis and death was 18.1 days (CI: 16.9 – 19.3) and showed no evidence of varying by age (heterogeneity P = 0.97). The estimated 90% percentile of time to death was 33.3 days (CI: 30.4 – 36.3; heterogeneity P = 0.85). The final age-specific model provided a good fit to the observed age-stratified mortality patterns.

Conclusions

Deconvolution was demonstrated to be a powerful analysis method that could be applied to extensive data sources worldwide. Such analyses can inform transmission dynamics models and CFR assessment in emerging outbreaks. Based on these Australian data it is concluded that death from COVID-19 occurs within three weeks of diagnosis on average but takes five weeks in 10% of fatal cases. Fatality risk is negligible in the young but rises above 40% in the elderly, while time to death does not seem to vary by age.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01314-w.

Back-projection of COVID-19 diagnosis counts to assess infection incidence and control measures: analysis of Australian data

Back-projection is an epidemiological analysis method that was developed to estimate HIV incidence using surveillance data on AIDS diagnoses. It was used extensively during the 1990s for this purpose as well as in other epidemiological contexts. Surveillance data on COVID-19 diagnoses can be analysed by the method of back-projection using information about the probability distribution of the time between infection and diagnosis, which is primarily determined by the incubation period. This paper demonstrates the value of such analyses using daily diagnoses from Australia. It is shown how back-projection can be used to assess the pattern of COVID-19 infection incidence over time and to assess the impact of control measures by investigating their temporal association with changes in incidence patterns. For Australia, these analyses reveal that peak infection incidence coincided with the introduction of border closures and social distancing restrictions, while the introduction of subsequent social distancing measures coincided with a continuing decline in incidence to very low levels. These associations were not directly discernible from the daily diagnosis counts, which continued to increase after the first stage of control measures. It is estimated that a one week delay in peak incidence would have led to a fivefold increase in total infections. Furthermore, at the height of the outbreak, half to three-quarters of all infections remained undiagnosed. Automated data analytics of routinely collected surveillance data are a valuable monitoring tool for the COVID-19 pandemic and may be useful for calibrating transmission dynamics models.

Extending Bayesian back-calculation to estimate age and time specific HIV incidence

CD4-based multi-state back-calculation methods are key for monitoring the HIV epidemic, providing estimates of HIV incidence and diagnosis rates by disentangling their inter-related contribution to the observed surveillance data. This paper, extends existing approaches to age-specific settings, permitting the joint estimation of age- and time-specific incidence and diagnosis rates and the derivation of other epidemiological quantities of interest. This allows the identification of specific age-groups at higher risk of infection, which is crucial in directing public health interventions. We investigate, through simulation studies, the suitability of various bivariate splines for the non-parametric modelling of the latent age- and time-specific incidence and illustrate our method on routinely collected data from the HIV epidemic among gay and bisexual men in England and Wales.

The primate vaginal microbiome: comparative context and implications for human health and disease

The primate body hosts trillions of microbes. Interactions between primate hosts and these microbes profoundly affect primate physiology, reproduction, health, survival, and ultimately, evolution. It is increasingly clear that primate health cannot be understood fully without knowledge of host-microbial interactions. Our goals here are to review what is known about microbiomes of the female reproductive tract and to explore several factors that influence variation within individuals, as well as within and between primate species. Much of our knowledge of microbial variation derives from studies of humans, and from microbes located in nonreproductive regions (e.g., the gut). We review work suggesting that the vaginal microbiota affects female health, fecundity, and pregnancy outcomes, demonstrating the selective potential for these agents. We explore the factors that correlate with microbial variation within species. Initial colonization by microbes depends on the manner of birth; most microbial variation is structured by estrogen levels that change with age (i.e., at puberty and menopause) and through the menstrual cycle. Microbial communities vary by location within the vagina and can depend on the sampling methods used (e.g., swab, lavage, or pap smear). Interindividual differences also exist, and while this variation is not completely understood, evidence points more to differences in estrogen levels, rather than differences in external physical environment. When comparing across species, reproductive-age humans show distinct microbial communities, generally dominated by Lactobacillus, unlike other primates. We develop evolutionary hypotheses to explain the marked differences in microbial communities. While much remains to be done to test these hypotheses, we argue that the ample variation in primate mating and reproductive behavior offers excellent opportunities to evaluate host-microbe coevolution and adaptation.

Estimation of HIV-testing rates to maximize early diagnosis-derived benefits at the individual and population level

Background

In HIV infection, initiation of treatment is associated with improved clinical outcom and reduced rate of sexual transmission. However, difficulty in detecting infection in early stages impairs those benefits. We determined the minimum testing rate that maximizes benefits derived from early diagnosis.

Methods

We developed a mathematical model of HIV infection, diagnosis and treatment that allows studying both diagnosed and undiagnosed populations, as well as determining the impact of modifying time to diagnosis and testing rates. The model’s external consistency was assessed by estimating time to AIDS and death in absence of treatment as well as by estimating age-dependent mortality rates during treatment, and comparing them with data previously reported from CASCADE and DHCS cohorts.

Results

In our model, life expectancy of patients diagnosed before 8 years post infection is the same as HIV-negative population. After this time point, age at death is significantly dependent on diagnosis delay but initiation of treatment increases life expectancy to similar levels as HIV-negative population. Early mortality during HAART is dependent on treatment CD4 threshold until 6 years post infection and becomes dependent on diagnosis delay after 6 years post infection. By modifying testing rates, we estimate that an annual testing rate of 20% leads to diagnosis of 90% of infected individuals within the first 8.2 years of infection and that current testing rate in middle-high income settings stands close to 10%. In addition, many differences between low-income and middle-high incomes can be predicted by solely modifying the diagnosis delay.

Conclusions

To increase testing rate of undiagnosed HIV population by two-fold in middle-high income settings will minimize early mortality during initiation of treatment and global mortality rate as well as maximize life expectancy. Our results highlight the impact of achieving early diagnosis and the importance of strongly work on improving HIV testing rates.

