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Biomedical subjects

A Grulich

Publications and source records attributed to A Grulich.

At least 19 recordsLinked to original sources
PubMed2005

Is there a difference in the efficacy of peripartum antiretroviral regimens in reducing mother-to-child transmission of HIV in Africa?

BACKGROUND: Peripartum antiretroviral regimens have been shown to prevent mother-to-child transmission of HIV (MTCT) in randomized clinical trials; however, direct comparison of published results is impossible given methodological and population differences. OBJECTIVE: To directly compare the efficacy of different antiretroviral regimens in reducing the risk of 6-week MTCT rate in African breastfeeding populations. METHODS: Pooled analysis including all mother-infant pairs from any relevant trial: West African ZDV-placebo trials, Petra ZDV+3TC [two regimens A (pre/intra/post-partum) and B (intra/post-partum), placebo from Uganda and Tanzania], SAINT (NVP and Petra arm B), HIVNET012 (NVP, ultra short ZDV pp) and the Vitamin A trial (as placebo arm in South Africa). Peripartum HIV infection was any positive RNA or DNA polymerase chain reaction test < day 60. The MTCT risk was estimated at 6 weeks for each treatment arm and compared with placebo or single-dose NVP using logistic regression adjusting for maternal CD4 cell count, breastfeeding and birthweight. RESULTS: Overall, 4125 singleton live-births were included; 3629 (88%) were assessed for HIV status at 6 weeks of age. In comparison with placebo, zidovudine + lamivudine (ZDV+3TC) arm A [adjusted odds ratio (AOR), 0.23; P < 0.0001], ZDV+3TC arm B (AOR, 0.49; P < 0.001), antenatal ZDV short (AOR, 0.55; P = 0.006) and nevirapine (NVP) (AOR, 0.60; P = 0.0007) significantly reduced MTCT. In comparison with NVP, only the longest regimen of ZDV+3TC (AOR, 0.39, P < 0.0005) was significantly more effective. CONCLUSION: These results are in line with current World Health Organisation guidelines suggesting equivalence of choice between single-dose NVP and short-course ZDV, and confirm the greater efficacy of ZDV+3TC than with any single antiretroviral drug.

Adult↗
PubMed2005

Occupational exposure to pesticides and risk of non-Hodgkin's lymphoma.

Pesticide exposure may be a risk factor for non-Hodgkin's lymphoma, but it is not certain which types of pesticides are involved. A population-based case-control study was undertaken in 2000-2001 using detailed methods of assessing occupational pesticide exposure. Cases with incident non-Hodgkin's lymphoma in two Australian states (n = 694) and controls (n = 694) were chosen from Australian electoral rolls. Logistic regression was used to estimate the risks of non-Hodgkin's lymphoma associated with exposure to subgroups of pesticides after adjustment for age, sex, ethnic origin, and residence. Approximately 10% of cases and controls had incurred pesticide exposure. Substantial exposure to any pesticide was associated with a trebling of the risk of non-Hodgkin's lymphoma (odds ratio = 3.09, 95% confidence interval: 1.42, 6.70). Subjects with substantial exposure to organochlorines, organophosphates, and "other pesticides" (all other pesticides excluding herbicides) and herbicides other than phenoxy herbicides had similarly increased risks, although the increase was statistically significant only for "other pesticides." None of the exposure metrics (probability, level, frequency, duration, or years of exposure) were associated with non-Hodgkin's lymphoma. Analyses of the major World Health Organization subtypes of non-Hodgkin's lymphoma suggested a stronger effect for follicular lymphoma. These increases in risk of non-Hodgkin's lymphoma with substantial occupational pesticide exposure are consistent with previous work.

Adult↗
PubMed2005

Trends and predictors of HIV-positive community attachment among PLWHA.

