AIDS--the second decade: a global perspective

Direct and indirect cardiovascular and cardiometabolic sequelae of the combined anti-retroviral therapy on people living with HIV

With reports of its emergence as far back as the early 1900s, human immunodeficiency virus (HIV) has become one of the deadliest and most difficult viruses to treat in the era of modern medicine. Although not always effective, HIV treatment has evolved and improved substantially over the past few decades. Despite the major advancements in the efficacy of HIV therapy, there are mounting concerns about the physiological, cardiovascular, and neurological sequelae of current treatments. The objective of this review is to (Blattner et al., Cancer Res., 1985, 45(9 Suppl), 4598s-601s) highlight the different forms of antiretroviral therapy, how they work, and any effects that they may have on the cardiovascular health of patients living with HIV, and to (Mann et al., J Infect Dis, 1992, 165(2), 245-50) explore the new, more common therapeutic combinations currently available and their effects on cardiovascular and neurological health. We executed a computer-based literature search using databases such as PubMed to look for relevant, original articles that were published after 1998 to current year. Articles that had relevance, in any capacity, to the field of HIV therapy and its intersection with cardiovascular and neurological health were included. Amongst currently used classes of HIV therapies, protease inhibitors (PIs) and combined anti-retroviral therapy (cART) were found to have an overall negative effect on the cardiovascular system related to increased cardiac apoptosis, reduced repair mechanisms, block hyperplasia/hypertrophy, decreased ATP production in the heart tissue, increased total cholesterol, low-density lipoproteins, triglycerides, and gross endothelial dysfunction. The review of Integrase Strand Transfer Inhibitors (INSTI), Nucleoside Reverse Transcriptase Inhibitors (NRTI), and Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTI) revealed mixed results, in which both positive and negative effects on cardiovascular health were observed. In parallel, studies suggest that autonomic dysfunction caused by these drugs is a frequent and significant occurrence that needs to be closely monitored in all HIV + patients. While still a relatively nascent field, more research on the cardiovascular and neurological implications of HIV therapy is crucial to accurately evaluate patient risk.

Rights-Based Approaches to Preventing, Detecting, and Responding to Infectious Disease

Policymakers have come to look to human rights law in framing national health policy and global health governance. Human rights law offers universal frameworks to advance justice in public health, codifying international standards to frame government obligations and facilitate accountability for realising the highest attainable standard of health. Addressing threats to individual dignity as ‘rights violations’ under international law, health-related human rights have evolved dramatically to offer a normative framework for public health.

[Combined HIV prevention? Systematic review of interventions with women from low- and middle-income countries]

The scope of this systematic review was to characterize interventions for HIV prevention that included adult women and was conducted in low- and middle-income countries after 1996, identifying how they covered individual, social and programmatic vulnerabilities. Databases were accessed from 1997 to July 2016 and the studies selected included adult women, with combined strategies or otherwise, only excluding biomedical or mass media interventions. Thus, 72 interventions developed in 32 countries were selected, most of them in African countries and/or in the upper-middle income bracket, with 26 focusing solely on women. Among the 64 interventions that evaluated results in behavioral, psychosocial and biomedical knowledge on HIV/STI and use of health services, 62 reported positive results, but also of no-effect (n = 52). Few of them reported a reduction in HIV/STI incidence (n = 9), in partner numbers (n = 12) and in stigma and violence reports (n = 7). The content analysis of the interventions revealed that the majority (n = 51) considered only individual vulnerabilities. The need to strengthen preventive approaches targeting structural determinants of the epidemic, encompassing the social contexts of women in a relational and intersectional perspective of vulnerabilities was discussed.

Geolocalization of HIV-1 subtypes and resistance mutations of patients failing antiretroviral therapy in Salvador - Brazil

Background

Geographical distribution of HIV variants is an important way to understand the circulation and spread of such viral strains.

Objectives

To evaluate the spatial distribution of HIV-1 variants in patients failing antiretroviral therapy, in Salvador, Brazil.

Methods

We performed a cross-sectional evaluation of HIV resistance test reports of patients who underwent genotyping tests in a referral center in Salvador, Brazil, for the years 2008–2014. The laboratory database contains around 2500 resistance reports of patients failing antiretroviral therapy. Genotypic tests were performed by sequencing of HIV-1 POL region (TrueGene, Siemens). We assessed HIV-1 resistance mutations and subtype, as well as residential address, age, and gender of patients.