Adherence and plasma HIV RNA response to antiretroviral therapy among HIV-seropositive injection drug users in a Canadian setting

HIV-positive individuals who use injection drugs (IDU) may have lower rates of adherence to highly active antiretroviral therapy (ART). However, previous studies of factors associated with adherence to ART among IDU have been limited primarily to samples drawn from clinical settings and in areas with financial barriers to healthcare.We evaluated patterns of ART adherence and rates of plasma HIV RNA response among a Canadian cohort of community-recruited IDU. Using data from a community-recruited cohort of antiretroviral-naive HIV-infected IDU, we investigated ART adherence patterns based on prescription refill compliance and factors associated with time to plasma HIV-1 RNA suppression (<500 copies/mL) using Cox proportional hazards regression in a setting with universal health care, including free ART. Between 1996 and 2008, 267 antiretroviral-naive HIV-infected IDU initiated ART and had a median of 51 months (inter-quartile range: 17-95 months) of follow-up. Overall, 81 (30.3%) were ≥95% adherent during the first year of HAART and 187 (70.0%) achieved HIV RNA suppression at least once over the study period, for an incidence-density of 34.5 (95% confidence interval [CI]: 29.8-39.9) per 100 person-years. The Kaplan-Meier cumulative plasma HIV RNA suppression rates at 12 months after the initiation of ART were 80.8% (95% CI: 71.2-88.7) for adherent and 28.9% (95% CI: 22.8-36.1) for non-adherent participants. While several socio-demographic characteristics and drug-using behaviours were identified as barriers to successful treatment in unadjusted analyses, the factor most strongly associated with time to HIV RNA suppression in multivariate analysis was adherence to ART of at least 95% (adjusted hazard ratio [AHR] = 6.0, 95% CI: 4.2-8.6, p<0.001). These results demonstrate low rates of adherence to ART among a community-recruited cohort of IDU and reinforce the importance of adherence as the key determinant of successful virological response to antiretroviral therapy.

High HIV prevalence and diagnosis rates in New York City black men

We sought to identify population and subpopulation disparities in rates of HIV diagnosis and prevalence among black males 13 years and older in New York City. We used population-based data from the New York City HIV/AIDS surveillance registry and US Census 2000 to calculate HIV prevalence in 2006 and HIV diagnosis rates in 2007. Black males were the largest demographic group of new HIV diagnoses (n = 1,161, 33%) and persons living with HIV/AIDS in New York City (n = 24,294, 29%) and had the highest diagnosis rates (1.7 per 1,000 population) and prevalence (3.7%). Prevalence and diagnosis rates among black males were higher in higher-poverty neighborhoods than in lower-poverty neighborhoods (p < 0.01). However, very high prevalence (19.3%) was found among black males in three adjacent Manhattan neighborhoods with relatively low poverty rates, and where overall diagnosis rates among black males (7.4 per 1,000) and proportions attributable to men who have sex with men (60.0%) were high. HIV-related disparities exist not only between black males and other groups but also within black males. Success addressing the citywide HIV epidemic will be linked to success in the various portions of this highly affected, heterogeneous population.

US national estimation of emergency department utilization by patients given 'HIV/AIDS-related illness' as their primary diagnosis

BACKGROUND

The emergency department (ED) is one of the most frequent sources of medical care for many HIV-infected individuals. However, the characteristics and ED utilization patterns of patients with HIV/AIDS-related illness as the primary ED diagnosis (HRIPD) are unknown.

METHODS

We identified the ED utilization patterns of HRIPD visits from a weighted sample of US ED visits (1993-2005) using the National Hospital Ambulatory Medical Care Survey, a nationally representative survey. Data on visits by patients≥18 years old were analysed using procedures for multiple-stage survey data. We compared the utilization patterns of HRIPD vs. non-HRIPD visits, and patterns across three periods (1993-1996, 1997-2000 and 2001-2005) to take into account changes in HIV epidemiology.

RESULTS

Overall, 492 000 HRIPD visits were estimated to have occurred from 1993 to 2005, corresponding to 5-in-10 000 ED visits. HRIPD visits experienced longer durations of stay (5.2 h vs. 3.4 h; P=0.001), received more diagnostic tests (5.1 vs. 3.3; P<0.001), were prescribed more medications (2.5 vs. 1.8; P<0.001) and were more frequently seen by physicians (99.5%vs. 93.8%; P<0.001) compared with non-HRIPD visits. HRIPD visits were more likely to result in admission [adjusted odds ratio (OR) 7.67; 95% confidence interval (CI) 5.14-11.44]. The proportion of HRIPD visits that required emergent/urgent care or were seen by attending physicians, and the number of diagnostic tests ordered, significantly increased over time (P<0.05), while the wait time (P=0.003) significantly decreased between the second and third study periods (P<0.05).

CONCLUSIONS

Although HRIPD visits were infrequent relative to all ED visits, HRIPD visits utilized significantly more resources than non-HRIPD visits and the utilization also increased over time.

Cost-effectiveness of strategies to improve HIV testing and receipt of results: economic analysis of a randomized controlled trial

BACKGROUND

The CDC recommends routine voluntary HIV testing of all patients 13-64 years of age. Despite this recommendation, HIV testing rates are low even among those at identifiable risk, and many patients do not return to receive their results.

OBJECTIVE

To examine the costs and benefits of strategies to improve HIV testing and receipt of results.

DESIGN

Cost-effectiveness analysis based on a Markov model. Acceptance of testing, return rates, and related costs were derived from a randomized trial of 251 patients; long-term costs and health outcomes were derived from the literature. SETTING/TARGET POPULATION: Primary-care patients with unknown HIV status.

INTERVENTIONS

Comparison of three intervention models for HIV counseling and testing: Model A = traditional HIV counseling and testing; Model B = nurse-initiated routine screening with traditional HIV testing and counseling; Model C = nurse-initiated routine screening with rapid HIV testing and streamlined counseling.

MAIN MEASURES

Life-years, quality-adjusted life-years (QALYs), costs and incremental cost-effectiveness.

KEY RESULTS

Without consideration of the benefit from reduced HIV transmission, Model A resulted in per-patient lifetime discounted costs of $48,650 and benefits of 16.271 QALYs. Model B increased lifetime costs by $53 and benefits by 0.0013 QALYs (corresponding to 0.48 quality-adjusted life days). Model C cost $66 more than Model A with an increase of 0.0018 QALYs (0.66 quality-adjusted life days) and an incremental cost-effectiveness of $36,390/QALY. When we included the benefit from reduced HIV transmission, Model C cost $10,660/QALY relative to Model A. The cost-effectiveness of Model C was robust in sensitivity analyses.

