The practical significance of potential biases in estimates of the AIDS incubation period distribution in the UK register of HIV seroconverters

Life and Disability Insurance for People with or at Risk of HIV: Aligning Policy with Evidence

Antiretroviral medications have substantially improved life expectancy for people with HIV. These medications are also highly effective in preventing HIV acquisition in people who do not have HIV, a strategy known as HIV preexposure prophylaxis (PrEP). Despite these advances, some life and disability insurers continue to deny or limit coverage for people with HIV, and some have even refused to cover people who are using PrEP to protect themselves. These policies unfairly deny people with HIV, PrEP users, and their families the peace of mind and financial protection that can come with life and disability insurance coverage. This article summarizes the current evidence on HIV treatment and prevention, arguing that underwriting decisions by life and disability insurers should not be made based on HIV status or use of PrEP.

Epigenetic aging in older people living with HIV in Eswatini: a pilot study of HIV and lifestyle factors and epigenetic aging

BACKGROUND

People living with HIV (PLHIV) on effective antiretroviral therapy are living near-normal lives. Although they are less susceptible to AIDS-related complications, they remain highly vulnerable to non-communicable diseases. In this exploratory study of older PLHIV (OPLHIV) in Eswatini, we investigated whether epigenetic aging (i.e., the residual between regressing epigenetic age on chronological age) was associated with HIV-related parameters, and whether lifestyle factors modified these relationships. We calculated epigenetic aging focusing on the Horvath, Hannum, PhenoAge and GrimAge epigenetic clocks, and a pace of biological aging biomarker (DunedinPACE) among 44 OPLHIV in Eswatini.

RESULTS

Age at HIV diagnosis was associated with Hannum epigenetic age acceleration (EAA) (β-coefficient [95% Confidence Interval]; 0.53 [0.05, 1.00], p = 0.03) and longer duration since HIV diagnosis was associated with slower Hannum EAA (- 0.53 [- 1.00, - 0.05], p = 0.03). The average daily dietary intake of fruits and vegetables was associated with DunedinPACE (0.12 [0.03, 0.22], p = 0.01). The associations of Hannum EAA with the age at HIV diagnosis and duration of time since HIV diagnosis were attenuated when the average daily intake of fruits and vegetables or physical activity were included in our models. Diet and self-perceived quality of life measures modified the relationship between CD4+ T cell counts at participant enrollment and Hannum EAA.

CONCLUSIONS

Epigenetic age is more advanced in OPLHIV in Eswatini in those diagnosed with HIV at an older age and slowed in those who have lived for a longer time with diagnosed HIV. Lifestyle and quality of life factors may differentially affect epigenetic aging in OPLHIV. To our knowledge, this is the first study to assess epigenetic aging in OPLHIV in Eswatini and one of the few in sub-Saharan Africa.

Epigenetic aging in older people living with HIV in Eswatini: a pilot study of HIV and lifestyle factors and epigenetic aging

Background

People living with HIV (PLHIV) on effective antiretroviral therapy (ART) are living near-normal lives. Although they are less susceptible to AIDS-related complications, they remain highly vulnerable to non-communicable diseases (NCD). In this exploratory study of older PLHIV (OPLHIV) in Eswatini, we investigated whether biological aging (i.e., the difference between epigenetic age and chronological age, termed 'epigenetic age acceleration [EAA]') was associated with HIV-related parameters, and whether lifestyle factors modified these relationships. We calculated EAA focusing on the second-generation epigenetic clocks, PhenoAge and GrimAge, and a pace of aging biomarker (DunedinPACE) among 44 OPLHIV in Eswatini.