Results

We evaluated 1300 reports, 772 (59.4%) of them from male patients. As expected, subtype B predominated (79%) followed by subtypes F1 (6.7%) and BF (6.5%). The most frequent mutations in HIV-1 reverse transcriptase were 184V (79.1%), 41L (33.5%), 67N (30.4%), 103N (42.4%), and 108I (11.1%). Most frequent mutations in HIV-1 protease were 63P (52.4%), 36I (47.9%), 15 V (33.0%), 62 V (28.1%) and 13 V (25.8%). Some mutations (41L, 215Y, 210W) were significantly more frequent among men. We detected a significantly higher accumulation of 103N mutation in specific areas of Salvador. We identified a more restricted circulation pattern for subtype FB (more frequent in some regions), and F1 (almost absent in a specific region).

Conclusion

Our results suggest that specific subtypes/resistance mutations present a distinct frequency rate in specific areas of Salvador, probably due to a restricted circulation pattern. This trend to clustering was observed in regions covered by AIDS referral centers, suggesting that pattern of care for such patients can interfere in virological outcomes.

Conceptualizing a Human Right to Prevention in Global HIV/AIDS Policy

Given current constraints on universal treatment campaigns, recent advances in public health prevention initiatives have revitalized efforts to stem the tide of HIV transmission. Yet, despite a growing imperative for prevention-supported by the promise of behavioral, structural and biomedical approaches to lower the incidence of HIV-human rights frameworks remain limited in addressing collective prevention policy through global health governance. Assessing the evolution of rights-based approaches to global HIV/AIDS policy, this review finds that human rights have shifted from collective public health to individual treatment access. While the advent of the HIV/AIDS pandemic gave meaning to rights in framing global health policy, the application of rights in treatment access litigation came at the expense of public health prevention efforts. Where the human rights framework remains limited to individual rights enforced against a state duty bearer, such rights have faced constrained application in framing population-level policy to realize the public good of HIV prevention. Concluding that human rights frameworks must be developed to reflect the complementarity of individual treatment and collective prevention, this article conceptualizes collective rights to public health, structuring collective combination prevention to alleviate limitations on individual rights frameworks and frame rights-based global HIV/AIDS policy to assure research expansion, prevention access and health system integration.

Promotion of children's rights and prevention of child maltreatment

In medical literature, child maltreatment is considered as a public-health problem or an issue of harm to individuals, but less frequently as a violation of children's human rights. Public-health approaches emphasise monitoring, prevention, cost-effectiveness, and population strategies; protective approaches concentrate on the legal and professional response to cases of maltreatment. Both approaches have been associated with improvement in outcomes for children, yet maltreatment remains a major global problem. We describe how children's rights provide a different perspective on child maltreatment, and contribute to both public-health and protective responses. Children's rights as laid out in the UN convention on the rights of the child (UNCRC) provide a framework for understanding child maltreatment as part of a range of violence, harm, and exploitation of children at the individual, institutional, and societal levels. Rights of participation and provision are as important as rights of protection. The principles embodied in the UNCRC are concordant with those of medical ethics. The greatest strength of an approach based on the UNCRC is that it provides a legal instrument for implementing policy, accountability, and social justice, all of which enhance public-health responses. Incorporation of the principles of the UNCRC into laws, research, public-health policy, and professional training and practice will result in further progress in the area of child maltreatment.

International travel and sexually transmitted diseases

Despite concerted efforts to control sexually transmitted diseases (STDs) worldwide, they still remain a major public health problem. Out of the 25 organisms known to be transmitted sexually, travelers are at greater risk of acquiring HIV and other STDs in developing countries in view of the high prevalence rates in these countries, particularly after sexual exposure to local commercial sex workers (CSWs). Some of the STDs acquired during international travel are more likely to be resistant to standard antimicrobial regimens for the STDs. HIV, gonorrhoea, syphilis, non-specific urethritis, hepatitis B, hepatitis C, and other STDs are a significant risk for travelers who engage in unprotected sex, especially with overseas CSWs. It is recognized that barrier contraceptives provide considerable protection against STDs, but they are not regarded as 100% protective. Sexual abstinence and sexual monogamy with a 'known' partner carry a much lower risk than the safest of 'safer sex' practices. However, in the event of a sexual exposure to a new partner in the country being visited, prior hepatitis B immunization and the consistent and proper use of a latex condom are strongly advised, followed by proper medical investigations and physical examination on returning home, before sexual activity is resumed.

