Survival after diagnosis of AIDS: a prospective observational study of 2625 patients. Royal Free/Chelsea and Westminster Hospitals Collaborative Group

Performance evaluation of the Pima™ point-of-care CD4 analyser using capillary blood sampling in field tests in South Africa

Background

Point-of-care CD4 testing can provide immediate CD4 reporting at HIV-testing sites. This study evaluated performance of capillary blood sampling using the point-of-care Pima™ CD4 device in representative primary health care clinics doing HIV testing.

Methods

Prior to testing, prescribed capillary-sampling and instrument training was undertaken by suppliers across all sites. Matching venous EDTA samples were drawn throughout for comparison to laboratory predicate methodology (PLG/CD4). In Phase I, Pima™ cartridges were pipette-filled with EDTA venous blood in the laboratory (N = 100). In Phase II (N = 77), Pima™ CD4 with capillary sampling was performed by a single operator in a hospital-based antenatal clinic. During subsequent field testing, Pima™ CD4 with capillary sampling was performed in primary health care clinics on HIV-positive patients by multiple attending nursing personnel in a rural clinic (Phase-IIIA, N = 96) and an inner-city clinic (Phase-IIIB, N = 139).

Results

Pima™ CD4 compared favourably to predicate/CD4 when cartridges were pipette-filled with venous blood (bias -17.3 ± STDev = 36.7 cells/mm³; precision-to-predicate %CV < 6%). Decreased precision of Pima™ CD4 to predicate/CD4 (varying from 17.6 to 28.8%SIM CV; mean bias = 37.9 ± STDev = 179.5 cells/mm³) was noted during field testing in the hospital antenatal clinic. In the rural clinic field-studies, unacceptable precision-to-predicate and positive bias was noted (mean 28.4%SIM CV; mean bias = +105.7 ± STDev = 225.4 cells/mm³). With additional proactive manufacturer support, reliable performance was noted in the subsequent inner-city clinic field study where acceptable precision-to-predicate (11%SIM CV) and less bias of Pima™ to predicate was shown (BA bias ~11 ± STDev = 69 cells/mm³).

Conclusions

Variable precision of Pima™ to predicate CD4 across study sites was attributable to variable capillary sampling. Poor precision was noted in the outlying primary health care clinic where the system is most likely to be used. Stringent attention to capillary blood collection technique is therefore imperative if technologies like Pima™ are used with capillary sampling at the POC. Pima™ CD4 analysis with venous blood was shown to be reproducible, but testing at the point of care exposes operators to biohazard risk related to uncapping vacutainer samples and pipetting of blood, and is best placed in smaller laboratories using established principles of Good Clinical Laboratory Practice. The development of capillary sampling quality control methods that assure reliable CD4 counts at the point of care are awaited.

A standardized algorithm for determining the underlying cause of death in HIV infection as AIDS or non-AIDS related: results from the EuroSIDA study

OBJECTIVES

Analyzing changes in causes of death over time is essential for understanding the emerging trends in HIV population mortality, yet data on cause of death are often missing. This poses analytic limitations, as does the changing approach in data collection by longitudinal studies, which are a natural consequence of an increased awareness and knowledge in the field. To monitor and analyze changes in mortality over time, we have explored this issue within the EuroSIDA study and propose a standardized protocol unifying data collected and allowing for classification of all deaths as AIDS or non-AIDS related, including events with missing cause of death.

METHODS

Several classifications of the underlying cause of death as AIDS or non-AIDS related within the EuroSIDA study were compared: central classification (CC-reference group) based on an externally standardised method (the CoDe procedures), local cohort classification (LCC) as reported by the site investigator, and 4 algorithms (ALG) created based on survival times after specific AIDS events.

RESULTS

A total of 2,783 deaths occurred, 540 CoDe forms were collected, and 488 were used to evaluate agreements. The agreement between CC and LCC was substantial (κ = 0.7) and the agreement between CC and ALG was moderate (κ < 0.6). Consequently, a stepwise algorithm was derived prioritizing CC over LCC and, in patients with no information available, best-fit ALG. Using this algorithm, 1,332 (47.9%) deaths were classified as AIDS and 1,451 (52.1%) as non-AIDS related.

CONCLUSIONS

Our proposed stepwise algorithm for classifying deaths provides a valuable tool for future research, however validation in another setting is warranted.

Regional and temporal changes in HIV-related mortality in British Columbia, 1987-2006

BACKGROUND

HIV-related mortality has been declining in Canada; however, little is known about regional differences in HIV-related mortality. The objective of this study was to characterize regional changes in HIV-related mortality from 1987-2006 in British Columbia (BC).

METHODS

BC Vital Statistics provided death certificate data for individuals > or =18 years who died of an HIV-related cause in BC between 1987 and 2006. Annual mortality rates were calculated for all BC, five regional health authorities, and two areas within Vancouver. Joinpoint regression analyses measured changes in mortality rates.

RESULTS

There were 3899 HIV-related deaths in BC from 1987-2006. Over time, HIV-related mortality rates were highest in the densely populated, southern regions, and lowest in the north. In BC, mortality significantly increased from 1987-1994 (annual percent change [APC] 16.3%). In 1994, the trend changed to a significant decrease in mortality from 1994-1998 (APC -20.0%), followed by a sustained reduction from 1998-2006. Four of the five health authorities showed mortality trends similar to the province; however, the north showed significantly increasing mortality from 1987-2006 (APC 6.7%). In Vancouver, the City Centre showed a mortality pattern similar to the province, but the Downtown Eastside had rising mortality rates until 1997, followed by a modest decline.

CONCLUSION

In most areas of BC, HIV-related mortality declined after the introduction of effective antiretroviral therapy; however, this decline was delayed or absent in some regions. These regional variations may reflect differential access to health care, even in a setting where antiretroviral therapy is provided at no cost to patients.

Impact of housing on the survival of persons with AIDS

BACKGROUND

Homeless persons with HIV/AIDS have greater morbidity and mortality, more hospitalizations, less use of antiretroviral therapy, and worse medication adherence than HIV-infected persons who are stably housed. We examined the effect of homelessness on the mortality of persons with AIDS and measured the effect of supportive housing on AIDS survival.

