A person with open sores in the genital area is much more likely both to contract and to transmit HIV. Chancroid and syphilis are the main bacterial causes of sores: if they are correctly diagnosed and treated, these routes of HIV transmission can be reduced. Genital herpes also facilitates HIV transmission. Genital herpes causes recurrent genital ulcers. An ulcer in the genital area provides an open door, through which HIV can easily pass. Chlamydia, gonorrhoea and trichomoniasis can also facilitate the transmission of HIV although they do not cause sores. This may be due to the fact that genital inflammation associated with these STIs can cause microscopic cuts in genital tissues, creating potential sites where HIV can enter the body.