Results

Among participants, the PhenoAge clock showed older epigenetic age (68 years old [63, 77]) but a younger GrimAge epigenetic age (median=56 years old [interquartile range=50, 61]) compared to the chronological age (59 years old [54, 66]). Participants diagnosed with HIV at an older age showed slower DunedinPACE (β-coefficient [95% Confidence Interval]; -0.02 [-0.04, -0.01], p=0.002) and longer duration since HIV diagnosis was associated with faster DunedinPACE (0.02 [0.01, 0.04], p=0.002). The average daily dietary intake of fruits and vegetables was associated with faster DunedinPACE (0.12 [0.03, 0.22], p=0.01) and modified the relationship between HIV status variables (number of years living with HIV since diagnosis, age at HIV diagnosis, CD4+ T cell counts) and PhenoAge EAA, and DunedinPACE.

Conclusions

Biological age is accelerated in OPLHIV in Eswatini, with those living with HIV for a longer duration at risk for faster biological aging. Lifestyle factors, especially healthier diets, may attenuate biological aging in OPLHIV. To our knowledge, this is the first study to assess biological aging in Eswatini and one of the few in sub-Saharan Africa.

Analysis and forecast of the HIV/AIDS epidemic in Mainland China, 1985-2016

BACKGROUND

We aimed to forecast the number of unidentified and newly acquired HIV-infected individuals each year and to estimate the effectiveness of government prevention and control programs in China.

METHODS

Dynamic and stochastic models were established based on officially published data regarding the four main modes of transmission: male homosexual sexual behavior, heterosexual sexual behavior, injection drug use (IDU) and plasma donation. Finally, we performed sensitivity analyses on model parameters.

RESULTS

Nationally, by December 2016, approximately 280 790 individuals were estimated to have an unidentified HIV infection, with transmission via male homosexual sexual behavior (n = 100 710), heterosexual sexual behavior (n = 174 310), IDU (n = 5 620) and plasma donation (n = 150). Moreover, 196 970 newly acquired HIV-infected individuals were expected in 2016, via male homosexual sexual behavior (n = 78 610), heterosexual sexual behavior (n = 116,540), IDU (n = 1820), and plasma donation (n < 2).

CONCLUSIONS

Our results show that HIV transmission via IDU and plasma donation has been effectively controlled; transmission via heterosexual sexual contact is being somewhat controlled; however, transmission via male homosexual sexual contact is not controlled. Hence, China should strengthen efforts aimed at control of unsafe sexual behaviors.

Developing a Bayesian adaptive design for a phase I clinical trial: a case study for a novel HIV treatment

The design of phase I studies is often challenging, because of limited evidence to inform study protocols. Adaptive designs are now well established in cancer but much less so in other clinical areas. A phase I study to assess the safety, pharmacokinetic profile and antiretroviral efficacy of C34-PEG₄ -Chol, a novel peptide fusion inhibitor for the treatment of HIV infection, has been set up with Medical Research Council funding. During the study workup, Bayesian adaptive designs based on the continual reassessment method were compared with a more standard rule-based design, with the aim of choosing a design that would maximise the scientific information gained from the study. The process of specifying and evaluating the design options was time consuming and required the active involvement of all members of the trial's protocol development team. However, the effort was worthwhile as the originally proposed rule-based design has been replaced by a more efficient Bayesian adaptive design. While the outcome to be modelled, design details and evaluation criteria are trial specific, the principles behind their selection are general. This case study illustrates the steps required to establish a design in a novel context. Copyright © 2016 John Wiley & Sons, Ltd.

Loss to follow-up in the Australian HIV Observational Database

BACKGROUND

Loss to follow-up (LTFU) in HIV-positive cohorts is an important surrogate for interrupted clinical care, which can potentially influence the assessment of HIV disease status and outcomes. After preliminary evaluation of LTFU rates and patient characteristics, we evaluated the risk of mortality by LTFU status in a high-resource setting.

METHODS

Rates of LTFU were measured in the Australian HIV Observational Database for a range of patient characteristics. Multivariate repeated measures regression methods were used to identify determinants of LTFU. Mortality by LTFU status was ascertained using linkage to the National Death Index. Survival following combination antiretroviral therapy initiation was investigated using the Kaplan-Meier (KM) method and Cox proportional hazards models.