CONCLUSIONS

In a primary-care population, nurse-initiated routine screening with rapid HIV testing and streamlined counseling increased rates of testing and receipt of test results and was cost-effective compared with traditional HIV testing strategies.

Estimation of HIV incidence in the United States

CONTEXT

Incidence of human immunodeficiency virus (HIV) in the United States has not been directly measured. New assays that differentiate recent vs long-standing HIV infections allow improved estimation of HIV incidence.

OBJECTIVE

To estimate HIV incidence in the United States.

DESIGN, SETTING, AND PATIENTS

Remnant diagnostic serum specimens from patients 13 years or older and newly diagnosed with HIV during 2006 in 22 states were tested with the BED HIV-1 capture enzyme immunoassay to classify infections as recent or long-standing. Information on HIV cases was reported to the Centers for Disease Control and Prevention through June 2007. Incidence of HIV in the 22 states during 2006 was estimated using a statistical approach with adjustment for testing frequency and extrapolated to the United States. Results were corroborated with back-calculation of HIV incidence for 1977-2006 based on HIV diagnoses from 40 states and AIDS incidence from 50 states and the District of Columbia.

MAIN OUTCOME MEASURE

Estimated HIV incidence.

RESULTS

An estimated 39,400 persons were diagnosed with HIV in 2006 in the 22 states. Of 6864 diagnostic specimens tested using the BED assay, 2133 (31%) were classified as recent infections. Based on extrapolations from these data, the estimated number of new infections for the United States in 2006 was 56,300 (95% confidence interval [CI], 48,200-64,500); the estimated incidence rate was 22.8 per 100,000 population (95% CI, 19.5-26.1). Forty-five percent of infections were among black individuals and 53% among men who have sex with men. The back-calculation (n = 1.230 million HIV/AIDS cases reported by the end of 2006) yielded an estimate of 55,400 (95% CI, 50,000-60,800) new infections per year for 2003-2006 and indicated that HIV incidence increased in the mid-1990s, then slightly declined after 1999 and has been stable thereafter.

CONCLUSIONS

This study provides the first direct estimates of HIV incidence in the United States using laboratory technologies previously implemented only in clinic-based settings. New HIV infections in the United States remain concentrated among men who have sex with men and among black individuals.

Monitoring the incidence of HIV infection in the United States

The Centers for Disease Control and Prevention maintains a national surveillance system that provides data about the HIV/AIDS epidemic for program planning and resource allocation. Until recently, incidence of HIV infection (i.e., the number of individuals recently infected with HIV) has not been directly measured. New serologic testing methods make it possible to distinguish between recent and long-standing HIV-1 infection on a population level. This article describes the new National HIV Incidence Surveillance System.

Spirituality, coping, and HIV risk and prevention in a sample of severely mentally ill Puerto Rican women

Hispanics have been disproportionately impacted by HIV/AIDS. Although HIV risk is significantly elevated among severely mentally ill persons (SMI), the risk of infection appears to be even greater among those SMI who are Hispanic, reflecting the increased risk of HIV among Hispanics. We report on findings from the first 41 participants in a qualitative study examining the context of HIV risk and risk reduction strategies among severely mentally ill Puerto Rican women residents in northeastern Ohio. Individuals participated in a baseline interview, two follow-up interviews, and up to 100 hours of shadowing. Interviews and shadowing activities were recorded and analyzed using a grounded theory. The majority of individuals reported using identification with a religious faith. A large proportion of the participants reported that their religious or spiritual beliefs were critical to their coping, had influenced them to reduce risk, and/or provided them with needed social support. Several participants also reported having experienced rejection from their faith communities. The emphasis on spirituality among Puerto Rican SMI is consistent with previous research demonstrating the importance of spirituality in the Hispanic culture and reliance on spiritual beliefs as a mean of coping among SMI. Our results support the incorporation of spiritual beliefs into secular HIV prevention efforts.

Preventing HIV, eliminating disparities among Hispanics in the United States

HIV/AIDS has disproportionately impacted Hispanics/Latinos in the United States. This literature review focuses on the disparities that exist in the impact of HIV/AIDS across Hispanic subgroups. Elimination of these disparities requires attention to underlying biological, behavioral and psychological, social and cultural, and economic and structural factors. Attention to factors within these domains has important implications for the reduction of other health-related disparities that exist across Hispanic/Latino subgroups in the United States.

Prevalence of HIV infection among young adults in the United States: results from the Add Health study

OBJECTIVES

We estimated HIV prevalence rates among young adults in the United States.

METHODS

We used survey data from the third wave of the National Longitudinal Study of Adolescent Health, a random sample of nearly 19000 young adults initiated in 1994-1995. Consenting respondents were screened for the presence of antibodies to HIV-1 in oral mucosal transudate specimens. We calculated prevalence rates, accounting for survey design, response rates, and test performance.

RESULTS

Among the 13184 participants, the HIV prevalence rate was 1.0 per 1000 (95% confidence interval [CI] = 0.4, 1.7). Gender-specific prevalence rates were similar, but rates differed markedly between non-Hispanic Blacks (4.9 per 1000; 95% CI=1.8, 8.7) and members of other racial/ethnic groups (0.22 per 1000; 95% CI=0.00, 0.64).

CONCLUSIONS

Racial disparities in HIV in the United States are established early in the life span, and our data suggest that 15% to 30% of all cases of HIV occur among individuals younger than 25 years.

Estimating the Distribution of a Renewal Process from Times at which Events from an Independent Process Are Detected

The analysis of length-biased data has been mostly limited to the interarrival interval of a renewal process covering a specific time point. Motivated by a surveillance problem, we consider a more general situation where this time point is random and related to a specific event, for example, status change or onset of a disease. We also consider the problem when additional information is available on whether the event intervals (interarrival intervals covering the random event) end within or after a random time period (which we call a window period) following the random event. Under the assumptions that the occurrence rate of the random event is low and the renewal process is independent of the random event, we provide formulae for the estimation of the distribution of interarrival times based on the observed event intervals. Procedures for testing the required assumptions are also furnished. We apply our results to human immunodeficiency virus (HIV) test data from public test sites in Seattle, Washington, where the random event is HIV infection and the window period is from the onset of HIV infection to the time at which a less sensitive HIV test becomes positive. Results show that the estimator of the intertest interval length distribution from event intervals ending within the window period is less biased than the estimator from all event intervals; the latter estimator is affected by right truncation. Finally, we discuss possible applications to estimating HIV incidence and analyzing length-biased samples with right or left truncated data.