METHODS

The San Francisco AIDS registry was used to identify homeless and housed persons who were diagnosed with AIDS between 1996 and 2006. The registry was computer-matched with a housing database of homeless persons who received housing after their AIDS diagnosis. The Kaplan-Meier product limit method was used to compare survival between persons who were homeless at AIDS diagnosis and those who were housed. Proportional hazards models were used to estimate the independent effects of homelessness and supportive housing on survival after AIDS diagnosis.

RESULTS

Of the 6,558 AIDS cases, 9.8% were homeless at diagnosis. Sixty-seven percent of the persons who were homeless survived five years compared with 81% of those who were housed (p < 0.0001). Homelessness increased the risk of death (adjusted relative hazard [RH] 1.20; 95% confidence limits [CL] 1.03, 1.41). Homeless persons with AIDS who obtained supportive housing had a lower risk of death than those who did not (adjusted RH 0.20; 95% CL 0.05, 0.81).

CONCLUSION

Supportive housing ameliorates the negative effect of homelessness on survival with AIDS.

Illness meanings of AIDS among women with HIV: merging immunology and life experience

Little attention has been paid to illness meanings held by those with HIV in the presence of highly active antiretroviral therapy (HAART). This article illustrates how elucidating illness meanings might aid our understanding of HAART adherence and other important health behaviors. Using multiple qualitative methods, including in-depth interviews, free lists, and drawings, I explore meanings surrounding the concept of AIDS among women with HIV in New Orleans, Louisiana. Illness meanings of AIDS reflect the women's negotiation of physical, social, and emotional threats posed by HIV. HIV-positive women displace death and stigma away from an HIV diagnosis to an AIDS diagnosis, creating a sense of safety and normalcy for themselves. Women with AIDS diagnoses, however, struggle to construct illness meanings of AIDS that resist its association with ostracism and death. Drawings produced by the women provide rich insights and illustrate the value of drawings as a visual method in exploring illness meanings.

Managing Medicare's HIV caseload in the era of suppressive therapy

OBJECTIVES

The 1996 introduction of antiretroviral medications changed Medicare's role in providing HIV care. We analyzed Medicare's patient database in an effort to document the new HIV therapies' effects on expenditures and outcomes.

METHODS

We examined the medical billing records of a 5% national Medicare sample from 1997 through 2003. The cohort was stratified by year and categorized by age, race/ethnicity, gender, and Medicare status. Population summaries were categorized according to presence of major chronic diseases and HIV-related conditions.

RESULTS

The number of Medicare beneficiaries with HIV increased from 42520 in 1997 to 76500 in 2003, whereas mortality among this group fell by 35%. HIV-associated infections declined by as much as 43% (mycoses). Heart and liver disease and diabetes increased by more than 50%. Adjusted annual per person Medicare expenditures fell 28%; expenditures were 49% higher for Blacks than for Whites.

CONCLUSIONS

Improved HIV medical management has led to fewer deaths and has shifted treatment toward chronic care. However, successful management is complicated by conditions that have not been historically linked to HIV and whose effects vary according to race/ethnicity.

Decline in esophageal candidiasis and use of antimycotics in European patients with HIV

BACKGROUND

Esophageal candidiasis (EC) remains one of the most common AIDS defining illnesses in patients with human immunodeficiency virus (HIV) in the era of highly active antiretroviral therapy (HAART), but little is known about factors associated with EC after starting HAART.

OBJECTIVES

To describe changes in the use of antimycotic medication, the incidence of EC and factors associated with EC before and after starting HAART.

METHODS

Patients from EuroSIDA, a pan-European longitudinal, prospective observational study. Generalized linear models and poisson regression models were used to investigate the relationships.

RESULTS

A total of 9,873 patients did not have EC at recruitment, subsequently 537 (15.8%) developed EC. The proportion of patients taking any antimycotic dropped from 18% at January 1995 to 2% at January 2004 (p < 0.0001); the duration of treatment declined from 10 to 3 months over the same period (p < 0.0001). There was a 32% annual decline in the incidence of EC (95% CI 30-35%, p < 0.0001). There was a significant annual decline in the incidence of EC pre-HAART in time-updated, adjusted models, (incidence rate ratio (IRR) 0.80, 95% CI 0.76-0.85, p < 0.0001) but not post-HAART (IRR 0.97; 95% CI 0.90-1.06, p= 0.54). Older patients and those with low CD4 counts had the greatest incidence of EC in the post-HAART era.

CONCLUSIONS

There has been a marked decline in the incidence of EC between 1994 and 2004. This was accompanied by a decline in markers associated with fungal disease, including use of antimycotics and a decline in duration of treatment.

Spectrum of clinical disease in a series of 135 hospitalised HIV-infected patients from north India

BACKGROUND

Literature on the spectrum of opportunistic disease in human immunodeficiency virus (HIV)-infected patients from developing countries is sparse. The objective of this study was to document the spectrum and determine the frequency of various opportunistic infections (OIs) and non-infectious opportunistic diseases, in hospitalised HIV-infected patients from north India.

METHODS

One hundred and thirty five consecutive, HIV-infected patients (age 34 +/- 10 years, females 17%) admitted to a tertiary care hospital in north India, for the evaluation and management of an OI or HIV-related disorder between January 2000 and July 2003, were studied.

RESULTS

Fever (71%) and weight loss (65%) were the commonest presenting symptoms. Heterosexual transmission was the commonest mode of HIV-acquisition. Tuberculosis (TB) was the commonest OI (71%) followed by candidiasis (39.3%), Pneumocystis jiroveci pneumonia (PCP) (7.4%), cryptococcal meningitis and cerebral toxoplasmosis (3.7% each). Most of the cases of TB were disseminated (64%). Apart from other well-recognised OIs, two patients had visceral leishmaniasis. Two cases of HIV-associated lymphoma were encountered. CD4+ cell counts were done in 109 patients. Majority of the patients (82.6%) had CD4+ counts <200 cells/microL. Fifty patients (46%) had CD4+ counts <50 cells/microL. Only 50 patients (37%) received antiretroviral therapy. Twenty one patients (16%) died during hospital stay. All but one deaths were due to TB (16 patients; 76%) and PCP (4 patients; 19%).

CONCLUSIONS

A wide spectrum of disease, including both OIs and non-infectious opportunistic diseases, is seen in hospitalised HIV-infected patients from north India. Tuberculosis remains the most common OI and is the commonest cause of death in these patients.

