In a sense, all sexually transmitted diseases (STDs) are parasitic, in that whether it’s caused by an insect, virus, bacteria or anything else, these are organisms living off the resources and materials of a host body, in this case a human body.
But as a matter of convention, bacterial STDs (e.g., gonorrhea), viral STDs (e.g., herpes), and fungal STDs (e.g., yeast infections) are given their own categories, with the remainder falling under the category of parasitic STDs.
The most common parasitic STDs are pubic lice (or “crabs”), scabies, and trichomoniasis. Let’s look at each in turn:
1. Pubic lice
Pubic lice are a different species of louse from head lice and body lice, the other two species that attack humans. They most commonly infest the pubic hair, hence the name, though they can be found elsewhere on the body where there is hair, including the eyelashes. They bite, and live off human blood, though they do not burrow inside to become internal parasites, only external.
It is possible to catch pubic lice from inanimate objects such as bedding, towels, or clothing rather than a sex partner, but not easy, as the lice don’t live long off the body.
Pubic lice are so small as to be barely visible without magnification. They are whitish-gray and look like tiny crabs. Their eggs are pearl-colored ovals and are even harder, but not impossible, to see. The skin around an affected area can be red and scaly under the hair or have tiny blue spots marking the louse bites.
The much more noticeable indication of pubic lice, however, is the itching in the genitals (or wherever there is hair that they have infested) which can be severe.
The treatment for pubic lice is to eliminate or make less hospitable their preferred environment by shaving the area completely or combing through it carefully with a fine comb. It is also necessary to treat the area with a topical pesticide, most often permethrin, which is contained in over-the-counter lotions such as Rid and Nix. Contact with any bedding, clothes, etc. that is suspected of containing lice should be avoided for at least 72 hours, or alternately such items should be dry cleaned or cleaned thoroughly in hot water.
Scabies are tiny mites that burrow under the skin to lay eggs. Scabies are spread by direct contact, including sexual, with an infected person. Less often they can be spread through shared use of bedding, clothes, etc., though scabies do not live long off the body.
Scabies can be present not just in the genital area, but elsewhere on the body, including the abdomen, ankles, breasts, buttocks, fingers, thighs, and wrists.
A scabies infestation is marked by itching, which can be especially severe at night. Often a rash develops as an allergic reaction. It’s hard to resist the temptation to scratch, but scratching can cause sores and infection.
The treatment for scabies is a topical pesticide, most often permethrin, which is contained in over-the-counter lotions such as Rid and Nix. Stronger concentrations of permethrin are available by prescription. Because scabies are not limited to one area of the body, the lotion must be applied to the whole body below the neck. Contact with any bedding, clothes, etc. that is suspected of containing lice should be avoided for at least 72 hours, or alternately such items should be dry cleaned or cleaned thoroughly in hot water.
Trichomoniasis is caused by a single-cell protozoa. Transmission is from women, and to men or women.
Men have no symptoms or milder symptoms (discomfort in the penis, pain during urination, discharge). Symptoms for women can include frothy, colored discharge; strong odor; pain during urination; or itching.
A single oral dose of metronidazole is usually sufficient treatment for trichomoniasis. Trichomoniasis is both one of the most common and one of the most curable of STDs.
“Common Sexually Transmitted Diseases (STDs).” 4Parents.gov.
“Parasitic & Fungal Diseases.” About.com.
“Sexually Transmitted Diseases Guide.” STD-gov.org.