Abstinence and abstinence-only education: a review of U.S. policies and programs

Abstinence from sexual intercourse is an important behavioral strategy for preventing human immunodeficiency virus (HIV), other sexually transmitted infections (STIs), and pregnancy among adolescents. Many adolescents, including most younger adolescents, have not initiated sexual intercourse and many sexually experienced adolescents and young adults are abstinent for varying periods of time. There is broad support for abstinence as a necessary and appropriate part of sexuality education. Controversy arises when abstinence is provided to adolescents as a sole choice and where health information on other choices is restricted or misrepresented. Although abstinence is theoretically fully effective, in actual practice abstinence often fails to protect against pregnancy and STIs. Few Americans remain abstinent until marriage; many do not or cannot marry, and most initiate sexual intercourse and other sexual behaviors as adolescents. Although abstinence is a healthy behavioral option for teens, abstinence as a sole option for adolescents is scientifically and ethically problematic. A recent emphasis on abstinence-only programs and policies appears to be undermining more comprehensive sexuality education and other government-sponsored programs. We believe that abstinence-only education programs, as defined by federal funding requirements, are morally problematic, by withholding information and promoting questionable and inaccurate opinions. Abstinence-only programs threaten fundamental human rights to health, information, and life.

Survey of human immunodeficiency virus (HIV)-seropositive patients with mycobacterial infection in Japan

OBJECTIVE

To assess DNA polymorphisms in mycobacterial isolates obtained from human immunodeficiency virus (HIV)-seropositive patients with tuberculosis in Japan from 1996 to 2003.

METHODS

Restriction fragment length polymorphisms (RFLP) from Mycobacterium tuberculosis and Mycobacterium avium isolates obtained from individual seropositive patients with tuberculosis (n=78) were analysed with the use of IS6110 and (CGG)(5) or IS1245 and IS1311, respectively, as markers. As a control, the same procedures were applied to isolates from HIV-seronegative tuberculosis patients (n=87).

RESULTS

Of 86 mycobacterial strains, M. tuberculosis, M. avium and Mycobacterium chelonae were identified in 48 (55.8%), 36 (41.9%) and 2 (2.3%) isolates, respectively. The obtained RFLP patterns of M. tuberculosis isolates from both the HIV-seropositive and -seronegative groups were variable, suggesting no obvious clustering among the isolates. Similar results were obtained in isolates of M. avium.

CONCLUSIONS

This is the first report on the molecular epidemiology of Mycobacterium spp. isolated from HIV-seropositive patients in Japan. The results indicate that no particular clones of M. tuberculosis or M. avium prevail in HIV-seropositive patients in Japan. Further monitoring of mycobacterial infection associated with HIV infection in Japan should be continued.

Future trends of HCV-related cirrhosis and hepatocellular carcinoma under the currently available treatments

The epidemic of hepatitis C virus (HCV) infection is a major public health issue. We conducted a comprehensive analysis to estimate future HCV-related morbidity and mortality, using a model which is the first to take into account currently available treatments. We reconstructed the incident infections per year in the past that progressed to chronic hepatitis C (CHC) in Greece. Then, the natural history of the disease was simulated in subcohorts of newly infected subjects in the presence or absence of treatment using yearly estimates of the number of treated patients obtained from national databases. Annual estimates of the incidence and prevalence of CHC by fibrosis stage, hepatocellular carcinoma (HCC) and mortality were obtained up to 2030. The current proportion of naïve CHC patients receiving treatment in Greece is 1.2% per year. Treatment of 1.2-10% of naïve CHC patients per year would reduce the cumulative number of incident cirrhosis and HCC cases from 2002 to 2030 by 10.8-39.4% and 12.8-39.8%, respectively and decrease the number of prevalent cirrhosis and HCC cases in 2030 by approximately 17-48% compared with the number estimated under the assumption of no treatment. Approximately 17 cirrhosis cases or six HCC cases or 10 premature deaths would be prevented for every 100 treated patients. However, the prevalent cirrhotic/HCC cases because of HCV and HCV-related deaths would not plateau until 2030. Despite the introduction of effective treatment, HCV-related morbidity and mortality will likely increase during the next 20-30 years in Greece. Intensive primary prevention efforts coupled with increased access to the currently available treatments are necessary to control the chronic consequences of HCV epidemic.

Uncertainty due to model choice in variant Creutzfeldt-Jakob disease projections

For some statistical applications, uncertainty due to unverifiable assumptions can be much greater than that arising from the random variability that is quantified by conventional confidence intervals. The case of projecting possible maximum numbers of eventual deaths due to variant Creutzfeldt-Jakob disease in the United Kingdom provides an extreme example of this phenomenon. The need for parametric extrapolation of the incubation distribution, along with non-identifiability of the number of infected persons, makes assumptions very influential. Several publications in leading science journals gave upper bounds that were 100-fold to 20 000-fold lower than projections from other plausible models given here that fit the data about as well. The crucial assumption for projections is how the risk of death increases with time since infection, and exponential growth is an obvious choice for pessimistic models. Parametric extrapolation from the generalized lambda, generalized F, or lognormal distributions produced upper bounds much lower than exponential extrapolation (i.e. assuming a Gompertz distribution, which fit the data up to early 2002 quite well). Had the publications considered such possibilities, they would have reached much weaker conclusions and been less suitable for leading general science journals. The scientific publication process may have inherent disincentives for thorough assessment of uncertainty.

Cost-effectiveness of screening for HIV in the era of highly active antiretroviral therapy

BACKGROUND

The costs, benefits, and cost-effectiveness of screening for human immunodeficiency virus (HIV) in health care settings during the era of highly active antiretroviral therapy (HAART) have not been determined.

METHODS

We developed a Markov model of costs, quality of life, and survival associated with an HIV-screening program as compared with current practice. In both strategies, symptomatic patients were identified through symptom-based case finding. Identified patients started treatment when their CD4 count dropped to 350 cells per cubic millimeter. Disease progression was defined on the basis of CD4 levels and viral load. The likelihood of sexual transmission was based on viral load, knowledge of HIV status, and efficacy of counseling.