RESULTS

Of 3,413 patients included in this analysis, 1,632 (47.8%) had at least one episode of LTFU after enrolment. Multivariate predictors of LTFU included viral load (VL)>10,000 copies/ml (rate ratio [RR] 1.63; 95% CI 1.45, 1.84; ref ≤400), time under follow-up (per year; RR 1.03; 95% CI 1.02, 1.04) and prior LTFU (per episode; RR 1.15; 95% CI 1.06, 1.24). KM curves for survival were similar by LTFU status (P=0.484). LTFU was not associated with mortality in Cox proportional hazards models (univariate hazard ratio [HR] 0.93; 95% CI 0.69, 1.26) and multivariate HR 1.04 (95% CI 0.77, 1.43).

CONCLUSIONS

Increased risk of LTFU was identified amongst patients with potentially higher infectiousness. We did not find significant mortality risk associated with LTFU. This is consistent with timely re-engagement with treatment, possibly via high levels of unreported linkage to other health-care providers.

Do people with HIV infection have a normal life expectancy in the era of combination antiretroviral therapy?

There is evidence that the life expectancy (LE) of individuals infected with the human immunodeficiency virus (HIV) has increased since the introduction of combination antiretroviral therapy (cART). However, mortality rates in recent years in HIV-positive individuals appear to have remained higher than would be expected based on rates seen in the general population. A low CD4 count, whether due to late HIV diagnosis, late initiation of cART, or incomplete adherence to cART, remains the dominant predictor of LE, and thus the individual's disease stage at initiation of cART (or thereafter) certainly contributes to these higher mortality rates. However, individuals with HIV also tend to exhibit lifestyles and behaviors that place them at increased risk of mortality, particularly from non-AIDS causes. Thus, although mortality rates among the HIV population may indeed remain slightly higher than those seen in the general population, they may be no higher than those seen in a more appropriately matched control group. Thus, further improvements in LE may now only be possible if some of the other underlying issues (for example, modification of lifestyle or behavioral factors) are tackled.

[Cohort studies and their contribution to the study of HIV infection: main characteristics and limitations]

In this paper, we provide a definition of cohort studies and reviews the main types of cohort studies used in the context of HIV infection. We discuss how the main sources of selection biases in cohort studies are those derived from the lack of observation of the event that determines the origin and/or of the event of interest due to losses to follow-up or development of a competing event, and how this bias must be appropriately taken into account following specific epidemiological methods. Although cohort studies play an essential role in the study of HIV infection, they are logistically complex and require considerable resources. Therefore, strategic planning on the quality and quantity of the information collected must always be accompanied by a resource allocation plan.

Twenty-five years of the AIDS epidemic in Brazil: principal epidemiological findings, 1980-2005

The Brazilian AIDS epidemic is undergoing important changes in its third decade. The present article reviews some central findings: the proportional reduction in cases related to injection drug use; the stability, in recent years, of new cases in the male homosexual/bisexual population; and the relative and absolute increment in heterosexual transmission, even though the estimates of incident rates still point to the first two categories mentioned as those most affected by the epidemic. Still should be detached the persistent increase in incidence rates among women and its stability in the younger age groups, probably the result of behavior changes (such as the consistent use among youth of condoms in sexual relations with casual partners and a reduction in cases related to injection drug use). It is well-know that HIV prevalence in the general population has stabilized at less than 1%, which characterizes Brazil as one of the countries with a concentrated epidemic. The article also emphasizes the growth of AIDS morbidity-mortality in the less favored socioeconomic strata and in women, and the stability of the mortality rate among men.

