Trichomoniasis (Trich): Signs, Causes, Treatment

Trichomoniasis is one of the most common sexually transmitted infections (STIs) in the United States (US). 

STIs are infections that are transmitted through unprotected sex with an infected partner. 

In 2020, WHO estimated 156 million new infections with trichomoniasis, higher than cases of chlamydia, syphilis, and gonorrhea. 

Read on to learn more about trichomoniasis.

What is trichomoniasis (trich)?

Trichomoniasis is an STI caused by the parasitic protozoa T. vaginalis. It is also known as trich, and it is the most common non-viral STI in the United States. 

Trichomoniasis is frequently seen with concomitant STIs such as gonorrhea or other vaginal conditions such as bacterial vaginosis (BV). 

Men and women can get trichomoniasis, but the risk is increased with unprotected sex, having multiple sex partners, or a concomitant STI. 

Is trichomoniasis and chlamydia the same? 

No. Trichomoniasis and chlamydia are not the same, although both of these infections may present with similar symptoms, such as abnormal vaginal discharge, painful urination, and pain during sexual intercourse. 

The table below distinguishes the two different diseases.

	Trichomoniasis	Chlamydia
Caused by	Protozoa (T. vaginalis)	Bacteria (C. trachomatis or C. pneumoniae)
Treatment	Antibiotic and antiprotozoal medication	Antibiotics

How common is trichomoniasis?

Trichomoniasis is the most common non-viral STI in the United States. In terms of prevalence, there are an estimated 156 million new cases worldwide in 2020 alone. 

Trichomoniasis affects about 2.1% of women aged 14 to 59 years old and 0.5% of men aged 15 to 49 years old. 

A recent study also found that trichomonas infection rates in the US are higher than gonorrhea and chlamydia infection rates combined.

Signs and symptoms

The signs and symptoms of trichomoniasis vary in different genders and age groups. Nearly half of the infected women and almost all infected men remain asymptomatic. Thus, if they are not screened, the diagnosis will be missed. 

An asymptomatic person can still infect their sex partner if they engage in unprotected sex. 

When the person is asymptomatic, trichomoniasis can still lead to adverse health outcomes.

Trichomoniasis in Women

Women who show symptoms typically complain of:

• Abnormal vaginal discharge (typically frothy, but can be thick or bloody)
• Yellow or greenish vaginal discharge (color of the discharge may vary)
• Abnormal vaginal odor (commonly a musty odor) 
• Vulvovaginal itchiness, redness, or a burning sensation
• Painful urination 
• Pain during sexual intercourse
• Lower abdominal pain or pelvic pain

Trichomoniasis is also common with a coexisting gonorrheal infection, candidiasis, and bacterial vaginosis. 

The severity of the symptoms depends on the degree of the body’s response to the infection. 

Some of the factors that may influence the host inflammatory responses are:

• Hormonal levels such as high estrogen and progesterone levels
• Abnormal vaginal flora
• Strain and relative concentration of T. vaginalis in the vagina

Trichomoniasis in Men

Men who get trichomoniasis are usually asymptomatic. However, some will develop mild or acute symptoms such as:

• Penile discharge (scanty or thick in nature)
• Painful urination
• Increase in frequency of urination
• Cloudy urine 
• Urethral itchiness 
• Testicular pain
• Lower abdominal pain 

Men with trichomoniasis are more likely to have a much faster natural disease resolution, which means they tend to recover faster. Their symptoms are usually intermittent and self-limiting.

Trichomoniasis in Children

In some cases, children or infants can get trich. Children with trichomoniasis may present with symptoms similar to adults. 

Children exhibiting symptoms of trichomoniasis could be a result of sexual abuse or vertical transmission. 

Vertical transmission can happen, although rarely, when a female infant is exposed to the infected vaginal fluids of her mother during labor. 

Infants who get trichomoniasis from their mothers can remain asymptomatic for a long time.

Female infants with trichomoniasis may have:

• Fever
• Respiratory distress
• Decreased urine output
• Abnormal vaginal discharge during the first week of life
• Seizures

How does trichomoniasis spread?

The parasitic protozoa T. vaginalis causes trichomoniasis. T. vaginalis is transmitted primarily via contact with infected vaginal secretions in women or urethral secretions in men. 

There is a higher risk of getting trichomoniasis in people who are sexually active. 

