Although other methods of contraception may provide the same level or better protection against pregnancy, they provide little, if any protection against HIV and STDs. Although spermicides may have activity against gonorrhea and chlamydia and have demonstrated activity against HIV in the laboratory, their use, particularly if frequent, has been associated with an increase in mucosal irritation and even genital ulcers. A recent clinical trial conducted by UNAIDS in Africa and Thailand among sex workers with an average of over three partners per day found significantly increased rates of HIV seroconversion in nonoxynol-9 users as compared to placebo.