What is a parasitic STI?
A parasitic STI is a sexually transmitted infection that’s caused by a parasite, rather than bacteria or a virus. A parasite is an organism that lives on or in a host organism (in this case, a human body) and gets its food from or at the expense of its host. Trichomoniasis is the most common parasitic STI, though scabies, lice, and giardia are also common parasitic STIs.
Each of these infections has a different clinical syndrome. Scabies and lice are examples of parasites that are also commonly transmitted through non-sexual contact. Giardia is an example of a parasite that can be spread through unclean food and water, though it can also be spread sexually.
The symptoms and presentation of parasitic STIs vary depending on the parasite and the person affected. Trichomoniasis especially affects younger women, and those affected can often be asymptomatic. When symptoms are present, they may include irritation, itching, and burning in the genital area, as well as painful urination and increased discharge, which may have an unpleasant or fishy odor to it. Men may have no symptoms at all or can have urethral discharge, as well as irritation or burning with urination or ejaculation.
Giardia is more commonly transmitted between men who have sex with men and can cause diarrhea and stomach cramping. Scabies and lice are common in all types of people and can be transmitted through any kind of close contact. Itching is the most prominent symptom of scabies and lice.
In general, parasitic STIs are not too dangerous, though they can be very bothersome and cause uncomfortable symptoms.
There are a number of ways to prevent STIs in general, and you can prevent parasitic STIs with the same approach. It’s important to talk with any potential partners about STIs, choose your partners wisely, and try to limit your number of partners. Be sure to use condoms for barrier protection and use them correctly. If you have any questions about how to use condoms correctly, the CDC website has a great visual tutorial.
While there are no vaccinations for parasitic STIs, there are existing vaccinations for other viral STIs. If you have not been vaccinated for HPV or Hepatitis B, it’s important to talk with your provider about those vaccinations. Lastly, there are pills that you can take to help prevent acquiring HIV if you are at risk.
Parasitic STIs are generally treated with pills or topical medications. For trichomoniasis and giardia specifically, treatment involves medications that can be taken orally.