These STIs are parasites that are passed from person-to-person during sexual activity.

These are the three most common: Trichomoniasis, Pubic Lice and Scabies


Trichomoniasis, or trich (pronounced “trick”), is a common STI caused by single celled protozoan parasite called Trichomonas vaginalis. Women are more vulnerable than men and it is the most common non-viral STI in the world, with an estimated 248 million new cases per year. Trichomoniasis is spread through sexual or genital contact with an infected person. Most patients (70%), especially men, do not show symptoms of a trich infection. Some general symptoms for women may include: discharge from the vagina, vaginal odour, painful urination and irritation or itchiness of the vagina. For men symptoms may include: mild discharge, irritation or redness at the top of the penis, burning during urination.

Trichomoniasis is spread through having anal or vaginal sexual intercourse with an infected person.

Many people, particularly men, will not have symptoms of a trich infection. If symptoms do appear, they usually appear within one week of infection, though they can take up to six months. For some people, symptoms may go away and then return later. About half of women will have symptoms of a trich infection. In men, trichomoniasis is rare and most men will not have symptoms.
For women, symptoms may include:

  • Discharge from the vagina
  • Vaginal odour
  • Pain during intercourse or urination
  • Irritation or itchiness of the vagina

For men symptoms may include:

  • Mild discharge
  • Irritation or redness at the top of the penis
  • Burning sensation during urination
  • Men may often become unknowing carriers of trich infections. Treatment is required to ensure that a trich infection is completely gone

A person can tell if they have trichomoniasis if they know what symptoms to look for, otherwise, testing can be done by a physical examination or lab test to detect the parasite.

In some cases, the tiny sores caused by trichomoniasis may be detected during a routine smear test for women.

Fortunately, trichomoniasis is curable. Patients are orally given a single dose of antibiotic medication (either metronidazole or tinidazole) pills. For 95% of cases, infection is resolved after one dose of metronidazole. The condition can even improve without any treatment in men.
The use of condoms greatly reduces the risk of getting or spreading trichomoniasis. Always keep up your personal hygiene as this parasitic protozoan dies in water. It is important to check in with doctors if any symptoms start to develop.

Pubic Lice

‘Crabs’ or ‘pubic lice’ are tiny lice (like head lice) that live in pubic hair, around the genitals. They measure in at about a millimetre tall, bury their heads into the skin, and live off human blood. They lay their egg sacks (nits) near the base of the pubic hair. A substance they secrete into the skin can cause intense itching, and the bites of adult lice turn small patches of skin to a bluish-grey colour. Fine black particles maybe spotted in the infected person’s underwear. Unlike head lice, pubic lice have small, wide bodies and arms that resemble crabs (hence the nickname). These lice can also be found in chest, armpit and facial hair, eyebrows and eyelashes. ‘Crabs’ or ‘pubic lice’ affect 2% of the world population. Pubic lice can spread during intimate skin-to-skin contact and through sexual intercourse. They can also be transmitted by sharing bedding, towels and clothing belonging to person who has pubic lice.

Pubic lice can spread during close body contact. They do this by crawling from one person to another. Pubic lice can also live for one to two days in bedding, towels and clothing belonging to an infected person, and these items can be a source of transmission. Pubic lice are not related to poor hygiene. Anyone can get lice, though it’s most common among sexually active people and in situations where people are in close contact.

Pubic lice are small and can be difficult to spot. Infected individuals may experience:

  • Skin irritation and inflammation accompanied by itchiness and redness
  • Small blue spots on the skin where lice have bitten
  • Louse feces (poo), which look like tiny black particles in a person’s underwear.

When you go to the doctor, they will inspect the area for the pubic lice and eggs. Adult lice can easily be identified just by looking at the area with a magnifying glass, or viewing a sample of the area under a microscope.

Pubic lice are really easy to treat. You can get the permethrin cream/shampoo without a prescription, over the counter in the pharmacy.

You can lessen your chances of getting pubic lice by improving personal hygiene, washing clothes, especially underwear regularly. Sharing of unwashed clothes and towels should be avoided. Hair removal, e.g. shaving, will not get rid of pubic lice if you have them.


Scabies are parasitic mites that dig holes (burrow) under the surface of the skin and lay eggs. The larvae that hatch move to new areas of the body and spread the infection. Mites prefer warm areas such as the folds of skin on the elbows, wrists, buttocks, knees, shoulder blades, waist, breasts, and penis, between the fingers, and under the nails.

Scabies are spread through close contact with someone who is infected. Scabies can live for three days on clothing, towels and bedding. These can be a source of transmission, but that is much less likely than skin-to-skin contact.

Scabies are not related to poor hygiene. Anyone can get scabies, though it’s most common among sexually active people and in situations where individuals are in close contact.

Within three to four weeks of coming into contact with scabies, an infected person could experience:

  • Intense itchiness, especially at night-time or after bathing. This is caused by an allergic reaction to the mites’ feces
  • Reddish rash on fingers, wrists, armpits, waist, nipples, or penis
  • With reoccurrences, the same symptoms occur more rapidly within hours to days of a re-infestation
  • Severe infections are commonly seen in people with compromised immune systems or HIV. The skin can become scaly or crusty, requiring more complex and aggressive treatment.

Diagnosing scabies can be difficult, but a healthcare professional examines the area to determine if the patient is infected. A sample may be scraped from the skin and analyzed under a microscope if necessary.

  • A special lotion is prescribed by a doctor and applied to the whole body.
  • Some treatments are available without a prescription. Ask your pharmacist.
  • Clothes, towels, bedding and other possible contaminated items should be washed with hot water or dry-cleaned, or bagged for three days to one week. This kills the mites.
  • Items that cannot be cleaned should be vacuumed.