Biomedical subjects

J Kaldor

Publications and source records attributed to J Kaldor.

At least 19 recordsLinked to original sources

PubMed2005

Risk of cancer after low doses of ionising radiation: retrospective cohort study in 15 countries.

OBJECTIVES: To provide direct estimates of risk of cancer after protracted low doses of ionising radiation and to strengthen the scientific basis of radiation protection standards for environmental, occupational, and medical diagnostic exposures. DESIGN: Multinational retrospective cohort study of cancer mortality. SETTING: Cohorts of workers in the nuclear industry in 15 countries. PARTICIPANTS: 407 391 workers individually monitored for external radiation with a total follow-up of 5.2 million person years. MAIN OUTCOME MEASUREMENTS: Estimates of excess relative risks per sievert (Sv) of radiation dose for mortality from cancers other than leukaemia and from leukaemia excluding chronic lymphocytic leukaemia, the main causes of death considered by radiation protection authorities. RESULTS: The excess relative risk for cancers other than leukaemia was 0.97 per Sv, 95% confidence interval 0.14 to 1.97. Analyses of causes of death related or unrelated to smoking indicate that, although confounding by smoking may be present, it is unlikely to explain all of this increased risk. The excess relative risk for leukaemia excluding chronic lymphocytic leukaemia was 1.93 per Sv (< 0 to 8.47). On the basis of these estimates, 1-2% of deaths from cancer among workers in this cohort may be attributable to radiation. CONCLUSIONS: These estimates, from the largest study of nuclear workers ever conducted, are higher than, but statistically compatible with, the risk estimates used for current radiation protection standards. The results suggest that there is a small excess risk of cancer, even at the low doses and dose rates typically received by nuclear workers in this study.

Dose-Response Relationship, Drug↗

PubMed2005

Contexts for last occasions of unprotected anal intercourse among HIV-negative gay men in Sydney: the health in men cohort.

The objective of the paper was to compare encounters involving unprotected anal intercourse (UAI) and protected anal intercourse (PAI) among HIV-negative gay men in Sydney. Data were from those completing baseline face-to-face interviews to end June 2003 for the Health in Men open cohort of HIV-negative gay men in Sydney. The 1,148 participants ranged in age from 18 to 75 years (median = 36). Three hundred and fifty-two (30.7%) reported an occasion of UAI with a casual partner in the previous 6 months and 531 (46.3%) reported an occasion of UAI with a regular partner in that same time. The men's most recent sexual contact with a casual partner involving UAI was distinguished from those involving PAI by a greater likelihood for both partners to disclose HIV serostatus (p = 0.006) and by respondents being more inclined to restrict themselves to the insertive position or to practise withdrawal during occasions involving any UAI than when a condom was used (p = 0.003 and p = 0.001 respectively). Neither location nor recreational drug use differentiated men's most recent sexual contacts involving UAI from those involving PAI. The decision by HIV-negative gay men to use condoms during sexual encounters with either regular or casual partners is guided more by HIV serostatus and risk reduction strategies than by other factors.

Adolescent↗

PubMed2004

Use of the WHO lymphoma classification in a population-based epidemiological study.

BACKGROUND: Non-Hodgkin's lymphoma (NHL) is pathologically diverse. Epidemiological investigations into its increasing incidence and aetiology require accurate subtype classification. PATIENTS AND METHODS: Available pathology reports of 717 cases aged from 20 to 74 years in an Australian, population-based epidemiological study of NHL were reviewed by one anatomical pathologist to assign a World Health Organization (WHO) classification category. High or low confidence was assigned to the diagnosis of NHL, cell phenotype and WHO category and reasons given for low confidence. RESULTS: The most informative biopsy reports were from open tissue biopsy (79% of cases), tissue core biopsy (8%), cytology (4%) and bone marrow (9%); 8% of cases had inadequate biopsies for diagnostic purposes. Immunohistochemistry or flow cytometry reports were available for 96% of cases, gene rearrangement studies for 6% and cytogenetics for 3%. The reviewer assigned high confidence to the diagnosis of NHL in 93% of cases and also the phenotype in 88%. While a WHO classification could be assigned in 91% of cases, confidence was high in only 57.5%; insufficient immunophenotyping was the commonest reason for low confidence. CONCLUSIONS: Expert pathology review of a population-based sample of NHL can provide a WHO classification category for most cases. A high level of confidence in the classification, however, would require review of diagnostic material and additional phenotyping.