The incubation period for T. vaginalis in the body is 5 to 28 days. This means that it can take 5 to 28 days from the time of contact to the time of the infection. 

During this period, you should get tested if you suspect you are infected. Many people who are infected do not show symptoms. 

It can take around 6 months for someone previously asymptomatic to start showing symptoms. However, even though you are asymptomatic, you can still spread the infection.

T. vaginalis cannot be transmitted through saliva, such as by kissing or sharing food. However, it can still be transmitted from having oral sex with an infected partner. 

Risk factors for getting trichomoniasis

Several studies have shown that trichomoniasis is more prevalent in:

• People who have unprotected sex with an infected partner
• People who are sexually active or have sex with multiple sex partners
• Women whose age at first sex is young
• Those with a past STI or who currently have an STI
• People who abuse intravenous (IV) drugs
• People who are African-Americans compared to Hispanics or Caucasians

Some of these risk factors can be overcome, such as practicing safe sex. You can use a barrier contraceptive method such as a condom. 

If you suspect that you or your partner are infected, you should abstain from having sex until both of you have completed your treatment and are no longer showing symptoms.

Complications

Studies have shown that if left untreated, trichomoniasis can lead to several complications. Untreated trichomoniasis can increase the risk of women getting:

• Pelvic inflammatory disease (PID) and tubo-ovarian abscess
• Cervicitis or inflammation of the cervix
• Other STIs such as human immunodeficiency virus (HIV), herpes, gonorrhea, chlamydia, and syphilis infections. 
• Ectopic pregnancy, which is a condition when a fertilized egg implants itself outside of the womb 
• Tubal infertility, which is a condition of the fallopian tubes where there is a blockage, thereby not allowing the sperm to fertilize the egg
• Cervical intraepithelial neoplasia (CIN), which is a premalignant condition of the uterine cervix
• Post-hysterectomy infection 

Complications of trichomoniasis in men, if left untreated, include:

• Prostatitis (inflammation of the prostate gland)
• Epididymitis (inflammation of the epididymis at the back of the testicle)
• Urethral strictures
• Infertility

Trichomoniasis during pregnancy

Trichomoniasis during pregnancy is commonly seen in both developing and developed countries. 

Symptoms of trichomoniasis during pregnancy are the same in non-pregnant women, such as vaginal itching and discharge. 

Besides causing discomfort to the pregnant woman, trichomoniasis has been associated with an increased risk of:

• Premature labor and delivery
• Intrauterine infection, which is when the membranes that surround the fetus in the womb are infected 
• Having a baby with a low birth weight
• Congenital infections
• Transmitting trichomoniasis to a female infant during delivery (vertical transmission)

If you are at risk or suspect that you may have trichomoniasis during pregnancy, consult your healthcare provider immediately. 

Your healthcare provider can treat trichomoniasis with a drug called metronidazole. They may also ask that your partner get treated as well. 

The treatment for trichomoniasis usually takes up to a week for the infection to go away. If you are an infected new mother, you should not breastfeed during your treatment. 

When should I see a doctor?

If you develop any of the symptoms of trichomoniasis or think you may be infected, consult your healthcare provider immediately. Trichomoniasis is a curable infection. 

Your healthcare provider can either rule out or diagnose trichomoniasis after conducting some examinations and tests. 

Your healthcare provider will:

• Perform a complete examination of your genitals and pelvis. 
• Take a sample from your vagina or penis to be tested in the laboratory. 

How to test for trichomoniasis?

The Centers for Disease Control and Prevention (CDC) recommends molecular diagnostic tests such as nucleic acid amplification tests (NAATs). NAAT is sensitive and can yield accurate results. 

If the test shows you have trichomoniasis, they will prescribe you an antibiotic and anti-protozoal medication such as metronidazole to treat you. 

It is important that your current sexual partner and any other recent partners are also tested and treated to prevent reinfection in the future.

Treatment

Although having a parasitic protozoon in your body may sound scary, trichomoniasis is curable. 

In the US, the class of medications used to treat trichomoniasis is 5-nitroimidazole medications. These medications are highly effective against trichomoniasis, with an expected cure rate of 95%. 

