Alarm bells are ringing in New Zealand following studies in America and Britain that show high numbers of young men with HIV unaware they were infected with the disease. The New Zealand AIDS Foundation says it's a warning to New Zealand men not to assume anything about the HIV status of their sexual partners. Three-quarters of the HIV+ men in the American study were unaware they were infected, while in Britain the figure was one-third. Half of the infected-unaware men in the American study had unprotected anal sex in the previous six months, with half of these men not using condoms because they either "knew" they were negative; "knew" their partners were negative; or they thought their partners were at low risk of being positive. Nearly three-quarters had previously tested HIV-negative, and close to two-thirds perceived themselves to be at low-risk for HIV infection. NZAF senior researcher Peter Saxton says men in New Zealand are making similar assumptions. "One third of MSM in the Gay Auckland Periodic Sex Survey reported they still believed they were "definitely" HIV negative, even though they had had at least one instance of unprotected anal intercourse since their last HIV negative test," he says. "What these studies show is that some sexual partners simply will not know they are HIV positive, even those who have previously tested negative."