Potential biases in estimates of hepatitis C RNA clearance in newly acquired hepatitis C infection among a cohort of injecting drug users

Estimates of hepatitis C virus (HCV) clearance following acute infection range from 14 to 46%. This wide range is likely to be due to the characteristics of the populations studied and analysis methods. This paper examines how differing definitions of clearance parameters affect estimates of viral clearance in a cohort of 85 injecting drug users with newly acquired HCV infection. Kaplan-Meier estimates of time to HCV clearance were determined using varying definitions of eligible cohort, viral clearance, date of infection and date of clearance. Based on which combinations of definitions were used, the number of subjects eligible for analysis ranged from 27 to 75, clearance rate ranged from 14 to 68% and time to achieving 25% clearance ranged from approximately 5 months to 14 months. Standardized definitions and methodologies are required to enable valid comparisons of rates of clearance across newly acquired HCV infection natural history studies.

Trends in AIDS and Mortality in HIV-Infected Subjects With Hemophilia From 1985 to 2003

OBJECTIVE

To study trends in progression to AIDS, all-cause mortality, and cause-specific mortality (AIDS-related, liver disease, and hemorrhagic complications) over calendar periods with different exposure to highly active antiretroviral therapy (HAART) in a cohort of hemophiliacs in Spain, taking into account the competing risks of the causes of death.

METHODS

Multicenter cohort of HIV-infected hemophiliacs. HIV seroconversion was estimated using mathematic techniques for interval-censored data from 1979 through 1985. Rates of AIDS and cause-specific death were calculated by Poisson regression, allowing for late entry, for the periods 1985 through 1992, 1993 through 1996, 1997 through 2000 (early HAART), and 2001 through 2003 (late HAART), also allowing for competing risks.

RESULTS

Of 585 subjects, 44% were younger than 15 years of age, 82% had severe hemophilia, 86% had type A hemophilia, and the median seroconversion date was October 1982. Calendar period and age at HIV seroconversion strongly influenced AIDS and death rates. Compared with 1993 through 1996, decreases of 75% (relative risk [RR] = 0.25, 95% confidence interval [CI]: 0.14 to 0.43) and 72% (RR = 0.28, 95% CI: 0.12 to 0.63) in the RR of AIDS were observed in early and late HAART. For all-cause mortality, 72% (RR = 0.28, 95% CI: 0.18 to 0.42) and 83% (RR = 0.17, 95% CI: 0.09 to 0.33) decreases were observed by 1997 through 2000 and 2001 through 2003. For liver-related deaths, increases were observed in the late-HAART period (RR = 2.80, 95% CI: 0.94 to 8.36) compared with 1993 through 1996, but using competing risks, this RR was substantially reduced (RR = 1.70, 95% CI: 0.57 to 5.04).

DISCUSSION

Major reductions in AIDS and death rates were observed from 1997 to 2003 in hemophiliacs. These survival improvements are largely attributable to decreases in AIDS-related deaths and have been accompanied by increases in liver disease death rates, which are overestimated if competing risks are not taken into account.

Should resistance testing be performed for treatment-naive HIV-infected patients? A cost-effectiveness analysis

BACKGROUND

Data from the United States and Europe show a population prevalence of baseline drug resistance of 8%-10% among human immunodeficiency virus (HIV)-infected patients who are antiretroviral naive. Our objective was to determine the clinical impact and cost-effectiveness of genotype resistance testing for treatment-naive patients with chronic HIV infection.

METHODS

We utilized a state-transition model of HIV disease to project life expectancy, costs, and cost-effectiveness in a hypothetical cohort of antiretroviral-naive patients with chronic HIV infection. On the basis of a US survey of treatment-naive patients from the Centers for Disease Control and Prevention, we used a baseline prevalence of drug resistance of 8.3%.

RESULTS

A strategy of genotype-resistance testing at initial diagnosis of HIV infection increased per-person quality-adjusted life expectancy by 1.0 months, with an incremental cost-effectiveness ratio of 23,900 dollars per quality-adjusted life-year gained, compared with no genotype testing. The cost-effectiveness ratio for resistance testing remained less than 50,000 dollars per quality-adjusted life-year gained, unless the prevalence of resistance was < or =1%, a level lower than those reported in most regions of the United States and Europe. In sensitivity analyses, the cost-effectiveness remained favorable through wide variations in baseline assumptions, including variations in genotype cost, prevalence of resistance overall and to individual drug classes, and sensitivity of resistance testing.