RESULTS

Given a 1 percent prevalence of unidentified HIV infection, screening increased life expectancy by 5.48 days, or 4.70 quality-adjusted days, at an estimated cost of 194 dollars per screened patient, for a cost-effectiveness ratio of 15,078 dollars per quality-adjusted life-year. Screening cost less than 50,000 dollars per quality-adjusted life-year if the prevalence of unidentified HIV infection exceeded 0.05 percent. Excluding HIV transmission, the cost-effectiveness of screening was 41,736 dollars per quality-adjusted life-year. Screening every five years, as compared with a one-time screening program, cost 57,138 dollars per quality-adjusted life-year, but was more attractive in settings with a high incidence of infection. Our results were sensitive to the efficacy of behavior modification, the benefit of early identification and therapy, and the prevalence and incidence of HIV infection.

CONCLUSIONS

The cost-effectiveness of routine HIV screening in health care settings, even in relatively low-prevalence populations, is similar to that of commonly accepted interventions, and such programs should be expanded.

Predicting the impact of a nonsterilizing vaccine against human immunodeficiency virus

Studies of human immunodeficiency virus (HIV) vaccines in animal models suggest that it is difficult to induce complete protection from infection (sterilizing immunity) but that it is possible to reduce the viral load and to slow or prevent disease progression following infection. We have developed an age-structured epidemiological model of the effects of a disease-modifying HIV vaccine that incorporates the intrahost dynamics of infection, a transmission rate and host mortality that depend on the viral load, the possible evolution and transmission of vaccine escape mutant viruses, a finite duration of vaccine protection, and possible changes in sexual behavior. Using this model, we investigated the long-term outcome of a disease-modifying vaccine and utilized uncertainty analysis to quantify the effects of our lack of precise knowledge of various parameters. Our results suggest that the extent of viral load reduction in vaccinated infected individuals (compared to unvaccinated individuals) is the key predictor of vaccine efficacy. Reductions in viral load of about 1 log(10) copies ml(-1) would be sufficient to significantly reduce HIV-associated mortality in the first 20 years after the introduction of vaccination. Changes in sexual risk behavior also had a strong impact on the epidemic outcome. The impact of vaccination is dependent on the population in which it is used, with disease-modifying vaccines predicted to have the most impact in areas of low prevalence and rapid epidemic growth. Surprisingly, the extent to which vaccination alters disease progression, the rate of generation of escape mutants, and the transmission of escape mutants are predicted to have only a weak impact on the epidemic outcome over the first 25 years after the introduction of a vaccine.

If the condom fits, wear it: a qualitative study of young African-American men

OBJECTIVE

To extend the current knowledge base pertaining to condom failure among young African-American men by assessing their experiences with male condom use.

METHODS

Qualitative assessments were conducted with 19 African-American men (aged 18-29 years) who had just been diagnosed with an STI and reported using condoms in the previous 3 months.

RESULTS

Five categories were identified from the data. These categories pertained to: (1) the "fit and feel" of condoms; (2) condom brand and size; (3) application problems; (4) availability of condoms and lubricants; and (5) commitment to condom use. Common themes included reasons why men believed condoms would break or slip off during sex. Comfort problems, including tightly fitting condoms and condoms drying out during intercourse, were mentioned frequently. Condom associated erection problems were often described. Many men also noted that condom use reduced the level of sexual satisfaction for their female partners. Men noted that finding the right kind of condom was not always easy and it became apparent during the interviews that men typically did not acquire lubrication to add to condoms. Despite their expressed problems with using condoms, men were, none the less, typically emphatic that condom use is an important part of their protective behaviour against STIs.

CONCLUSION

Men were highly motivated to use condoms; however, they experienced a broad range of problems with condom use. With the exception of losing the sensation of skin to skin contact, the vast majority of these problems may be amenable to behavioural interventions.

Estimates of the Annual Number and Cost of New HIV Infections Among Women Attributable to Trichomoniasis in the United States

BACKGROUND

Clinical evidence suggests that trichomoniasis facilitates the sexual transmission and acquisition of HIV.

GOAL

The goal of this study was to estimate the annual number and cost of new HIV infections among women in the United States attributable to trichomoniasis.

STUDY

We used a mathematical model of HIV transmission to estimate the probability that a woman with trichomoniasis would acquire HIV as a result of her trichomoniasis-mediated increased susceptibility to HIV infection or as a result of increased HIV infectiousness in a trichomoniasis-infected male partner.

RESULTS

Our results indicate that each year in the United States, an estimated 746 new HIV cases among women can be attributed to the facilitative effects of trichomoniasis on HIV transmission. The lifetime cost of treating these trichomoniasis-attributable HIV infections is approximately $167 million.

CONCLUSIONS

Efforts to prevent trichomoniasis could help prevent HIV transmission and could reduce the economic burden associated with trichomoniasis-attributable HIV cases that occur each year. Because trichomoniasis is so common, however, a substantial number of cases would need to be detected and treated to have a discernible impact on HIV. Future research is needed to examine the cost-effectiveness of trichomoniasis prevention as a tool for HIV prevention.

Age and variant Creutzfeldt-Jakob disease

The young and stable median age of those who die of variant Creutzfeldt-Jakob disease has been attributed to age-dependent infection rates. This analysis shows that an influence of age on risk for death after infection better explains age patterns, suggesting that biologic factors peaking in the third decade of life may hasten disease.

Psychosocial Determinants of Adherence to Highly Active Antiretroviral Therapy among Injection Drug Users in Vancouver

Background

Sub-optimal adherence to highly active antiretroviral therapy (HAART) among injection drug users (IDUs) is a significant concern. As such, there is an urgent need to identify psychosocial determinants of adherence that can be incorporated into interventions designed to promote optimal adherence.

Objective

To identify psychosocial determinants of adherence to HAART, as well as self-reported reasons for missing doses of HAART among HIV-infected IDUs.

