Heterosexual Transmission

“Mandy Webb, 42, was horrified when she was diagnosed HIV positive, especially as she hadn’t had sex for over a decade…Mandy first noticed something was wrong back in 1990, when her son, Ben, was two. She says: ‘I kept getting bruises…”. She went to her GP for blood tests and the results showed Mandy’s platelets were dangerously low…she was put on steroids to help her blood clot. However the drugs made her weight balloon. In 1991, doctors offered Mandy another option – to have her spleen removed and be given injections of factor Vlll (a blood protein) to help her blood to clot. Mandy went ahead but after surgery she kept getting chest infections. And, over the years, her health deteriorated. Suffering from diarrhoea, Mandy’s weight plummeted to under eight stone and her periods stopped. She developed painful mouth ulcers and night sweats…Her GP diagnosed irritable bowel syndrome and prescribed anti-depressants for stress... which Mandy didn’t take. “I tried to make the best of things,” she explains, “but it got worse and worse…” Then, six years ago, Mandy had problems walking and became disorientated. Her mum took her to another GP, who suggested an HIV test. A stunned Mandy replied: “Why? I haven’t had sex for 14 years!” Ben had been the product of a drunken one-night stand when Mandy was a 21-year-old drama student in Portsmouth. Doctors admitted Mandy to hospital and she was found to be in the third stage of HIV infection – the final one before it progresses to full-blown Aids. As doctors treated her with antibiotics and introduced anti-Aids medications, Mandy slowly began to recover…“No one knew how I’d caught HIV. I believe it was either from unprotected sex in my youth or from contaminated factor Vlll.”… [however] by 1991, when Mandy started having factor-Vlll treatment, blood products were screened. She was told it was unlikely to be the cause…Dependent on her mum to care for her, Mandy left hospital in a wheelchair. After three months, she began to recover and walk again. Today, she has high cholesterol [associated with protease inhibitors] and continuing problems with walking and balance. No one knows yet what permanent damage HIV has had on her [and nobody wants to know what damage the drugs have done]…“It’s World Aids day on Monday and I’m speaking out to try to dispel the myths about HIV and reduce the stigma so that people aren’t afraid to go and get tested…” [despite no good explanation for how she became HIV+, although an immune reaction to Factor VIII causing a false positive HIV test isn’t a bad guess]”

“Heterosexual transmission continues to drive the epidemic among sex workers, their clients, and their clients’ partners. In addition, prisoners, injecting drug users, as well as men who have sex with men, may also engage in heterosexual relationships. In sub-Saharan Africa almost 60% of adults living with HIV were women, 48% in the Caribbean. [Yet, worldwide, women are always less promiscuous than men, so this consistent pattern should be impossible with a heterosexually transmitted epidemic]”

“ In 1997, UNAIDS chief Peter Piot gloomily foretold that "AIDS will cut through Asian populations like a hot knife through cold butter." Aside from a few explosive heterosexual epidemics within large commercial sex networks in Thailand, Myanmar, Cambodia and several states in India in the late 1980s to early 1990s, Dr. Piot's dire and colorful prediction never occurred.”

“An HIV-positive man who didn’t tell his girlfriend he had the condition was sentenced to 12 years in prison Thursday…Neither [his girlfriend nor another sexual partner] contracted HIV despite their long-term relationship with Hunter, Jones said…Court documents said Hunter has hemophilia and got HIV through a blood transfusion when he was 7 years old. He attended the University of Arkansas, where he met at least one of the women.”

“Of 18 525 Ugandans aged 15–59 years who had HIV serological testing, 1092 (5.9%) were HIV-infected…64% were female…100 (9%) of those who had ever had sex stated that they knew all their partners’ HIV status and 2% knew some of their partners’ HIV status…99% of HIV-infected persons had had sex and 77% were sexually active in the last year, including 86% of men and 72% of women…86% reported having had sex only with their spouses in the last year, including 75% of men and 96% of women…Of all married HIV-infected persons, 13% reported only one sexual partner in their life…Of last sex acts of HIV-infected persons, 83% were unprotected and 84% of these took place with married and cohabitating partners, 13% with steady partners and 3% with casual partners. Among those who had had sex, 67% reported never having used a condom”

“Sera were obtained from 2103 South African individuals (862 miners, 95 sex workers, 731 female and 415 male township residents; mean age 33.2 years). All sera were tested for antibodies to KSHV [Kaposi’s Sarcoma Herpes Virus, believed by some to be the cause of this skin cancer or cancer-like condition]…, HIV, gonococcus, herpes simplex virus type 2 (HSV-2), syphilis and chlamydia. Information on social, demographic and high-risk sexual behavior was linked to laboratory data…Overall KSHV and HIV prevalences were 47.5% and 40%, respectively…No significant difference in KSHV infection was observed among the residential groups. KSHV was not associated with any of the STI or any measures of sexual behavior.”