Delayed progression to death and to AIDS in a Hong Kong cohort of patients with advanced HIV type 1 disease during the era of highly active antiretroviral therapy

BACKGROUND

The magnitude of the impact of highly active antiretroviral therapy (HAART) since its introduction in non-Western countries is not entirely clear. We studied disease progression among adult patients with advanced human immunodeficiency virus type 1 (HIV-1) infection in the pre-HAART (i.e., 1996 and earlier) and HAART eras in Hong Kong.

METHODS

The cohort of patients seen at the Integrated Treatment Center (Hong Kong) from 1984 through mid-2003 was retrospectively examined with respect to 3 clinical end points: death after the diagnosis of acquired immunodeficiency syndrome (AIDS), progression to AIDS after achieving a CD4 cell count of <200 cells/microL, and death after achieving a CD4 cell count of <200 cells/microL.

RESULTS

A total of 581 patients with advanced HIV-1 disease had AIDS and/or a CD4 cell count of <200 cells/microL. The incidences of death after AIDS (52.3% vs. 13.6%), AIDS progression after a CD4 cell count of <200 cells/microL (47.7% vs. 20.9%), and death after a CD4 cell count of <200 cells/microL (38.8% vs. 7.0%) were significantly higher among patients in the pre-HAART era than among those in the HAART era (P<.001 for all). On the basis of life-table analysis, the probabilities of death after AIDS (P<.0001), AIDS after a CD4 cell count of <200 cells/microL (P=.0063), and death after a CD4 cell count of <200 cells/microL (P<.0001) diminished in the HAART era, compared with the pre-HAART era. Median survival after AIDS increased from 29.8 months during the pre-HAART era to >70 months during the HAART era (P<.001). Compared with patients in the pre-HAART era, adjusted hazard ratios of clinical events were 0.15 (95% confidence interval [CI], 0.08-0.26) for death after AIDS, 0.38 (95% CI, 0.24-0.60) for AIDS after a CD4 cell count of <200 cells/microL, and 0.25 (95% CI, 0.15-0.40) for death after a CD4 cell count of <200 cells/microL for patients in the HAART era. CONCLUSIONS. The clinical outcome of patients with advanced HIV-1 disease in Hong Kong significantly improved during the HAART era. Our findings of extended durations of survival and AIDS-free status may be relevant to the expected health impacts associated with increased access to HAART in non-Western countries.

The creation of a large UK-based multicentre cohort of HIV-infected individuals: The UK Collaborative HIV Cohort (UK CHIC) Study

OBJECTIVES

This paper describes the development of the UK Collaborative HIV Cohort (CHIC) Study. The aim of the study is to collate routinely collected data on HIV-infected individuals attending one of seven clinical centres in the UK since 1 January 1996, with the objectives of describing changes over time in the frequency of AIDS-defining illnesses, describing the uptake of and response to highly active antiretroviral therapy (HAART), and identifying factors associated with virological and immunological responses to HAART.

METHODS

By December 2002, demographic, clinical and laboratory data had been collected on HIV-positive patients seen at six of the seven HIV centres. Missing and inconsistent data had been investigated and the datasets audited. Records identified as relating to the same patient had been merged, and cross-checks made with UK death registers to improve the accuracy of death reporting.

RESULTS

The cohort currently contains information on 13,833 individuals. Eighty-two per cent of the cohort are male, and the median age was 34 years at first follow-up. The main risk factors for HIV infection have been determined as sex between men (63%) and sex between men and women (24%). Twenty-five per cent of the cohort are known to have developed AIDS, and 8% have died.

CONCLUSIONS

The UK CHIC Study provides important information on the status of individuals infected with HIV in the UK, and provides a means to study the response to HAART and to monitor changes in the clinical event and death rates that have occurred since the introduction of HAART in the UK.

Acute myocardial infarction in patients infected with human immunodeficiency virus

BACKGROUND

Recent clinical and post-mortem reports suggests that human immunodeficiency virus (HIV) infection may participate in the process of atherosclerosis independent of other coronary risk factors. In this prospective and observational study, we investigated whether an associative link exists between HIV infection and coronary artery disease.

METHODS

Of 690 patients admitted to our hospital in a 3-year period, 29 patients (28 men and 1 woman) with a mean age of 46 +/- 10 years had an acute myocardial infarction (AMI) on the basis of acute prolonged chest pain, ischemic electrocardiogram abnormalities, and elevated serum markers of myocardial necrosis at presentation.

RESULTS

ST-segment elevation MI was present in 15 patients, and non-ST-segment elevation MI was present in 14 patients. Twenty-two patients (76%) were <55 years; 17 of these patients had no or 1 coronary risk factor, and 5 patients had 2 or 3 risk factors. Five patients >55 years had 1 coronary risk factor, and 2 patients had 2 risk factors. Thirteen patients underwent a myocardial revascularization procedure, and 1 patient died during hospitalization.

CONCLUSIONS

HIV infection, as a cause of endothelial injury, may initiate the inflammatory process of early atherosclerosis and participate in the evolution of the atherothrombotic lesion responsible for AMI. This study suggests that the association of HIV infection and acute coronary syndrome may be more common than previously reported and underscores the need for further clinical studies.

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.

Low socioeconomic status is associated with a higher rate of death in the era of highly active antiretroviral therapy, San Francisco

Highly active antiretroviral therapy (HAART) has dramatically improved survival after AIDS. The benefits of HAART have not been equally realized for all communities, however. We characterize the association of socioeconomic status (SES) with survival after AIDS diagnosis in San Francisco in the period before (1980-1995) and after (1996 - 2001) the wider use of HAART. Using citywide surveillance data, we examined differences in survival after AIDS diagnosis by neighborhood household income using Kaplan-Meier survival analysis and Cox proportional hazards analysis to adjust for significant covariates. Residing in higher SES neighborhoods significantly predicted better survival after AIDS from 1996 to 2001 (hazard ratio = 0.92 per $10,000 increase in neighborhood household income, 95% CI: 0.85-0.99) after adjusting for CD4 count at diagnosis, age, and injection drug user status. Persons living in poorer neighborhoods were less likely to use HAART at any time in the past compared with persons in wealthier neighborhoods. Moreover, no association between survival and neighborhood SES was evident in the era prior to the wide use of HAART. Finally, the difference in survival by neighborhood income level disappeared after controlling for the use of HAART, suggesting that use of or access to treatment explained the association. From 1996 to 2001, survival with AIDS was worse for people living in poorer neighborhoods compared with those living in wealthier neighborhoods of San Francisco as a result of unequal access to or use of HAART.