Communities most affected by HIV/AIDS have been instrumental in shaping Australia's responses to the threat of the epidemic. There are recent signs that levels of engagement in communities based around HIV-positivity have changed: a diminished sense of an AIDS crisis, the relative success of highly active antiretroviral therapy (HAART), and an increasing individualization of the HIV experience may be contributing to changes in the way HIV-community is experienced. In this paper, we explore levels of engagement in HIV-positive community among a cohort of people living with HIV/AIDS (PLWHA) and seek to explain why some PLWHA engage in an HIV-positive community while others do not. Using multivariate logistic regression, we found that three factors were independently related to feeling part of an HIV-positive community: having been diagnosed with HIV prior to the advent of HAART; having more recently taken Bactrim or Septrin for PCP; and finding it easier to take 'pills' on time. Taken together, these results suggest that both historical effects, such as the introduction of HAART, and effects related to living with HIV, such as the experience of an AIDS-related illness, help explain HIV-positive community engagement among PLWHA.

Acculturation↗
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↗
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

In a minority of gay men, sexual risk practice indicates strategic positioning for perceived risk reduction rather than unbridled sex.

The aim of this analysis was to examine gay men's sexual risk practice to determine patterns of risk management. Ten cross-sectional surveys of gay men were conducted six-monthly from February 1996 to August 2000 at Sydney gay community social, sex-on-premises and sexual health sites (average n = 827). Every February during this period, five identical surveys were conducted at the annual Gay and Lesbian Mardi Gras Fair Day (average n = 1178). Among the minority of men who had unprotected anal intercourse which involved ejaculation inside with a serodiscordant regular partner, there was a clear pattern of sexual positioning. Few regular couples were both receptive and insertive. Most HIV-positive men were receptive and most HIV-negative men were insertive. Among the minority of men who had unprotected anal intercourse which involved ejaculation inside with casual partners, there was also a pattern of sexual positioning. Whereas many casual couples were both receptive and insertive (especially those involving HIV-positive respondents), among the remainder HIV-positive men tended to be receptive and HIV-negative men tended to be insertive. These patterns of HIV-positive/receptive and HIV-negative/insertive suggest strategic risk reduction positionings rather than mere sexual preferences among a minority of gay men. If so, they point not to complacency but to an ever more complex domain of HIV prevention.

Adolescent↗
PubMed2001

Modelling the effect of combination antiretroviral treatments on HIV incidence.

OBJECTIVE: To assess the competing effects on HIV incidence in homosexual men of the decreased infectiousness of men with HIV receiving effective combination antiretroviral treatments and homosexual men engaging in unprotected anal intercourse with increased numbers of partners (levels of unsafe sex). METHODS: A mathematical model of HIV transmission in homosexual men was developed, based on the HIV epidemic in Australia in 1996, when effective antiretroviral treatments first became widely available. Uncertainties in parameters were modelled using 1000 simulations. The effect of treatments on decreasing infectiousness was randomly sampled with a median 10-fold decrease in infectiousness (range 100-fold to no decrease). Levels of unsafe sex were randomly sampled with a median 50% increase in unsafe sex (range 100% to no increase). The percentage change in HIV incidence after one year was obtained by comparison with a null model in which there was no decrease in infectiousness as a result of treatment and no change in unsafe sex. RESULTS: Results of the models suggested that whereas increased levels of unsafe sex were linearly associated with increases in HIV incidence, decreases in infectiousness because of treatments were non-linearly associated with decreases in HIV incidence. An assessment of the competing effects suggested that decreases in infectiousness of two-, five-, and 10-fold would be counterbalanced by increases in unsafe sex of approximately 40, 60 and 70%, respectively. CONCLUSION: These models suggest that apparently large decreases in infectiousness as a result of treatment could be counterbalanced in terms of new HIV infections by much more modest increases in unsafe sex.

Anti-HIV Agents↗
PubMed2001

Gay men's casual sex encounters: discussing HIV and using condoms.

