Heterosexual transmission of human immunodeficiency virus

The impact of HIV infection and AIDS on insurance in the United Kingdom

1.1 In March 1987 the Futures Committee of the Institute considered a preliminary report (Daykin, 1987) on the possible impact of AIDS in the United Kingdom and the consequences for life insurance. The Committee recommended the setting up of a Working Party to study the problem. The Working Party on AIDS was accordingly established, under the auspices of the Research Committee. The authors of this paper formed the membership of the Working Party, under the chairmanship of C. D. Daykin.

Behavioral mechanisms in HIV epidemiology and prevention: past, present, and future roles

In the 1980s, behavioral variations across geographically and socially defined populations were the central focus of AIDS research, and behavior change was seen as the primary means of controlling HIV epidemics. Today, biological mechanisms--especially other sexually transmitted infections, antiretroviral therapy, and male circumcision--predominate in HIV epidemiology and prevention. We describe several reasons for this shift in emphasis. Although the shift is understandable, we argue for a sustained focus on behavioral mechanisms in HIV research in order to realize the theoretical promise of interventions targeting the biological aspects of HIV risk. We also provide evidence to suggest that large reductions in HIV prevalence may be accomplished by small changes in behavior. Moreover, we contend that behavioral mechanisms will find their proper place in HIV epidemiology and prevention only when investigators adopt a conceptual model that treats prevalence as a determinant as well as an outcome of behavior and that explicitly recognizes the dynamic interdependence between behavior and other epidemiological and demographic parameters.

Enhancement of natural killer cell activation and antibody-dependent cellular cytotoxicity by interferon-alpha and interleukin-12 in vaginal mucosae Sivmac251-infected Macaca fascicularis

We studied the innate immune system of Cynomolgus monkeys (Macaca fascicularis) experimentally infected via the vaginal mucosae with a virulent simian immunodeficiency virus isolate SIVmac251. Animals were evaluated for their natural killer (NK) cell activity, and for their antibody-dependent cellular cytotoxicity. NK cells from SIVmac251-infected macaques show impaired NK cell activity compared to cells from uninfected animals. Subsequent treatment of NK cells with interferon-a (IFN-alpha) or interleukin-12 (IL-12) alone partially restored the NK activity. However, either treatment of NK cells with both IFN-alpha and IL-12 completely reversed the impairment of cytotoxicity induced by simian immunodeficiency virus (SIV) infection. Incubation of NK cells from infected but not from uninfected monkeys with IFN-alpha and IL-12 for 8 days increased the percentage of CD16+/CD56+ cells twofold to five-fold and enhanced antibody-dependent cellular cytotoxicity (ADCC) activity. Thus IFN-alpha and IL-12 greatly enhance both the NK cell and ADCC activities of peripheral blood cells from SIVmac251-infected animals and increase the number of NK cells in longer term culture. The combined effect of IFN-alpha and IL-12 in enhancing NK cell activity may provide a novel therapeutic approach for the restoration of depressed NK cell activity observed in human immunodeficiency virus (HIV)-infected patients.

Fertility options for HIV patients

PURPOSE OF REVIEW

This paper reviews the latest reproductive options for HIV infected couples. In light of the new treatment options and improved prognosis for HIV patients, policymakers have issued recent statements to guide physicians in the care of HIV patients desiring fertility. We will review the advances in reproductive technologies and ethical considerations that have led to these most recent statements.

RECENT FINDINGS

Millions of young adults of reproductive age are afflicted with the HIV virus. With the improvement in treatment options for HIV patients and the increase in their life expectancy it is not surprising that many HIV patients desire children. Assisted reproductive technologies can assist serodiscordant couples in achieving pregnancy while at the same time minimizing risk of HIV transmission to the uninfected partner. Several European fertility clinics have a great deal of experience in providing both intrauterine inseminations and in-vitro fertilization to serodiscordant couples without seroconversion of the uninfected female partners. This is both a medical and an ethical issue. Guidelines from policymakers regarding this issue have changed over the years as a result of both changes in disease prognosis and the reproductive technologies.