Roles and responsibilities of epidemiologists

Two distinct views of the roles and responsibilities of epidemiologists have emerged in a decades-long debate: one keeps professional practice constrained to science; the other adds active participation in public health policymaking. In defense of the narrower view are several claims: that epidemiologists lack expertise in policymaking; that advocating policy adversely affects scientific objectivity; that the limits of epidemiologic science work against translating results into policy; and that participation in policy can bring on personal attacks. In this study, each claim is addressed. Epidemiologists already participate fully in educational, research funding, and editorial policymaking and thereby have an experiential foundation in some of the basics of policymaking. Policymaking can enhance scientific objectivity because it requires not only the use but more importantly the improvement of empirical methods. Finally, the comforts of professional life are not the primary yardsticks of our responsibilities. Arguments in favor of active involvement in public health policymaking are presented. Epidemiologists have been mixing science and policymaking for a long time and there is a strong sense that the benefits of public stewardship outweigh the risks. The American College of Epidemiology's Ethics Guidelines support this view. Active participation in public heath policymaking will, however, require curriculum changes in graduate training programs. With additional training and a broader recognition that public health policymaking is an appropriate professional pursuit, epidemiologists can look to a bright and challenging future in the science and practice of public health.

IgG subclass distribution in serum and various mucosal fluids of HIV type 1-infected subjects

We measured total IgG1, IgG2, IgG3, and IgG4 concentrations by ELISA in serum (S), total saliva (TS), cervicovaginal secretions (CVS), seminal secretions (SPE), and rectal secretions (RS) from either CDC II/III HIV-1-infected subjects or healthy volunteers. Human serum albumin was measured in parallel to calculate the relative coefficient of excretion (RCE). Levels of IgG1 and IgG3 directed against gp120 MN also were measured by ELISA in all samples, and the specific activity (SA) calculated. HIV-1-specific IgG2 and IgG4 were not compared, as total IgG2 and total IgG4 levels in HIV-1-infected subjects were found to be lower than in the healthy controls. Despite substantial interindividual variability, total IgG1 and IgG3 concentrations in all fluids were greater in the HIV-1-infected subjects than in the healthy controls. Calculations of RCE indicated predominantly a transudative origin for IgG subclasses in the different mucosal fluids, except for CVS, in which IgG1, IgG2, and IgG4 was produced locally. The transduction behavior of IgG3 in secretions appears to be different from that of other IgG subclasses. HIV-1-infected subjects were considered positive for IgG1 and IgG3 antibodies against gp120 MN if their antibody levels exceeded the maximum titer measured in the control group. Positive levels of anti-gp120 MN IgG1 were detected for 100% of HIV-1-infected individuals in S, CVS, and SPE, 97% in TS, and 75% in RS. Fewer subjects had positive levels of IgG3 to gp120 MN in their secretions (maximum 67% in CVS). Despite the low concentrations of total IgG3, mean SA values for IgG3 to gp120 MN were greater in secretions than in serum. No significant difference in the SA values for IgG1 to gp120 MN was observed between the different fluids. Only CVS had a local production of HIV-specific IgG1 Our results highlight the importance of an HIV-specific IgG1 and IgG3 immune response in mucosal fluids from HIV-1-infected subjects.