Some gay men disclose their HIV serostatus to enable them to decide to discard condoms in at least some casual encounters. In this paper we consider under what circumstances this occurs. We draw on data from the Sydney Men and Sexual Health cohort study, including both structured and semi-structured interviews. We find that casual sexual encounters among gay men are complex events, involving a broad range of types of partner and circumstance. A significant minority of men disclose their HIV serostatus; 36.3% of those who discussed their serostatus with casual partners engaged in unprotected anal intercourse (UAI) with those partners, while only 9.9% of those who did not discuss their serostatus engaged in UAI with those partners. We also find that disclosure of HIV serostatus, discussion and use of condoms during casual encounters are affected by the particular circumstances of those encounters, including the degree of familiarity between casual partners.

Adult↗
PubMed2001

Increasing realism among gay men in Sydney about HIV treatments: changes in attitudes over time.

It is important to know if optimism about HIV treatments is widespread and whether it is growing. To this end, cross-sectional surveys of gay men were conducted 6-monthly in Sydney between February 1997 and February 1999 (n = 3012). Recruitment was consistent at 4 gay community venues. The participants responded True, False or Unsure to 5 statements about the effectiveness of HIV treatments (2 items), and transmission (2 items) and 'worry' (1 item) in the context of treatments. In terms of effectiveness, HIV-positive men were more likely than non-positive men to dismiss 'cure' (P < 0.05) and more likely to support 'treatments prevent serious illness' (P < 0.001). Uncertainty about effectiveness decreased over time (P < 0.001 for each item). In terms of transmission, HIV-positive men were more likely than non-positive men to reject notions of reduced infectivity (P < 0.001). Over time, there was less uncertainty among non-positive men about undetectable viral load and transmission possibilities (P < 0.001). Overall, HIV-positive men were less 'worried' than non-positive men (P < 0.001) but there were no changes over time. On the whole, gay men in Sydney are now less uncertain about highly active antiretroviral therapies (HAART) than at the time of their introduction. Most men remain sceptical that these treatments can cure HIV infection and prevent HIV transmission, but in regard to managing illness among those infected, some initial uncertainty is being replaced by a growing optimism about the efficacy of treatments.

Adolescent↗
PubMed1998

Solar keratoses: a risk factor for melanoma but negative association with melanocytic naevi.

Solar keratoses have been associated with increased risk of squamous-cell and basal-cell carcinomas, but their association with melanoma is less clear. This study investigated solar keratoses as a risk factor for cutaneous melanoma in Australia, also associations between solar keratoses and other host factors associated with melanoma. A total-body naevus count was made of 258 melanoma cases and 281 controls recruited from New South Wales, Australia, and solar keratoses were counted on the left forearm. Solar elastosis was also assessed by clinical examination on the face and the side of the neck. Solar keratoses were a significant risk factor for melanoma in Australia. The presence of 10 or more solar keratoses on the left forearm (compared with none) was associated with an odds ratio of 4.7 (95% CI, 2.0-10.9). A highly significant association was found between number of solar keratoses and a past history of multiple basal-cell carcinomas in cases and controls respectively. Numbers of common and atypical naevi decreased significantly with age, while solar keratoses were more common in older individuals. Solar keratoses were found more commonly in men than women in cases and in controls (p < 0.0001). A negative association was found between numbers of common naevi and numbers of solar keratoses in cases and controls, and this remained significant after stratifying for age, gender and hair colour (p < 0.0001 and p < 0.0016 respectively). Solar keratoses were more common in males with melanoma on the head and neck as compared with melanoma on any other site. Solar keratoses and naevi were independently predictive of increased melanoma risk. The fact that these 2 phenotypes were found to be negatively associated suggests that susceptibility to melanoma may be expressed via 2 distinct cutaneous phenotypes which may be genetically determined.

Adolescent↗
PubMed1998

The association between naevi and melanoma in populations with different levels of sun exposure: a joint case-control study of melanoma in the UK and Australia.