CONCLUSIONS

Genotype-resistance testing of chronically HIV-infected, antiretroviral-naive patients is likely to improve clinical outcomes and is cost-effective, compared with other HIV care in the United States. Resistance testing at the time of diagnosis should be the standard of care.

[Imputation of the date of HIV seroconversion in cohorts of haemophiliacs]

OBJECTIVES

To describe the methods used to impute HIV seroconversion date in the haemophiliac cohorts from GEMES project and to validate its use.

METHOD

632 haemophiliacs coming from three hemophilia units identified as HIV+ and 1.092 individuals coming from 5 project GEMES cohorts with a seroconversion window (time among test HIV and HIV+) less than 3 years where mid point (PM) was assumed as seroconversion date. For both groups, seroconversion date was imputed after estimating the probability distribution of seroconversion by means of the EM algorithm. Two imputation methods are used: one obtained from the expected value and the other from the geometric mean of 5 random samples. from the estimated distribution. Imputations have been validated in the non haemophiliacs cohorts comparing with the PM seroconversion date. Also AIDS free time and survival from the different seroconversion imputed dates were compared.

RESULTS

Median seroconversion date is located in May of 1993 for the non haemophiliacs and in 1982 for the haemophiliacs. Not big differences are observed among the imputed seroconversion dates and the mid-point seroconversion date in the non-haemophiliac cohorts. Similar results are found for the haemophiliac cohorts. Also no differences are observed in the estimated AIDS-free time for both groups of cohorts.

CONCLUSIONS

Geometric mean imputation from several random samples provides a good estimate of the HIV seroconversion date that can be used to estimate AIDS-free time and survival in haemophiliac cohorts where seroconversion date is ignored.

The empirical evidence for the impact of HIV on adult mortality in the developing world: data from serological studies

BACKGROUND

Although national data in many African countries indicate rapidly rising mortality levels in the 1990s, only studies with information on the HIV serostatus of study subjects can provide the direct evidence that these changes are caused by HIV and quantify its contribution.

SURVIVAL

Median estimated survival from HIV seroconversion appears to be 8-9 years for individuals infected at 20-29 years, and is considerably shorter for older ages. Differences between estimates include: age structure, survivorship bias and mortality rates in uninfected persons.

MORTALITY RATES

Mortality rates for uninfected individuals in developing countries are 2-5 deaths per 1000 PY for those in their teens and twenties, increasing to 5-17 per 1000 PY for those in their thirties and forties; already 10 and 20-fold the rates in industrialized countries. Rates for infected individuals are higher still and vary considerably: 25-45, 70-120, 90-150, and 90-200 deaths per 1000 PY for those in their teens, twenties, thirties and forties respectively. Standardized for age, those infected experience 9-20 and 15-25 times the mortality rates of uninfected men and women respectively.

CONCLUSION

The impact of HIV on adult mortality in developing countries has been greatest in individuals in their twenties and thirties and is proportionately larger in women than men. Combining the available data yields a clearer picture, which could inform policy on delivery of potent anti-HIV therapy in resource-poor countries, and act as the baseline against which the impact of therapy at the population level can be assessed.

Progression of HIV infection and mortality by hepatitis C infection in patients with haemophilia over 20 years