Adult↗

PubMed2004

Prevalence of sexually transmitted diseases and human immunodeficiency virus among women attending prenatal services in Apia, Samoa.

There is no routine prenatal screening for sexually transmitted diseases (STDs) and human immunodeficiency virus (HIV) in pregnancy in Samoa. Testing for chlamydial infection is not available. To gather information on pregnant women, a prevalence survey was conducted in Apia, Samoa, utilizing two prenatal hospital clinics. Pregnant (n=427) women were tested for Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis using polymerase chain reaction (PCR), and for syphilis (n=441) by rapid plasmid reagin (RPR) and HIV (n=441) by enzyme-linked immunosorbent assay (ELISA). Results were: chlamydia 30.9% (132); trichomoniasis 20.8%; gonorrhoea 3.3%; syphilis 0.5%; and HIV 0%. Overall 42.7% had at least 1 STD. Young women aged <25 years were three times more likely to have a STD than older women (odds ratio=3.0, 95% confidence intervals 2.0, 4.5). The lack of inexpensive, reliable field diagnostics remain a barrier to sustainable STD control programmes for pregnant women living in developing countries.

Adolescent↗

PubMed2003

HIV lipodystrophy: prevalence, severity and correlates of risk in Australia.

OBJECTIVE: To establish the prevalence, severity and factors associated with the HIV lipodystrophy syndrome. METHODS: Cross-sectional study of lipodystrophy conducted in high HIV caseload primary care sites and HIV outpatient clinics. A subset of patients was examined using dual energy X-ray absorptiometry (DEXA) and single cut abdominal computerized tomography (CT) at the L4 vertebral level to quantify regional and total body fat. Factors associated with lipodystrophy, lipoatrophy and lipohypertrophy were assessed using multiple logistic regression based on assignment of cases and non-cases. RESULTS: One thousand, three hundred and forty-eight patients (95% male) were surveyed, 20% had AIDS, the mean CD4 lymphocyte count was 486 cells/microL, and 55% had <500 HIV-1 RNA copies/mL. Most participants (87%) had previously received or were currently receiving combination antiretroviral therapy, 73% with at least one protease inhibitor (PI) and 14% a non-PI-containing regimen. Lipodystrophy prevalence was 53% and of these, 55% reported both peripheral lipoatrophy and central lipohypertrophy, 31% experienced peripheral lipoatrophy only and 14% had central lipohypertrophy only. The prevalence of any body habitus change was 62% in PI-experienced patients, 33% in PI-naive patients and 21% in antiretroviral-naive patients. Lipodystrophy severity was less in antiretroviral-naive patients and most severe in PI-experienced patients. Increasing severity of lipodystrophy was both positively and significantly correlated with elevated liver enzymes, decreased testosterone levels, decreased skin-fold thickness, lower levels of total and peripheral fat (DEXA) and higher levels of visceral fat (CT). Lipodystrophy was also significantly associated with increasing age, symptomatic HIV disease, effective viral suppression, and increasing duration of therapy with both nucleoside reverse transcriptase inhibitors and PIs. CONCLUSIONS: The prevalence and severity of lipodystrophy reflects both length and type of treatment with antiretroviral therapy and is associated with decreased testosterone, increases in liver enzymes and greater suppression of HIV RNA. The reports of lipodystrophy in a small percentage of antiretroviral-naive patients suggests that factors other than antiretroviral therapy may be involved in the aetiology of this syndrome or that some conditions, such as wasting or age-associated obesity, may mimic lipoatrophy and lipohypertrophy, respectively.