SUMMARY

Reproductive technologies provide a logical way to minimize HIV transmission for HIV couples desiring pregnancy. Although the most recent research is compelling, much more needs to be performed in order to establish the safety of these techniques. Protocols need to be put in place in order to assist physicians in better serving these patients. In addition, many ethical and legal issues need to be addressed before these treatments can become standard of care in the United States.

Drug use, street crime, and sex-trading among cocaine-dependent women: implications for public health and criminal justice policy

The linkages between the sex-for-crack exchanges, prostitution, and rising rates of HIV and other sexually transmitted diseases among cocaine-dependent women have been well documented. As crack began to disappear from the headlines during the 1990s, however, it was assumed by many that crack had fallen on hard times in the street drug culture. Within this context, this article examines the extent to which crack has remained primary in the culture of cocaine-dependent women. Data are drawn from a study of 708 cocaine-dependent women in Miami, Florida, during the years 1994 to 1996, and qualitative data gathered during 1998 and 1999 in the same field areas. Analyses focus on drug use, criminality and HIV/AIDS risk behaviors. Implications for policy alternatives in criminal justice and public health approaches for assisting this population are discussed.

Factors associated with slow disease progression in macaques immunized with an adenovirus-simian immunodeficiency virus (SIV) envelope priming-gp120 boosting regimen and challenged vaginally with SIVmac251

Rhesus macaques were immunized with a combination vaccine regimen consisting of adenovirus type 5 host range mutant-simian immunodeficiency virus envelope (Ad5hr-SIVenv) recombinant priming and boosting with native SIV gp120. Upon intravaginal challenge with SIVmac251, both persistently and transiently viremic animals were observed (S. L. Buge, E. Richardson, S. Alipanah, P. Markham, S. Cheng, N. Kalyan, C. J. Miller, M. Lubeck, S. Udem, J. Eldridge, and M. Robert-Guroff, J. Virol. 71:8531-8541, 1997). Long-term follow-up of the persistently viremic immunized macaques, which displayed significantly reduced viral burdens during the first 18 weeks postchallenge compared to controls, has now shown that one of four became a slow progressor, clearing virus from plasma and remaining asymptomatic with stable CD4 counts for 134 weeks postchallenge. Reboosting of the transiently viremic macaques did not reactivate latent virus. Rechallenge with two sequential SIVmac251 intravaginal exposures again resulted in partial protection of one of two immunized macaques, manifested by viral clearance and stable CD4 counts. No single immune parameter was associated with partial protection. Development of a strong antibody response capable of neutralizing a primary SIVmac251 isolate together with SIV-specific cytotoxic T lymphocytes were implicated, while CD8(+) T-cell antiviral activity and mucosal immune responses were not associated with delayed disease progression. Our data show that even a third immunization with the same Ad5hr-SIVenv recombinant can elicit significant immune responses to the inserted gene product, suggesting that preexisting Ad antibodies may not preclude effective immunization. Further, the partial protection against a virulent, pathogenic SIV challenge observed in two of six macaques immunized with a vaccine regimen based solely on the viral envelope indicates that this vectored-vaccine approach has promise and that multicomponent vaccines based in the same system merit further investigation.

Human immunodeficiency virus type 1--serodiscordant couples can bear healthy children after undergoing intrauterine insemination

OBJECTIVE

To use semen from men who were seropositive for human immunodeficiency virus type 1 (HIV-1) to inseminate their partners without infecting them.

DESIGN

Prospective study.

SETTING

Private practice.

PATIENT(S)

Sixty-three HIV-1-seropositive men and their HIV-1-seronegative female partners.