Hepatitis C virus (HCV) infection is an important cause of mortality in human immune deficiency virus (HIV)-positive haemophiliacs. This study describes progression to AIDS, death from HCV end-stage liver disease (ESLD) and all-cause mortality over 20 years. All HIV-positive haemophiliacs in La Paz University Hospital were included in this cohort. HIV seroconversion was estimated using mathematical techniques for interval-censored data from 1979 to 1985. Poisson regression was used to estimate rates of AIDS, death from ESLD and all causes in different periods: before 1988, 1988-89, 1990-91, 1992-93, 1994-95, 1996-97 and 1998-2001 using competing risk models. Among 383 cohort members, global AIDS incidence was 9.7 per 100 person-years, peaking in 1992-93 and dropping by 87% in 1998-2001 compared with before 1988 [incidence rate ratio (IRR) 0.13; 95% CI: 0.03-0.53]. Overall mortality was 7.5 per 100 person-years, was highest from 1992 to 1997, and fell by 66% in 1998-2001 compared with before 1988 (IRR 0.34; 95% CI: 0.14-0.81). Eighteen (5%) persons died of ESLD which represented 19% of deaths before 1988, 4% during 1988-89, 1990-91 and 1992-93, 2% in 1994-95, 10% in 1996-97 and 33% in 1998-2001. Overall death rate from ESLD was 0.5 cases per 100 person-years with no statistically significant trend observed over time. Important reductions in HIV disease progression to AIDS and death have been observed from 1998 to 2001, and can be attributed to highly active antiretroviral therapy. Although no increase in the rate of HCV-related deaths can be demonstrated, HCV accounts for an increasing proportion of deaths in the recent years.

Determinants of survival following HIV-1 seroconversion after the introduction of HAART

BACKGROUND

Highly active antiretroviral therapy (HAART) was introduced in 1997. We aimed to assess the continuing effect of this treatment on survival and progression to AIDS after HIV-1 seroconversion.

METHODS

We used Cox models to estimate the effect of calendar year on time to AIDS and death in 22 cohorts of people from Europe, Australia, and Canada who had seroconverted. Retrospective and prospective data were used. We compared the effects of age at seroconversion, exposure category, sex, and presentation during acute HIV-1 infection pre-1997 (pre-HAART), in 1997-98 (limited use of HAART), and 1999-2001 (widespread use of HAART).

FINDINGS

Of 7740 seroconverters, 2000 (26%) had died. Compared with pre-1997 data, the hazard ratio (HR) for death fell sharply to 0.47 [95% CI 0.39-0.56] in 1997, dropping further to 0.16 [0.12-0.22] in 2001. Correspondingly, the proportion of person-time on HAART increased from 22% in 1997 to 57% in 2001. By contrast with the pre-HAART era, injecting drug users had significantly higher mortality in 1999-2001 than did men infected through sex with men (HR 4.28 [2.86-6.41]). However, whereas pre-1997 the risk of AIDS was higher in those aged 45 years or older at seroconversion than in people who were 16-24 years (2.03 [1.67-2.47]), in 1999-2001 there was little evidence of a difference in risk by age (HR=1.17 [0.60-2.30]; interaction p=0.06). No such attenuation in the effect of age on survival was observed (p=0.63).

INTERPRETATION

Predicted survival for people with HIV-1 has continued to increase, since the introduction of HAART; however, the importance of age and exposure category as determinants of progression seems to have changed.

Effectiveness of highly active antiretroviral therapy in Spanish cohorts of HIV seroconverters: differences by transmission category

OBJECTIVE

To evaluate the population effectiveness of highly active antiretroviral therapy (HAART) in HIV progression and determine the heterogeneity of the effect of HAART in GEMES (Spanish multicenter study of seroconverters).

DESIGN

Multicenter cohort study.

METHODS

Data from 1091 persons with well-documented HIV seroconversion dates from 1980s to January 2000 were analysed. Risk of AIDS and death in subjects with same duration of HIV infection were compared in different calendar periods; before 1992, 1992-1995 (reference), 1996-1997, 1998 and 1999 with Kaplan-Meier methods and Cox proportional hazards models, allowing for late entry, fitting calendar period as time-dependent covariate and adjusting for transmission category, age and gender.

