Trichomonas vaginalis and other Ameba Infections Doç.Dr.Hrisi BAHAR

Trichomonas vaginalis

Morphology and life cycle ☻ Trophozoite Pear-shaped and actively motile, 14-17 µm X 5-15 µm Four anterior flagella A single nucleus Axostyle An undulating membrane

Four anterior flagella The single lateral flagellum (the undulating membrane

Life cycle ☻ Life cycle There is only trophozoite stage in life cycle. Women: vagina and urethra Trophozoites Men: urethra or prostate, testes, epididymis

☻ The infection is acquired by sexual activity or some indirect ways Only trophozoites in life cycle, no cyst stage The infective stage is trophozoite The trophozoites multiply by binary fission

Epidemiology ☻Trichomoniasis is a vaginal infections caused by T. vaginalis. ☻ This infection is among most common conditions in women attending reproductive health care centers.

Epidemiology ☻ Most prevalent in age group 20-45. ☻Worldwide, over 180 million cases. ☻T. vaginalis accounts for 15-20% of all vaginitis.

Trichomonas vaginalis ☻ The vagina is the most common site of infection in women, and the urethra (urine canal) is the most common site of infection in men. ☻ Women can acquire the disease from infected men or women, but men usually contract it only from infected women.

Signs and Symptoms Women: Signs and symptoms of infection range from having no symptoms (asymptomatic) to very symptomatic. Typical symptoms include : ☻Foul smelling , pale yellow or gray-green discharge from the vagina ☻Vaginal itching or redness.

Signs and Symptoms Other symptoms can include ☻Lower abdominal discomfort ☻The urge to urinate ☻ The vaginal mucosa often is deeply erythematous. ☻ The cervix is friable and diffusely inflamed, sometimes covered with numerous petechiae ("strawberry cervix").

Signs and Symptoms Men: ☻Urethritis and, more rarely, epididymitis or prostatitis can develop in infected males ☻Most are asymptomatic. ☻Reinfection is common. Trichomonas vaginalis is considered an important cofactor in amplifying human immunodeficiency virus transmission.

☻ Finding trophozoites Diagnosis ☻ Finding trophozoites In women: vaginal discharge In the male: urethral discharge , prostates secretions, centrifuged urine. Finding trophozoites Methods: direct smear or culture

T. vaginalis Microscopic Diagnosis ☻ Microscopy Saline wet mount 50-60% sens in women, 30% sens in men, low specificity Pap smear 50 % sensitivity, 90% specificit Low PPV in low prevalence pop

T.vaginalis Culture Diagnosis In-Pouch TV 85-95% sens in women, >95% spec 60 % sens and high specificity in men

T. vaginalis Antigen Detection OSOM Trichomonas Rapid Test (Genzyme Diagnostics, Cambridge, MA) ☻ 10 min point-of-care test ☻ 83.3% sensitive 98.8% specific vs. culture ☻(wet mount 71.4% sensitive)

T. vaginalis Molecular Methods ☻ PCR >90% sensitive and >95% specific for females >90% sensitive and specific for males Culture 70% sensitive vs. PCR

Recommended Treatment by CDC ☻ Metronidazole 2 g ………orally in a single dose     OR Tinidazole 2 g ……………orally in a single dose Alternative Regimen ☻ Metronidazole 500 mg......... orally twice a day for 7 days Patients should be advised to avoid consuming alcohol during treatment with metronidazole or tinidazole. Abstinence from alcohol use should continue for 24 hours after completion of metronidazole or 72 hours after completion of tinidazole.

Free Living Amebas

Free Living Amebas ► Acanthamoeba ► Naegleria Small free-living amebas belonging to the genera : ► Acanthamoeba ► Naegleria occur world-wide .

Acanthamoeba spp ► At least 5 species of Acanthamoeba have been identified in human tissues, this is one of the most common amebas in soil and freshwater. ► Trophozoits occur only as amoeboid forms:

Acanthamoeba spp Trophozoits occur only as amoeboid forms:

Acanthamoeba spp Life Cycle Stages Free-living trophozoites and cysts occur in both the soil and freshwater.

Acanthamoeba spp. ► Granulomatous amebic meningoencephalitis. These species cause 2 pathological effects ► Granulomatous amebic meningoencephalitis. ► Inflammation and opacity of the cornea.

Acanthamoeba spp Symptoms ► Foreign body sensation, severe ocular pain, photophobia and blurred vision. ► Often pain is more severe than signs in early course of the disease.

Acanthamoeba spp Most of these ocular infections were in contact lens wearers who used home-made saline water.

Acanthamoeba spp. ► Early diagnosis a prognostic factor of Management ► Early diagnosis a prognostic factor of a successful outcome. ► Topical anti-amoeba agents. ► Penetrating keratoplasty in a severe progressive keratitis.

Naegleria spp ► Free-living in freshwater and soil including thermal pools ► They have even been isolated from bottled mineral water in Mexico.

Naegleria spp

Life cycle of Naegleria

Naegleria spp ► N. fowleri is the only species of Naegleria genus that is pathogenic to humans ► It lives in nature fresh water, lakes and ponds (especially warm water) .

Naegleria spp ► Flagellate form ,do not divide Exists in 3 forms ► Trophozoite invasive, reproductive form (7- 20 µ m) which lives in temperatures from 35- 46 .C ► Flagellate form ,do not divide ► Resistant cyst form 7 -10 µm in size

Primary Amoebic Meningoencephalitis (PAM) ► Acute, suppurative infection of the brain and meninges caused by N. fowleri ► First described in 1965 by R.F. Carter and M. Fowler in Australia ► Usually affects immunocompetent children and young adults.

Naegleria spp ► N. fowleri has been isolated all over the world Epidemiology ► N. fowleri has been isolated all over the world ► As of 1997, approximately 200 cases have been reported worldwide with 81 cases in the US (primarily in central and southeast) ► Risk factors: jumping/diving, IgA defic ► Males/females =3/1 ► Mortality rate > 95%

Naegleria spp Pathophysiology ► Trophozoites penetrate the nasal mucosa and the cribiform plate during inhalation or aspiration of contaminated dust/water ► The organisms migrate via the olfactory nerves to invade brain tissue ► Enzymes are produced resulting in diffuse and rapid hemorrhage and necrosis of the brain

Naegleria spp Clinical manifestation ► Indistinguishable from acute bacterial meningitis ► Symptoms begin 2 -14 days from exposure ► Initially may notice change in taste/smell ► fever, nausea, vomiting. ► Mental status changes seen in 66% ► Myocarditis has been reported ► Rapid progression with death occurring in 3-7days-

Naegleria spp Diagnosis ► Lab studies reveal leukocytosis , hyperglycemia and glycosuria leukocytosis, ► Molecular studies PCR/DNA probes under research

Naegleria spp CT scan of head ► Not diagnostic for PAM ► May be normal early in disease ► Later, may show signs of elevated leptomeningeal enhancement

Naegleria spp

Important notes ► Consider Naegleria when all studies point to bacterial meningitis but the gram stain is negative ► Overall mortality is near 95% therefore you need a high index of suspicion ► Plug your nose or wear nose clips when jumping into fresh water

Naegleria spp Treatment ► Amphotericin B is the mainstay of therapy ► Successful outcomes are reported with high dose systemic and intrathecal ampho b. ► Other adjunctive therapy includes miconazole and oral rifampin ► New studies show that azithromycin may be a useful addition to therapy.