Structure life cycle pathogenesis and control measure of Trichomonas Vaginalis.

Trichomonas vaginalis:

Trichomonas vaginalis is a flagellated protozoan parasite and the causative agent of trichomoniasis. It is the most common pathogenic protozoan infection of human in industrialized countries. Infection rates between men and women are similar with women being symptomatic, while infections in men are usually asymptomatic. Transmission usually occurs via direct, skin -to skin, most often through vaginal intercourse. The WHO has estimated that 160 million cases of infection are acquired annually worldwide. The estimates for North America alone are between 5 and 8 million new infections each year, with an estimated rate of asymptomatic cases as high as 50%. Usually, treatments consist of metronidazole and tinidazole.

Morphology or Structure:

Unlike other parasitic protozoa (Giardia lamblia, Entamoeba histolytica etc.), Trichomonas Vaginalis exists only one morphological stage, a trophozoite, and cannot encyst. The T.Vaginalis trophozoite is over as well as flagellated, or "pear" shaped as seen on a wet-moult. It is slightly larger than a white blood cell, measuring 9x7 micrometer. Five flagellated arises near the cytostome; four of these immediately extend outside the cell together, while the fifth flagellum wraps backwards along the surface of the organism. The functionality of the fifth flagellum is not known. In addition, a conspicuous barb-like axostyle projects opposite the four-flagella bundle. The axostyle may be used for attachment to surfaces and may also cause the tissue damage seen in trichomoniasis infections.

While T.vaginalis does not have a cyst form, organisms can survive for up to 24 hours in urine, semen, or even water samples.

Life-cycle of Trichomonas vaginalis:

T. vaginalis is a monogenetic parasite. The natural hosts are human beings , where the parasite lives as a colourless pyriform flagellated measuring usually 15 to 18 microns in length and 5 to 15 microns in breadth. They exist only in trophozoite phase and there is no cystic phase. A single elongated nucleus lies at the round anterior end.

A cheft like depression (cytostome) lies at the side of the nucleus. Cytoplasm contains numerous cytoplasmic granules and sausage-shaped parabasal body. There are 3 to 5 anterior flagella which are free. Besides these, a relatively thicker flagellum passes backward along the side of the body forming a short undulating membrane.

The flagella originate from blepharoplast. The axostyle runs down the middle of the body which ends in the pointed tail like extremity. The parasite is less active and occasionally exhibit non-directional jerky movement.

The exact mode of nutrition is not well known. Powell(1936) observed that T.vaginalis ingest particulate substance by amoeboid movement of the cytoplasm. During culture, it was found to ingest bacteria ,starch, and erythrocytes. The parasite reproduces by longitudinal binary fission.

Mode of Transmission:

The mode of transmission is direct. The man is the only source of infection. Infection from infected female to healthy one passes on through sexual intercourse in which male play and intermediary role. Since the parasites are also found in the urethra of males, the transmission may occur from infected male to the healthy female and vice versa. The parasite does not survive more than 24 hours outside the body of the host.

Diagnosis:

Classically, with a cervical smear, infected women have a transparent halo" around their superficial cell nucleus. It is unreliably detected by studying a genital discharge or with a cervical smear because of their low sensitivity. T.vaginalis was traditionally diagnosed via a wet mount, in which "cock screw" mortality was observed. Currently, the most common method of diagnosis is via overnight culture with a sensitivity range of 75-95%. Newer methods, such as rapid antigen testing and transcription-mediation amplification, have been greatly sensitivity but are not in widespread use. The presence of T.vaginalis can also be diagnosed by PCR, using primers specific for GENBANK/L23861.

Symptoms and pathogen:

Trichomonas vaginalis , a sexually transmitted infection of the urogenital tract, is a common cause of vaginitis in women, while men with this infection can display symptoms of urethritis. 'Frothy', greenish vaginal discharge with a 'musty' malodorous smell is characteristic.

The parasite produces symptoms which are collectively called as Trichomonas vaginalis. The disease is characterised by burning sensation, itching, and creamy white frothy discharge from the vagina.The vaginal walls become tender and prone to bacterial infection.

Urethral infection in male causes dysuria, frequency of urination and dirty-white discharge containing leukocytes, epithelial cells, and trichomonads. Secondary bacterial infection may occur.

Treatment and Prevention:

Treatment: Drugs heaving arsenic and iodine compounds are useful. Antibiotics like Aureomycin and Terramycin are also being used. Local cleaning and drying of the vaginal mucosa also help to control the parasite population. Carbasone is used in case of infection in males. Metronidazole has replaced the old treatment.

Prevention:

• The attention of personal feminine hygiene.
• Detection and treatment of infected male and female partners.

Reference:

http://www.yourarticlelibrary.com/essay/parasite-trichomonas-vaginalis-life-cycle-mode-of-infection-and-treatment/24244/

https://en.wikipedia.org/wiki/Trichomonas_vaginalis

http://www.fpa.org.uk/sexually-transmitted-infections-stis-help/trichomonas-vaginalis

http://bioweb.uwlax.edu/bio203/s2009/strous_mary/basic_info.htm

http://www.healthline.com/health/trichomonas-infection