Natural history of human immunodeficiency virus disease in southern India

There are few reports of the natural history of human immunodeficiency virus (HIV) infection from Asia. In a retrospective analysis of 594 patients (72.9% male; baseline CD4 cell count, 216 cells/microL) receiving care at YRG Center for AIDS Research and Education, a tertiary HIV referral center in southern India, the mean duration of survival from serodiagnosis was 92 months. Ninety-three percent of the patients acquired infection through heterosexual contact. The most common acquired immune deficiency syndrome-defining illnesses were pulmonary tuberculosis (49%; median duration of survival, 45 months), Pneumocystis carinii pneumonia (6%; median duration of survival, 24 months), cryptococcal meningitis (5%; median duration of survival, 22 months), and central nervous system toxoplasmosis (3%; median duration of survival, 28 months). Persons with a CD4 lymphocyte count of <200 cells/microL were 19 times (95% confidence interval [CI], 5.56-64.77) more likely to die than were those with CD4 cell count of >350 cells/microL. Patients who had > or =1 opportunistic infection were 2.6 times more likely to die (95% CI, 0.95-7.09) than were those who did not have an opportunistic infection. Antiretroviral therapy for patients with low CD4 lymphocyte counts improved the odds of survival (odds ratio, 5.37; 95% CI, 1.82-15.83).

Changing demographics in an HIV-infected population: results from an observational cohort study in Western Denmark

We present demographic data from an observational database of HIV and AIDS in the Western part of Denmark, a region with a population of 2,935,156 individuals (55.1% of the population of Denmark). Five centers in the region treat HIV-positive adults; all patients attached to these centers since 1995 are included in this study. In total, 749 adult HIV-infected individuals were enrolled as of 31 December, 1999. Estimates of prevalence and incidence of HIV infection in the area were 25.9/100,000 and 2.6/100,000, respectively, which are lower than average for the country. The number of newly diagnosed HIV-infected patients remained constant during the period 1995-99, with an average of 62 diagnoses per year. The number of HIV-related deaths declined from 43 in 1995 to 15 in 1999. Of the enrolled patients, 70.9% were of Danish origin, 75% were Caucasians, 69.7% were male and 47.2% had heterosexual contact as their primary risk behavior. There seems to have been a shift in the HIV epidemic in recent years, with a higher proportion of newly diagnosed HIV patients having contracted the infection through heterosexual contact, a higher proportion being immigrants from less developed countries and newly diagnosed individuals getting older.

Gender and clinical outcomes after starting highly active antiretroviral treatment: a cohort study

OBJECTIVE

To examine gender differences in clinical response to highly active antiretroviral treatment (HAART).

METHODS

A cohort of HIV-positive individuals was examined. Outcomes assessed were hospital admission and disease progression (either a new AIDS diagnosis or death) after starting HAART. Hazard ratios (HRs) derived using Cox regression methods compared female-to-male rates, adjusting for other factors independently associated with outcome.

RESULTS

Four hundred ninety-seven men and 146 women were followed up over a median of 13 months after starting HAART. Eighty-one percent of men were white, and 75% were homosexual. Fifty-eight percent of women were black African, and 86% were in the heterosexual risk category. The baseline CD4 count was higher in men than in women (191 vs. 145 x 10; p < .01), but viral loads were similar (5.2 vs. 5.1 log copies/ml, respectively; p = .13). Fifty-six percent of men and women were treatment naïve. Eighteen percent of men and women were admitted during follow-up, with 17% of male admissions and 12% of female admissions being the result of an AIDS-defining illness. The HR for admission was 0.76 (95% confidence interval [CI]: 0.46-1.27; p = .30) for women relative to men. Eleven percent of the men and 8% of the women experienced progression. Eighty-eight percent of progressions were the result of a new AIDS diagnosis (46 in men, 11 in women), and 8 men died. The HR for progression was 0.70 (CI: 0.36-1.33; p = .28).

CONCLUSIONS

Our results suggest a possible benefit in women compared with men in the rate of outcomes after HAART. Further analysis with longer follow-up or greater numbers would enable a more powerful analysis to be performed.

Optimal investment in a portfolio of HIV prevention programs

OBJECTIVES

In this article, the authors determine the optimal allocation of HIV prevention funds and investigate the impact of different allocation methods on health outcomes.

METHODS

The authors present a resource allocation model that can be used to determine the allocation of HIV prevention funds that maximizes quality-adjusted life years (or life years) gained or HIV infections averted in a population over a specified time horizon. They apply the model to determine the allocation of a limited budget among 3 types of HIV prevention programs in a population of injection drug users and nonusers: needle exchange programs, methadone maintenance treatment, and condom availability programs. For each prevention program, the authors estimate a production function that relates the amount invested to the associated change in risky behavior.

RESULTS

The authors determine the optimal allocation of funds for both objective functions for a high-prevalence population and a low-prevalence population. They also consider the allocation of funds under several common rules of thumb that are used to allocate HIV prevention resources. It is shown that simpler allocation methods (e.g., allocation based on HIV incidence or notions of equity among population groups) may lead to alloctions that do not yield the maximum health benefit.

CONCLUSIONS

The optimal allocation of HIV prevention funds in a population depends on HIV prevalence and incidence, the objective function, the production functions for the prevention programs, and other factors. Consideration of cost, equity, and social and political norms may be important when allocating HIV prevention funds. The model presented in this article can help decision makers determine the health consequences of different allocations of funds.

Survival of AIDS patients in Croatia prior to the introduction of combined antiretroviral therapy with protease inhibitors

We report our experience on survival of adults with AIDS, treated at the University Hospital of Infectious Diseases, Zagreb, Croatia from October 1986 to December 1998. The median survival of our 116 patients was 15.8 months. Multivariate analysis showed that factors independently associated with survival were type of presenting AIDS indicator disease and CD4+ cell count.

Gender differences in virologic response to treatment in an HIV-positive population: a cohort study

OBJECTIVE

To establish whether a gender difference in virologic response to highly active antiretroviral treatment (HAART) exists.

METHODS

A cohort of HIV-positive individuals was examined.

OUTCOMES

Achievement of viral load <500 copies/ml and "failure" (failure to suppress viral load <500 copies/ml after 24 weeks or two consecutive measurements above this level after having suppressed below it). Hazard ratios (HRs) comparing the rate in women to that in men were derived using the Cox model.