RESULTS

Statistically significant reductions in the risk of AIDS were first observed in 1998 [hazard ratio (HR), 0.59; 95% confidence interval (CI), 0.35-1.01] becoming more pronounced in 1999 (HR, 0.45; 95% CI, 0.24-0.84). Reduction in the risk of death was seen in 1997, though only reached borderline significance in 1999 (HR, 0.53; 95% CI, 0.26-1.07). Progression to AIDS and death was slower in women (HR, 0.68; 95% CI, 0.46-0.99 and HR, 0.53; 95% CI, 0.33-0.87, respectively). Compared with men who have sex with men (MSM), intravenous drug users (IDU) had lower reductions in the risk of AIDS and death.

CONCLUSIONS

Reductions in incidence of AIDS and death in GEMES are seen after 1998 and 1999, respectively, compared with 1992-1995, being more pronounced in MSM compared with IDU, the commonest category in Spain.

Factors influencing HIV progression in a seroconverter cohort in Madrid from 1985 to 1999

OBJECTIVE

To study HIV progression from seroconversion over a 15 year period and measure the population effectiveness of highly active antiretroviral therapy (HAART).

METHODS

A cohort study of people with well documented dates of seroconversion. Cumulative risk of AIDS and death were calculated by extended Kaplan-Meier allowing for late entry. Cox proportional hazards models were used to study variables associated with HIV progression. To assess the impact of HAART, calendar time was divided in three periods; before 1992, 1992-6, and 1997-9.

RESULTS

From January 1985 to May 2000, 226 seroconverters were identified. The median seroconversion interval was 11 months, median seroconversion date was March 1993. 202 (89%) were men, 76% of whom were homo/bisexual. A 66% reduction in progression to AIDS was observed in 1997-9 compared to 1992-96 (HR 0.34 95% CI: 0.16 to 0.70). People with primary education appeared to have faster progression to AIDS compared to those with university studies (HR 2.69 95%CI: 1.17 to 6.16). An 82% reduction in mortality from HIV seroconversion was observed in 1997-9 (HR 0.18 95% CI: 0.05 to 0.68) compared to 1992-6. Progression to death for people with primary education was twice as fast as for those with university education (p 0.0007). People without confirmation of an HIV negative test had faster progression (HR 4.47 95% CI: 1.18 to 16.92).

CONCLUSIONS

The reduction in progression to AIDS and death from seroconversion from 1992-6 to 1997-9 in Madrid is likely to be attributable to HAART. HIV progression was faster in subjects with primary education; better educational level may be associated with better adherence to medication.

[AIDS epidemic dynamics in the municipality of Rio de Janeiro, Brazil, 1988-1996: Spatial-temporal statistic modeling]

This study uses a spatial-temporal model to analyze the spatial spread of the AIDS epidemic (adult cases) in the municipality of Rio de Janeiro, Brazil, during three periods: 1988-1990, 1991-1993, and 1994-1996. City districts were used as the geographic units of analysis. A spatial analysis was also performed for pediatric AIDS cases due to vertical HIV transmission, according to period of birth, 1985-90 and 1991-96. For total adult AIDS cases, the initial period was characterized by a polygonal cluster located around the harbor area, which expanded from west to east. Among homosexual cases, in situ growth predominated, and a decrease in the intensity of the diffusion process was observed from the second to the final period. Among heterosexual cases, the epidemic displayed a relevant geographic spread, mainly from 1988-1990 to 1991-1993. Among female cases in the final time period, a cluster of high incidence rates was found towards the northwest, including very poor areas. Among pediatric cases in 1991-1996, a significant correlation was found between AIDS incidence rates and poverty levels in the respective municipal districts. The results suggest that a more complete understanding of AIDS spatial-temporal dynamics can make a major contribution to preventive measures.

Cytomegalovirus seroconversion as a cofactor for progression to AIDS

OBJECTIVE

To study the impact of cytomegalovirus (CMV) seroconversion on HIV-1 disease progression.

DESIGN

Follow-up of CMV-seronegative subjects enrolled in the French SEROCO/HEMOCO cohorts of HIV-infected subjects.

