Receptive and insertive anal intercourse without consistent use of prophylactics have been identified as the major homosexual routes of transmission for HIV. This knowledge and the consequent need for either abstinence or prophylactic usage have been widely disseminated in Auckland. The concept of "at-risk behavior," while central to safer sex education, is not the sole determinant of risk from HIV, however. In statistical terms, the probability of HIV transmission in a community is determined by at least three factors: prevalence of infection in the community, prevalence of transmission behaviors (that is, frequency of at-risk behavior), and the probability of a particular at-risk behavior transmitting the virus. At an individual level co-determinants include the HIV antibody status of one's partner(s), the amount of virus, possibly the frequency of exposure to the virus, and possibly the degree of trauma caused by that behavior.
The study also showed a number of men unable or unwilling to modify behavior known to be at high risk of transmitting the virus. Given that 98.6% of the sample had heard of safer sex, clearly this is not simply the result of lack of information. Of the thirty respondents engaging in sexual activity at high risk of transmitting HIV (that is, anal intercourse, never using condoms), eight respondents engaging in receptive anal intercourse and ten respondents engaging in insertive anal intercourse reported having multiple partners. While these numbers appear small, they are far from unimportant. In a low-incidence area for HIV, a small group of people having a great deal of unsafe sex with a large number of partners, combined with intermittent condom usage by a sizable group, may lead to more spread of the virus than a large number of people engaging in unsafe sex with a small number of partners.39 The targeting of programs for this sub-group to promote, motivate, and sustain behavior change would appear to be vital if HIV transmission in homosexual and bisexual males is to be halted.
This finding concurs with Ross and Herbert's [ 1987] results:
What is now needed urgently is a second-generation educational programme which is research-based and utilizes empirical data to motivate and promote behavioral changes. . . . Further expenditure on education alone without an adequate research base cannot reach a significantly greater number of individuals (at least not homosexually-active men who frequent homosexual meeting places). [p. 280].