Transcript Document
Case 8 General hospital of TSGH Clinical laboratory I2 蔡宗穎 94-09-12 Patient Sex : Male Age : 43 Y/O Race : American Chief Complaint Abdominal pain, severe watery-nonbloody diarrhea since returning to the United States Present Illness a month-long trip to visit his uncle, Who was a pig farmer in New Guinea (Papua New Guinea ) Suffered from abdominal pain, severe watery-nonbloody diarrhea since returning to the United States from the trip. Medical Course Initially, family physician for help Stool / R , Stool / C: R/O Shigella dysenteriae dysentery bacillus ->Bacillus dysentery of bacillary dysentery Amoeba's protozoon of R/O Entamoeba histolytica dysentery ->amebic dysentery Lab Result Stool / C (-) Trichrome-stained smear negative for parasites Wet preparation: a moderate number of large beanshaped ciliated trophozoites Ciliary Large bean-shaped ciliated trophozoites Large bean-shaped ciliated trophozoites QUESTIONS 1.Which protozoan parasite would fit the morphological description of the parasite observed in the microscopic wet mount? What is this condition called? 2.Describe the appearance of characteristic trophozoites of this parasite. 3.Describe the appearance of characteristic cysts of this parasite. 4.Why do you think the permanent trichrome stained smear was negative for thisparasite? Diarrhea Harrison's Principles of internal medicine - 16th Ed. Problem-Oriented Medicine Diagnosis 7th Ed. General hospital of the army Clinical laboratory I2 the tip Diarrhea Definition: Frequent passage of loose stools Two major components: 1.loose stool consistency (pourable stools) 2.increased stool frequency (more than two bowel movements daily). 3rd component: increased stool weight ( > 200 g/24 hr ) Diarrhea Acute Diarrhea: Sudden , <14 days Chronic Diarrhea: >2 or 3 wks or appeared acute, ebbed, and recurred within 2 weeks Acute Diarrhea Acute Diarrhea Pear shape flagellate Latent sporozoite Ring sporozoite Dysentery amoeba's protozoon Little pole nematode of excrement Parasite All very nuclear living beings A , protozoon (Protozoa) : Unicellular parasite B , worm ( Helminths) : Many cell's parasites C , arthropod Protozoon (Protozoa) Three doors (phyla) First, flagellate's door out of shape (Sarcomastigophors) (1)Amoeba's key link : Dysentery amoeba , large intestine Amoeba , freedom job amoeba (2)Flagellate's key link : Vagina trichomonad, pear shape whip Caterpillar , Leishman's protozoon , awl worm Protozoon (Protozoa) Three doors (phyla) Second, sporozoite's door (Apicomplexa) : (1)Ball worm's subclass: Latent sporozoite, with the shape Sporozoite , plasmodium (2)Piroplasmea: Worm then , shellfish of Palestine , (3)Lung sporozoite 原蟲 (Protozoa) – 三個門 (phyla) 三、纖毛蟲門 (Ciliophora) ： 大腸纖毛蟲 (Balantidium coli) 大腸纖毛蟲 (Balantidium coli) (Balantidiasis) 2003 Report of the Committee on Infectious Diseases - 26th Ed. 2005 INFECTIOUS DISEASES: The Clinician's Guide to Diagnosis, Treatment, and Prevention Clinical Manifestations The only ciliate causes human disease Humans are incidental hosts Most human infection：asymptomatic Clinical symptoms usually consist of chronic intermittent diarrhea and weight loss, but acute dysentery occurs in about 5% of cases Clinical Manifestations Acute infection ：rapid onset of nausea, vomiting, abdominal discomfort or pain, and bloody or watery mucoid diarrhea Clinical Manifestations Rarely, organisms spread to mesenteric nodes, pleura, or liver. Inflammation of the GI tract and local lymphatic vessels Colitis produced by Balantidium coli often is indistinguishable from that produced by Entamoeba histolytica ETIOLOGY Balantidium coli, a ciliated protozoan, is the largest pathogenic protozoan known to infect humans. EPIDEMIOLOGY Pigs are believed to be the primary host reservoir of B coli Cysts excreted in feces can be transmitted directly from hand to mouth or indirectly through fecally contaminated water or food. EPIDEMIOLOGY The excysted trophozoites infect the colon A person is infectious as long as cysts are excreted The cysts may remain viable in the environment for months. The incubation period is unknown but may be several days. DIAGNOSTIC TESTS 1. Scraping lesions via sigmoidoscopy 2. Histologic examination of intestinal biopsy specimens 3. Ova and parasite examination of stool Diagnosis usually is established by demonstrating trophozoites in stool or tissue specimens DIAGNOSTIC TESTS Shedding of organisms can be intermittent －＞ repeated stool examination Microscopic examination of fresh diarrheal stools must be performed promptly, because trophozoites quickly degenerate. TREATMENT Tetracycline x 10 days 40 mg/kg per day, maximum of 2 g/day, divided into 4 doses Alternative drugs： iodoquinol and metronidazole Picturess Balantidium coli Cyst INFECTIOUS DISEASES: The Clinician's Guide to Diagnosis, Treatment, and Prevention (2005) 報告完畢 QUESTIONS 1 Which protozoan parasite would fit the morphological description of the parasite observed in the microscopic wet mount? What is this condition called? 桿菌性痢疾（Shigella dysenteriae ） Symtoms ： 桿菌性痢疾由四亞群之痢疾桿菌所 引起之大腸急性感染，會引起發 燒、粘液性血便、腹瀉或腹痛，有 裏急後重感等腸炎症狀。 典型：糞便中有血跡、黏液及細菌 群落形成之膿。 桿菌性痢疾（Shigella dysenteriae ） Infectious agent ： 1. S. dysenteriae 2. S. flexneri 3. S. boydii 4 .S. sonnei。 桿菌性痢疾（Shigella dysenteriae ） 傳染窩（Reservoir）： 唯一之帶菌者是人 然而，靈長類動物也曾發生集體感染 桿菌性痢疾（Shigella dysenteriae ） Mode of transmission ： 受傳染者主要是因接觸帶菌者糞便 沒有洗手或沒有清洗指甲間縫隙， 帶菌者因和人握手或間接由食品之 污染而傳染給別人。 蒼蠅可能散播病菌到食品。 桿菌性痢疾（Shigella dysenteriae ） Incubation period ： 潛伏期為12至96小時 （通常 1 至 3 天），有時長達1星期 痢疾阿米巴(Entamoeba histolytica)