Online Dermatologist > Bacterial Vaginosis (BV) vs Trichomoniasis: Which Is It?

Bacterial Vaginosis (BV) vs Trichomoniasis: Which Is It?

by | Mar 8, 2024 | Blog, Sexual Health

discharge of white fluid - bv or tricho

Key Takeaways


  • Differentiating Symptoms: BV typically presents with a fishy odor and grayish discharge, whereas Trichomoniasis features frothy, greenish-yellow discharge and genital irritation.
  • Diagnosis is Crucial: Accurate diagnosis through medical evaluation is key, as treatments for BV and Trichomoniasis differ significantly.
  • Prevention Measures: Practicing safe sex and avoiding douching can help prevent both BV and Trichomoniasis.
  • Health Impacts: Untreated BV and Trichomoniasis can lead to serious reproductive health issues, emphasizing the need for timely treatment.

Trichomoniasis is a sexually transmitted disease (STD) that is often confused with Bacterial Vaginosis (BV), a condition that affects the vaginal flora. Accurate diagnosis and treatment are crucial for both conditions, as they can have different impacts on health and well-being.

BV is characterized by an imbalance in the normal vaginal bacteria, leading to symptoms such as discharge, itching, and burning during urination. However, it is essential to distinguish BV from Trichomoniasis, as the latter is caused by the Trichomonas vaginalis parasite and is transmitted through sexual contact.

Bacterial Vaginosis (BV) Overview

Bacterial Vaginosis (BV) is a common vaginal infection characterized by an imbalance in the normal bacteria that reside in the vagina. This condition is not considered a sexually transmitted infection (STI) but can be influenced by sexual activity.

Causes of Bacterial Vaginosis:

  • BV occurs when the normal balance of bacteria in the vagina is disrupted, leading to an overgrowth of harmful bacteria such as Gardnerella vaginalis.[1]
  • Multiple factors contribute to this imbalance, including sexual activity, douching, or changes in hormonal levels.



  • Bacterial Vaginosis is one of the most common vaginal infections among women of reproductive age.
  • While Studies suggest that approximately 29% of women in the United States aged 14-49 have BV at any given time.[2] The prevalence may vary across different populations and regions.


Symptoms of Bacterial Vaginosis:

  • Vaginal Discharge: One of the hallmark symptoms of BV is an abnormal vaginal discharge that is often described as  thin grayish-white, with a distinct, fishy odor.[3]
  • Itching or Irritation: Some women may experience mild itching or irritation in the genital area.
  • Burning Sensation: A burning sensation during urination may occur in some cases.


Trichomoniasis Overview

Trichomoniasis is a common sexually transmitted infection caused by the Trichomonas vaginalis parasite.[4] This protozoan parasite primarily affects the urogenital tract, leading to various symptoms in both men and women. Understanding how Trichomoniasis is transmitted and its prevalence is essential for effective management and treatment.

Causative Agent and Transmission:

  • Trichomoniasis is primarily caused by the single-celled parasite Trichomonas vaginalis.
  • The infection is predominantly transmitted through sexual contact, including vaginal intercourse.



  • Trichomoniasis is a prevalent STI, with millions of new cases reported globally each year.According to the Centers for Disease Control and Prevention (CDC), an estimated 3.7 million people in the United States are infected with Trichomoniasis and most do not have any signs or symptoms.[5]
  • Women are more commonly affected than men, and the prevalence varies across different demographic groups and geographic regions.


Symptoms of Trichomoniasis:

  • Vaginal Discharge: Trichomoniasis often presents with a frothy, greenish-yellow or gray vaginal discharge. Unlike the typical odor associated with BV, the discharge in Trichomoniasis may have a distinct, unpleasant smell.
  • Genital Itching and Redness: Some women may experience itching and redness in the genital area.[6]
  • Discomfort During Intercourse: Pain or discomfort during sexual intercourse is a possible symptom.
  • Urinary Symptoms: Trichomoniasis may cause discomfort or a burning sensation during urination.