“During 5253 person-years at risk, 170 individuals [in an area of rural South Africa] became seropositive. The crude HIV incidence rate [new conversions to HIV seropositivity] per 100 person-years was 3.8 in women aged 15–49 years and 2.3 in men aged 15– 54 years.”

“we find that achieving the same equilibrium prevalence as MSM [men who have sex with men] requires heterosexual individuals to average 4.9 UVI [unprotected vaginal intercourse] partners annually, 2.7 times more partners than MSM [which could explain the characteristics of the AIDS epidemic in the US, but clearly not in Africa]”

“In June 2006, a 77-year-old Japanese man with an acute asthma attack was admitted to our hospital in Yokohama, Japan. A pre-admission HIV screening test by enzyme immunoassay unexpectedly detected his HIV seropositivity…strong seroreactivity to HIV-2, but not to HIV-1 [and further tests confirmed this]…He had no history of engaging in high risk sexual contact and substance abuse in the past. Both his spouse (72 years old) and their son (34 years old) were HIV-negative. He, however, had a near-fetal[sic] motor accident in Senegal in June 1971…he received a large unit of blood from a number of volunteer Senegalian donors. He has never been transfused with blood products except on that occasion…After 8 days, he was discharged from hospital…His CD4 cell count was 827 cells/µL…He continues to be [a] long-term nonprogressor [Obviously his wife and him had unprotected sex after the accident, 36 years ago, but it did not result in transmission]”

“The prevalence of HIV infection was 2.3% among the male participants and 8.8% among the female participants. The corresponding prevalence of HCV infection was 16.6% and 29.2%, respectively. The most important risk factor was injection drug use. The prevalence of HIV infection was 7.2% among the male injection drug users and 0.5% among the male non-users. Among the women, the rate was 20.6% among the injection drug users, whereas none of the non-users was HIV positive. The prevalence of HCV infection was 53.3% among the male injection drug users and 2.6% among the male non-users; the corresponding values among the women were 63.6% and 3.5%.”

“Violence and rape are believed to fuel the HIV epidemic in countries affected by conflict. We compared HIV prevalence in populations directly affected by conflict with that in those not directly affected and in refugees versus the nearest surrounding host communities in sub-Saharan African countries…Seven countries affected by conflict (Democratic Republic of Congo, southern Sudan, Rwanda, Uganda, Sierra Leone, Somalia, and Burundi) were chosen since HIV prevalence surveys within the past 5 years had been done and data, including original antenatal-care sentinel surveillance data, were available. We did a systematic and comprehensive literature search using Medline and Embase. Only articles and reports that contained original data for prevalence of HIV infection were included…Of the 295 articles that met our search criteria, 88 had original prevalence data and 65 had data from the seven selected countries. Data from these countries did not show an increase in prevalence of HIV infection during periods of conflict, irrespective of prevalence when conflict began. Prevalence in urban areas affected by conflict decreased in Burundi, Rwanda, and Uganda at similar rates to urban areas unaffected by conflict in their respective countries. Prevalence in conflict-affected rural areas remained low and fairly stable in these countries. Of the 12 sets of refugee camps, nine had a lower prevalence of HIV infection[!], two a similar prevalence, and one a higher prevalence than their respective host communities. Despite wide-scale rape in many countries, there are no data to show that rape increased prevalence of HIV infection at the population level. [Note that rape being a violent crime should increase the transmission of a virus because of a greater likelihood of contact with blood due to violent penetration, beating of women and so on. The fact that this is not the case indicates that HIV is not behaving like a sexually transmitted virus]”

“All analyses were limited to the 3993 women with complete data on the number of lifetime sexual partners and the corresponding ages of those partners…The (weighted) mean reported number of partners was 2.3. The estimated overall prevalence of HIV among sexually active women was 21.2%…Estimates of HIV prevalence ranged from 15.2% among women reporting one lifetime partner to 23.1% for two partners, 28.7% for three partners, and 28.5% among those with more than three partners…for the 3993 women included in the models above, the estimated mean (median) number of reported contacts per relationship was approximately 82…[making some assumptions results in the estimate] that the per-contact probability of HIV transmission are in the range of 1/50 to 1/16 contacts [compared to about 1/1000 estimated by Nancy Padian in 1997 in North America] [No other possible reasons for young black women reacting positive on HIV tests were considered in this study]…we also found that for the 3993 women included in the models above, the estimated mean (median) number of reported contacts per relationship was approximately 82…[after making some assumptions] These estimates suggest that the per-contact probability of HIV transmission [is] in the range of 1/50 to 1/16 contacts…we also found that 4% of young women who reported never having had sex were infected with HIV, indicating the presence of reporting error in this study [or other reasons for young black women to test positive on HIV tests at such a high rate, a possibility not considered by this, or most other research]”

“[Among 778 Ukrainian IV drug users]…With regard to sexual risk behaviors, those who were abstinent were more likely to be HIV positive than those who were sexually active. Those who had an HIV-positive sex partner, however, were twice as likely to be HIV positive themselves as those who did not have an HIV-positive partner or who did not know the status of their partner.”