Comparison of the distribution of IgG and IgA antibodies in serum and various mucosal fluids of HIV type 1-infected subjects

We compared IgG and IgA distribution in serum, three different salivary samples, two different rectal secretion samples, cervicovaginal secretions, and seminal secretions from asymptomatic CDC stage II/III HIV-1-infected subjects (n = 44) and from HIV-1-seronegative volunteers (n = 52). In-house ELISAs were used to measure total IgG and total IgA levels, as well as HIV-specific anti-gp120 MN and anti-p24 LAI IgG and IgA. Human serum albumin was titrated in parallel to calculate the relative coefficient of excretion (RCE). In spite of substantial interindividual variability, total IgG concentrations in all fluids were found to be significantly greater in the HIV-1-infected group than in the seronegative subjects. Calculation of RCE values revealed three different types of mucosal secretion: secretions with no local Ig production, such as sperm; secretions with local production of IgA and transudative origin of IgG, such as salivary and rectal samples; and secretions with local production of both IgG and IgA, such as in cervicovaginal secretions. For all mucosal specimens from HIV-1-infected subjects, the response to HIV-1 was predominantly IgG, with highest titers observed in cervicovaginal secretions (although these were lower than serum levels). In contrast, the specific IgA response appeared weaker in the mucosa than in serum.

Mortality in young adults in England and Wales: the impact of the HIV epidemic

OBJECTIVE

To quantify the contribution of the HIV epidemic to premature mortality in England and Wales 1985-1996.

DESIGN

Surveillance of deaths in HIV-infected individuals and causes of death from death certificates.

MAIN OUTCOME MEASURES

Time trends in age-specific mortality rates among 15-44 year olds and years of potential life lost (YPLL) to age 65 associated with HIV infection and other important causes of death in young adults.

RESULTS

The crude age-specific mortality rates for all causes of death in the 15-44 year age band remained fairly constant between 1985 and 1996: in other age bands a decrease was seen. Deaths from both suicide and HIV increased in men aged 15-44 years. Although suicide accounted for a greater number of deaths throughout the period investigated, the largest proportional and absolute increase was seen for deaths in HIV-infected people. By 1996, the contribution of HIV to YPLL to age 65 varied from less than 0.5% in most rural localities to 20% of total YPLL in one London health authority.

CONCLUSIONS

While part of the adverse trend in mortality in younger adults since 1985 was attributable to suicide, most resulted from HIV infection. The impact of HIV infection on mortality was greatest in London.

Development and standardization of methods to evaluate the antibody response to an HIV-1 candidate vaccine in secretions and sera of seronegative vaccine recipients

Enzyme-linked immunosorbent assays (ELISA) were developed to test, in serum and mucosal samples, total IgG, total IgA, serum albumin, and anti-gp120 MN and anti-p24 LAI IgG and IgA levels. These ELISAs were optimized according to reagents and experimental conditions. Inter- and intra-assay coefficients of variation ranged from 3.3% to 18.6%. The ELISA results were linear and precise, and for anti-HIV-1 IgG and IgA, the analytical recovery was close to 100%. For IgG and IgA titration against gp120 MN and p24 LAI, standards were made using pooled sera or gammaglobulins with assigned titres in ELISA units per ml (EU/ml). These standards were used to obtain a linear regression curve that could then be used to obtain the titres of experimental samples. The cut-offs for positivity were determined for sera and mucosal fluid using healthy controls. Validation conditions were defined for ELISAs, and samples that did not satisfy these conditions were retested. Measurement of total IgG and IgA allowed normalization and comparison of the results of specific immunoglobulin levels between different samples. Serum albumin was tested as a marker of transudation from serum to mucosal fluid, allowing calculation of the relative coefficient of excretion, which is one element required to determine the origin of the immunoglobulin detected in mucosal samples. These ELISAs were developed with samples from HIV-1-infected and healthy subjects. We now have the tools to study and understand mucosal immunity in seronegative subjects vaccinated with an HIV-1 candidate vaccine.

Changing patterns of mortality across Europe in patients infected with HIV-1. EuroSIDA Study Group

BACKGROUND

The introduction of combination antiretroviral therapy and protease inhibitors has led to reports of falling mortality rates among people infected with HIV-1. We examined the change in these mortality rates of HIV-1-infected patients across Europe during 1994-98, and assessed the extent to which changes can be explained by the use of new therapeutic regimens.

METHODS

We analysed data from EuroSIDA, which is a prospective, observational, European, multicentre cohort of 4270 HIV-1-infected patients. We compared death rates in each 6 month period from September, 1994, to March, 1998.