INTERVENTION(S)

The men provided 107 semen samples that were prepared with the use of the Percoll and swim-up techniques. The presence of HIV-1 was determined in the fraction of motile spermatozoa obtained after washing. If HIV-1 was not detected. IUI was performed in stimulated cycles.

MAIN OUTCOME MEASURE(S)

Human immunodeficiency virus type 1 RNA and DNA were detected with the use of the polymerase chain reaction technique modified for spermatozoa.

RESULT(S)

One hundred seven semen samples were washed. Human immunodeficiency virus type 1 was not detected in 101 samples (94.4%) and was detected in 6 samples (5.6%). In the latter cases, IUI was not performed. One hundred one IUI procedures were performed in 63 women. Thirty-one pregnancies resulted, for a pregnancy rate of 30.7% per cycle and 49.2% per inseminated woman. Thirty-seven healthy children were born. The results of tests for the detection of HIV-1 and antibodies to HIV-1 in the inseminated women were negative.

CONCLUSION(S)

On the basis of these results, testing for HIV-1 with the use of the polymerase chain reaction technique on the semen fraction obtained after washing appears to prevent infection in the inseminated woman. This method makes it possible to help HIV-1-seropositive men to have children without infecting their female partners.

An adenovirus-simian immunodeficiency virus env vaccine elicits humoral, cellular, and mucosal immune responses in rhesus macaques and decreases viral burden following vaginal challenge

Six female rhesus macaques were immunized orally and intranasally at 0 weeks and intratracheally at 12 weeks with an adenovirus type 5 host range mutant (Ad5hr)-simian immunodeficiency virus SIVsm env recombinant and at 24 and 36 weeks with native SIVmac251 gp120 in Syntex adjuvant. Four macaques received the Ad5hr vector and adjuvant alone; two additional controls were naive. In vivo replication of the Ad5hr wild-type and recombinant vectors occurred with detection of Ad5 DNA in stool samples and/or nasal secretions in all macaques and increases in Ad5 neutralizing antibody in 9 of 10 macaques following Ad administrations. SIV-specific neutralizing antibodies appeared after the second recombinant immunization and rose to titers > 10,000 following the second subunit boost. Immunoglobulin G (IgG) and IgA antibodies able to bind gp120 developed in nasal and rectal secretions, and SIV-specific IgGs were also observed in vaginal secretions and saliva. T-cell proliferative responses to SIV gp140 and T-helper epitopes were sporadically detected in all immunized macaques. Following vaginal challenge with SIVmac251, transient or persistent infection resulted in both immunized and control monkeys. The mean viral burden in persistently infected immunized macaques was significantly decreased in the primary infection period compared to that of control macaques. These results establish in vivo use of the Ad5hr vector, which overcomes the host range restriction of human Ads for rhesus macaques, thereby providing a new model for evaluation of Ad-based vaccines. In addition, they show that a vaccine regimen using the Ad5hr-SIV env recombinant and gp120 subunit induces strong humoral, cellular, and mucosal immunity in rhesus macaques. The reduced viral burden achieved solely with an env-based vaccine supports further development of Ad-based vaccines comprising additional viral components for immune therapy and AIDS vaccine development.

Spectrum of opportunistic infections among AIDS patients in Tamil Nadu, India

A retrospective case note review of 100 AIDS patients attending a large Indian centre was performed. Of these 100 patients, 94% gave a history of heterosexual HIV transmission, 68% were male. The majority of females were aged 21 to 30 years. The most common mode of presentation was tuberculosis (61%), both pulmonary (46%) and extrapulmonary (15%). Oral candidiasis extending on to the oesophagus was the second most predominant opportunistic infection. This study also highlights the difficulty in detecting AIDS cases in India owing to difficulties in taking a sexual history and lack of laboratory facilities.