“Britain is funding a study into how tens of thousands of HIV-positive Kenyans have mysteriously not passed the virus to their husbands or wives…early surveys showed that up to 40% of people with HIV in the area had not passed the virus to their partners, despite regularly engaging in unprotected sex over long periods of marriage”

“Abstinence and sexual fidelity have played virtually no role in the much-heralded decline of AIDS rates in the most closely studied region of Uganda”

“Public health and political authorities have ascribed the apparent decline in Ugandan HIV or AIDS rates to increased rates of sexual abstinence or condom use. However, what appears to be special about Uganda is that in the middle to late 1980s there was a growing public awareness of health care risks. Given the lack of evidence for transmission of HIV to healthy persons by penile-vaginal intercourse, the improvement in injection safety is the best candidate for declining HIV and AIDS rates.”

“At Kenyatta National Hospital VCT centre, an estimate 10% to 15% of the couples who get tested turn out to be discordant [one HIV+, one HIV-]…’the infected partner is not getting opportunistic infections despite having the virus for a long time’, says Dr. Moses Otsyula, an HIV expert…Their CD4 counts are not declining…And they have very low viral loads…out of 31 couples [recently] tested, 23 were discordant couples. Some of them have stayed in a sexual relationship with the infected partner for more than six years without the infected one passing the virus to the other. And when these discordant couples brought their children for testing, all of them were free of the virus…In the Kenya AIDS Vaccine Initiative case, commercial sex workers in Majengo slums were found to remain HIV negative even after having unprotected sex with infected men”

“There is substantial dissonance between much of the epidemiologic evidence and the current orthodoxy that nearly all of the HIV burden in sub-Saharan Africa can be accounted for by heterosexual transmission and the sexual behaviour of Africans. The mounting toll of HIV infection in Africa is paralleled by a mounting number of anomalies in the many studies seeking to account for it. We propose that existing data can no longer be reconciled with the received wisdom about the exceptional role of sex in the African AIDS epidemic…Yaounde (in Cameroon, a nation with low and stable prevalence) had the highest level of risky behavioural markers. Ndola (in Zambia, a nation that has experienced a rapid rise in HIV) had the smallest proportion of both men and women who reported a non-spousal sex partner in the previous 12 months. Ndola’s other markers were similar to those in Dakar, Senegal and Cotonou, Benin, other areas with low, stable prevalence…We are aware of no study from sub-Saharan Africa suggesting cyclic sexual network architecture. Without evidence of appropriate network configurations on a scale considerably larger than that observed in developed countries, rapid propagation of HIV in Africa would be difficult to sustain…Similarly, there are persistent reports of HIV in infants with seronegative mothers.”

“The conventional wisdom that heterosexual transmission accounts for most adult HIV infections in Africa emerged as a consensus among influential HIV/AIDS experts no later than 1988. In that year, the World Health Organization’s (WHO) Global Program on AIDS circulated estimates that 80% of HIV infections in Africa was due to heterosexual transmission…By mid-1989, an overview of global HIV epidemiology by leading AIDS experts at the Fifth International Conference on AIDS, did not even mention medical injections as a risk for HIV…[based on 13 studies up to 1988] 7 PAFs [Population Attributable Fraction, the portion of HIV infection estimated due to a single cause] for HIV associated with injections average 48%…The 14 available PAFs for risk by blood transfusion average 5%. 4 PAFs for scarification range from <0% to 23% and average 6%. The 9 reflecting risk for reporting more than one sexual partner average 16%. The 3 for contact with prostitute women average 36%. Lastly, the 12 for reported or current STD average 27%…[Reasons why the association of medical injections with HIV might have been ignored include] First, it was in the interests of AIDS researchers in developed countries—where HIV seemed stubbornly confined to MSMs, IDUs, and their partners—to present AIDS in Africa as a heterosexual epidemic…Second, there may have been an inclination to emphasize sexual transmission as an argument for condom promotion, coinciding with pre-existing programmes and efforts to curb Africa’s rapid population growth. Third, ‘the role of sexual promiscuity in the spread of AIDs in Africa appears to have evolved in part out of prior assumptions about the sexuality of Africans’…Fourth, health professionals in WHO and elsewhere worried that public discussion of HIV risks during health care might lead people to avoid immunizations.”