RESULTS

Of 366 male subjects, 79% were white and 82% were homosexual. Sixty-three percent of the 91 female subjects were African and 87% were heterosexual. The median follow-up after HAART was 94 weeks. The baseline CD4 count was higher in men (228 x 106 per liter) than in women (171 x 106 per liter) (p =.01), but the viral load was similar (p =.88). The median time to <500 copies/ml was 16 weeks. Women achieved a viral load of <500 copies/ml at a faster rate than men, with an adjusted HR of 1.46 (95% confidence interval [CI]: 0.99-2.16; p =.06). Some 261 patients failed treatment (58% of men and 53% of women) with an HR of 0.78 (95% CI: 0.51-1.21; p =.27).

CONCLUSIONS

Women may achieve virologic suppression at a faster rate than men and have a more durable response. Further research should examine these responses in conjunction with clinical outcomes, because gender differences in virologic response may ultimately be of little relevance if clinical outcomes are similar.

Human herpesvirus 8 and oral health care: an update

OBJECTIVE

The purpose of this report was to review the current literature on human herpesvirus 8 (HHV-8) with particular attention to the aspects of interest for dental health care workers.

MATERIAL AND METHODS

The authors searched original research and review articles on specific aspects of HHV-8 infection, including virology, epidemiology, transmission, diagnosis, natural history, therapy, and oral aspects. The relevant material was evaluated and reviewed.

RESULTS

HHV-8 is a recently discovered DNA virus that is present throughout the world but with major geographic variation. In the Western world, the virus, transmitted mainly by means of sexual contact, is strongly associated with Kaposi's sarcoma and body cavity-based lymphoma and more controversially with multiple myeloma and non-neoplastic disorders. There is no specific effective treatment, but human immunodeficiency virus protease inhibitors may play an indirect role in the clearance of HHV-8 DNA from peripheral blood mononuclear cells of patients infected with human immunodeficiency virus. HHV-8 DNA is present in saliva, but as yet, there are no documented instances of nosocomial transmission to health care workers. The prevalence of HHV-8 among dental health care workers is probably similar to that in the general population.

CONCLUSION

HHV-8 does not appear to be ubiquitous in most populations, particularly in western Europe and the United States, where it may be restricted to a population at risk of having Kaposi's sarcoma develop (men infected with human immunodeficiency virus and patients who are iatrogenically immunosuppressed). Most serologic studies suggest a global HHV-8 seroprevalence of 2% to 10% and show that the virus may be under immunologic control in people who are healthy but infected with HHV-8. Also, HHV-8 certainly has the means to overcome cellular control and immune responses and thus predispose to malignancy. To date, there are no data to suggest that health care staff members are at particular risk of HHV-8 acquisition through occupational routes.

Are there gender differences in starting protease inhibitors, HAART, and disease progression despite equal access to care?

OBJECTIVES

To describe gender differences in starting and response to treatment regimens and long-term clinical outcome in a well-characterized regional population from the Southern Alberta HIV Clinic (SAC) of 1403 patients, where all medical care for HIV, including physician fees, laboratory tests, and antiretroviral drug costs is provided free of charge.

DESIGN

Observational cohort study.

METHODS

Cox proportional hazards models were used to examine the relative risk of starting treatment regimens and disease progression (new AIDS-defining illness or death).

RESULTS

There are 126 women in the SAC (9.0%). The median CD4 lymphocyte count at first visit among all patients was 350 cells/mm3, and was significantly higher among women than men (428 cells/mm3 versus 345 cells/mm3, respectively; p = 0.0024). Participating women were less well educated than participating men; 29% of women did not proceed beyond a tenth grade education compared with 13% of men; only 28% of women went to college or received a degree in contrast to 40% of men (p <. 001). The proportion of women in the cohort has increased over the past 5 years (p <.001). During a median follow-up period of 35 months that dates back as far as 1985, 572 patients (40.8%) died or progressed to a new AIDS-defining illness, of whom 30 were women (5. 2%). In a multivariate Cox model stratified by calendar quartile of first visit and adjusted for latest CD4, AIDS status, age, exposure group, education, and prior treatment, women were significantly less likely to start highly active antiretroviral therapy (HAART; defined as at least three antiretrovirals taken consecutively; relative hazard [RH], 0.69; 95% confidence interval [CI], 0.49-0.98; p =.033), significantly less likely to start a protease inhibitor containing treatment regimen (RH, 0.71; 95% CI, 0.52-0.98; p =.040) and significantly less likely to start a HAART regimen including a protease inhibitor (RH, 0.69; 95% CI, 0.48-1.00; p =.049). After adjustment for potentially confounding variables such as CD4 lymphocyte count and treatment regimen, no difference in disease progression was found between men and women (RH, 0.77; 95% CI, 0. 49-1.19; p =.24). Among patients who started HAART, the CD4 lymphocyte count and viral load at starting treatment regimens was similar between men and women, as were the immunologic and virologic response following initiation of treatment.

CONCLUSIONS

Despite free access to antiretrovirals, women in the SAC were significantly less likely to start HAART treatment regimens, and the reasons for this need further investigation. Response to treatment was similar between genders. No evidence was found for a poorer long-term clinical outcome in women, but given the proven large clinical benefits of HAART, this may change in the future.

Impact of protease inhibitors and other antiretroviral treatments on acquired immunodeficiency syndrome survival in San Francisco, California, 1987-1996

The authors assessed temporal trends in acquired immunodeficiency syndrome (AIDS) survival for 15,271 persons in San Francisco, California, diagnosed between 1987 and 1996 with an opportunistic illness included in the 1987 AIDS case definition. Predictors of survival were evaluated for 5,686 persons who were diagnosed between 1993 and 1996 and met the 1993 AIDS case definition. Median survival was 19 months for persons diagnosed between 1987 and 1989, 17 months for persons diagnosed between 1990 and 1992, 15 months for persons diagnosed between 1993 and 1994, and 31 months for persons diagnosed between 1995 and 1996. Decreased mortality was associated with use of antiretroviral therapy without protease inhibitors before AIDS (relative hazard (RH) = 0.88, 95% confidence interval (CI): 0.8, 1.0) and after AIDS (RH = 0.83, 95% CI: 0.7, 0.9) and use of antiretroviral agents with protease inhibitors before AIDS (RH = 0.25, 95% CI: 0.2, 0.3) and after AIDS (RH = 0.36, 95% CI: 0.3, 0.4). Increased mortality was found for persons aged > or = 40 years (RH = 1.43, 95% CI: 1.3, 1.6), persons initially diagnosed with an opportunistic illness (RH = 1.97, 95% CI: 1.8, 2.2), and homosexual injection drug users (RH = 1.33, 95% CI: 1.2, 1.5). Survival after AIDS has increased. Treatment with antiretroviral agents, particularly protease inhibitors, strongly predicts improved survival.

