Prof. Dr. Md. Akram Hossain March 09

1 trichomonas vaginalisProf. Dr. Md. Akram HossainMarch 09 IntroductionTrichomonas vaginalis, a genital flagellate, isthe most common pathogenic protozoan is found fromvaginal secretions andsecretions fromthe male urogenital Akram , TrichomonasEpidemiology Occurs worldwide. More than 200 million people worldwide are infected with this parasiteeach year. Pregnant women infected withT. vaginalisare 30% morelikelythanuninfectedwomentodeliverpr etermortohavealowbirthlikelythanuninfect edwomentodeliverpretermortohavealowbirth weight infant.

2 Age & Sex distribution :Symptomatic cases are more in female thanmale and it is common in adults. Risk groups Higher prevalence among persons with multiple sexual partners or othervenereal diseases. The prevalence ofT. vaginalisinfection at clinics treating sexuallytransmitted diseases (STDs) varies from 8-31%.1/7/20143 Prof. Akram , TrichomonasTaxonomy Phylum- Metamonida, Class - Trichomonidea, Order-Trichomonidida, Order-Trichomonidida, Family - Trichomonadidae, Genus - trichomonas , Species - T. vaginalis1/7/20144 Prof. Akram , TrichomonasMorphologyIt has only trophozoite stage, there is no has a pear-shaped body 7 to 23 mlong, asingle anterior nucleus, three to fiveforward-directed flagella, and a hyaline rod-like structure, the axostyle, runsthrough the length of the body and exits atthe posterior vaginalisinhabits the vagina in women, theprostate and seminal vesicles in men, andthe urethra in both is by longitudinal binary Akram , Trichomonaslife cycle Trichomonads have the simplest kind of protozoan life cycle.

3 Inwhich the organismoccurs only as a trophozoite (NOCYST). It passes its life cycle in only one host, humans. Trophozite stageistheinfectivestageandistransmitted primarilyviasexualistheinfectivestageand istransmittedprimarilyviasexualcontact. It is occasionally found in virginal females/males and newborninfants suggesting that it is transmitted via contaminatedwashcloths, clothes and towels. It multiplies by longitudinal binary fission. Reproduction of the parasites occurs every 8-12 Akram , TrichomonasLife cycle1/7/20147 Prof. Akram , TrichomonasLife cycle at a glanceLife cycle at a glanceLife cycle stages : Only Trophozoites, NO CYSTI nfective stage : TrophozoitesPathogenic stage : TrophozoiteRoute of infection : Sexual & occassionaly via fomitesSite of localization : Vagina in women, prostate and seminal vesicles in men, and the urethra in both Akram , TrichomonasVirulence factors T.

4 Vaginalisis not a highly virulent parasite. Its virulence is lowand mostly associatedwithasymptomaticinfectionormil dinfection. Inflammatory response of the host due to thepresence of the parasite may explain Akram , TrichomonasPathogenesis Most strains are of such low pathogenicity that the infectedperson isvirtually asymptomatic. Other strains cause intense inflammation, withitching and a copious white discharge (leucorrhea) that is swarming withtrichomonads. They feed on bacteria, leukocytes and cell exudates and arethemselves ingested by monocytes.

5 Afterinfectionthereisdegenerationoftheva ginalepitheliumfollowedby Afterinfectionthereisdegenerationoftheva ginalepitheliumfollowedbyleukocytic infiltration - vaginal secretions become abundant and white orgreenish and the tissue will become intensely inflamed. Acute infectionwill become chronic with occasional flare-ups. In men trichomonasinfection is usually asymptomatic - although there may be anirritatingurethritis or prostatitis trichomonas vaginaliswas isolated in 14-60% of male partners ofinfected women and in 67-100% of female partners of infectedmen.

6 Itmay be due to the effect of prostatic fluid that contains zincand othersubstances on Akram , TrichomonasClinical Features Clinical manifestations of trichomoniasis varies with sexes. In women -About 50% of women are asymptomatic carriers and theother 50% complain of vaginitis with a purulent discharge and can beaccompanied by vulvar and cervical lesions, abdominal pain, dysuria anddyspareunia. or cystitis. It is seldom symptomatic before theonset of mensesin a young girl (menarche). In pregnancy, the infection can be passedfrom a mother to a newborn daughter.

7 In men -the infection is frequently asymptomatic; occasionally, urethritis,epididymitis, and prostatitis can occur. The infection canprogress toprostatitis, urethritis, epididymitis and superficial penile Akram , TrichomonasLaboratory Diagnosis Principle : Demonstration of the parasite by microscopic Detection of parasite by culture is helpful in asymptomaticcases. DNAbased tests (PCR) are also Akram , TrichomonasTreatment The treatment of choice ismetronidazole, except in the first trimesterof pregnancy, when clotrimazole is used topically for 14 days.

8 A largesingle dose of 2 gm by mouth is as effective as longer term treatment of500 mg twice daily for 7 days. The 2 gm metronidazole dose has a90-95% cure rate and good compliance since it is an all at once dose. It has also been suggested that the intravaginal application of thespermicide, nonoxynol-9, may have some effect against metronidazoleresistantTrichomonas. Other agents such as mebendazole and furazolidone may be effectivefor treatment of metronidazole-resistant trichomoniasis It is important that sexual partner must be treated, otherwise therewill be reinfection.

9 Metronidazole is also effective in treating Akram , TrichomonasPrevention Because of the frequent role of asymptomatic menin spreading trichomoniasis, control of this infectionnecessitatesexaminationand,ifne cessary, Avoidance of sexual intercourse and the use ofcondoms are effective ways to prevent transmission. Treatment of both sexual partners at the same timeis recommended to prevent "ping pong" Akram , TrichomonasOther Trichomonads T. tenax, and T. hominisare two other trichomonads thatare present in humans. They are usually commensal ofmouth and intestine respectively.

10 ,inhabitsthehumanoralcavity,occurring ,inhabitsthehumanoralcavity,occurringpar ticularly in tartar, cavities, and at the gingival has been reported, rarely, in lung or thoracic abscesses. T. hominisinhabits the intestinal tract in the area of thececum. There is no evidence that the parasite is pathogenic. 1/7/201415 Prof. Akram , TrichomonasSummary trichomonas vaginalisis a flagellate of genital tract, whichhas no CYSTIC stage, only pear shaped trophozoites withmedian body and 4-5 flagella found. The trophozoite formispathogenic, infective and diagnostic stage.