HIV seroconverters: using surveillance to characterise people with incident HIV infection in Victoria, Australia

Comparisons of trends in antiretroviral use and HIV notification rates between three Australian States

OBJECTIVE

Notification rates for HIV among men who have sex with men (MSM) have been increasing, but this increase has not been uniform across States and Territories. This paper aims to determine whether differences in the levels of antiretroviral therapy (ART) were associated with differences in HIV notification rates between Australian States.

METHODS

An ecological analysis of HIV notification and S100 drug prescribing data between 1998 and 2005.

MAIN RESULTS

HIV notification rates in 2005 per 100 individuals living with HIV were lowest in New South Wales (NSW) (4.5) and higher in Victoria (6.9) and Queensland (7.8). The proportion of individuals receiving ART in 2005 was lowest in NSW (40%) and higher in Victoria (60%) and Queensland (60%). There has been a significant decline in the proportion of individuals living with HIV receiving effective ART per year in NSW (p < 0.01) and Queensland (p < 0.01), but an increase in Victoria (p < 0.01).

CONCLUSION

Those States with the highest HIV notifications per 100 individuals living with HIV did not have the lowest proportion of individuals receiving ART.

IMPLICATIONS

These data indicate that the differences in HIV notifications between States do not appear to be due to differences in ART. However, changes in ART over time in some States may be contributing to the rise in HIV notifications.

Risk factors for incident HIV infection in men having sex with men: a case-control study

BACKGROUND

HIV notifications affecting men having sex with men (MSM) in Victoria, Australia have been increasing. This study aimed to determine current risk factors for HIV infection in this population.

METHODS

Case-control study. Cases were MSM infected within the previous year (incident cases) as indicated by a previous negative test or seroconversion illness. Controls were MSM with a negative HIV test at the same clinic. From May 2001 to May 2003, cases and controls were interviewed about sexual behaviour, drug and alcohol use and mental health and sexually transmissible infections (STI) in the year before their HIV diagnosis.

RESULTS

Twenty-six cases and 52 controls were recruited. Risk factors in the year before diagnosis of incident HIV infection included: receptive unprotected anal intercourse (UAI) with ejaculation with casual partners (odds ratio [OR] and 95% confidence interval 57.2 [6.7, 489.4]); insertive UAI with ejaculation with >1 casual partners (OR 19.2 [2.2, 168.9]); having >14 casual partners at sex venues (OR 3.2 [1.1, 9.1]); and consuming >60 g alcohol at one sitting at least weekly (OR 3.6 [1.1, 11.4]). Cases were also more likely to have anal sex with >100 partners in their life and cases had more casual partners than controls in the year before the test. Cases were more likely to have consumed alcohol or amphetamines during a high-risk sexual episode in the year before the test.

CONCLUSIONS

UAI remains the most important behavioural risk for HIV in Australian MSM. Risk is increased by larger numbers of partners, partners met at sex venues and sex under the influence of alcohol.

Risk factors for HIV seroconversion in homosexual men in Australia

BACKGROUND

Rates of newly acquired HIV infection are increasing in Australia, and sexual contact between men accounts for 85% of cases.

OBJECTIVE

To investigate behavioural risk factors for HIV seroconversion among gay and bisexual men from Sydney and Melbourne, Australia.

METHODS

103 men with newly acquired HIV infection were recruited from clinics in Sydney and Melbourne and behavioural risk factor questionnaires were administered between January 2003 and October 2004. Results were compared with a cross sectional and a cohort study performed by our group that enrolled similar populations of men.

RESULTS

The majority of seroconverters (73%) reported more than five sexual partners in the last six months. Ninety-five men (92%) were able to identify a high-risk event (HRE) that they thought had led to their HIV seroconversion. Most (70%) reported receptive unprotected anal intercourse (UAI), insertive UAI, or both at their HRE. Sixteen men (16%) reported no UAI in the preceding six months including the HRE. Men were more likely to report receptive UAI at their HRE when they perceived a partner to be HIV-negative as compared with when they perceived a partner to be HIV-positive (P = 0.05). Injection drug use was reported by 22% of the men in the previous six months, and 62% reported intoxication with alcohol (> or =5 drinks) or mood altering recreational drug use at the HRE.

CONCLUSIONS

Gay and bisexual men who have recently seroconverted are highly sexually active and report high rates of unprotected anal intercourse and recreational drug use at the HRE.