Concerning possibility of transfering STDS:
"Its possible, if your partner had infected fluid on his or her hand,
that an STD could be transmitted to your genitals when your partner
masturbated you. However, STDs are not likely to be transmitted
through mutual masturbation, especially HIV. It is much more unlikely
that STDs spread through skin-to-skin contact would be transmitted
"STDs spread by CONTACT (skin-to-skin):
HPV/Genital Warts, Herpes Simplex Virus (HSV), Molluscum Contagiosum,
Chancroid, Syphilis, Crabs/Pubic Lice, Scabies "
"Nonetheless, the chance of spreading any infection merely by hand
contact with the penis is pretty low. In particular, the chance of
spreading HIV is minimal. "
"Rarely, STDs like the virus that causes warts can be transmitted from
genitals-to-hands-to-genitals, but most STDs and HIV are not
transmitted this way"
"Kissing, mutual masturbation and frottage or dry humping are
considered safer-sex activities, with little to no risk of STD
Concening STDs in prostitutes:
"Since the advent of HIV/AIDS, many US states have passed legislation
requiring mandatory HIV testing of hookers convicted of, or in some
cases charged with, prostitution.10 Under a California law requiring
mandatory testing, if a prostitute tests positive, subsequent
prostitution convictions carry three-year sentences, whether the
prostitute practised safe sex or not."
"Early studies suggest that Canadian female prostitutes are no more
likely to be infected with HIV or other sexually transmitted diseases
than other women, unless they are also intravenous drug users."