Methods

We developed an eight-item adherence self-efficacy scale comprised of two sub-scales: adherence efficacy and self-regulatory efficacy. We examined correlates between adherence self-efficacy, outcome expectations, socio-demographic characteristics, drug use and risk behaviours, social support and HAART adherence among 108 HIV-infected participants in the Vancouver Injection Drug Users Study (VIDUS). Pharmacy-based adherence to HAART was obtained through a confidential record linkage to the province of British Columbia's HIV/AIDS Drug Treatment Program. Participants were defined as adherent if they picked-up 95% of their HAART prescriptions. Participants were also asked to indicate reasons for missing doses of HAART. Logistic regression was used to identify the factors independently associated with adherence to HAART.

Results

Seventy-one (66%) HIV-infected IDUs were less than 95% adherent. Forgetting was the most frequently cited reason (27%) for missing doses of HAART. Factors independently associated with adherence to HAART included adherence efficacy expectations [OR=1.8 (95% CI: 1.0–3.1); P=0.039] and negative outcome expectations [OR=0.8 (95% CI: 0.7–0.9); P=0.027].

Conclusions

We found low rates of adherence to HAART among IDUs. Psychological constructs derived from self-efficacy theory are highly germane to the understanding of adherence behaviour, and interventions that address these constructs should be developed and tested among HIV-infected drug users.

Estimating HIV Incidence and Detection Rates From Surveillance Data

BACKGROUND

Markov models that incorporate HIV test information can increase precision in estimates of new infections and permit the estimation of detection rates. The purpose of this study was to assess the functioning of a Markov model for estimating new HIV infections and HIV detection rates in Louisiana using surveillance data.

METHODS

We expanded a discrete-time Markov model by accounting for the change in AIDS case definition made by the Centers for Disease Control and Prevention in 1993. The model was applied to quarterly HIV/AIDS surveillance data reported in Louisiana from 1981 to 1996 for various exposure and demographic subgroups. When modeling subgroups defined by exposure categories, we adjusted for the high proportion of missing exposure information among recent cases. We ascertained sensitivity to changes in various model assumptions.

RESULTS

The model was able to produce results consistent with other sources of information in the state. Estimates of new infections indicated a transition of the HIV epidemic in Louisiana from (1) predominantly white men and men who have sex with men to (2) women, blacks, and high-risk heterosexuals. The model estimated that 61% of all HIV/AIDS cases were detected and reported by 1996, yet half of all HIV/non-AIDS cases were yet to be detected. Sensitivity analyses demonstrated that the model was robust to several uncertainties.

CONCLUSIONS

In general, the methodology provided a useful and flexible alternative for estimating infection and detection trends using data from a U.S. surveillance program. Its use for estimating current infection will need further exploration to address assumptions related to newer treatments.

Adherence to Antiretroviral Therapy and Cd4 T-Cell Count Responses among HIV-Infected Injection Drug Users

Objective

To evaluate the time to CD4 cell count response (≥50 cells/mm3) among patients initiating highly active antiretroviral therapy (HAART) with and without a history of injection drug use, and to examine the potential role of non-adherence to HAART on differential CD4 responses.

Methods

Population-based analysis of treatment-naive patients initiating HAART during the period 1 August 1996 to 31 July 2000 and who were followed until 31 March 2002. Patients were stratified based on 95% adherence and history of injection drug use, and Kaplan-Meier methods and Cox regression were used to evaluate CD4 response rates and factors associated with CD4 responses.

Results

Overall, the CD4 cell count response rate was slower among injection drug users in Kaplan-Meier analyses (log-rank: P<0.05). However, no differences existed when the analyses were restricted to adherent patients (log-rank: P=0.349). Similarly, the differences in the time to CD4 cell count response observed in univariate Cox regression analyses for patients with a history of injection drug use [relative hazard: 0.85 (95% CI: 0.75–0.97)] diminished after adjustment for adherence [adjusted relative hazard: 1.02 (95% CI: 0.89–1.16)].

Conclusion

These data demonstrate the importance of adherence on CD4 cell count responses and highlight the need for interventions to improve antiretroviral adherence among injection drug user.

The burden of infectious disease among inmates of and releasees from US correctional facilities, 1997

OBJECTIVES

This study developed national estimates of the burden of selected infectious diseases among correctional inmates and releases during 1997.

METHODS

Data from surveys, surveillance, and other reports were synthesized to develop these estimates.

RESULTS

During 1997, 20% to 26% of all people living with HIV in the United States, 29% to 43% of all those infected with the hepatitis C virus, and 40% of all those who had tuberculosis disease in that year passed through a correctional facility.

CONCLUSIONS

Correctional facilities are critical settings for the efficient delivery of prevention and treatment interventions for infectious diseases. Such interventions stand to benefit not only inmates, their families, and partners, but also the public health of the communities to which inmates return.

HIV-associated histories, perceptions, and practices among low-income African American women: does rural residence matter?

OBJECTIVES

This study compared HIV-associated sexual health history, risk perceptions, and sexual risk behaviors of low-income rural and nonrural African American women.

METHODS

A cross-sectional statewide survey of African American women (n = 571) attending federally funded Special Supplemental Nutrition Program for Women, Infants, and Children clinics was conducted.

RESULTS

Adjusted analyses indicated that rural women were more likely to report not being counseled about HIV during pregnancy (P =.001), that a sex partner had not been tested for HIV (P =.005), no preferred method of prevention because they did not worry about sexually transmitted diseases (P =.02), not using condoms (P =.009), and a belief that their partner was HIV negative, despite lack of testing (P =.04).

CONCLUSIONS

This study provided initial evidence that low-income rural African American women are an important population for HIV prevention programs.

Adherence discourse among African-American women taking HAART

Low adherence is the single most important challenge to controlling HIV through the use of high acting anti-retrovirals (HAART). Non-adherence poses an immediate threat to individuals who develop resistant forms of the virus as well as a public health threat if those individuals pass on treatment-resistant forms of the virus. To understand the concerns and perceptions that promote or deter adherence to antiretroviral medication by HIV-positive African-American women, we conducted in-depth interviews with 15 African-American women taking HAART. We focused on the discourse and narratives women use in talking about their adherence practice. Discourse analysis was utilized to identify and explore the sources of influence used by these women in describing their adherence practice. Roughly a third of the sample fell into each of the three self-assessed adherence categories: always adherent, mostly adherent and somewhat adherent. Among the 'always adherent', 80% of the sources of influence cited supported adherence, while only 48% and 47% of the authoritative sources cited by women in the 'mostly' and 'somewhat' categories supported adherence. Each self-assessed adherence group was characterized by its own distinctive discourse style. Findings suggest that adherence to HAART among African-American HIV-positive women would be improved by identifying those influences undermining adherence. Focused study of the 'always adherent' types is recommended.