The Food and Drug Administration (FDA) has approved the following nitroimidazole medications:

• Metronidazole
• Tinidazole
• Secnidazole

The CDC recommended the following drug schedules in the treatment of trichomoniasis:

• A single 2-g dose of oral metronidazole, tinidazole, or secnidazole (usually taken with food)
• 500 mg of oral metronidazole, taken twice daily for 7 days

Some common side effects of these medications are nausea, vomiting, having a metallic taste in your mouth, and diarrhea. 

Studies have shown that topical medications have high failure rates. Hence, topical medications are not recommended. 

If symptoms persist despite medication, you should consult with your healthcare providers. You may require metronidazole susceptibility testing through the CDC.

After completing the course of treatment, it is recommended to get tested again in 3 months. 

Recurrent infections are common in sexually active people, with studies reporting up to 17% reinfection rates at 3-month follow-up visits. 

One of the ways to reduce reinfection rates is through expedited partner therapy. 

What is expedited partner therapy (EPT)?

Expedited partner therapy (EPT) is a means of treating the sexual partners of patients diagnosed with trichomoniasis. 

Many US states permit EPT, which enables healthcare providers to treat your sexual partner without performing a medical examination on them. 

Can I drink alcohol while on treatment for trichomoniasis?

No, you should not consume alcohol while on treatment for trichomoniasis. You should continue to abstain from alcohol for 24 to 72 hours after completing your course of treatment. 

Drinking alcohol while taking drugs like metronidazole and tinidazole can result in a disulfiram-like reaction. 

Some symptoms of a disulfiram-like reaction are excessive sweating, palpitations, facial flushing, nausea, vertigo, and dizziness.

Here are some precautions to undertake until you have completed your treatment for trichomoniasis:

• Abstain from alcohol to prevent an adverse interaction
• Inform your healthcare provider if you develop an allergic reaction to the medication
• Abstain from sex until you and your partner are asymptomatic
• Abstain from breastfeeding until your doctor gives you the clearance

Can trichomoniasis go away on its own?

Unfortunately, trichomoniasis is unlikely to go away without medical treatment. If left untreated, trichomoniasis can progress and cause complications such as adverse health outcomes. 

Trichomoniasis can be treated quickly and effectively. Your healthcare provider can prescribe oral medications to treat the infection. Hence, it is important to seek medical treatment quickly. 

Based on a study, single-dose metronidazole regimens have a 90 to 95% cure rate. Treating trichomoniasis can reduce morbidity and prevent the spreading of the infection to other people.

Prevention

Some of the ways to prevent getting trichomoniasis are by:

• Limiting the number of sex partners 
• Using barrier contraception such as male latex condoms and diaphragms
• Avoid vaginal douching
• Practice safe sex, including communicating with your partner about your concerns and getting tested for STIs

How often should I get tested for STDs?

If you are sexually active, you should get tested for STDs regularly to protect yourself and your partner(s). 

The frequency of STD testing depends on age, sexual orientation, pregnancy status and participation in high-risk activities such as sexual promiscuity and IV drug use. 

Having an open and honest conversation with your sex partner and healthcare provider can facilitate this process. 

All adults and adolescents aged 13 to 64 should be tested at least once for HIV. All sexually active people should get tested for STDs every year. All pregnant women should be tested for syphilis, HIV, hepatitis B, and hepatitis C during the first trimester. 

Anyone who engages in high-risk behaviors should get tested for HIV at least once a year. People who engage in oral or anal sex should consider throat and rectal testing options. 

Conclusion

Trichomoniasis is a ubiquitous STI. It affects both men and women, and can even affect infants and children. 

Signs and symptoms of trichomoniasis depend on gender and age. Many people, especially men who get trichomoniasis, are asymptomatic, while some develop symptoms. 

Women can develop symptoms such as abnormal vaginal discharge and vulvovaginal irritation. Men can develop symptoms like abnormal penile discharge and painful urination. 

Children can also get trichomoniasis from vertical transmission or, in some cases, sexual abuse. Infants with trichomoniasis develop symptoms such as respiratory distress and fever. 

The current recommended treatment for trichomoniasis is metronidazole. If left untreated, trichomoniasis can lead to complications, especially in pregnant women, where it is associated with adverse birth outcomes. 

Preventing trichomoniasis can be as simple as practicing safe sex, limiting sex partners, and getting tested for STDs.

Explore More

What You Should and Shouldn’t Do After Sex.