“Compared with group C [routine health services], the incidence rate ratio of HIV-1 was 0·94 in group A [behavioural interventions against STDs] and 1·00 in group B [behavioural interventions and STI treatment], and the prevalence ratio of use of condoms with last casual partner was 1·12 in group A and 1·27 in group B. Incidence of…active syphilis…and prevalence of gonorrhoea were both lower in group B than in group C [i.e. the interventions had no significant effect on rates of HIV positivity, even though they did reduce rates of sexually transmitted diseases, and did encourage use of condoms]”

“Of the 97 women who volunteered to disclose their history of risk factors for HIV-1 infection, 5 (5%) used to be commercial sex workers [and others reported risk factors with their husbands]…1 woman had late latent syphilis diagnosed, and 8 women (7.5%) were hepatitis B virus carriers. Of the 62 husbands who were also tested for anti-HIV-1 antibody, 18 (29%) were seronegative.”

“Epidemiologists who design computer models to support heterosexual transmission’s role in fuelling Africa’s HIV epidemic characteristically choose and/or adjust assumptions about sexual behaviour, rates of heterosexual transmission, and/or other parameters to allow the model to reproduce observed prevalence. These assumptions are often distant from empiric observations from African studies. While such models show that it is possible to imagine patterns of heterosexual transmission that can `explain’ the epidemic, they do not show that imagined patterns are realistic.

In one model, for example, Anderson and colleagues assumed a mean rate of annual partner change of 3.4. In contrast, surveys in 12 African countries show unweighted averages of 74% of men and 91% of women aged 15– 49 years with no non-regular sex partners in the past year, and only 3.7% of men and 0.7% of women with more than four non-regular partners. At about the same time, a survey in Denmark found that 19% of adults aged 18–59 years reported more than one sex partner in the past year; a survey in France found that 17% of men and 7.9% of women aged 18–44 years reported more than one sex partner in the past year; and a survey in the UK found that 17% of men and 8.4% of women aged 16–44 years reported more than one sex partner in the past year. Studies of sexual behaviour do not show as much partner change in Africa as modellers have assumed, nor do they show differences in heterosexual behaviour between Africa and Europe that could explain major differences in epidemic growth. During the last 14 years, a number of studies have reported adults contracting HIV without sexual exposures to HIV. A study in Zimbabwe in the 1990s found 2.1% HIV prevalence among 933 women with no sexual experience. In a 1988 study of discordant couples in Rwanda, 15 of 25 HIV-positive women with HIV-negative partners reported only one lifetime sex partner. In a 1990 study of teenagers in Uganda, 6.9% of women with no sex partners in the last five years were HIV-positive vs 23% for those with one or more partners; for men, 1% with no partners in the last five years were HIV-positive vs 2.5% of those reporting partners. Among young adults 15–24 years old in Tanzania, a 1995 study found HIV prevalence of 5.6% among men and 3.6% among women who did not report any lifetime sexual activity vs 4.8% and 12% for men and women reporting one or more sexual partners. In a 1999 study in South Africa, 6.8% of women and 1.2% of men 14–24 years old who reported never having sex were HIV-positive; however, a validation study found some under-reporting of sexual activity. In a case–control study in Uganda, in two of seven cases with only one lifetime sexual partner, the partner was HIV-negative, three were HIV-positive, and two others not tested.”

“The maintenance of seronegativity despite exposure to HIV has been observed in sexual partners of HIV infected persons [7 references given], infants born to HIV-infected mothers [3 references], commercial sex workers [4 references] and health care workers occupationally exposed to HIV-contaminated body fluids [2 references]”

“The prevalence of HIV infection in Africa is substantially higher among young women than it is among young men. Biological explanations of this difference have been presented but there has been little exploration of social factors. In this paper we use data from Carletonville, South Africa to explore various social explanations for greater female infection rates…[in Carletonville] at 15 years-of-age…an estimated 0.2% of men and 8% of women are HIV-positive; at 20 years-of-age 11% of men and 47% of women are positive…The age at sexual debut cannot explain the dramatic differences in the age-prevalence of HIV infection…For the younger age-group there is a small, and [statistically] significant, difference between the proportions of men and women who have different numbers of sexual partners. Girls are less likely to have had no partners and more likely to have had one or two…but none of the individual comparisons is significant and the overall distributions are similar…[the only positive association is found when the researchers] plotted the prevalence of infection in women against their age and the prevalence in men against the age of their sexual partners and scaled the prevalence in men up by a factor of 1.3 [but this is still no explanation for the lower HIV seroprevalence rate in men]”