Absorptiometry, Photon↗

PubMed2003

Seroconversion in context.

This paper describes the accounts that homosexually active men give of their HIV seroconversion and interrogates these accounts for risk discourses. In particular, this paper asks whether the risk discourses of HIV researchers and educators are present in the men's narratives of their own seroconversion. Such discourses make reference to 'unsafe' sex--particularly the practice of unprotected anal intercourse, numbers of sexual partners or 'promiscuity', and the disinhibiting effect of drugs and alcohol. The data are drawn from an ongoing case-series study of seroconversion in which men who had seroconverted were asked to give an account of the occasion on which they believe they were infected. A number of themes were identified in the men's accounts. The men's descriptions of what they believe to be the seroconversion event indicate that their attributions, i.e., the reasons they give for their HIV infection, vary depending on the context. Within regular relationships, breakdown of negotiated safety, love and intimacy, and fatalism were among the explanations given. Seroconversion attributed to casual sexual encounters was more likely to be explained in terms of pleasure, lack of control, and with reference to particular sexual settings. The ways in which men understood their HIV infection were informed both by the risk discourse of HIV researchers and also by the discourses of love and pleasure, as well as that of control.

Adult↗

PubMed2002

Creutzfeldt-Jakob disease in Australia 1970-1999.

OBJECTIVE: To ascertain all persons who developed a transmissible spongiform encephalopathy (TSE) within Australia during the 30-year period 1970 to 1999 through a comprehensive national surveillance program and subject the group to detailed epidemiologic analysis. METHODS: Cases were ascertained through reviews of morbidity separation coding data from all university-affiliated tertiary referral hospitals, as well as the centralized data bases of state and territory health departments, regular national death certificate searches, and semiannual mailout questionnaires to all neurologists and pathologists throughout Australia. Prospective monitoring commenced in September 1993. RESULTS: A total of 387 patients were confirmed as having TSE during this epoch. The majority of cases were sporadic Creutzfeldt-Jakob disease (CJD) (90.7%), with 7.2% heredofamilial and 2.1% iatrogenic. Over this 30-year period, the national average annual sporadic CJD incidence rate per million progressively increased from 0.31 for the decade 1970 through 1979 to 0.77 for 1980 through 1989, reaching 1.03 for 1990 through 1999. Death certificates were found to have a false-positive rate of 11.5% and sensitivity of 83.0% for sporadic CJD. CONCLUSIONS: Within Australia, there has been a gradual increase in the incidence of transmissible spongiform encephalopathy over the three-decade period 1970 through 1999, peaking in 1999 at 1.4/million/year for sporadic Creutzfeldt-Jakob disease. This increase is believed secondary to improved case ascertainment. Variant Creutzfeldt-Jakob disease was not identified during this period. Age- and sex-adjusted comparisons showed a decline in incidence rates in the elderly in both sexes, usually from age 74 years. Death certificates were a useful but imperfect method of case detection.

Adult↗

PubMed2001

Time trends in HIV incidence among homosexually active men seen at sexual health clinics in Australia, 1993-1999.