Effectiveness of highly active antiretroviral therapy among HIV-1 infected women

STUDY OBJECTIVE

To describe the impact of highly active antiretroviral therapy (HAART) on mortality, morbidity, and markers of HIV disease progression in HIV infected women.

DESIGN

Data collected from the Women's Interagency HIV Study, a prospective cohort study that enrolled women between October 1994 and November 1995.

SETTING

Six clinical consortia based in five cities in the United States (New York, NY; Washington, DC; Los Angeles, CA; San Francisco, CA; and Chicago, IL).

PARTICIPANTS

A total of 1691 HIV seropositive women with a study visit after April 1996.

MAIN RESULTS

Beginning in April 1996, the self reported use of HAART increased over time, with more than 50% of the cohort reporting HAART use in 1999. There was a 23% decline per semester in the incidence of AIDS from April 1996 (95% confidence intervals (CI) -29% to -16%). Furthermore, there was a 21% decline of the semiannual mortality rates among those with AIDS at baseline (95% CI -27% to -14%) and an 11% decline among those AIDS free at baseline (95% CI -3% to -18%). CD4+ lymphocyte counts either increased (women with baseline AIDS) or stabilised (women without baseline AIDS) after April 1996, and HIV RNA levels dramatically declined in both groups, although the percentage of women with HIV RNA above 4000 cps/ml remained stable at approximately 40% since mid-1997.

CONCLUSIONS

Despite concerns regarding the use of antiretroviral therapies in this population, the use of therapies led to improved immunological function, suppressed HIV disease activity, and dramatic declines in morbidity and mortality.

Reducing the risk of sexual HIV transmission: quantifying the per-act risk for HIV on the basis of choice of partner, sex act, and condom use

BACKGROUND

Sexual acquisition of HIV is influenced by choice of partner, sex act, and condom use. However, current risk-reduction strategies focus mainly on condom use.

GOAL

To estimate the contribution of choice of partner, sex act, and condom use on the per-act relative and absolute risks for HIV infection.

STUDY DESIGN

Per-act relative risk for HIV infection was calculated with use of estimates of HIV prevalence, risk of condom failure, HIV test accuracy, and per-act risk of HIV transmission for different sex acts. Absolute risks were calculated on the basis of these relative risk estimates.

RESULTS

Choosing a partner who tested negative instead of an untested partner reduced the relative risk of HIV infection 47-fold; using condoms, 20-fold; and choosing insertive fellatio rather than insertive anal sex, 13-fold. Choosing one risk-reduction behavior substantially reduces absolute risk of HIV infection for heterosexuals but not for men who have sex with men.

CONCLUSION

Clarifying the magnitude of risk associated with different choices may help people make effective and sustainable changes in behavior.

Health and federal budgetary effects of increasing access to antiretroviral medications for HIV by expanding Medicaid

OBJECTIVES. This study modeled the health and federal fiscal effects of expanding Medicaid for HIV-infected people to improve access to highly active antiretroviral therapy.

METHODS

A disease state model of the US HIV epidemic, with and without Medicaid expansion, was used. Eligibility required a CD4 cell count less than 500/mm3 or viral load greater than 10,000, absent or inadequate medication insurance, and annual income less than $10,000. Two benefits were modeled, "full" and "limited" (medications, outpatient care). Federal spending for Medicaid, Medicare, AIDS Drug Assistance Program, Supplemental Security Income, and Social Security Disability Insurance were assessed.

RESULTS

An estimated 38,000 individuals would enroll in a Medicaid HIV expansion. Over 5 years, expansion would prevent an estimated 13,000 AIDS diagnoses and 2600 deaths and add 5,816 years of life. Net federal costs for all programs are $739 million (full benefits) and $480 million (limited benefits); for Medicaid alone, the costs are $1.43 and $1.17 billion, respectively. Results were sensitive to awareness of serostatus, highly active antiretroviral therapy cost, and participation rate. Strategies for federal cost neutrality include Medicaid HIV drug price reductions as low as 9% and private insurance buy-ins.

CONCLUSIONS

Expansion of the Medicaid eligibility to increase access to antiretroviral therapy would have substantial health benefits at affordable costs.

Perinatal Transmission of HIV: Recognition and Treatment Interventions

Great strides have been made in the fight against vertical transmission of HIV-1. Improved understanding of mechanisms and timing of transmission of HIV-1 from mother to child have led to the development of effective intervention strategies that have reduced transmission rates to unprecedented low levels, below 2% in developed countries. New reports using shortened, more affordable courses of antiretrovirals prenatally or at the time of delivery have also shown a significant reduction in transmission, over 50% in studies conducted in the developing world. These advances, combined with ongoing studies using simplified effective treatment regimens, have made possible the potential to significantly reduce perinatal transmission worldwide. Future challenges include reduction of breast feeding transmission and the development of an effective HIV-1 vaccine to produce long-lasting protection.

Predictors of mother-adolescent discussions about condoms: implications for providers who serve youth

OBJECTIVE

To examine predictors of mother-adolescent communication about condoms.

METHODS

Interviews were conducted with 907 mothers of adolescents aged 14 to 17 years in the Bronx, New York; Montgomery, Alabama; and San Juan, Puerto Rico, to determine whether mothers had talked with their adolescent about condoms.

RESULTS

By univariate analysis, mother-adolescent communication about condoms was associated with greater knowledge about sexuality and acquired immunodeficiency syndrome, perception of having enough information to discuss condoms, information from a health-related source, less conservative attitudes about adolescent sexuality, perception that the adolescent was at risk for human immunodeficiency virus, greater ability and comfort in discussing condoms, stronger belief that condoms prevent human immunodeficiency virus/acquired immunodeficiency syndrome, and a more favorable endorsement of condoms. In multivariate analyses, mother-adolescent communication about condoms was associated with a less conservative attitude about abstinence until marriage (odds ratio [OR]: 0.73; 95% confidence interval [CI]: 0.54-0.74), greater skill in communicating about sex (OR: 1.13; 95% CI: 1.06-1.20), greater comfort in communicating about sex (OR: 1.31; 95% CI: 1.01-1.69), a more favorable endorsement of condoms (OR: 1.85; 95% CI: 1.17-2.78), and the perception that the adolescent's friends were sexually active (OR: 3.53; 95% CI: 1.97-7.16).