HIV transmission and the cost-effectiveness of methadone maintenance

OBJECTIVES

This study determined the cost-effectiveness of expanding methadone maintenance treatment for heroin addiction, particularly its effect on the HIV epidemic.

METHODS

We developed a dynamic epidemic model to study the effects of increased methadone maintenance capacity on health care costs and survival, measured as quality-adjusted life-years (QALYs). We considered communities with HIV prevalence among injection drug users of 5% and 40%.

RESULTS

Additional methadone maintenance capacity costs $8200 per QALY gained in the high-prevalence community and $10,900 per QALY gained in the low-prevalence community. More than half of the benefits are gained by individuals who do not inject drugs. Even if the benefits realized by treated and untreated injection drug users are ignored, methadone maintenance expansion costs between $14,100 and $15,200 per QALY gained. Additional capacity remains cost-effective even if it is twice as expensive and half as effective as current methadone maintenance slots.

CONCLUSIONS

Expansion of methadone maintenance is cost-effective on the basis of commonly accepted criteria for medical interventions. Barriers to methadone maintenance deny injection drug users access to a cost-effective intervention that generates significant health benefits for the general population.

Survival by AIDS defining condition in rural Uganda

OBJECTIVES

To report the initial AIDS defining conditions, CD4 lymphocyte counts around the time of AIDS diagnosis, and survival by AIDS defining condition in a population based cohort in rural Uganda.

METHODS

Participants in an HIV natural history cohort in rural Uganda were reviewed every 3 months at routine visits and at other times when they were ill. The date and nature of the first AIDS defining condition in participants developing AIDS during follow up between the start of the cohort in 1990 and the end of 1998 were noted. The CD4 count at, or within, 3 months of this time was recorded for those participants who developed AIDS (WHO stage 4) after 1993.

RESULTS

The median survival from developing AIDS to death was 9.3 months and the median CD4 lymphocyte count around the time of developing AIDS was 150 cells x 10(6)/l. The most frequent AIDS defining conditions were wasting syndrome, oesophageal candidiasis, and mucocutaneous herpes simplex virus infection (HSV) for more than 1 month. The median survival with wasting syndrome, Kaposi's sarcoma, and oesophageal candidiasis was less than 3.5 months; however, survival with cryptosporidial diarrhoea, chronic HSV, and extrapulmonary tuberculosis was greater than 20 months. There was little relation between CD4 count around the time of development of the AIDS defining condition and the median survival with that condition.

CONCLUSIONS

The survival for most AIDS defining conditions was generally shorter and the median CD4 lymphocyte count higher than studies reported from developed countries. However, the conditions with the longest survival (cryptosporidial diarrhoea, chronic HSV, and extrapulmonary tuberculosis) had a similar survival to that in developed countries and these conditions have a high background level in this population.

[Effect of antiretroviral treatment and prophylaxis for opportunistic infections on survival of patients with AIDS]

OBJECTIVE

To analyze the influence of anti-retroviral therapy (ART) and prophylaxis against opportunist disease on survival of patients with AIDS.

PATIENTS AND METHODS

Study of AIDS patients diagnosed from January 1996 to October 1997 in a Madrid hospital. An analysis was made of demographic, clinical, and immunological data, as well as ART and prophylaxis against Pneumocystis carinii pneumonia (PCP) and tuberculosis (TB). Both univariate and multivariate analyses were performed, as well as Kaplan-Meier curves.

RESULTS

A total of 205 patients were included in the study (83% male) with a median age of 34 years. ART, PCP prophylaxis, and TB prophylaxis were received by 147 (72%), 141 (69%) and 22 (11%) patients, respectively. Among individuals on ART, the likelihood of survival at 12 and 22 months since diagnosis of AIDS was made was 79% and 76%, respectively, and among non treated individuals 54% and 54%, respectively (p < 0.05). ART was associated with a 57% decrease in death risk, and regarding PCP prophylaxis, no benefit on survival was found.

CONCLUSIONS

ART was significantly associated with a lower risk of death among AIDS patients. The survival rate was not increased with PCP prophylaxis.

Disclosure of diagnosis and planning for the future in HIV-affected families in Europe

Information relating to disclosure of infection status in families affected by HIV and the existence of plans for the future social care of children with infected parents was collected as part of a larger survey on clinical and psychosocial service use of these families. Parents and alternative carers of HIV-affected children in follow-up in 10 paediatric centres from seven European countries were surveyed. A total of 182 questionnaires were returned: most (73%) were completed by parents, of whom 92% were HIV-infected. Of the 226 children cared for by the respondents, most (62%) were HIV-infected. Disclosure of both the child's and the parent's infection status was rare and found to be associated with child's age in both cases. Infected children living with their parents were less likely to know their diagnosis than those living in alternative care. Uninfected parents and carers were significantly more likely to want professional help with disclosing to an infected child than infected parents. Infected parents also face difficult decisions regarding the issue of who will care for their children when they are unable to. Half of the infected parents had made long-term plans for their children's future social care. European parents were more likely to have made such plans than those from elsewhere (mainly Africa) and parents with plans had known about their HIV infection for significantly longer than those without. Increasing numbers of vertically infected children are reaching adolescence as a result of improvements in the management of paediatric HIV infection. As both disclosure and planning for the future social care of HIV-affected children have been found to be strongly associated with child's age, the changing epidemiology of paediatric HIV highlights the need for more information on these issues in order to support families more effectively.

Effects of antiretroviral therapy and opportunistic illness primary chemoprophylaxis on survival after AIDS diagnosis. Adult/Adolescent Spectrum of Disease Group

OBJECTIVE

To examine the effects of antiretroviral therapy (ART) and opportunistic illness chemoprophylaxis on the survival of persons with AIDS and survival time based on year of AIDS diagnosis.

