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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.
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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 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 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 onlyciliate 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 • Balantidiumcoli, 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 periodis 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
Balantidium coli CystINFECTIOUS DISEASES: The Clinician's Guide to Diagnosis, Treatment, and Prevention (2005)
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
