protozoa of humans

Introduction

A sexually transmitted disease (STD), also known as sexually transmitted infection (STI) or venereal disease (VD), is an illness that has a significant probability of transmission between humans by means of sexual contact, including vaginal intercourse

Sexually Transmitted Infections

Bacterial Neisseria gonorrhoeae Treponema pallidum Chlamydia trachomatis Haemophilus ducryei (chancroid) Lymphogranuloma Mycoplasma Viruses Herpes simplex II Hepatitis B Hepatitis C HIV Papillomavirus
Yeasts and fungi Candida albicans Candida glabrata Candida tropicalis Parasites Trichomonas vaginalis Entamoeba histolytica Giardia intestinalis Ectoparasites Sarcoptes scabiei Phthirus pubis

Genus Trichomonas

OBJECTIVE: KOWING GENERAL STRUTURE KNOWING KEY LAB. WORKS KNOWING PATHOGENESIS, CLINICAL FEATURES KNOWING HOW TO TREAT YOUR PTS AND HOW TO PREVENT INFECTION KNOWING RISK AND PROGNOSIS FOR TRICHO. INFECTION

Genus Trichomonas

Its includes a group of flagellated protozoa It infect humans and animal Human Trichomonads: 3 species of trichomonads found in human. Two are normally harmless


Pentatrichomonas hominis T. tenax T. vaginalis which is a serious sexually transmitted pathogen.

Trichomonas vaginalis:

It is the etiological agent of trichomoniasis. Trichomoniasis is a common sexually transmitted disease with a worldwide distribution. transmittable, sexually and through contact with toilet seats and towel. T. vaginalis despite it name, infect both men and women. In females the organism inhabits the vagina and urethra In males it is found in the urethra, prostate or, seminal vesicles.


The life cycle consist only of a trophozoite stage which is transmitted by direct contact during sexual intercourse both sexes equally susceptible

T. Vaginalis trophozoite

Fg=flagella Bb=basal body Nu=nucleus Ax=axostyle um=undulating membrane Cy=cytostomal groove Cs=costa

MORPHOLOGY

SINGLE CELL PROTOZOA 3-5 ANTERIOR FLAGELLA LARGE ANTERIOR N. UNDULATING MEM.
PYRIFORM SHAPE POSTERIOR F. HYDROGENSOMES CONTAIN VIRUSES USUALLY


(B) T. vaginalis on the surface of a vaginal epithelial cell prior to ameboid transformation.
5 μm

(C) Ameboid morphology of T. vaginalis as seen in cell culture.

5 μm

Life cycle: flagella are found in the genital tract. Transmission: during dealings with contaminated matters (clothes, cotton..etc.

SignS and symptoms: T. vaginalis causes different manifestation in men and women. Women are more likely to exhibit symptoms which tend to persist longer Incubation period is 4-28 days. In female ranges from asymptomatic, to mild or moderate irritation, to extreme vaginitis 10 - 50%: asymptomatic The commonest symptoms: vaginal discharge, vulval itching, dysuria, or offensive odor , rare abdominal discomfort MAY INDUCE ABORTION

SGINS AND SYMPTOMES

Vaginal discharge: up to 70% - varying in consistency from thin and scanty to profuse and thick; the classical discharge of frothy yellow occurs in 10-30% of women Extreme cases associated with vulvitis and vaginitis 2%: strawberry cervix appearance to the naked eye. Higher rates are seen on colposcopic examination. 5-15%: no abnormalities on examination. In male 50-90% are asymptomatic mild dysuria or pruritus minor urethral discharge
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Focus on pathogen: T. vaginalis

females get a disintegration of vaginal epithelial lining. Natural flora (bacteria ) keep the pH of the vagina at 4-4.5 and ordinarily this discourages infections. T. vaginalis can survive at a low pH. Once established it causes a shift toward alkalinity (pH 5-6) which further encourages its growth. There is a tendency to explain stillbirths, spontaneous abortions, morbidity to women who have vaginitis. Induces vaginal pH change, erosion of normal mucosa in women

Physical Examination

Pelvic examination: Inspection of external genitalia. Speculum examination: insertion and visualization of vagina and cervix, obtaining swabs and slide specimens.

Vaginitis - Trichomoniasis

Profuse, frothy discharge, yellow-greenish in color foul odor, vulvar pruritus Patchy vaginal erythema and (strawberry cervix)


Diagnosis: 1-Specimens: vaginal discharge urine sediment prostatic secretion 1.Vaginal pH 2. Whiff test 3.Wet mount 4. VAGINAL smear 5. Culture 6. Direct immunoflouresence assay 7. Polymerase chain reaction

Potassium hydroxide amine test (Whiff test) :

Whiff test: 10 % KOH
Upon application of 10% potassium hydroxide (KOH) to a vaginal swab sample, a fishy odor is released, which can suggest trichomoniasis or bacterial vaginitis.



Treatment: Metronidazole ( flagyl) Tinidazole is an alternative drug Vinegar douche (decreases pH) Control: The use of latex or polyurethane condoms during intercourse can prevent the transmission of trichomoniasis Limit the number of sex partner Both husband and wife should be advised to engage in treatment.
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Phylum Ciliophora Possess cilia simple cilia or compound ciliary organelles during some part of their life cycle Most species have 2 kinds of nuclei: macronuclei and micronuclei Some members of the phylum engage in sexual reproduction, involving conjugation, autogamy, and ctyogamy Most ciliates are free-living; however, a few groups are commensals or parasitic

Family Balantidiidae, which includes only one genus and species (Balantidium coli) are found in the intestinal tract of arthropods and some vertebrates, including mammals Pathogens of humans, dogs and monkeys Swine are non-pathogenic carrier Mostly infect at Cecum,large intestine Balantidium coli cause Balantidiosis Ciliary dysentery Balantidiosis is most often found in tropical regions throughout the world It is not a common human disease; the infection rate is less than 1% Pigs are a good source of infection for humans in areas where they share habitation Cyst transmission (fecal oral)

Balantidium trophozite

Balantidium coli cyst

Life Cycle

Both asexual and sexual reproduction present Asexual by binary fission Sexual by conjugation Conjugation two opposite mating types pair & exchange genetic material

Pathogenesis

Balantidium coli produces proteolytic enzymes that break down and digest the intestinal epithelium.Colon ulceration develops which allows for infiltration by lymphocytes and leukocytes.Hemorrhaging and secondary bacterial infections will develop next.Perforation of the large intestine and appendix will occur.



Clinical Signs Mild infections occur with diarrhea, Abdominal pain Alternating periods of constipation Ulceration of the gut wall Diagnosis Cysts-formed stools Active trophs-diarrheic stools

Control

Eradication of fecal contamination of food and water. Cysts killed by boiling Resistant to low doses chlorine (halide tablets) Avoid practices that allow fecal-oral contact Improved sanitation in institutions.