METHODS

A total of 290 subjects were CMV-seronegative at enrolment in the cohort. Serological testing for CMV infection was done at enrolment and then every 6 months in CMV-seronegative subjects. The person-years method was used to calculate the incidence of CMV seroconversion. After adjustment for age, the CD4+ cell count at enrolment and the HIV exposure group in a Cox model, we studied CMV seroconversion as a time-dependent variable in progression to a CD4+ cell count below 200 x 10(6) cells/l and to clinical AIDS.

RESULTS

Overall, 61 CMV seroconversions were observed. The overall incidence rate was 4.4 per 100 person-years [95% confidence interval (CI), 3.3-5.5]. The risk of progression to a CD4+ cell count below 200 x 10(6) cells/l was not increased in CMV seroconverters. However, the risk of progression to AIDS was increased two-fold in CMV seroconverters compared with subjects who remained CMV-seronegative [relative risk (RR) = 2.09; 95% CI, 1.16-3.74; P = 0.01].

CONCLUSION

This analysis of 61 CMV seroconversions, the largest study in the literature, confirms the impact of recent CMV infection on progression to AIDS.

Effect of ignoring the time of HIV seroconversion in estimating changes in survival over calendar time in observational studies: results from CASCADE

OBJECTIVE

To compare estimates of changes in HIV survival over time derived from seroconverter and prevalent cohorts.

DESIGN AND METHODS

Using pooled data from 19 seroconverter cohorts (CASCADE), the relative risk of death from HIV seroconversion by calendar time at risk from 1 January 1991 was examined. The analyses were repeated, ignoring knowledge of the time of seroconversion, but adjusting for the CD4 cell count at the time the participant came under observation, thus mimicking a prevalent cohort. Estimates from the 'prevalent' cohort approach were compared with those obtained from the seroconverter cohort.

RESULTS

Of 5428 subjects at risk on 1 January 1991 or later, 1312 (24.2%) had died. In the analysis based on time from seroconversion, estimates of the effect of calendar year showed marked reductions in mortality in 1997-1999 only, with no evidence of a linear trend over the period 1991-1996 (P-trend = 0.85). Using the prevalent cohort approach a decrease in the relative risk of death was observed from 1991 to 1998-1999, with a statistically significant trend of a decrease in risk from 1991 to 1996 (P-trend = 0.002). Similar findings were observed when the analyses was repeated taking the start date of the cohort as 1 January 1988.

CONCLUSION

Lack of knowledge of HIV infection duration may lead to biased and exaggerated estimates of survival improvements over time. The adjustment for duration of infection in prevalent HIV cohorts through laboratory markers may compensate inadequately for this.

A disseminação da epidemia da AIDS no Brasil, no período de 1987-1996: uma análise espacial

As taxas médias de incidência da AIDS em adultos no Brasil foram estimadas para os períodos 1987-89, 1990-92 e 1993-96, segundo o município de residência dos casos. Nas análises foram utilizadas as variáveis "tamanho da população do município de residência"; "proporção de população que vive em área urbana" e "concentração de pobreza", estratificando-se por sexo e categoria de exposição. A Região Sudeste apresenta menor ritmo de crescimento em contraste com os aclives acentuados das regiões Norte e Sul, do 2º ao 3º intervalo. Cotejando-se as variações das taxas de incidência de 1990-92 a 1993-96 por região ou tamanho de população, obtém-se maiores aumentos relativos entre as mulheres. Nas cidades grandes, a categoria "homo/bissexuais" prevalece, decrescendo proporcionalmente à medida que cresce o número de casos por transmissão heterossexual. Nos municípios médios predominam os usuários de drogas injetáveis e nos menores há aumento dos casos por transmissão heterossexual. A epidemia - ainda fenômeno urbano - dá sinais de expansão nos municípios rurais, intensificando-se naqueles situados abaixo do limite crítico regional do índice de pobreza. Há disseminação crescente da epidemia nos municípios mais pobres.