Genitourinary manifestations of the acquired immunodeficiency syndrome

As the number of HIV-1 infected individuals and AIDS patients continues to increase, more cases involving the genitourinary tract will be encountered. Often, genitourinary manifestations will be the initial presentation of AIDS. Proper diagnosis will require awareness and a high index of suspicion. In addition to routine cultures, opportunistic infections with unusual organisms will require staining for fungi and acid-fast bacilli. Repeat cultures of blood, urine, seminal fluid, and abscess cavities may be required to establish a diagnosis. Prolonged courses of antibiotic treatment for prophylaxis and for relapses are usually required. Clinical understaging and rapid progression of tumors distinguish HIV-1-associated malignancies involving the genitourinary tract. Treatment for these malignancies will depend on the stage of HIV-1 infection. Any concomitant drug therapy and evidence of malnutrition will be important factors in selecting the proper timing and mode of therapeutic intervention. Although AIDS predominantly affects individuals between 30 and 50 years of age, an increasing percentage of patients over 50 years of age are being diagnosed. Common risk factors for acquisition of HIV include homosexuality or bisexuality and transfusion of blood or blood products. For the urologist, it is important to recognize that older patients more frequently present with AIDS at the time of diagnosis of HIV infection. A more rapid course of deterioration and high mortality is noted in this population. Clearly, protocols including surveillance, dosing regimens, and surgical intervention will need to be established and clarified to treat an anticipated increasing number of affected patients. In addition, it appears that adequate adherence to universal precautions is far from being achieved. Close monitoring and active surveillance of infection control may be needed to improve compliance.

Sexual practices, sexually transmitted diseases and other risk factors for HIV among injecting drug users

Data were collected from 814 clients attending anonymously for counselling before tests for human immunodeficiency virus (HIV) infection at the Burnett Clinic in Auckland. Just over 10 per cent of clients (n = 83) reported ever having injected drugs. This group was matched according to age, gender, ethnicity and sexual orientation with an equal sized control group drawn from clients who had not injected drugs. The groups were compared in terms of their sexual practices, sexual partnerships, other drug use, current and past health status and their perception of HIV risk. The injecting drug users reported more sex partners than the nonusers, they were less likely to be in a relationship and they were less likely to be monogamous. Vaginal and oral sex were the most common practices in both groups but anal sex was more common among users than the nonusers. Regular condom use was reported by less than a quarter of each group. The health status of drug users was generally poorer than that of the nonusers. They reported greater use of alcohol and other drugs, more mental health problems, and more symptoms of ill health. They also had experienced more sexually-transmitted diseases. Only 1 per cent of users and 2 per cent of nonusers tested positively for HIV, although users saw themselves and their partners as at greater risk of HIV infection than the nonusers.

Mortality of intravenous drug users in Rome: a cohort study

A historical cohort study was carried out in Rome to examine overall and cause-specific mortality among intravenous drug users (IVDUs). A total of 4200 IVDUs (3411 men and 789 women) enrolled in methadone treatment centers between 1980 and 1988 were studied. There were 239 deaths during the follow-up period. The overall SMR was 10.10 in the entire cohort (95% confidence interval, 8.86-11.47), 9.30 in males and 18.07 in females. A large excess of mortality in both sexes was found for infectious, circulatory, respiratory, and digestive diseases as well as for violence, overdose, AIDS, and unknown or ill-defined causes. Tumors and suicide were excessive only in males. Deaths due to drug overdose, violence or trauma, and cirrhosis accounted for 63.6%, AIDS for 7.1%, endocarditis and other bacterial infections for 7.1%, and neoplasms for 3.8% of total mortality. These findings document serious health consequences of drug abuse in Italy.