FINDINGS

By March, 1998, 1215 patients had died. The mortality rate from March to September, 1995, was 23.3 deaths per 100 person-years of follow-up (95% CI 20.6-26.0), and fell to 4.1 per 100 person-years of follow-up (2.3-5.9) between September, 1997, and March, 1998. From March to September, 1997, the death rate was 65.4 per 100 person-years of follow-up for those on no treatment, 7.5 per 100 person-years of follow-up for patients on dual therapy, and 3.4 per 100 person-years of follow-up for patients on triple-combination therapy. Compared with patients who were followed up from September, 1994, to March, 1995, patients seen between September, 1997, and March, 1998, had a relative hazard of death of 0.16 (0.08-0.32), which rose to 0.90 (0.50-1.64) after adjustment for treatment.

INTERPRETATION

Death rates across Europe among patients infected with HIV-1 have been falling since September, 1995, and at the beginning of 1998 were less than a fifth of their previous level. A large proportion of the reduction in mortality could be explained by new treatments or combinations of treatments.

Variation in virological parameters and antibody responses in macaques after atraumatic vaginal exposure to a pathogenic primary isolate of SIVmac251

We developed an animal model for the male-to-female transmission of human immunodeficiency virus, consisting of an atraumatic vaginal application of simian immunodeficiency virus onto the intact vaginal mucosa of cynomolgus macaques. Different doses of a pathogenic isolate of SIVmac251, with or without seminal plasma, were infused into the vaginas of female macaques. Infection of macaques could be achieved after a single exposure to the virus. Two patterns of infection were underscored with no relation to the virus dose inoculated: in 50% of the monkeys, SIV was persistently recovered and a strong antibody response to SIV was evidenced in blood and vaginal secretions. In the other infected animals, SIV infection was only transiently evidenced and a weak systemic antibody response was detected. It appeared that the presence of seminal plasma may be implicated in this variability only when low doses of virus are inoculated. Sequence analysis of the env gene of SIV revealed that most of the persistently viraemic animals were infected with a viral variant different from that of transiently viraemic macaques.

Comparison of hydroxychloroquine with zidovudine in asymptomatic patients infected with human immunodeficiency virus type 1

Hydroxychloroquine (HCQ), an antimalarial agent used to treat patients with autoimmune diseases, has been shown to suppress human immunodeficiency virus type 1 (HIV-1) replication in T cells and monocytes in vitro by inhibiting posttranscriptional modification of the virus. An initial randomized, placebo-controlled clinical trial conducted in 38 asymptomatic HIV-1-infected patients who had CD4+ counts between 200 and 500 cells/mm3 demonstrated that the amount of recoverable virus declined significantly in the HCQ group compared with the placebo group over the 8-week study period. These preliminary observations were expanded into a second 16-week clinical trial comparing the efficacy of HCQ with that of zidovudine (ZDV) in 72 asymptomatic HIV-1-infected patients with CD4+ counts between 200 and 500 cells/mm3. Patients were randomly assigned to receive either HCQ 800 mg/d (n = 35) or ZDV 500 mg/d (n = 37) for 16 weeks. No adverse reactions to the study medications were observed in either the HCQ or ZDV group. Patients in both groups had reduced levels of recoverable HIV-1 RNA in the plasma, reduced levels of cultured virus, and reduced levels of serum p24 antigen after the 16-week study period. However, no difference was noted in absolute CD4+ counts between the two groups. Interleukin-6 and serum immunoglobulin G levels were significantly reduced in the HCQ group but not in the ZDV group. These findings support the results of the previous clinical trial. Thus HCQ may be potentially useful in the treatment of patients with HIV-1 infection.

Urbs in rure redux: changing risk factors for rural HIV infection

The purpose was to ascertain risk factors for HIV infection in a predominantly rural population using descriptive epidemiologic studies performed at a university health sciences center. Participants included adult patients with HIV infection or AIDS who were cared for between January 1982 and January 1993. The relative frequency of cases in minority and female heterosexual patients increased significantly. The male to female ratio among blacks with HIV infection declined to 1.1:1 during the final 3 years of the study. Patients who believed they had acquired infection in Virginia were more likely to cite a rural area of acquisition and to have had multiple heterosexual partners but were less likely to have had male homosexual contact than patients who believed they had been infected in other states. HIV continued to spread into rural areas of Virginia, and the gender ratio among blacks with HIV declined throughout the study. Having multiple heterosexual partners, the main risk factor for HIV transmission worldwide, may now result in HIV infection in rural Virginia.