DESIGN

Longitudinal medical record review.

SETTING

Ninety-three hospitals and clinics in nine cities in the USA.

PATIENTS

We observed 19,565 persons with AIDS from 1990 through January 1998.

INTERVENTIONS

Prescribed use of antiretroviral monotherapy, dual- and triple-combination therapies, primary prophylaxis against Pneumocystis carinii pneumonia and Mycobacterium avium complex, and pneumococcal vaccine.

MAIN OUTCOME MEASURES

Time from AIDS diagnosis to death in the presence and absence of ART. Survival curves were compared of AIDS cases diagnosed during 1990-1992 and 1993-1995.

RESULTS

Triple ART had the greatest effect on the risk of death [relative risk (RR), 0.15; 95% confidence limit (CL), 0.12, 0.17], followed by dual ART (RR, 0.24; 95% CL, 0.22, 0.26), and monotherapy (RR, 0.38; 95% CL, 0.36, 0.40). Risk of death was decreased among persons receiving Pneumocystis carinii pneumonia prophylaxis (RR, 0.79; 95% CL, 0.70, 0.89) and Mycobacterium avium complex prophylaxis (RR, 0.76; 95% CL, 0.68, 0.86). Median survival increased from 31 months [95% confidence interval (CI), 30-32 months] for AIDS cases diagnosed during 1990-1992 to 35 months (95% CI, 35-38 months) for cases diagnosed during 1993-1995.

CONCLUSIONS

The risk of death was decreased for persons receiving triple ART compared with persons receiving dual therapy and persons receiving monotherapy. Increased use of ART and improved ART regimens probably contributed to prolonged survival of persons whose diagnosis was made during 1993-1995 compared with persons whose diagnosis was made during 1990-1992.

Costs and benefits to the mother of antenatal HIV testing: estimates from simulation modelling

OBJECTIVE

To assess the health service costs and benefits for the woman of an earlier HIV diagnosis as a result of antenatal HIV testing.

DESIGN

A model of maternal disease progression was developed based on the rate of decline in CD4 cell counts and applied to two matched simulated cohorts of women with identical initial CD4 cell levels and decline rates but whose HIV diagnosis occurred at different times as a result of antenatal HIV testing. UK data on CD4 cell count at HIV diagnosis and annual health service costs of care excluding antiretroviral therapy (ART) incurred at defined states of CD4 cell count were taken from published UK data. Costs of triple ART were added and effectiveness modelled by retarding the rate of CD4 cell count decline. Discounting costs at 6% and life-years at 2% per year, the additional costs per life-year gained by screening were calculated. Uncertainty was explored using sensitivity analysis.

RESULTS

Costs per life-year gained by antenatal diagnosis of women were pound sterling 51258 ($76887) assuming untested women were diagnosed a median of 20.4 months later than tested women, ART was initiated at a CD4 cell count of 350x10(6) cells/l and ART efficacy retarded decline in CD4 cell counts by 40% for life. Sensitivity analyses showed results were most sensitive to the assumed efficacy of lifetime ART and time assumed to HIV diagnosis for women not tested in pregnancy.

CONCLUSION

This model provides a way of estimating the additional costs and benefits of future care for the woman resulting from an earlier HIV diagnosis through antenatal testing. These should be included with the paediatric costs averted and life-years gained from interventions to reduce mother-to-child transmission in order to evaluate the cost-effectiveness of antenatal screening in different populations and settings.

The changing pattern of admissions to a London hospital of patients with HIV: 1988-1997. Royal Free Centre for HIV Medicine

OBJECTIVE

To describe the changes over time in incidence of hospital admissions among patients with HIV, reasons for hospital admission, duration of stay, relationship with CD4 T-cell count and with antiretroviral treatment.

METHODS

The incidence of hospital admissions during each calendar year from 1988 to 1997 inclusive was calculated using a person-years analysis. In addition the proportion of patient follow-up spent in hospital and the impact of changing treatment regimens among all patients with HIV aged > or = 14 years and with at least one CD4 T-cell count seen at the Royal Free Hospital, London was also described.

RESULTS

A total of 1806 patients were investigated with median follow-up of 21.1 months. Among all patients, the proportion of follow-up time spent as an in-patient decreased from 3.9% in 1988 to 1.3% in 1997 (P = 0.0015; test for trend). Hospital admissions for any cause peaked during 1989 at 72.0 per 100 patient years of follow-up (PYFU) and was 28.5 per 100 PYFU during 1997 (P < 0.0001; test for trend). There was a statistically significant decline in the proportion of follow-up time spent as an in-patient among patients with CD4 T-cell counts of < 50 x 10(6)/l from > 30% before 1990 to < 5% during 1997 (P = 0.026; test for trend). Hospital admissions varied greatly according to treatment regimen; in 1996 and 1997 just 0.1% of follow-up time of patients on triple antiretroviral treatment regimens was spent as a hospital admission.

CONCLUSIONS

Admissions to hospital began falling before the introduction of combination therapy and declined strikingly during 1996 and 1997 following the introduction of highly active antiretroviral therapy. These results have important implications for future allocation of resources and for patient management.

Increasing survival time after AIDS in Italy: the role of new combination antiretroviral therapies. Tuscany AIDS Study Group

BACKGROUND

In Italy, antiretroviral combination therapy was adopted in mid-1995 and protease inhibitors in mid-1996.

OBJECTIVE

To conduct a prospective, population-based, observational study to evaluate the effect of these therapies on the survival of persons with AIDS (PWA).

METHODS

PWA living in the Tuscany region diagnosed between 1985 and 31 March 1997 (National AIDS Registry) were studied. Information on antiretroviral drugs, prophylactic treatment, CD4 cell count, and AIDS-defining illnesses was collected for PWA still alive at 1 January 1996 and those diagnosed thereafter (analysis cut-off date, 30 November 1997). Kaplan-Meier curves were calculated by year of diagnosis. A Cox model was then used to estimate the adjusted (by sex, age, HIV exposure category, CD4 cell count, type and number of AIDS-defining illnesses) relative hazard (RH) of death by year of diagnosis and calendar date (considered as a time-dependent variable). Similar analyses were repeated for PWA diagnosed after 1989, having been stratified by disease-specific AIDS condition. A final analysis was performed for PWA still alive at 1 January 1996 or diagnosed thereafter for estimating the effect of single, double and triple combination therapy (time-dependent variables), having adjusted for the above variables and for prophylactic treatment.

