A surge in syphilis cases has prompted health officials in Cincinnati to issue an alert warning against unsafe sexual behavior and urging people to get tested. They're also concerned that the rise in syphilis cases could contribute to an HIV resurgence. Twelve early-stage cases of syphilis have been reported in Hamilton County so far this year, compared with 21 in all of 2004 and just three the year before. All the new cases involve white men between 20 and 45 who have sex with men. Officials say that while the outbreak appears small, the magnitude of the problem is probably underreported. And they say the spike is worrisome because genital sores caused by syphilis make it easier to transmit and acquire HIV, the virus that causes AIDS.