Comparison: Bacterial Vaginosis (BV) and Trichomoniasis

Characteristic/ Condition

Bacterial Vaginosis (BV)


Discharge Characteristics

  • Grayish-white discharge
  •  Fishy odor
  • Varying texture
  • Frothy, greenish, or yellow discharge
  • Strong, foul odor
  • Distinct texture

Physical Symptoms

  • Genital itching
  • Redness
  • Discomfort during intercourse
  • Pain or burning sensation during urination
  • Genital itching
  • Redness
  • Discomfort during intercourse
  • Pain or burning sensation during urination

Causative Agent

  • Bacterial overgrowth (multiple species) such as Gardnerella vaginalis
  • Imbalance in vaginal flora
  • Protozoan parasite Trichomonas vaginalis


  • Not considered a sexually transmitted infection (STI).
  • Predominantly through sexual contact


  • Common among women of reproductive age
  • Approximately 30% of women in the United States may experience BV at some point
  • Global prevalence with millions of new cases each year.
  • Women more commonly affected than men.

Vaginal pH

  • Often associated with higher pH levels
  • Elevated pH (>4.5)
  • May cause lower or more acidic pH
  • Elevated pH (>4.5)

Microscopic Examination

  • Characteristic bacterial overgrowth observed (Clue cells present in discharge.)
  • Presence of motile Trichomonas parasite under the microscope

Additional Symptoms

  • May be asymptomatic in some cases
  • Often presents with more noticeable symptoms


  • Increased risk of preterm birth, pelvic inflammatory disease (PID) and STIs.
  • Increased risk of HIV transmission and other STIs.

Risk Factors

  • Douching, new sexual partners, smoking, lack of condom use.
  • Multiple sexual partners, lack of condom use, history of STIs.

Duration of Symptoms

  • Can be chronic or recurrent if untreated.
  • Duration of symptoms may differ between individuals

Associations with Pregnancy

– Linked to preterm birth and low birth weight babies.

– Can increase the risk of preterm delivery and low birth weight infants.

Diagnostic Tests

  • Clinical evaluation, pH testing, microscopic examination of discharge.
  • Wet mount microscopy, culture tests, nucleic acid amplification tests (NAATs).

Response to Antibiotics

  • Typically responds well to antibiotics like metronidazole or clindamycin.
  • Treated with antibiotics like metronidazole or tinidazole; partner treatment is essential to prevent reinfection.

Recurrence Rates

  • Recurrence is common after treatment; around 30% within 3 months.
  • Recurrence rates can be high; reinfection is possible if both partners are not treated simultaneously.


The Impact on Health and Well-being from Bacterial Vaginosis (BV) vs. Trichomoniasis


Potential Risks of Untreated Bacterial Vaginosis (BV)


Psychological Effects:

  • Recurrent BV can negatively impact women’s social, personal, and work relationships, affecting their quality of life.
  • Symptoms of BV, such as vaginal malodor and abnormal discharge, can cause embarrassment, shame, and anxiety in affected individuals.


Complications in Pregnancy [7]

  • BV is associated with adverse birth outcomes like preterm delivery and low birth weight.
  • Untreated BV can lead to an increased risk of acquiring HIV and other sexually transmitted infections (STIs).

Further reading: Does Bacterial Vaginosis (BV) increase the risk of getting an STD?


Potential Risks of Untreated Trichomoniasis:


Psychological Effects:

  • Trichomoniasis may cause vaginitis and cervicitis in women, leading to emotional distress.
  • Symptoms of trichomoniasis can impact self-esteem and sexual relationships due to embarrassment and concerns about malodor.


Complications in Pregnancy:

  • Pregnant individuals with trichomoniasis have a higher risk of premature birth or low birth weight babies.
  • Trichomoniasis increases the risk of acquiring other STIs and HIV, posing additional health concerns.


Prevention Strategies for Bacterial Vaginosis (BV) and Trichomoniasis

Preventing Bacterial Vaginosis (BV) and Trichomoniasis involves adopting a combination of safe sex practices and maintaining regular medical check-ups. Here are concise tips for preventing these vaginal infections


Safe Sex Practices:

  • Consistent Condom Use: Consistently using condoms during sexual intercourse helps reduce the risk of both BV and Trichomoniasis. Condoms act as a barrier, preventing the transmission of infections between partners.
  • Limiting Sexual Partners: Limiting the number of sexual partners reduces exposure to potential sources of infection. A monogamous relationship can lower the risk of contracting BV or Trichomoniasis.


Hygiene Habits

  • Avoiding Douching: Douching disrupts the natural balance of bacteria in the vagina and increases the risk of BV. Avoiding douching helps maintain a healthy vaginal environment.
  • Gentle Cleaning: Practice gentle and regular cleaning of the genital area. Harsh soaps and hygiene products can irritate the vagina, potentially contributing to infections.