Drugs, sex and HIV: a mathematical model for New York City

A data-based mathematical model was formulated to assess the epidemiological consequences of heterosexual, intravenous drug use (IVDU) and perinatal transmission in New York City (NYC). The model was analysed to clarify the relationship between heterosexual and IVDU transmission and to provide qualitative and quantitative insights into the HIV epidemic in NYC. The results demonstrated the significance of the dynamic interaction of heterosexual and IVDU transmission. Scenario analysis of the model was used to suggest a new explanation for the stabilization of the seroprevalence level that has been observed in the NYC IVDU community; the proposed explanation does not rely upon any IVDU or sexual behavioural changes. Gender-specific risks of heterosexual transmission in IVDUs were also explored by scenario analysis. The results showed that the effect of the heterosexual transmission risk factor on increasing the risk of HIV infection depends upon the level of IVDU. The model was used to predict future numbers of adult and pediatric AIDS cases; a sensitivity analysis of the model showed that the confidence intervals on these prediction estimates were extremely wide. This prediction variability was due to the uncertainty in estimating the values of the models' thirty variables (twenty biological-behavioural transmission parameters and the initial sizes of ten subgroups). However, the sensitivity analysis revealed that only a few key variables were significant in contributing to the AIDS case prediction variability; partial rank correlation coefficients were calculated and used to identify and to rank the importance of these key variables. The results suggest that long-term precise estimates of the future number of AIDS cases will only be possible once the values of these key variables have been evaluated accurately.

Human immunodeficiency virus and migrant labor in South Africa

The authors investigate the impact of the migrant labor system on heterosexual relationships on South African mines and assess the implications for the future transmission of human immunodeficiency virus (HIV) infection. The migrant labor system has created a market for prostitution in mining towns and geographic networks of relationships within and between urban and rural communities. A section of the migrant workforce and a group of women dependent on prostitution for economic support appear especially vulnerable to contracting HIV infection since they are involved in multiple sexual encounters with different, changing partners, usually without condom protection. Furthermore, sexually transmitted disease morbidity is extensive in the general and mineworker populations. Historically, migration facilitated the transmission of sexually transmitted diseases and may act similarly for HIV. Problems of combating the HIV epidemic in South Africa are discussed.

Heterosexual behaviour in a large cohort of homosexually active men in England and Wales

This paper seeks to outline the range and type of heterosexual behaviour in a large non-clinic cohort of homosexually active males. A cohort of 930 homosexually active men were interviewed as part of a prospective study of the seroprevalence of HIV. The paper indicates that over 60% of these men have had at least one sexual experience with a female and that about 90% of these males have engaged in vaginal intercourse with a female. Twelve per cent of the cohort had sexual contact with females in the last year, and 5% had sex with females, in the month preceding interview. Amongst these behaviourally bisexual males the number of female partners is significantly lower than the number of male partners. However, the proportion of female partners with whom penetration occurs is very much higher than for male partners.

Monitoring HIV-1 infection prevalence among intravenous drug users in Vienna 1986-1990

A standardised method to monitor HIV-1 infection levels and trends among injecting drug users (IDUs) was periodically administered at the drug addiction outpatient ward of the Psychiatric University Clinic of Vienna. A total of 715 injecting drug users were examined. HIV-1 antibodies were found in 8.5% of the IDUs in 1985/86, 14.5% in 1986/87, 27.7% in 1988, 29.7% in 1989 and 26.9% in 1990. Sharing was extensive in infected IDUs. After introduction of methadone maintenance in Austria more than 50% of the IDUs were receiving methadone and, in 1990, 88% of the infected IDUs were treated with methadone.

Heterosexual sexual behaviour in a sample of homosexually active men

Three hundred and fifty six homosexually active men were recruited in 1988 for a study by interview of sexual behaviour. Thirty two per cent had homosexual passive anal sex in the previous month and 60% in the year before interview. Anal sex and unprotected anal sex were more common with regular than non-regular partners. Heterosexual sex was reported by 4% of men in the last month and 10% for the last year. Sixteen per cent of heterosexually active men reported anal sex with a female partner. Fewer men described themselves as bisexual than would be expected from the sample's recent sexual histories. More attention is needed to the definition and measurement of "bisexuality" to understand its role in HIV transmission.

