With Oregon syphilis rates reaching levels not seen in a decade, health workers in the Portland area are urging some men, particularly sexually active gay men, to get tested for the disease up to four times a year. The rise in syphilis cases is primarily among gay men age 35 and older who pick up male sexual partners over the Internet or in adult venues, according to Margaret Lentell of the Multnomah County Health Department. So far this year, the county has recorded 17 cases of recent syphilis infection in men who have sex with men, compared with 18 such cases for all of 2002 and just four in 2001. "Our message is, if you're a man who has sex with men and you're having more than one partner in a three-month period, that you get screened for syphilis every three to six months," Lentell said. She encouraged those who are HIV-positive to get tested every three months.