Regular Medical Check-ups

  • Routine Gynecological Exams: Regular visits to a healthcare provider for routine gynecological exams enable early detection and prompt treatment of infections. These exams allow for monitoring and addressing changes in vaginal health.
  • Screening for STIs: For individuals at risk of STIs, including Trichomoniasis, routine screenings are crucial. Early detection allows for timely intervention and prevention of complications.


Communication with Partners

  • Open Communication: Open communication with sexual partners about sexual health is essential. Discussing STI testing, sharing concerns, and ensuring mutual commitment to preventive measures contribute to a healthier sexual relationship.


Personal Health Practices:

  • Maintaining Overall Health: A healthy lifestyle, including a balanced diet, regular exercise, and adequate sleep, supports a robust immune system. A strong immune system is better equipped to resist and combat infections.

When to See a Doctor


Recognizing Symptoms that Warrant Professional Evaluation

  • Unusual vaginal discharge with a strong fishy smell, especially after sex.
  • Changes in the color and consistency of vaginal discharge, such as becoming greyish-white and thin.
  • Persistent itching, irritation, or discomfort in the genital area.
  • Burning sensation during urination.
  • Redness or soreness in the genital region.
  • Any unusual symptoms that cause concern or discomfort.


Importance of Accurate Diagnosis

  • Seeking medical attention promptly if you suspect Bacterial Vaginosis (BV) or Trichomoniasis is crucial for accurate diagnosis and appropriate treatment.
  • Healthcare providers, such as GPs or sexual health clinics, can perform internal examinations, pH measurements, and microscopic examinations to confirm the condition and rule out other infections.
  • Timely diagnosis is essential to prevent complications, especially during pregnancy, as untreated infections can lead to adverse birth outcomes.
  • Regular medical check-ups and screenings for sexually transmitted infections (STIs) are recommended to maintain reproductive health and overall well-being.


FAQ: About Bacterial Vaginosis and Trichomoniasis

Q: What is the difference between BV and Trichomoniasis?
A: BV is caused by an imbalance of bacteria in the vagina, while Trichomoniasis is caused by a parasite. BV is not considered an STI, while Trichomoniasis is a sexually transmitted infection.


Q: Can BV be treated during pregnancy?
A: Yes, BV can be treated during pregnancy with appropriate antibiotics.


Q: Can Trichomoniasis be asymptomatic?
A: Yes, about 70% of individuals infected with Trichomoniasis may not show any signs or symptoms. However, they can still pass on the infection to others.


Q: Can Trichomoniasis be transmitted through non-sexual contact?
A: Trichomoniasis is primarily spread through sexual contact without using a condom. It is not thought to be transmitted through kissing, hugging, sharing cups, plates, or toilet seats.


Q: What should I do if I suspect I have Trichomoniasis?
A: If you suspect you have Trichomoniasis or experience symptoms, it is important to see a healthcare provider for diagnosis and treatment promptly. Informing your current and recent sexual partners for testing and treatment is also crucial to prevent reinfection.

  1. Catlin BW. Gardnerella vaginalis: characteristics, clinical considerations, and controversies. Clinical Microbiology Reviews. 1992;5(3):213-237. doi:
  2. Koumans EH, Sternberg M, Bruce C, et al. The Prevalence of Bacterial Vaginosis in the United States, 2001–2004; Associations With Symptoms, Sexual Behaviors, and Reproductive Health. Sexually Transmitted Diseases. 2007;34(11):864-869. doi:
  3. Falconi-McCahill A. Bacterial Vaginosis: A Clinical Update with a Focus on Complementary and Alternative Therapies. Journal of Midwifery & Women’s Health. 2019;64(5):578-591. doi:
  4. Trichomonas vaginalis: Clinical relevance, pathogenicity and diagnosis T. Edwards, Patricia A. Burke, H. Smalley + 1 more authors 10 Nov 2014 – Google Search. Published 2014. Accessed March 2, 2024.
  5. Neglected Parasitic Infections in the United States Center for Global Health Division of Parasitic Diseases.
  6. F Y. Dealing with trichomoniasis. The journal of family health care. 2015;16(5). Accessed March 2, 2024.
  7. Wilson J. Managing recurrent bacterial vaginosis. Sexually Transmitted Infections. 2004;80(1):8-11. doi:


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