BACKGROUND: Increases in sexual risk behaviour have recently been reported among homosexually active men in Australia and in other industrialised countries, potentially facilitating an increase in HIV incidence. OBJECTIVE: To monitor HIV incidence among homosexually active men seen through a network of sexual health clinics in Australia. STUDY DESIGN: Selected metropolitan public sexual health clinics provided counts of the number of people seen at the clinics during a calendar year, the number voluntarily tested for HIV antibody and the number newly diagnosed with HIV infection, broken down by sex, age group, HIV exposure category and HIV antibody testing history. HIV incidence was estimated among homosexually active men with a history of a negative test in the 12 months prior to last being seen in a calendar year. RESULTS: Of 23924 men seen at the clinics in 1993-1999 with a reported history of male homosexual contact, 7440 (31.1%) had a negative test in the 12 months prior to last being seen in a calendar year. The percentage of men with a recent negative test declined significantly over time, from more than 33% in 1994-1996 to 29% in 1999 (P=0.003), and with increasing age, from 34.3% among men aged 25-29 years to 27.4% among men aged 40 years or older (P<0.0005). A total of 5346 (71.9%) men were retested for HIV antibody within 12 months of the last negative test. The percentage of men retested declined significantly over time, from 77.8% in 1994 to 67.2% in 1999 (P=0.021) but did not change by age group (P=0.132). Overall, 56 men were newly diagnosed with HIV infection. Estimated HIV incidence was 2.1% in 1993-1999; incidence did not change significantly by year (P=0.498) or age group (P=0.757). CONCLUSION: HIV incidence has remained stable among homosexually active men seen through a network of sexual health clinics in Australia.

Adolescent↗

PubMed2001

February asthma outbreaks in NSW: a case control study.

OBJECTIVES: To investigate individual factors associated with an asthma outbreak among children aged one to 14 years in Sydney in February 1999. METHODS: A case control study was undertaken with cases (n=92) defined as all children admitted to Sydney Children's Hospital for asthma in February 1999. Unmatched controls (n=76) were all children admitted for asthma in the previous three months. We obtained information by a structured telephone survey of parents. Logistic regression analyses were used to determine odds ratios for risk factors for hospital admission. RESULTS: Mean age for hospital admission of 4.7 years for cases and 4.4 years for controls. The presence of one or more siblings reduced the risk of admission during an asthma outbreak (OR=0.59, 95% CI 0.37 to 0.93). Children with older siblings aged 10 to 14 years were also less likely to be admitted (OR=0.3, 95% CI 0.12 to 0.74). An age effect was observed. Other demographic, clinical and environmental characteristics, including smoking, were not associated with admission during the outbreak. CONCLUSIONS: The main findings of this study are the protective effect of siblings and an age-dependent effect in risk of hospital admission during an asthma outbreak. These findings are consistent with an infective cause of the outbreak. IMPLICATIONS: Children without siblings, particularly older siblings, appear to be at highest risk of hospital admission during an asthma outbreak. Environmental and other factors need to be examined to further explain the episodicity of such outbreaks and to determine means of predicting and preventing future episodes.

Adolescent↗

PubMed2001

Incident sexually transmitted infections and their risk factors in an Aboriginal community in Australia: a population based cohort study.

OBJECTIVE: To identify risk factors for incident sexually transmitted infections (STI) in a remote Aboriginal community in Australia. DESIGN: A population based cohort study. SETTING: An Aboriginal community in central Australia. PARTICIPANTS: 1034 Aboriginal people aged 12-40 years, resident in the study region, seen during the period 1 January 1996 to 30 June 1998 for STI diagnosis. MAIN OUTCOME MEASURES: Incident rate of gonorrhoea, chlamydia, and syphilis per 100 person years. RESULTS: There were 313 episodes of incident gonorrhoea, 240 of incident chlamydial infection, and 17 of incident syphilis. For gonorrhoea, risk factors were age, substance abuse, and previous prevalent chlamydial infection with a rate ratio (RR) of 3.2 in people aged 15-19 years, 1.6 in people who abused alcohol, and 3.2 in women who had sniffed petrol on a regular basis. For chlamydia, risk factors were sex, age, and a previous history of STI with a RR of 2.7 in people aged 15-19 years. Similar factors were associated with an increased risk of syphilis but the associations were not statistically significant. CONCLUSION: This study identified objective predictors of incident STI which can be used to target interventions and maximise their impact. The results of this study may well have relevance to indigenous communities in other countries that are faced with high levels of STI and substance abuse.

Adolescent↗

PubMed2001

Syphilis in New South Wales (Australia) prisons.

