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
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
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 Clinical Manifestations
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