Lecture Notes on Parasitic Protozoa PDF

Order: Trichomonadida Trichomonas No cyst is present T. tenax, found in oral gingival and tracheobronchial sites. Pentatrichomonas hominis, isolated from the intestinal tract, is considered nonpathogenic and occur infrequently in humans. Tritrichomonas foetus causes the bovine trichomon...

Order: Trichomonadida Trichomonas No cyst is present T. tenax, found in oral gingival and tracheobronchial sites. Pentatrichomonas hominis, isolated from the intestinal tract, is considered nonpathogenic and occur infrequently in humans. Tritrichomonas foetus causes the bovine trichomoniasis. T. foetus can be invasive to the fetus, having been demonstrated in the placenta, fetal lung, gut, and lymph nodes and is a known cause of abortion in infected cattle. Various studies of African populations have reported the prevalence of vaginal trichomoniasis to be between 11 and 25% Little information is reported about the discovery of Trichomonas vaginalis between 1934 and 1939 by Procaccini Trichomoniasis, one of the most common sexually transmitted diseases STD, can be spread from one person to another through sexual intercourse. 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.  The incubation period of trichomoniasis is 4 days to 4 weeks. In females, the symptoms of Males who have this infection can include: trichomoniasis often don't show any symptoms. But if they do, the 1- abundant and frothy vaginal discharge ranging in symptoms can include: color from gray to green to yellow, with a watery to milky 1- mild urethral itching consistency 2- pain during urination 2- foul odor 3- pain during sex 3- itching around the vagina 4- inflammation of the 4- pain during sex prostate gland 5- pain during urination  Diagnosis 1- Microscopic examination Vaginal or urethral discharge is examined microscopically in saline wet mount preparation for characteristic jerky and twitching motility and shape. In males, trophozoites may be found in urine or prostatic secretions. Direct fluroscent antibody (DFA) is more sensitive than the wet mount. 2- Culture is recommended when direct microscopy is negative and is considered as sensitive method (95%) for the diagnosis of T. vaginalis infection. 3- Serelogical test 4- Molecular diagnosis (sensitivity 97%) Treatment: 1- Metronidazole (Furazol) 2- Tinidazole (Fasigyn) 3- Secnidazole (Flagentyl) Both sexual partners should be considered infected and treated at the same time, even if one has no symptoms Entamoeba histolytica  ≈ 20 (60) μm 10-20 μm 10-20 μm The chromatoid bodies are so called because they stain with hematoxylin, Each 8 h. like chromatin Symptoms 1- Non invasive intestinal disease (90%) no symptoms or mild symptoms as diarrhea, abdominal pain, 2- Invasive intestinal disease (10%) Amoebic dysentery Severe diarrhea with blood and mucous and pieces of intestinal tissue, ulcers, abscesses, necrosis (Flask-shaped intestinal lesion) bacterial infection, perianal ulceration 3- Extraintestinal amoebiasis Ulcers, abscesses, necrosis, peritonitis  Diagnosis 1- Stool examination at least 3 consecutive specimens should be examined Macroscopic: The stool is foul-smelling, semi-liquid, brownish black in color, and fused with blood and mucus. Microscopic: Actively motile trophozoites can be demonstrated in freshly-passed stool. Presence of ingested RBCs Cyst has a smooth and thin cell wall and contains round refractile chromatoid bars  Development of Entamoeba inside human colon Pass out Binucleate Uninucleate Quadrinucleate cyst in stool cyst cyst Precyst Enter with food In the lumen Attached Trophozoites to Binary fission mucosa Mucosa of large intestine 2- Mucosal Scrapings Scraping obtained by sigmoidoscopy. Examination method includes a direct wet mount and immunofluroscent staining. 3- Stool Culture Stool culture is a sensitive method in diagnosing chronic and asymptomatic intestinal amoebiasis 4- Serological tests Serological tests become positive only in invasive amoebiasis 5- Molecular diagnosis (rapid and specific method). 6- For extraintestinal amoebiasis pus aspirated from liver abscess, Imaging (CT scan, MRI, Ultrasound) Diagnostic stage: Naegleria brain-eating amoeba Entamoeba coli Naegleria(braim-eating amoeba) Acanthamoeba difficult to treat corneal infection, keratitis, and meningoencephalitis, a fatal infection of the central nervous system (CNS)