Trichomoniasis – Diagnosis and Treatment
Sexually transmitted diseases (STDs) are infections that pass from one person to another through sexual contact. Vaginitis is a common type of STD. It is an inflammation or infection of the vagina and can result from bacteria, yeast, or parasites.
A parasite causes trichomoniasis, which is a type of vaginitis. Trichomoniasis is one of the most common STDs. STIs like trichomoniasis can affect anyone who is sexually active.
Understanding the symptoms and risks of these infections is important. Early recognition and treatment protect both your health and your partner’s health.
Diagnosis
Healthcare providers use physical exams and laboratory tests to diagnose trichomoniasis. Symptoms like unusual vaginal or penile discharge, a fishy odor, or signs of irritation may lead to more tests.
A genital exam helps identify these signs and symptoms. Providers examine a sample of vaginal fluid or a urethral swab under a microscope to look for Trichomonas vaginalis.
If they see the parasite, they confirm the diagnosis and usually do not need further testing. If the initial tests do not find the parasite but suspicion remains, providers may use rapid antigen tests or nucleic acid amplification tests.
Providers may also test for other infections with similar symptoms, such as Gardnerella vaginalis. They might check for a high vaginal pH, a positive whiff test, and clue cells.
The table below shows common signs and testing methods:
| Sign or Test | Description |
|---|---|
| Purulent or unusual discharge | Thick yellow-green or grayish fluid |
| Fishy odor | May be detected during exam or testing |
| Whiff test | Detects odor when potassium hydroxide added |
| Microscopy | Identifies parasite in fluid samples |
| Nucleic acid testing | Finds genetic material of the organism |
| Other STI tests | Checks for similar conditions |
Doctors sometimes order extra tests to rule out other conditions with similar symptoms, such as:
- Bacterial vaginosis
- Vulvovaginal candidiasis (yeast infection)
- Atrophic vaginitis
If you are pregnant, your provider may monitor you more closely because trichomoniasis can raise the risk of low birth weight in newborns.
Treatment
Doctors treat trichomoniasis with oral antibiotics that target the infection. These drugs kill the parasite.
There are two main ways to take these antibiotics:
- Single Large Dose: Take a one-time, larger dose of metronidazole, tinidazole, or secnidazole.
- Multiple Smaller Doses: Take lower doses of metronidazole or tinidazole twice daily for seven days.
Take all of the medicine as prescribed, even if you feel better quickly. If you stop the medicine early, the infection can return. Treat all sexual partners at the same time to prevent reinfection.
Avoid sexual activity until you finish the medicine and symptoms disappear. This usually takes about one week after the last dose.
Possible antibiotics used:
| Medicine Name | How It’s Taken | Common Side Effects |
|---|---|---|
| Antibacterial and Antiprotozoal Agents | Oral, single or multiple doses | Nausea, headache, upset stomach, metallic taste |
| Lincosamide Antibiotic | Sometimes intravaginal Irritation | Irritation |
Note: Do not drink alcohol during and for a short time after taking these antibiotics. Alcohol can cause severe nausea and vomiting, especially with metronidazole and tinidazole.
Wait 24 hours after the last dose of metronidazole, 48 hours after secnidazole, and 72 hours after tinidazole before drinking alcohol.
Doctors often do a follow-up test within two weeks to three months after treatment. This ensures that the infection has cleared and checks for reinfection. You can get trichomoniasis again if you are exposed to someone who has it.
Getting Ready for Your Visit
Steps You Can Take
Being prepared helps make the appointment easier. Write down all symptoms, such as itching, burning, or soreness in the vagina, vulva, or penis.
Note when the symptoms began and if they have changed. List any previous infections involving the lower genital tract, like the urethra, cervix, or prostate. Mention if you are pregnant.
Be ready to share how many sexual partners you have had in recent years.
Use the list below to organize your thoughts:
Changes in discharge or odor
Pain during sex (dyspareunia) or urination
Redness or swelling in the genital area
If symptoms affect daily activities
Keep this information in a notebook or on your phone for your appointment.
What the Healthcare Provider Will Do
The provider will ask about your symptoms and may discuss your sexual history. Women usually have a pelvic exam, and the provider collects a small sample of vaginal fluid for testing.
Men may need to provide a urine sample for testing. During the checkup, the doctor looks for signs of irritation in the vagina, vulva, penis, or cervix.
The visit often includes a conversation about safe practices to reduce future risk. For pregnant women, the doctor may talk about how trichomoniasis could affect pregnancy and discuss any extra steps needed.
