Can pinworms be transmitted through oral sex even though there has not been any anal contact? how much one should wait after taking medication? how long is one contagious after taking medication?

Sexual transmission of pinworms (Enterobius vermicularis) is rare, and only by analingus (oral-anal sex). The risk is only for the oral partner who might be infected and later have develop his or her own rectal pinworm infection. Someone with anal pinworms can transmit sexually only to someone who performs anal sex on him or her. In that situation, best to wait a few days after treatment.