Trichomonas Vaginalis
Trichomonas Vaginalis, a flagellated protozoan, causes Trichomoniasis, an exogenous sexually transmitted disease. It manifests in male and female genitourinary tracts. In most men infection is asymptomatic, they are generally considered to be the carriers of this bacterium. In women a wide range of clinical picture ranging from acute to chronic or asymptomatic is observed. Recent data have shown that the annual incidence of Trichomoniasis is more than 170 million cases worldwide.
History of Disease: T. vaginalis is a primitive eukaryotic organism. Although it is similar in many respects to other eukaryotes, it differs in its energy metabolism and shows remarkable similarity to primitive anaerobic bacteria. Trichomonas vaginalis is a pear-shaped trophozoite (7 to 23 µm long) with four anterior flagella and a fifth forming the outer edge of a short undulating membrane. It was first described by Donne in 1836. The study of T. Vaginalis has been in progress throughout the last 60 years and has gone from developing cultures and defining nutritional requirements to finding an effective treatment. In the 1960s and 1970s, research focused on biochemical tests and microscopic examination to understand the growth characteristics and behavior of the organism. It was not until the 1980s that immunologic methods and molecular biological techniques became available for study. Research involving these techniques has provided information on identification and characterization of many virulence factors of T. vaginalis. However, the research to better understand this organism is still in progress. Trichomonas vaginalis is emerging as one of the most important cofactors in increasing HIV transmission, particularly in African-American communities of the United States.
Forms of the Organism: Humans are the only natural host for T. vaginalis. This parasite is a distinctive flagellate trophozoite. The organisms typically are transferred during sexual intercorse. T. vaginalis is observed more frequently in females attending STD clinics and also in prostitutes than in postmenopausal women and virgins. The flagellates die outside the human body unless they are protected from drying. In the United States, black women have higher rates of trichomoniasis than white women, and socioeconomic factors such as a lower level of education are associated with a higher prevalence rate of trichomoniasis.
Source of the Organism: The only carriers of T. vaginalis are humans, and can be found in the human urogenital tract. It is sexually transmitted to the other person. However, there have been cases reported where it was transmitted through toilet seats in public bathrooms.
Life Cycle: The trophozoite is the only form of this organism and appears to lack a cystic stage. The trophozoite lives in close association with the epithelium of the urogenital tract and reproduces by binary fission. T. vaginalis is anaerobic and contains no mitochondria in its cytoplasm. Instead, specialized granules called hydrogenosomes are found throughout the cytoplasm. T. vaginalis derives its carbon from reduction of glycogen and glucose into succinate, acetate, malate and hydrogen. It produces some carbon dioxide, but not via the Krebs cycle pathway. Transfer of the relatively delicate trophozoite is usually directly from person to person.
Clinical Symptoms: The incubation period for women ranges between 5 and 28 days. The classic symptoms associated with the clinical diagnosis of T. vaginalis include a yellowish-green discharge, dysuria, and also hemorrhagic lesions found on the cervix. In women it can also produce vulvovaginal soreness and also abdominal discomfort. Unfortunately these symptoms are also characteristics of other STD’s, so the best way to find the organism is isolation and microscopic examination. Even though the organism can be found in the endocervix, endocervical disease is not caused by T. vaginalis. Infected women can show inflammation of the exocervix, which is closely tied with this organism. Trichomonads an also be fond in the urethra and paraurethral glands in more then 95% of women, which shows the relation between the organism and urinary infections. Some cases showed the spread of T. vaginalis to the fallopian tubes, but is extremely rare. In Extreme cases complications can manifest in form of vaginitis emphysematosa, which shows manifestation of gas bubbles in the vaginal wall.
Treatment: Most strains of T. Vaginalis are susceptible to Metronidazole and related drugs. Metronidazole is administered in an inactive form and must be modified in the hydrogenosome to become cytotoxic. Recommended regimes are: Metronidazole 2g orally in a single dose or, Metranidazole 400- 500mg twice daily for 7 days. Patients should be advised not to take alcohol with this treatment, nor some 48 hours after, because of the possibility of allergic reactions, nausea and vomiting.
