A recent UCSF study found that 1 out of 7 sex workers in San Francisco were threatened with arrest by police officers unless they had sex with them, and 1 out of 5 reported that police officers paid them for sex. Clearly, the policing of sex work is problematic. Spending city resources on education and health outreach to sex workers and linking them to the array of excellent services in our city would be a much more humane and effective way to help sex workers. In addition, those arrests do little: nine cases went to trial last year, but there were no convictions.

The Police Department and district attorney use the presence of condoms as evidence of prostitution or other criminal activity. That is a significant barrier to the routine use of condoms by sex workers, who are increasingly reluctant to carry condoms or keep them at their place of work. In the earlier days of the AIDS epidemic, there was an agreement between then-District Attorney Arlo Smith and the Health Department not to use condoms as such evidence. Obviously, that agreement has been forgotten with potentially dire consequences.

In Austria, Australia, Germany, The Netherlands, New Zealand, Thailand and certain counties in Nevada, where payment for sex is allowed, sex workers are more likely to use condoms and have lower rates of sexually transmitted infections, including HIV.

Where sex work is criminalized, sex workers are much less likely to disclose their occupation when seeing a doctor. Without knowing the occupational risks of a patient, it is hard for doctors to provide good medical care. A senior neurologist at San Francisco General Hospital reminded me that, in addition to reducing sexual health problems, decriminalization could impact the high burden of neurological disease he sees in sex workers: "The initiative could be of great importance to make it easier for sex workers to obtain needed help and to be more able to openly seek the help of authorities without fear of prosecution. Receiving adequate treatment and follow-up is particularly important in the management of epilepsy and removing barriers to their care can only help these patients."

Critics of decriminalization have raised concerns about potential increases in street-based prostitution and decreases in neighborhood quality. A recent evaluation by the Government of New Zealand five years after the national decriminalization of prostitution showed no increases in sex work. Instead, they found actual improvements in neighborhood quality and public attitudes about sex workers, with reduced complaints and decreased crime (links.sfgate.com/ZETF).

The issue of prostitution by minors has also been cited as a reason to continue to criminalize sex work. In the UCSF study, the average age the sex workers began to work as prostitutes was 21. Minors are a small minority of sex workers, and sex between an adult and a minor remains against the law. Outreach to minors and linkages to services would be more effective than arrest and incarceration.

Last, and by no means least, the recognition that sex workers are not criminals has profound human rights implications. At this summer's International AIDS Conference, the Secretary-General of the United Nations, Ban Ki-moon, called for efforts to decriminalize sex work as a means to reduce the vulnerability of workers to HIV infection and violence. With decriminalization, sex workers increase their collective capacity to demand safer working conditions, access legal recourse for employer violations and obtain fair wages.

San Franciscans have always been leaders in the recognition of human rights. The expansion of human rights is closely linked to healthier behaviors and improved public health outcomes. Do your part. Vote yes on Prop. K.

Dr. Jeffrey D. Klausner is president of the California STD Controllers' Association. For more information, visit www.espu-ca.org or www.yesonpropk.org.