This paper describes the prevalence of, and risk factors for, exposure to syphilis in a random sample of male and female prisoners. We found that only 2% of male and 1% of female prison inmates in New South Wales (NSW) had confirmed evidence of untreated syphilis, and none appeared to be in an infectious phase. In the multivariate analysis, indigenous ethnicity remained the most potent predictor for confirmed syphilis (either past or present). There was some evidence to suggest that syphilis among indigenous prisoners may be associated with limited access to health services outside prison. The epidemiology of syphilis reflects that of the general community suggesting that prisons could be used as sentinel sites to help evaluate the effectiveness of STD prevention and control strategies.

Adult↗

PubMed2000

Characterization of three nef-defective human immunodeficiency virus type 1 strains associated with long-term nonprogression. Australian Long-Term Nonprogressor Study Group.

Long-term survivors (LTS) of human immunodeficiency virus type 1 (HIV-1) infection provide an opportunity to investigate both viral and host factors that influence the rate of disease progression. We have identified three HIV-1-infected individuals in Australia who have been infected for over 11 years with viruses that contain deletions in the nef and nef-long terminal repeat (nef/LTR) overlap regions. These viruses differ from each other and from other nef-defective strains of HIV-1 previously identified in Australia. One individual, LTS 3, is infected with a virus containing a nef gene with a deletion of 29 bp from the nef/LTR overlap region, resulting in a truncated Nef open reading frame. In addition to the Nef defect, only viruses containing truncated Vif open reading frames of 37 or 69 amino acids could be detected in peripheral blood mononuclear cells isolated from this patient. LTS 3 had a viral load of less than 20 copies of RNA/ml of plasma. The other two long-term survivors, LTS 9 and LTS 11, had loads of less than 200 copies of RNA/ml of plasma and are infected with viruses with larger deletions in both the nef alone and nef/LTR overlap regions. These viruses contain wild-type vif, vpu, and vpr accessory genes. All three strains of virus had envelope sequences characteristic of macrophagetropic viruses. These findings further indicate the reduced pathogenic potential of nef-defective viruses.

Amino Acid Sequence↗

PubMed2000

Herpes simplex virus type 2 in prisoners, New South Wales, Australia.

Our objectives were to determine the prevalence of, and risk factors for, herpes simplex virus type 2 (HSV-2) antibodies in male and female prisoners. A cross-sectional random sample was used consisting of 789 prisoners (657 males and 132 females) from 27 correctional centres across New South Wales (NSW), stratified by sex, age and Aboriginality. Participants were questioned about demographics and behavioural risk factors and were screened for serum antibody to HSV-2. The overall prevalence of HSV-2 antibodies was higher in females (58%) than males (21%), and in Aborigines (34%) compared with non-Aborigines (24%). HSV-2 prevalence increased with the number of sexual partners. Few prisoners (1%) reported a previous diagnosis of genital herpes. Independent risk factors for the presence of HSV-2 antibodies were increasing age and Aboriginality for men, and higher reported number of lifetime sexual partners and the presence of hepatitis C antibodies for women. HSV-2 infection is common in prison inmates. There is a need to incorporate information about STDs, including HSV-2, into education programmes for inmates.

Adult↗

PubMed1999

Investigation of a cluster of leukaemia in the Illawarra region of New South Wales, 1989-1996.