Skin disease in haemophiliacs with and without antibodies to the human immunodeficiency virus (HIV): further evidence of altered disease behaviour in different risk groups?

Forty-one patients routinely attending the Oxford Haemophilia Centre entered a controlled, blind investigation in order to determine whether HIV antibody status was related to the presence of skin disease. Twenty-four of the 41 patients (58.5%) were HIV antibody positive and none had any general symptoms. Comparison of the HIV antibody positive group with the HIV antibody negative group and with non-haemophiliac controls showed an increased prevalence of four HIV-associated dermatoses: 11 patients had seborrhoeic dermatitis (10 HIV antibody positive and one HIV antibody negative (P less than 0.05 chi 2 test], eight patients had folliculitis (six HIV antibody positive), four patients had mucocutaneous candidiasis, all were HIV antibody positive, and three patients had onychomycosis, all were HIV antibody positive. None of these conditions was seen in a group of 16 non-haemophiliac controls. These findings are different from those reported from a similar study of comparable groups of homosexual men and these results may be further evidence to support the belief that the behaviour of HIV infection differs between haemophiliacs and other risk groups.

Human immunodeficiency viruses in patients attending a sexually transmitted disease clinic in London, 1982-7

OBJECTIVE

To determine the prevalence of infection with the human immunodeficiency virus (HIV) in all patients attending a London sexually transmitted disease clinic over four weeks at the end of 1987 and to see how it varied from that in similar samples studied between 1982 and 1986.

DESIGN

Anonymous testing of serum samples from consecutive heterosexual and homosexual patients having routine serological investigations for syphilis. Testing was for anti-HIV-I, anti-HIV-II, and hepatitis B core antibody (anti-HBc) and P24 antigen. Age, nationality, sexual orientation, and past sexually transmitted diseases were recorded for each patient. Gonorrhoea rates by quarters were analysed among homosexual and bisexual men and heterosexual men and women from 1981 to 1987.

SETTING

Outpatient department of genitourinary medicine.

PATIENTS

A total of 1074 patients attending consecutively for syphilis serology. Thirty five homosexual and bisexual men were excluded (these were regular attenders as part of a prospective study of the natural course of HIV infection).

MEASUREMENTS AND MAIN RESULTS

The prevalence of anti-HIV-I in homosexual and bisexual men in 1987 was 25.6% (64/250). Results in the same clinic population between 1982 and 1984 had shown a rise in prevalence, which flattened out in 1985-6 and continued at that level. Among heterosexual attenders in 1987 the prevalence of anti-HIV-I was 1% (women 4/412; men 4/377), which contrasted with a prevalence of 0.5% (women 2/395; men 3/757) in January 1986. One homosexual man was seropositive for anti-HIV-II and seronegative for anti-HIV-I. Among homosexual and bisexual men the rate of gonorrhoea had declined by an average of 2.7% a year since 1981, such that by 1987--and for the first time in the clinic--there was no significant difference in the rates between these men and heterosexual men and women.

CONCLUSIONS

The appearance of HIV-I infection among heterosexuals indicates a need for more aggressive education programmes and intervention strategies along the lines adopted for homosexual men. Surveillance for HIV-II infection is needed to provide information for future policy in national screening programmes.

The sex industry, alcohol and illicit drugs: implications for the spread of HIV infection

A review is presented of the association between the sex industry and the use and misuse of alcohol and illicit drugs. It is concluded that both the latter are associated with 'high risk' sexual activities and that heavy drinking and illicit drug use are commonplace amongst prostitutes and their clients. Outside Africa evidence suggests that in some, though by no means all, areas prostitutes have low or zero levels of HIV seropositivity. It is concluded that far more information is needed on the patterns of AIDS-related knowledge, beliefs, attitudes and behaviours amongst male and female prostitutes and their clients. Vigorous policies are needed to increase levels of knowledge about AIDS risks amongst prostitutes and their clients and to foster the adoption of 'safer sex' practices.