“The study cohort consisted of 17 women who remained uninfected, despite a history of heavy exposure to HIV through repeated, unprotected sexual contact with an infected partner, and 12 of their regular, male HIV-positive partners. Criteria for inclusion were longstanding sexual partnership up to the time of the male partner’s first positive HIV test and/or continued unprotected intercourse after the male partner was infected and no other identified risk for HIV infection for the women. The HIV-negative status of the women was determined by HIV-1 antibody status, qualitative plasma DNA polymerase chain reaction, and cocultivation. HIV antibody–positive status was confirmed by repeat ELISA and Western blot tests...At enrollment, CD4 cell counts for the 12 HIV-positive male partners were 9–1903 cells/mm-cubed. In men, these high values were relatively stable during the observation period, as illustrated by the medians over time...In all, 13 women exhibited an immune response that could at least partly explain their persistent seronegativity...The lack of transmission cannot be ascribed to reduction in CD4 cell infectivity. The CD4 cells of 9 women all were readily infected, 5 by their partner’s virus. None of the women was homozygous for CCR5D32 or CCR2 promoter region mutations that disable receptors for HIV.”

“Overall, 26% of individuals in Kisumu and 28% in Ndola were HIV-positive. In both sites, HIV prevalence in women was six times that in men among sexually active 1 5-19 year olds, three times that in men among 20-24 year olds, and equal to that in men among 25-49 year olds. Age at sexual debut was similar in men and women, and men had more partners than women. Women married younger than men and marriage was a risk factor for HIV, but the disparity in HIV prevalence was present in both married and unmarried individuals. Women often had older partners, and men rarely had partners much older than themselves. Nevertheless, the estimated prevalence of HIV in the partners of unmarried men aged under 20 was as high as that for unmarried women. HIV prevalence was very high even among women reporting one lifetime partner and few episodes of sexual intercourse.”

“A total of 1022 heterosexual couples with discordant HIV-1 serology results (one partner HIV infected, the other HIV uninfected) were enrolled in a prospective study in Lusaka, Zambia and monitored at 3-month intervals…Median plasma VL [viral load] was significantly higher in transmitters than nontransmitters…the risk ratio (RR) for FTM [female-to-male] transmission was 7.6 for VL > 100,000 copies/ ml and 4.1 for VL between 10,000 and 100,000 copies/ml compared with the reference group of <10,000 copies/ml. Corresponding RRs for MTF [male-to-female] transmission were 2.1 and 1.2, respectively…We conclude that the association between increasing plasma viral load was strong for female to male transmission, but was only weakly predictive of male to female transmission in Zambian heterosexual couples.”

“The prevalence of HIV infection in men in Cotonou was 3.3%, in Yaoundé 4.1%, in Kisumu 19.8% and in Ndola 23.2%; the corresponding figures for women were 3.4%, 7.8%, 30.1% and 31.9% respectively…The prevalence of HIV infection among pregnant women in Dakar was less than 1% in 1998…The concurrency index k [reflecting the number of people with more than one sexual partner] at the time of interview was high in Yaoundé (0.98), intermediate in Kisumu (0.44) and Cotonou (0.33) and low in Ndola (0.26) and Dakar (0.18) [In other words, the prevalence of HIV bears no relationship to the frequency of promiscuity]”

“174 monogamous couples, in which one partner was HIV-1 positive, were retrospectively identified from a population cohort in Rakai, Uganda . . . The mean frequency of intercourse was 8·9 per month, which declined with age and HIV-1 viral load. Members of couples reported similar frequencies of intercourse. The overall unadjusted probability of HIV-1 transmission per coital act was 0·0011 (95% CI 0·0008-0·0015). Transmission probabilities increased from 0·0001 per act at viral loads of less than 1700 copies/mL to 0·0023 per act at 38 500 copies/mL or more (p=0·002), and were 0·0041 with genital ulceration versus 0·0011 without (p=0·02). Transmission probabilities per act did not differ significantly by HIV-1 subtypes A and D, sex, STDs, or symptoms of discharge or dysuria in the HIV-1-positive partner...In 97 couples, the male partner was HIV-1-positive, 17 of whom transmitted the virus to their wives (17.5%). In 77 couples, the woman was the HIV-1-positive partner, 21 of whom transmitted HIV-1 to their husbands (27.3%)...The probability of transmission per act from HIV-1-positive women to their HIV-1-negative male partners was 0.0013, compared with a transmission probability of 0.0009 per act from HIV-1-positive men to HIV-1-negative women [The overall transmission rate is similar to North America, which makes it difficult to understand why the AIDS epidemic in North America is mostly among men]”