CONCLUSION

Parents who communicate effectively about sexuality and safer sex behaviors can influence their adolescents' risk-taking behavior. Health care providers, particularly physicians, can facilitate this communication by providing to parents information about the sexual behavior of adolescents, the risks that adolescents encounter, condom use, condom effectiveness, and how to discuss condoms. They also can make referrals to programs that teach communication skills.

HIV in the United States at the turn of the century: an epidemic in transition

OBJECTIVES

The current status of and changes in the HIV epidemic in the United States are described.

METHODS

Surveillance data were used to evaluate time trends in AIDS diagnoses and deaths. Estimates of HIV incidence were derived from studies done during the 1990s; time trends in recent HIV incidence were inferred from HIV diagnoses and seroprevalence rates among young persons.

RESULTS

Numbers of deaths and AIDS diagnoses decreased dramatically during 1996 and 1997 but stabilized or declined only slightly during 1998 and 1999. Proportional decreases were smallest among African American women, women in the South, and persons infected through heterosexual contact, HIV incidence has been roughly constant since 1992 in most populations with time trend data, remains highest among men who have sex with men and injection drug users, and typically is higher among African Americans than other racial/ethnic groups.

CONCLUSIONS

The epidemic increasingly affects women minorities, persons infected through heterosexual contact, and the poor. Renewed interest and investment in HIV and AIDS surveillance and surveillance of behaviors associated with HIV transmission are essential to direct resources for prevention to populations with greatest need and to evaluate intervention programs.

Improving participation in HIV clinical trials: impact of a brief intervention

PURPOSE

To determine if a brief intervention that provides information about AIDS clinical trials to HIV-infected patients at the initiation of primary care increases the participation of women, persons of color, and injection drug users (IDUs) in clinical trials.

METHOD

196 outpatients beginning HIV primary care at a municipal hospital were followed from September 1994 to April 1996. During the intake assessment, each patient met briefly with a research assistant who described the purpose, role, and availability of clinical trials. Contacts for further information about trials were given to patients who expressed interest. At the end of the 20-month period, enrollment rates of all patients, including women, persons of color, and IDUs, into clinical trials were compared with previously published enrollment rates of patients at the same hospital but prior to the development of this brief intervention.

RESULTS

The characteristics of the 196 HIV-infected patients were: 27% women; 47% IDUs; 14% gay/bisexual men; and 76% persons of color. Overall enrollment in AIDS clinical trials was 14.8% during the 20-month follow-up period. There was no significant difference in participation rates between males and females (p =.20), whites and persons of color (p =.71), and IDUs compared with non-IDUs (p =.90), whereas previously published data had shown significantly higher enrollment rates among males, whites, and non-IDUs.

CONCLUSION

Providing all HIV-infected patients with information about the meaning, role, and availability of AIDS clinical trials at the initiation of HIV primary care reduces differences in participation rates by gender, race, and history of drug use.

Effective detection of HIV

Biomedical advances, new HIV testing technologies, and policy shifts in the last 15 years have created substantial new challenges and opportunities for service providers, policy makers, and researchers regarding broad scale identification of HIV-seropositive persons. Effective HIV testing will be achieved when we: (1) increase the number of high-risk persons tested; (2) decrease the time from HIV infection to detection; (3) increase testing acceptability; (4) increase the proportion of individuals tested who receive their results; and (5) increase the proportion of individuals tested seropositive who are linked to care. Strategies to enhance effectiveness include implementing new testing technologies and delivery modalities; expanding access to client-controlled testing; targeting providers' knowledge, attitudes, and behaviors regarding HIV testing; mainstreaming HIV testing as routine clinical care; targeting persons who engage in high-risk behaviors and those in high-risk groups; and implementing a national behavioral surveillance system. Addressing these challenges will improve HIV detection in the United States, which is vital to both HIV prevention and treatment.

The Changing Epidemic of HIV

Now in its third decade, the epidemiology of human immunodeficiency virus (HIV) transmission in the United States has changed considerably since the epidemic began. Our increased understanding of the virus has fueled development of new treatments to prolong life, and research into a viable vaccine offers hope to those at risk in developed and less developed countries alike. In this review, we provide information about the current trends in HIV and Acquired Immune Deficiency Syndrome (AIDS) among those in the United States who are hardest hit by the epidemic. We also offer insights into and explanations of these changes; update the epidemiology of HIV subtypes and antiretroviral resistance; and describe current strategies for HIV surveillance.

Association of race and gender with HIV-1 RNA levels and immunologic progression

CONTEXT

HIV-1 RNA and lymphocyte subset levels are the principal indications for antiretroviral treatment. Past reports have differed with regard to the effect of gender and race on these measures and in measures of disease progression.

OBJECTIVE

To assess racial and gender differences in HIV-1 RNA levels and CD4+ lymphocyte decline.

DESIGN

A longitudinal study based in the two largest HIV natural history cohort studies conducted in 7 metropolitan areas of the United States.

RESULTS

In all, 1256 adult women and 1603 adult men for whom multiple data points were available prior to initiation of antiretroviral therapy were included. Women were more likely to be nonwhite, to have a history of injection drug use, and to have HIV-associated symptoms. After adjustment for differences in measurement method, baseline CD4+ cell count, age, and clinical symptoms, HIV-1 RNA levels were 32% to 50% lower in women than in men at CD4+ counts >200 cells/mm3 (p <.001) but not at CD4+ cell counts <200 cells/mm3. HIV-1 RNA levels were also 41% lower in nonwhites than in whites (p <.001) and 21% lower in persons reporting a prior history of injection drug use (p <.001). Women had more rapid declines in CD4+ cell counts over time than men (difference in slope of 46 cells/year) and nonwhite individuals had slower decline in CD4 cell counts than whites (difference of 39 cells/year).

CONCLUSIONS

Both race and gender influence the values of HIV-1 RNA and the rate of HIV-1 disease progression as indicated by decline in CD4 cell counts over time. These effects could provide clues regarding the factors that influence HIV-disease progression and may indicate that guidelines for therapy should be adjusted for demographic characteristics.