Two case-control studies were set up to investigate the relationship between melanocytic naevi and risk of melanoma and to compare the naevus phenotype in two countries exposed to greatly different levels of sun exposure and different melanoma rates. In England 117 melanoma cases and 163 controls were recruited from the North-East Thames Region and 183 melanoma cases and 162 controls from New South Wales, Australia. Each subject underwent a whole-body naevus count performed by the same examiner in each country. Relative risks associated with melanocytic naevi in each country were calculated with comparison of naevus data in controls between Australia and England. Atypical naevi were strong risk factors for melanoma in both countries: the odds ratio (OR) for three or more atypical naevi was 4.6 (95% CI 2.0-10.7) in Australia compared with 51.7 (95% CI 6.5-408.4) in England. Common naevi were also significant risk factors in Australia and England with similar odds ratios in the two countries. Prevalence of atypical naevi was greater in Australian controls than in English controls: OR 9.7 (95% CI 1.2-81.7) for three or more atypical naevi in Australia compared with England. For young age groups, the median number of common naevi was greater in Australia than in the UK, whereas for older individuals this difference in naevi number between the two countries disappeared. The prevalence of naevi on non-sun-exposed sites in controls was not significantly different between the two countries. The atypical mole syndrome (AMS) phenotype was more prevalent in Australian controls (6%) than in English controls (2%). The results of this study support the role of sun exposure in the induction of atypical naevi in adults. There was a trend towards stronger risk factors associated with atypical naevi in England compared with Australia. The atypical mole syndrome, usually associated with a genetic susceptibility to melanoma, was more common in Australia than in England, suggesting genetic environmental interactions with the possibility of phenocopies induced by sunlight.

Adolescent↗
PubMed1997

Sexual practices in a broad cross-sectional sample of Sydney gay men.

The aim of this study was to provide current data on the sexual practices in a broad cross-sectional sample of gay and homosexually active men in Sydney. Anonymous, short questionnaires were completed by 1611 gay men recruited at the 1996 Gay and Lesbian Mardi Gras Fair Day or at one of six venues (including two sexual health centres) across the metropolitan area during the following week. The sample was diverse, but the men tended to be of Anglo-Australian background, well educated, professionally employed, attached to gay community and gay identified. They mainly had sex with other men rather than with men and women. Most (86.0 per cent) had been tested for human immunodeficiency virus. Excluding 241 men recruited in sexual health centres, 11.2 per cent were HIV-positive and 73.4 per cent were negative. Where it occurred in regular relationships, unprotected anal intercourse was usually between seroconcordant partners (78.5 per cent). Unprotected anal intercourse between discordant or nonconcordant regular partners was much less common, and in about half the cases involved withdrawal prior to ejaculation exclusively rather than ejaculation inside. Almost 12 per cent of the men had at least 'occasionally' engaged in unprotected anal intercourse with a casual partner in the previous six months, with approximately half of these men having adopted a withdrawal strategy on every occasion. We conclude that short surveys can provide valuable and timely data on sexual practices in a broad cross-sectional sample of gay and homosexually active men. Key messages for those involved in gay men's education are the high rates of unprotected anal intercourse between casual partners and the extensive practice of withdrawal.

Adolescent↗
PubMed1996

Cancer in Rwanda.

Data are presented on the frequency of malignant tumours registered at the population-based cancer registry in the southern prefecture of Butare, Rwanda, from May 1991 until 2 months before the outbreak of civil war in April 1994. Beginning in 1992, subjects were also interviewed about socio-demographic and life-style factors that have been associated with cancer risk in the West. The distribution of cancer in Rwanda is similar to that in other countries in sub-Saharan Africa. The most frequent cancers are those with possible infectious aetiologies: liver cancer (12%), cervical cancer (12%) and stomach cancer (9%). In addition, cancers known to be associated with HIV infection are relatively frequent (Kaposi's sarcoma [6%] and non-Hodgkin's lymphoma [3%]). Chronic infection, including infection with HIV, high parity and multiple sexual partners are important determinants of cancer incidence in this population. Tobacco consumption is low in Rwanda and there are few tobacco-related tumours, such as lung and laryngeal cancer. Other tumours believed to be associated with aspects of Western life-style, such as colorectal and breast cancer, are also relatively infrequent.

Adolescent↗