AIDS in Namibia

The purpose of this article is to examine the AIDS epidemic in Namibia, a country for which little data currently exists. An examination of published and unpublished literature about the historical, socioeconomic and health factors as well as an analysis of updated data from other sub Saharan countries presented at the IXth International Conference on AIDS in Berlin may shed light on the pandemic as it relates to Namibia. Despite inadequate data, it is clear that the AIDS epidemic has already reached Namibia, though the country has not been afflicted as severely as some of its neighbors. Because of 75 years of apartheid, the new government is faced with a formidable array of problems, both in health care and in the economic domain. The strategies being adopted to confront the AIDS epidemic will take years to evolve, a period of time the nation can ill-afford if it is to wrest control over a virus that is relentlessly spreading into susceptible populations.

A model for HIV in Asia

A model is proposed in which the spread of HIV/AIDS in the community is mainly due to the sexual interaction between a core group of female prostitutes and young unmarried males. Several threshold parameters are obtained that determine persistence of endemic proportions, persistence of total population, and the persistence of infective population given the extinction of endemic proportions in a population tending to infinity. Conditions are given for the existence of multiple endemic equilibria as well as the existence of multiple stable equilibria with separatrix and their asymptotic behavior and biological significance are discussed. In all cases, global analysis is accompanied by bifurcation diagrams, and numerical examples are provided for some particular cases of interest. This model was proposed with the recent rapid growth of the HIV/AIDS epidemic in Asia in mind.

The effects of disease progression and zidovudine therapy on semen quality in human immunodeficiency virus type 1 seropositive men

OBJECTIVE

To investigate the effects of disease progression and zidovudine antiretroviral therapy on semen parameters in human immunodeficiency virus type 1 (HIV-1) seropositive men.

DESIGN

Cross-sectional analysis of semen parameters of 166 HIV-1 seropositive men in various stages of disease progression as defined by peripheral CD4+ cell count. Clinical symptoms and zidovudine therapy status were obtained from medical records and clinical interviews.

PATIENTS

Human immunodeficiency virus type 1 seropositive men participating in clinical studies at the Fenway Community Health Center (Boston, MA), the University of San Francisco (San Francisco, CA), and Brown University (Providence, RI).

MAIN OUTCOME MEASURES

Ejaculate volume; sperm concentration, motility, forward progression, morphology, total sperm count; seminal immature germ cell; and white blood cell (WBC) concentrations.

RESULTS

Human immunodeficiency virus type 1 seropositive men that were not on zidovudine therapy and were in early disease stage (> 200 CD4+ cells/mm3) had normal semen parameters as defined by World Health Organization criteria. In contrast untreated men in advanced disease stage (< or = 200 CD4+ cells/mm3) had significant reductions in sperm concentration and total sperm count and an increased percentage of abnormal sperm forms. Men receiving zidovudine antiretroviral therapy, regardless of disease stage, had normal semen parameters similar to those of untreated early disease stage patients. Seminal WBC concentrations were not affected significantly by disease progression but were reduced in patients receiving zidovudine.

CONCLUSION

Most HIV-1-infected men in this study had semen parameters consistent with fertility. Disease progression was associated with reduced semen quality, but this effect appeared to be abrogated by zidovudine therapy. Zidovudine was also associated with a significant reduction of WBC numbers in semen. As seminal WBC are principal HIV-1 host cells in ejaculates of HIV-1-infected men, this effect could explain recent laboratory and epidemiological evidence that zidovudine therapy is associated with a reduced prevalence of HIV-1 in semen and a lower rate of sexual transmission.

The political history of syphilis and its application to the AIDS epidemic

The history of syphilis control from the mid-19th century through the present time is a strong argument for the need to enhance the public health efforts to find cases of human immunodeficiency virus (HIV) infection and to notify the partners of infected individuals. To do this, public policy must be changed to allow better case-finding (mandatory testing) and partner notification (mandatory reporting). The history of syphilis is such that one person in 22 was infected in this country in 1918. If we are to use this history to control the current HIV epidemic, control measures used for syphilis (before penicillin) are needed; these are equal attention to education, available health care, case-finding, and partner notification.