“This report describes the field and laboratory investigation of eight patients who had clinical evidence of HIV infection, but repeatedly negative HIV-1 antibody screening results in the course of their clinical care. In all patients, HIV infection was proven [sic] by other diagnostic methods [PCR/viral load, p24 antigen and culture techniques]...Patient 6...became acutely ill after vaccination for measles, mumps and rubella...[she had a] negative HIV EIA on 2 occasions, a positive HIV-1 p24 antigen result, and a positive HIV-1 DNA PCR result. Prior HIV EIA results were negative 2 years, 1 year and 2 weeks before hospitalization...Of her 17 lifetime sexual partners, four were tested at CDC by HIV EIA and HIV-1 DNA PCR; all test results were negative”

“This report describes the field and laboratory investigation of eight patients who had clinical evidence of HIV infection, but repeatedly negative HIV-1 antibody screening results in the course of their clinical care. In all patients, HIV infection was proven [sic] by other diagnostic methods [PCR/viral load, p24 antigen and culture techniques]...Patient 2...HIV EIA result was negative during admission, but HIV infection was identified by HIV p24 antigen testing and DNA PCR...His wife was tested for HIV infection by HIV EIA and DNA PCR; the results of both tests were negative”

“Overall HIV concordance [both man and woman being HIV-positive, given that one of them was] was 45% in the couples. HIV concordance was not found to be related to the sexual practices within the studied unions [anal sex, sex during menstruation, oral sex] nor to the clinical status of the index case [first person identified HIV-positive in the couple] [Major factors were relationship over a year, a history of genital sores and recent cocaine use]”

“The overall seroprevalence amongst the 77 [Ugandan] men tested was 31%, slightly lower than the 51% of 59 women tested…The highest seroprevalence was recorded in the 'high income' women from the trading town, of whom eight out of 11 were HIV-positive”

“85% (336 of 395 cases) [originally reported as heterosexual exposure in Chicago] were reclassified into different transmission categories. Most notably, 69% were reclassified into transmission categories that did not involved heterosexual contact, including NIR [No Identified Risk]. The cumulative percentage of cases attributable to heterosexual contact declined from 8% to 5% as a reult of reclassification. Additionally, reclassification resulted in a reduction of nearly 50% in the number of AIDS cases attributable to heterosexual contact diagnosed in 1993 and 1994.”

“We followed 175 HIV-discordant couples over time, for a total of approximately 282 couple-years of follow-up...The longest duration of follow-up was 12 visits (6 years). We observed no seroconversions after entry into the study...only 75% reported consistent condom use in the 6 months prior to their final follow-up visit. Forty-seven couples who remained in follow-up for 3 months to 6 years used condoms intermittently, and no seroconversions occurred among exposed partners.”

“Between 1986 and 1996 we followed 104 consecutive pregnancies in 92 HIV-negative women with HIV-positive partners…Most of the men were symptom-free, 14 (13%) had HIV-related symptoms and one died of AIDS…21 men were receiving antiretroviral therapy at the time of conception…No seroconversions occurred within the first 3 months following conception. Seroconversion was observed in two women at 7 months of pregnancy and in two others post-partum…Our findings are compatible with seroconversion rates in the order of 1 per 1000 ”

“A highly selected cohort of 24 HIV-1 seronegative subjects with histories of multiple high-risk sexual exposures to HIV-1 were studied. The cohort [included 7] homosexual men who reported sex with multiple HIV-1-infected partners, [5] homosexual men with predominantly a single HIV-1-infected partner, and [13] heterosexual individuals reporting sex predominantly with a single HIV-1-infected partner…Among the individuals reporting exposure to predominantly a single HIV-infected partner, most were in long-term relationships involving unprotected sexual intercourse over many years during which time several partners succumbed to AIDS. All subjects were HIV-1 negative by commercially available enzyme-linked immunsorbent assay (ELISA) tests and by diagnostic polymerase chain reaction (PCR)”

“Among the 435 initially discordant couples [one HIV-positive, the other negative], 121, who did not systematically use condoms for each sexual contact, were followed for a mean of 23.7 months…the estimated number of unprotected sexual contacts per couple ranged from three to 430 (mean 84); 12 (9.9%) of the partners seroconverted: 8/73 (11.0%) female partners and 4/48 (8.3%) male partners…Using the Bernoulli model, estimates of per-contact transmission probabilities…were 0.0005 for male-to-female transmission and 0.0003 for female-to-male transmission…Fitting the simple alternative model to the data at study entry (independently of the sex of the index case), it was estimated that only 17% of the index cases were infectious, but that infectious individuals transmitted infection at the first contact with an uninfected partner. This alternative model fit the data significantly better than did the constant infectivity model.”