OBJECTIVES: To investigate a cluster of leukaemia among young people and assess the plausibility of a disease-exposure relationship. DESIGN: Descriptive analysis of population-based leukaemia incidence data, review of evidence related to the causation of leukaemia, assessment of environmental exposures to known leukaemogens, and resulting risks of leukaemia. SETTING: Illawarra region of New South Wales, Australia, focusing on suburbs between the Port Kembla industrial complex and Lake Illawarra (the Warrawong area). MAIN OUTCOME MEASURES: Standardised incidence ratios (SIRs) for leukaemia; current measured and past estimated ambient air benzene concentrations; and expected leukaemia cases attributable to estimates of ambient air benzene concentrations. RESULTS: In 1989-1996, 12 leukaemia cases among Warrawong residents aged less than 50 years were observed, more than the 3.49 cases expected from the rate in the rest of the Illawarra region (SIR, 343.8; 99% CI, 141.6-691.7). These people lived in suburbs immediately to the south-southwest of a coke byproducts plant (a major industrial source of benzene, one of the few known leukaemogens). The greatest excess was among 15-24-year-olds (SIR, 1085.6; 99% CI, 234.1-3072.4). In 1996, ambient air concentrations of benzene averaged less than 1 part per billion (ppb). Since 1970, ambient air concentrations of benzene were estimated to have averaged up to 3 ppb, about one-thousandth of the level at which leukaemia risk has been identified in occupational epidemiological studies. Using the risk assessment model developed by the US Environmental Protection Agency, we estimate that past benzene levels in the Warrawong area could have resulted in 0.4 additional cases of leukaemia in 1989-1996. CONCLUSIONS: The excess occurrence of leukaemia in the Warrawong area in 1989-1996 is highly unusual. Current environmental benzene exposure and the reconstructed past environmental benzene exposure level are too low to explain the large excess of leukaemia. The cause of the cluster is uncertain.

Adolescent↗

PubMed1999

Surgical treatment and risk of sporadic Creutzfeldt-Jakob disease: a case-control study.

BACKGROUND: Apart from the small number of iatrogenic and familial cases, the cause of most cases of Creutzfeldt-Jakob disease (CJD) is not known. We aimed to identify risk factors for sporadic CJD. METHODS: In a case-control study, we compared the medical history and selected demographic characteristics of 241 definite (neuropathologically confirmed) and probable (clinically likely) patients with CJD, ascertained from the Australian National Creutzfeldt-Jakob Disease Registry between Jan 1, 1970, and October 31, 1997, and of 784 controls, recruited from the community by random telephone interview in August, 1997. Standard logistic regression was used for the comparisons. FINDINGS: Surgical procedures were significantly associated with the development of sporadic CJD. This risk progressively increased with the number of surgical treatments to a maximum for three procedures (odds ratio 2.13 [95% Cl 1.34-3.41], p=0.002). There was also a significant association between risk of CJD and residence or employment on a farm (p<0.001) or market garden (p=0.002) for longer than 10 years. We found no significant risk associated with a history of blood transfusion, organ transplantation, major dental work, or occupation. INTERPRETATION: Our findings accord with the hypothesis that a range of surgical treatments may serve as unrecognised contamination events and account for a proportion of cases of sporadic CJD. Possible biases in different methods and times for the acquisition of data on cases and controls suggest our findings need to be replicated in independent studies with community controls.

Adolescent↗

PubMed1999

Seroprevalence of markers for hepatitis B, C and G in male and female prisoners--NSW, 1996.

OBJECTIVES: 1. Establish the prevalence of markers for hepatitis B (HBV), C (HCV) and G (HGV) in a sample of male and female inmates. 2. Examine exposure to multiple viruses. 3. Compare risk factors for HGV infection with known risk factors for HBV and HCV. DESIGN: Cross-sectional random sample stratified by sex, age and Aboriginality. Inmates were screened for three hepatitis markers. Participants were 789 inmates (657 male, 132 female) in 27 correctional centres in New South Wales, 1996. RESULTS: Overall detection of each of the three screening markers was 35% for HBV, 39% for HCV and 10% for HGV. Exposure rates were higher in female prisoners than males. Increased rates of anti-HBc were observed in Aboriginal inmates compared with non-Aboriginals (54% cf. 27%); anti-HCV and HGV-RNA were comparable between the two groups (36% cf. 41% and 9% cf. 10%). Markers were significantly higher in female injecting drug users (IDU), particularly HCV (90% cf. 66%). Thirty-five per cent of inmates were unaware of their HCV status. For HBV, 72% did not self-report past or present exposure despite serological evidence to the contrary. The multivariate analysis identified Aboriginality, long-term injecting and injecting while in prison as risk factors for HBV. HCV risk factors were female sex, non-Aboriginality, institutionalisation and IDU-associated behaviours. For HGV, female sex and previous imprisonment were significant risk factors but IDU was not. CONCLUSIONS: Blood-borne hepatitis viruses are common in prison inmates, particularly females (HBV, HCV and HGV), Aboriginals (HBV) and IDU (HBV and HCV). Infection can be related to a number of risk factors, which appear similar for HBV and HCV, but distinct from HGV.

