San Francisco health officials reported an alarming increase in new syphilis cases last year after years of declines. New syphilis cases rose 55.8 percent in 2008 over the previous year, San Francisco public health officials reported. The increase was significantly lower than the dramatic spikes reported early in the decade, when new infections increased 167 percent from 2001 to 2002. But last year's rise would seem to indicate an increase in unsafe sexual practices, which could lead to a rise in HIV infection rates.