“we studied 50 sexually active couples with discordant antibody results, assessing the agreement between these serological results and those obtained by p24 antigen testing, the polymerase chain reaction (PCR), and culture. 49 of 50 seropositive sexual partners were also positive for HIV by PCR; the remaining seropositive partner was positive by culture [no other seropositive partners were tested in this way]. All seronegative partners also had negative results in the other three tests. Moreover, seronegative partners continued to have negative results in all tests for a mean follow-up period of 17 months despite ongoing sexual relations with their seropositive partners. Seronegative infection was not documented in these partners at risk for sexual transmission of HIV. HIV-negative individuals in stable, monogamous sexual relationships with HIV-infected partners apparently do not have a high incidence of infection despite continued sexual exposure…approximately one-half of each group reported some instances of unprotected intercourse…intercourse with outside partners was uncommon in both groups, as was current illicit drug use…All 50 index cases were positive for HIV by EIA and western blot [antibody] testing. All 50 historically negative partners were negative by EIA, and 47 were negative by western blot [the remaining 3 were classified as 'indeterminate']…None of the 50 seronegative partners had p24 antigen in their serum. 22 (44%) of the seropositive partners had detectable p24 antigen.”

“The annual seroconversion rate was 5.7% and 9.7%, respectively, in [the initially seronegative female partner of an HIV-positive man] never or not always using condoms and was reduced to 1.1% in those who always used this device [note the risk is lower in those never using condoms than those ‘not always’ using them]…Women seronegative at the time of inclusion after long-standing relationships (>1 year) with an infected man had 70% less risk of seroconversion…Small and nonsignificant risks were observed among women reporting a higher frequency of sexual intercourse. This result does not agree with what we observed in the cross-sectional part of the study, where women reporting sexual intercourse more than two times weekly had a twofold risk increase. A lack of consistency of the risk of transmission per each single sexual act with an infected person has been noted in other studies…No seroconversion was observed among the 22 women using oral contraceptives [although no reason is given]…[Note that this study did not consider other factors, such as drug use, that may be correlated with frequency of sexual intercourse, immune system health, anal intercourse and type of birth control used]”

“a history of multiple sexual partners was an independent predictor of HIV infection in women. However, about one fifth (21%) of the HIV-infected women in this study had sexual histories that were unremarkable as compared with those of other groups of women in the United States. In 1988 and 1989, surveys of national samples of adults found that the mean number of sexual partners for women was 3.3. In a study of the sexual behavior of college women in 1989, 52% reported having had two to five sexual partners, and 21 percent reported six or more partners. In a study of women attending family-planning clinics in 1987, 13% reported 3 or more sexual partners in the preceding year [and higher levels of sexual partners is sometimes associated with drug use and prostitution, which is associated with race, socio-economic status and so on]”

“41 antibody-negative heterosexual partners of HIV-infected persons were also PCR-negative [i.e. after repeated exposure to HIV, these 41 people persistently remained negative by both antibody and PCR tests]”

“In 85% of these infected couples, only one member was HIV-1 seropositive despite repeated unprotected sex...A correlation between a recent history of having had sex with a prostitute and HIV-1 seropositivity could not be demonstrated in men who did not have a past history of GUD [genito-urinary disease]”

“of >1,600 investigated monogamous sex partners of [HIV]-infected persons in North America and Europe, only about 15% are infected with HIV…this may be an overestimate…since some partners of intravenous drug abusers may share needles with infected mates…90% of 777 infected hemophilic men have not transmitted HIV-1 to their monogamous sexual partners…24 women who had >100 unprotected genital episodes with their transfusion-infected husbands…remained uninfected”

“Between 1984 and 1987, 56 reportedly asymptomatic female sex partners of HIV-infected hemophilic men were enrolled…Category A comprised the 35 women whose male partner had developed AIDS [30/35], AIDS-related complex (ARC), or peripheral generalized lymphadenopathy…At the time of enrollment of the most recent of these women in April 1987, they represented the spouses/steady sex partners of approximately 10% of the hemophilic men with AIDS in the United States. Category B comprised 21 women identified as sex partners of asymptomatic HIV-infected hemophilic men…Of the 35 women in category A…four (11%) were seropositive at initial evaluation…Of the 7 seronegative women retested approximately 1 year later, none had seroconverted. Of the 21 women in category B, one (5%) was seropositive at enrollment. Of the 12…who were re-evaluated, one was reported in 1986 to have seroconverted [10%]…Category A women were similar in age and in several aspects of general sex practices to category B women…28% had partners who used condoms at least ‘sometimes’, only 12% used them ‘nearly always’…[in conclusion] the two groups did not differ significantly with respect to the [sexual] activities”

“In one study, none of the husbands of four seropositive women were infected despite regular sexual contact for as long as three years. In another study involving 12 couples, no transmission from the infected woman to the male partner occurred after more than 100 sexual contacts. Thus, vaginal intercourse may carry a low risk to the insertive partner, as does anal intercourse.”