Adolescent↗

PubMed1999

Serum antibody response to Cryptococcus neoformans in cats, dogs and koalas with and without active infection.

Anti-cryptococcal antibodies were measured in normal cats, dogs, horses and koalas, and cats, dogs and koalas with cryptococcosis using an enzyme immunoassay. Antibody levels were expressed as absorbance readings. Over 80% of cats and dogs with cryptococcal infection had elevated antibody levels at the time of diagnosis, during or after successful therapy. Antibody levels in these patients either remained elevated or declined slowly after treatment. For cats, anti-cryptococcal antibody levels were higher in C. neoformans var. gattii than var. neoformans infections, and lower in mild than in moderate or severe infections. The persistence of increased anti-cryptococcal antibody levels in over half of the feline and canine cases following active infection suggested the use of antibody determinations as a seroepidemiologic marker of previous infection. Consequently, antibody measurements from 'normal' animals indicated a prevalence of previous cryptococcal infection of 10% in cats and dogs, compared with 3% in horses and 5% in koalas. Preliminary studies of young animals suggested that anti-cryptococcal antibody levels were substantially lower in the young cats but not the young dogs surveyed, compared with their mature counterparts. The cut-offs used in the present work may thus be erroneously high, with a corresponding underestimation of the prevalence of inapparent cryptococcosis.

Aging↗

PubMed1998

Cultures of sexual adventurism as markers of HIV seroconversion: a case control study in a cohort of Sydney gay men.

A case control analysis within an ongoing cohort study was used to examine differences between seroconverters and men who remained HIV-negative. The cases were interviewed within one to 13 months prior to their seroconversion. Their responses to a structured questionnaire were compared with those of HIV-negative controls drawn from the same time period and from the same longitudinal study, Sydney Men and Sexual Health. Data collected from both cases and controls included: demographic and contextual variables, knowledge of HIV transmission, sexual practices, drug and alcohol use and attitudinal factors. The aim was to compare the sexual behaviours, and the social and cultural contexts of such behaviours, of men prior to their HIV seroconversion with men who did not seroconvert. Twenty-three men had seroconverted within the cohort. Cases were identified by a positive HIV antibody test or self-report of positive HIV status following a previous negative HIV test. Three-hundred-and-sixty-nine controls were selected on the basis of being HIV negative at interview in 1994, and having at least one subsequent medically-confirmed negative HIV antibody test. Univariate predictors of seroconversion were: being in a regular relationship with a known HIV-positive partner, drug use, and engaging in a range of anal and esoteric sexual practices. Practices commonly used to enhance sexual pleasure, such as group sex, watching and being watched having sex, the use of sex toys and dressing up/fantasy, were engaged in more frequently by seroconverters. Engaging in these esoteric sexual practices was highly correlated with drug use, involvement in the gay community and engagement in a wide range of anal practices. In the multivariate analysis independent predictors of seroconversion were: younger age; being in a regular relationship with a known HIV-positive partner; believing withdrawal to be safe with regard to HIV transmission; and range of esoteric practices. These results indicate the importance of the social and cultural contexts of particular sexual practices and consequent HIV transmission. Sexually adventurous men may be at increased risk for HIV because they seek sex within particular sexual sub-cultures.

Adult↗