AIDS and the neurosurgeon--an update

Over the past decade, acquired immunodeficiency syndrome (AIDS) has become the leading public health crisis in the United States, Western Europe, and Africa. Despite improvements in the diagnosis and treatment of AIDS-related disorders, the number of people infected with the human immunodeficiency virus (HIV-1) continues to grow, requiring a greater proportion of limited financial, medical, and human resources. Since nearly one half of symptomatic AIDS patients have neuropathologic disease, clinicians must be aware of the myriad neurologic manifestations of AIDS and use the most effective methods to diagnose and treat them. The work-up of the AIDS patient with neurologic symptoms includes a careful history and physical examination, laboratory studies, and radiographic imaging. Gadolinium-enhanced magnetic resonance (MR) imaging has become the radiographic screening study of choice. MR imaging can be used to predict which patients should undergo stereotactic biopsy before an empirical trial of antitoxoplasmosis therapy. Any patient with a mass lesion that does not respond to empirical therapy for toxoplasmosis should also undergo biopsy to exclude another treatable disorder. While the number of patients with neurological complications can be expected to increase in the near future, better imaging techniques may obviate the need for biopsy in many of these patients. The increasing threat of HIV-1 infection in the workplace requires meticulous care both in and out of the operating room to minimize accidental exposure of health-care workers.

Progress in the understanding of HIV infection: an overview

The worldwide epidemic of human immunodeficiency virus (HIV) infection will likely be considered the most important public health event of the twentieth century. During the past 15 years, a wealth of information relating to the epidemiology, diagnosis, natural history, and treatment of HIV infection has accumulated. This article details the recent progress in each of these areas.

Complement-mediated binding of naturally glycosylated and glycosylation-modified human immunodeficiency virus type 1 to human CR2 (CD21)

Particulate glycoproteins lacking sialic acid, such as desialylated enveloped viruses, readily activate complement through the alternative pathway. Human immunodeficiency virus type 1 (HIV-1) contains two heavily glycosylated and partially sialylated envelope glycoproteins: a surface gp120 and a transmembrane gp41. The abilities of naturally glycosylated HIV-1 and glycosylation-modified HIV-1 to interact with the complement system were examined with a biological assay which measured the binding of whole virus particles to cells expressing CR2 (CD21), the complement receptor found naturally in abundance on follicular dendritic cells and immature B cells. HIV-1 IIIB was synthesized in the presence or absence of the mannosidase II inhibitor, swainsonine, to give rise to high-mannose-type, nonsialylated, nonfucosylated carbohydrate moieties. The virus also was treated with neuraminidase or endo-beta-galactosidase to remove terminal sialic acids. An enzyme immunoassay specific for HIV-1 p24 core protein was used to quantitate the amount of virus bound to cell surfaces. Virus particles incubated with 1:3-diluted, fresh HIV-1-negative human serum as a source of complement readily bound to MT-2 (CD4+ CR2+) and Raji-3 (CD4- CR2+) cells but not to CEM (CD4+ CR2-) cells, suggesting that the virus bound to CR2 independently of CD4. Compared with heat-inactivated or C3-deficient sera, fresh complement increased binding by as much as 62 times for naturally glycosylated virus, and 5 times more than this for glycosylation-modified virus. Similar observations were made with freshly isolated, non-mitogen-stimulated peripheral blood mononuclear cells. Additional evidence that HIV-1 bound to CR2 independently of CD4 was provided by the fact that binding was blocked by monoclonal antibody OKB7 (anti-CR2) but not by OKT4a (anti-CD4). Also, the virus bound to transfected K562 cells (CD4-) which expressed recombinant human CR2 but did not bind to untransfected K562 cells. Results obtained with complement component-deficient sera indicated that binding required the alternative complement pathway. Raji-3 and transfected K562 cells could not be infected with HIV-1 in the presence of complement, suggesting that utilization of CR2 as a receptor in the absence of CD4 does not allow virus entry. The demonstration of CR2 as a receptor for HIV-1 in the presence of complement, together with the ability to enhance binding by desialylation, provides new insights into mechanisms of HIV-1-induced immunity and immunopathogenesis.