“Of the 4911 consecutive patients [attending a Baltimore city clinic for sexually transmitted diseases] from whom serum was obtained, 256 (5.2%) were seropositive for HIV…No significant association was found between HIV-antibody status and a history of blood transfusions since 1978, sex with a prostitute, or the number of sexual partners in the previous month.”

“Antibody [to HIV] was found in 2 of 25 husbands [of HIV-positive women] and 10 of 55 wives [of HIV-positive men]. One infected woman had had only a single sexual contact, and another had only eight. Eleven wives [of HIV-positive men] remained uninfected after more than 200 sexual contacts with their infected spouse. Compared with the seronegative wives, the seropositive wives tended to have fewer sexual contacts [!], although the difference was not statistically significant...Condoms were rarely used”

“The total number of exposures to the index case (sexual contacts with ejaculation [with the HIV+ partner]) and the specific practice of anal intercourse, also with the infected partner, were associated with transmission. Neither condom use, total number of sexual partners since 1978, nor lifetime number of sexually transmitted diseases was associated with infection.”

“All 4 HIV seropositive women [wives of hemophliacs] with available data had vaginal intercourse without a condom, but risk of seropositivity did not appear to be affected by the frequency of vaginal intercourse or by hysterectomy.”

“From Oct 15 through 25, 1984, 2400 Mama Yemo Hospital employees were enrolled in [this] study…Seroprevalence was significantly higher among women than among men…[and] was higher among unmmarried persons than among married persons.”

“41 sequential cases of HTLV-III disease (ARC/AIDS) were evaluated…In 15 (37%) of 41 patients…HTLV-II infection appeared to have been heterosexually acquired. This included 10 males and 5 females. Exposure to HTLV-III was confirmed by virus isolation in 11 of these 15 patients, and all 15 patients demonstrated serum antibody to HTLV-III structural proteins by Western blot techniques [omitting the 2 or 3 ELISA tests that are now standard practice to reduce false positives on Western Blots]…HTLV-III was most likely to have been acquired by recurrent heterosexual contact with a sexual partner who was a member of a high-risk group for AIDS in three patients [but the other 12 had no documented contact with an HIV positive person and only 7 of the 15 had AIDS rather than ARC]”

“…despite a high prevalence of asymptomatic clinical and immunologic abnormalities in the hemophiliacs, we found their wives, on average, to be normal with respect to T-cell subsets and other surrogate laboratory markers”

“7 cases of acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC) associated with human T-cell leukemia (lymphotropic) virus (HTLV)-III [HIV] infection were documented in married males whose family members consented to medical evaluation. Five spouses also had evidence of HTLV-III infection documented by isolation of virus and [incorrect, should be 'or'] by detection of serum antibody directed against viral structural proteins [2 of 6 tested had virus 'isolated' and 4 of 7 tested had antibody. 2 were negative by both isolation and antibody testing]. Three of the five HTLV-positive spouses also had clinical evidence of ARC. The remaining four spouses were clinically healthy…[notwithstanding these limitations, the authors claim] These data support the opinion that close household contact to patients with ARC or AIDS is not an efficient mechanism for virus transmission, while demonstrating that HTLV-III can be transmitted by repeated heterosexual contact.”

“65% of [hemophiliac, clotting factor] concentrate recipients had an abnormal T-helper to T-suppressor cell ratio, 40% had a depressed absolute T-helper cell level, and 29% had an elevated absolute T-suppressor cell count. To determine whether horizontal transmission of T-cell subset abnormalities from hemophiliacs to their female sexual partners occurred, we studied 41 spouses. We found no correlation between paired husband and wife values for T-cell ratio or any other immune parameter studied…We conclude that there is no evidence to date for heterosexual or household-contact transmission of T-cell subset abnormalities from hemophiliacs to their spouses in our study population.”

“5 apparently healthy wives of asymptomatic factor-VIII-deficient [hemophiliac] patients who had OKT4/T8 [CD4/CD8] ratios of less than 1 were…studied…All of these women had regular sexual relations with their husbands, and often assisted in administration of their factor VIII concentrate therapy…The lymphocyte proliferative responses of the wives were normal, and their lymphocyte subpopulation ratios, although lower, were not significantly different from control values…[because there was no control group] the abnormalities…could be related to factors other than sexual contact with their hemophiliac husbands”