RESULTS

A total of 1683 (79.5%) out of 2118 PWA died before 1 December 1997. Use of more potent combination therapies, including protease inhibitors, greatly increased during 1997. Median survival was 2.9, 12.3, 13.4, 11.4 and 17.6 months for diagnoses before 1987, in 1987-1990, 1991-1993, 1994 and 1995, respectively; an estimated 62% of those diagnosed in 1996-1997 had survived 15 months after diagnosis. The Cox model showed a trend of decrease of RH for calendar time starting in the first half of 1996, compared with 1994. When stratifying by specific AIDS-defining disease there was no statistically significant evidence that the improved overall survival was due to increased survival only for certain diseases. The final multivariate analysis for the 771 PWA still alive at 1 January 1996 or diagnosed thereafter estimated significant RH < 1.0 for double and triple therapy (RH, 0.61 and 0.36, respectively) compared with no therapy.

CONCLUSIONS

A significant reduction in risk of death after AIDS was observed from the second half of 1996, apparently due to the widespread use of antiretroviral combination therapies.

Psychotropic medications and HIV medicine: A rational approach

New drugs available for HN infection treatment have produced significant improvements in quality and quantity of life in affected individuals. These new agents are metabolized by the same hepatic microsomal system that is responsible for breakdown of psychotropic drugs. Thus, toxic drug levels and undesirable side-effects are possible when anti-retroviral drugs are used in combination with psychotropic medication. The treatment of HN-infected individuals presenting with neuropsychiatric and psychological morbidity is reviewed. A rational approach should involve the selection of drugs that minimize interaction with metabolism of the other medications.

Disease progression and survival in HIV-1-infected Africans in London

OBJECTIVE

To examine differences in progression to AIDS and death between HIV-1-positive Africans (most infected in sub-Saharan Africa and therefore with non-B subtypes) and HIV-1-positive non-Africans in London.

DESIGN

Retrospective cohort study of 2048 HIV-1-positive individuals.

SETTING

HIV-1-infected individuals attending 11 of the largest HIV/AIDS units in London.

PATIENTS

Subjects were 1056 Africans and 992 non-Africans seen between 1982-1995.

RESULTS

There were no differences in crude survival from presentation to death between Africans and non-Africans (median 82 and 78 months, respectively; P = 0.22). Africans progressed more rapidly to AIDS [hazard ratio (HR), 1.21; 95% confidence interval (CI), 1.02-1.45] but after adjustment for age, sex, Centers for Disease Control and Prevention category B symptoms and CD4+ lymphocyte count at presentation, year of HIV diagnosis and hospital attended, this difference was no longer significant (adjusted HR, 1.15; 95% CI, 0.93-1.43). Africans with AIDS had a reduced risk of death compared with non-Africans (HR, 0.78; 95% CI, 0.63-0.96) but not after adjustment for age, CD4+ lymphocyte count at AIDS, initial AIDS-defining conditions (ADC) and hospital attended (HR, 0.98; 95% CI, 0.76-1.27). Tuberculosis as the first ADC was associated with a 64% reduction in the risk of death. CD4+ lymphocyte decline was not significantly different between Africans and non-Africans (P = 0.18).

CONCLUSIONS

Differences in progression to AIDS and death and CD4+ lymphocyte decline between HIV-1-infected Africans and non-Africans in London could not be attributed to ethnicity or different viral subtypes. Age and the clinical and immunological stage at presentation, or AIDS, were the major determinants of outcome. Compared with other diagnoses, tuberculosis as the initial ADC was associated with increased survival. Lack of access to health care and exposure to environmental pathogens are the most likely causes of reduced survival with AIDS in Africa, rather than inherently different rates of progression of immune deficiency due to racial differences or viral subtypes.

Cardiac involvement in acquired immunodeficiency syndrome--a review to push action. The Committee for the Study of Cardiac Involvement in AIDS

As more effective therapies have produced longer survival times for human immunodeficiency virus (HIV)-infected patients, new complications of late-stage HIV infection including HIV-related heart disease have emerged. Almost any agent that can cause disseminated infection in patients with acquired immunodeficiency syndrome (AIDS) may involve myocardium, but clinical evidence of cardiac disease is usually overshadowed by manifestations in other organs, primarily the brain and lungs. Cardiac abnormalities are found at autopsy in two-thirds of patients with AIDS, and more than 150 reports of cardiac complications have been published. Cardiac involvement in HIV disease includes pericardial effusion, myocarditis, dilated cardiomyopathy, and/or endocardial involvement at any stage of the disease. This review deals with all the cardiac manifestations of AIDS and serves to highlight two problems and one indication. First of all, there are very few clinical studies. Current knowledge is based almost exclusively on echocardiography and autopsy studies. Observational or clinical trials would be useful. Second, there exists very poor information on the impact of treatment; and epidemiologic and clinicopathologic studies are mandatory for obtaining detailed data concerning the mechanisms of myocardial damage in AIDS. Finally, because cardiac complications are often clinically inapparent or subtle in the initial stages, periodic screening of HIV-positive patients by electrocardiogram and echocardiogram is probably indicated. In addition, AIDS may also provide the opportunity to gain insights into the pathogenesis of little understood cardiac diseases such as lymphocytic myocarditis and dilated cardiomyopathy.

Human herpes virus 8 (Kaposi's sarcoma herpesvirus)

Human herpes virus 8 (HHV-8) is a recently discovered herpesvirus related to Herpesvirus saimiri and Epstein-Barr virus (EBV). It has been assigned to the Rhadinovirus genus (gamma-2 herpesvirus) on the basis of its genomic sequence and structure. HHV-8 is the first member of this genus known to infect humans and it is now evident that it is the likely cause of Kaposi's sarcoma (KS). The virus is present in endothelial and spindle cells of KS, and in HIV disease the presence of HHV-8 in peripheral blood, and/or serum IgG antibodies to HHV-8, predicts the development of AIDS-related KS. HHV-8 can also infect CD19 + B cells and is of aetiological significance in the development of body cavity B cell lymphomas of AIDS. Of note, the translation products of viral open reading frames (ORFs) reveal HHV-8 to be a molecular pirate, capable of producing homologues of several human gene products that may result in alterations in cell cycle arrest, inhibit apoptosis and cell-mediated immune responses, and thus provide the potential for tumour production.