[Tuberculosis morbidity between 1982 and 1990 in Algiers]

Information on notified tuberculosis cases collected by the Algerian Ministry of Health and Social Affairs (Ministère de la Santé et des Affaires Sociales Algérien) from 1982-1990 show that 13,916 cases were notified in 1982 and 10,864 in 1990, of which 67%-71% were cases of pulmonary tuberculosis (TP) and 25-29% cases of extrapulmonary tuberculosis (TEP). New cases of smear-positive TP represented 49-55.4% of all cases and the majority of TP (69-79% depending on the year). These forms particularly affected men aged between 20 and 39 and both men and women over the age of 60. The annual incidence of tuberculosis of all forms fell by 40.3% in 9 years, from 72 cases per 100,000 in 1982 to 43 cases in 1990. Similarly, the annual incidence of smear-positive TP fell from 32 per 100,000 to 22 cases (a decline of 37%), and mainly affected the age group 20-39 years. Lymphadenitis remained the most common TEP (a total of 32% in 1990), the fall in incidence of which was similar to that of TP, although slightly less marked. Whilst a firm diagnosis of new TP cases is provided mainly by direct smear examination, TEP are unfortunately rarely confirmed. The HIV pandemic, which has hardly touched Algeria as yet, does not for the moment play a significant role in tuberculosis morbidity in the community.

Evaluation of a rapid membrane enzyme immunoassay (Testpack HIV-1/HIV-2) at zonal, regional and district hospital laboratories in Tanzania

The performance of a rapid and simple membrane enzyme immunoassay for antibodies to HIV-1 and HIV-2 (Testpack HIV-1/HIV-2) was evaluated by testing 1000 sera from the Kilimanjaro region of Tanzania. A sensitivity of 100% (118/118 positives) and specificity of 95.1% were obtained following the manufacturer's procedure. The specificity was significantly enhanced to 97.2% (P = 0.026) by modifying the Testpack procedure by including an extra was after serum adsorption to the unit membrane. The testing of a single specimen could be completed in 8 min and up to 10 individual tests could be run simultaneously. There was complete agreement in interpretation when the results were read independently by two trained technicians. A built-in control insured against incorrect procedures or inactive reagents. In a subsequent field trial including 450 sera, one strongly reactive sample failed to be detected at a participating field hospital for unknown reasons. The Testpack reagents proved stable for up to one year at room temperature (25-30 degrees C). The data indicate that Testpack is suitable for the detection of serum antibodies to HIV and is especially applicable in laboratories with limited facilities. When used to test African sera which are known to produce a high degree of false positivity, an extra wash of the membrane after serum adsorption is recommended.

Sexually transmitted diseases and travelers

Sexually active travelers are at risk for a variety of STDs, including traditional venereal infections such as gonorrhea, chlamydial urethritis, syphilis, chancroid, and herpes simplex infection. More recently, hepatitis B, hepatitis C, and HIV-1 have also been described. Risk varies depending on the geographic area of travel and the type of sexual contact. Physicians should be aware of the prevalence of antimicrobial resistance of N. gonorrhoeae and H. ducreyi because this will affect empiric antibiotic therapy. Prevention should focus on proper and consistent usage of barrier contraceptives.

HIV worldwide. What has happened? What has changed?

The human immunodeficiency virus (HIV) has resulted in a worldwide pandemic of infection. By 1991 more than 350,000 AIDS cases had been reported to the World Health Organization, but it is estimated that there are now more than 10 million people infected worldwide. HIV can rapidly spread in new populations: The pandemic is composed of multiple smaller epidemics. In the United States, it is estimated that over a million people are infected with HIV. Methods of estimating this number include extrapolation from the number of reported cases of AIDS, use of mathematical modeling and back-calculation, and seroprevalence surveys. Minorities continue to be overrepresented among those infected, and the prevalence of HIV in women is increasing. In serosurveys, it has been found that as HIV prevalence rates rise, the ratio of infected males to infected females approaches 1:1, suggesting an increased proportion of hetero-sexual transmission. HIV is now variably present but widespread across the United States. The epidemiology of HIV-related illnesses is also changing, as can be seen with current patterns of tuberculosis. HIV continues to be an increasingly complex and dangerous global burden.