Trichomonas Vaginalis, a flagellated protozoan, causes Trichomoniasis, an exogenous sexually transmitted disease. It manifests in male and female genitourinary tracts. In most men infection is asymptomatic, they are generally considered to be the carriers of this bacterium. In women a wide range of clinical picture ranging from acute to chronic or asymptomatic is observed. Recent data have shown that the annual incidence of Trichomoniasis is more than 170 million cases worldwide.
History of Disease: T. vaginalis is a primitive eukaryotic organism. Although it is similar in many respects to other eukaryotes, it differs in its energy metabolism and shows remarkable similarity to primitive anaerobic bacteria. Trichomonas vaginalis is a pear-shaped trophozoite (7 to 23 µm long) with four anterior flagella and a fifth forming the outer edge of a short undulating membrane. It was first described by Donne in 1836. The study of T. Vaginalis has been in progress throughout the last 60 years and has gone from developing cultures and defining nutritional requirements to finding an effective treatment. In the 1960s and 1970s, research focused on biochemical tests and microscopic examination to understand the growth characteristics and behavior of the organism. It was not until the 1980s that immunologic methods and molecular biological techniques became available for study. Research involving these techniques has provided information on identification and characterization of many virulence factors of T. vaginalis. However, the research to better understand this organism is still in progress. Trichomonas vaginalis is emerging as one of the most important cofactors in increasing HIV transmission, particularly in African-American communities of the United States.
Forms of the Organism: Humans are the only natural host for T. vaginalis. This parasite is a distinctive flagellate trophozoite. The organisms typically are transferred during sexual intercorse. T. vaginalis is observed more frequently in females attending STD clinics and also in prostitutes than in postmenopausal women and virgins. The flagellates die outside the human body unless they are protected from drying. In the United States, black women have higher rates of trichomoniasis than white women, and socioeconomic factors such as a lower level of education are associated with a higher prevalence rate of trichomoniasis.
Source of the Organism: The only carriers of T. vaginalis are humans, and can be found in the human urogenital tract. It is sexually transmitted to the other person. However, there have been cases reported where it was transmitted through toilet seats in public bathrooms.
Life Cycle: The trophozoite is the only form of this organism and appears to lack a cystic stage. The trophozoite lives in close association with the epithelium of the urogenital tract and reproduces by binary fission. T. vaginalis is anaerobic and contains no mitochondria in its cytoplasm. Instead, specialized granules called hydrogenosomes are found throughout the cytoplasm. T. vaginalis derives its carbon from reduction of glycogen and glucose into succinate, acetate, malate and hydrogen. It produces some carbon dioxide, but not via the Krebs cycle pathway. Transfer of the relatively delicate trophozoite is usually directly from person to person.
Clinical Symptoms: The incubation period for women ranges between 5 and 28 days. The classic symptoms associated with the clinical diagnosis of T. vaginalis include a yellowish-green discharge, dysuria, and also hemorrhagic lesions found on the cervix. In women it can also produce vulvovaginal soreness and also abdominal discomfort. Unfortunately these symptoms are also characteristics of other STD’s, so the best way to find the organism is isolation and microscopic examination. Even though the organism can be found in the endocervix, endocervical disease is not caused by T. vaginalis. Infected women can show inflammation of the exocervix, which is closely tied with this organism. Trichomonads an also be fond in the urethra and paraurethral glands in more then 95% of women, which shows the relation between the organism and urinary infections. Some cases showed the spread of T. vaginalis to the fallopian tubes, but is extremely rare. In Extreme cases complications can manifest in form of vaginitis emphysematosa, which shows manifestation of gas bubbles in the vaginal wall.
Treatment: Most strains of T. Vaginalis are susceptible to Metronidazole and related drugs. Metronidazole is administered in an inactive form and must be modified in the hydrogenosome to become cytotoxic. Recommended regimes are: Metronidazole 2g orally in a single dose or, Metranidazole 400- 500mg twice daily for 7 days. Patients should be advised not to take alcohol with this treatment, nor some 48 hours after, because of the possibility of allergic reactions, nausea and vomiting.
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