Snapshot A 26-year-old woman presents to the emergency room for large amounts of watery, nonbloody diarrhea, abdominal cramping, and lots of flatulence. She was trying to hydrate with water and sports drinks; however, she started feeling lightheaded and was brought to the hospital for treatment. She recently did a 5-day hike in Patagonia in South America. On physical exam, she demonstrated signs of dehydration but otherwise has no significant findings. Stool studies are sent and return with cysts on microscopy. (Giardia lamblia infection) Introduction Protozoa single-celled eukaryotes, often parasitic, that feed on organic tissues Infections of Protozoa Central Nervous System Gastrointestinal Visceral Infections Hematologic Infections Sexually Transmitted Diseases Toxoplasma gondii Naegleria fowleri Trypanosoma brucei Acanthamoeba Giardia lamblia Entamoeba histolytica Cryptosporidium Trypanosoma cruzi Leishmania donovani Plasmodium Babesia Trichomonas vaginalis Giardia lamblia Introduction clinical syndrome giardiasis demographics very common, especially in South America and Southeast Asia transmission ingestion of cysts in contaminated water pathogenesis only requires a few cysts to cause giardiasis risk factors camping and hiking poor sanitation IgA deficiencies Burton agammaglobulinemia common variable immunodeficiency selective IgA deficiency Presentation 1-2 weeks after exposure abdominal pain and bloating flatulence large-volume, watery, foul-smelling, fatty diarrhea Studies stool microscopy microscopy multinucleated trophozoites cysts stool antigen test Treatment metronidazole first-line if asymptomatic, patients may not need treatment unless they are at risk for severe disease (immunosuppression) paromomycin pregnant women Entamoeba histolytica Introduction clinical syndrome amebiasis hepatic abscess demographics tropical areas transmission ingestion of cysts in contaminated water fecal-oral risk factors poor sanitation pregnancy immunosuppression Presentation fever bloody or watery diarrhea right upper quadrant pain should raise suspicion for liver abscess Imaging abdominal computed tomography (CT) or ultrasound liver abscess Studies stool antigen test stool detection of DNA with polymerase chain reaction (PCR) stool microscopy trophozoites with ingested red blood cells in the cytoplasm cysts with multiple nuclei histology flask-shaped lesions Treatment metronidazole symptomatic patients paromomycin or iodoquinol asymptomatic patients with cysts detected in stool needle aspiration or percutaneous drainage of abscess liver abscess often has an “anchovy paste” or red-brown exudate Cryptosporidium Introduction clinical syndrome cryptosporidiosis transmission ingestion of oocysts in contaminated water fecal-oral risk factors immunosuppression HIV/AIDS Prevention filter all drinking water Presentation immunosuppressed patients severe and prolonged nonbloody diarrhea may be fatty weight loss immunocompetent patients mild watery diarrhea Studies acid-fast stain oocysts detection of antigen Treatment nitazoxanide immunocompetent patients Microsporidium Introduction clinical syndrome microsporidiosis transmission fecal-oral risk factors immunosuppression HIV/AIDs organ transplant Presentation weight loss nonbloody and watery diarrhea nausea and vomiting can also cause keratoconjunctivitis Studies stool detection of DNA with polymerase chain reaction (PCR) stool microscopy with trichrome stain ovoid spores with bright red walls gram-positive Treatment albendazole first-line topical fumagillin keratoconjunctivitis
QUESTIONS 1 of 9 1 2 3 4 5 6 7 8 9 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.MC.17.4753) A 26-year-old male presents to his primary care physician complaining of diarrhea. He recently returned from a two-week hike in the Peruvian Andes mountains, during which time he ate undercooked chicken and beef. Since returning, he has experienced frequent bloating, flatulence, and several foul-smelling watery stools per day. He has recently noticed blood on the toilet paper after wiping. His past medical history is notable for asthma. He takes albuterol and low-dose budesonide. His temperature is 100°F (37.8°C), blood pressure is 120/70 mmHg, pulse is 90/min, and respirations are 20/min. A stool sample is shown in Figure A. What is the most appropriate treatment for this patient? Tested Concept QID: 108889 FIGURES: A Type & Select Correct Answer 1 Metronidazole 85% (216/253) 2 Ciprofloxacin 4% (11/253) 3 Amipicillin 3% (7/253) 4 Vancomyin 4% (11/253) 5 Sulfasalazine 1% (2/253) M 3 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.MC.15.2) A 19-year-old male recently returned home from a camping trip. He is planning on heading back to college but is worried that he may have a parasitic infection after drinking unfiltered stream water on his trip. He sets up an appointment with his primary care physician. The patient denies any diarrhea, constipation, bloating, or flatulence. He is adamant about having a fecal exam, so the primary care physician obliges. His stool sample is shown in Figure A. What is the most appropriate next step in this patient's care? Tested Concept QID: 102943 FIGURES: A Type & Select Correct Answer 1 Treatment with metronidazole to prevent future symptoms, as he is infected with giardia lamblia. 46% (31/67) 2 Treatment with azithromycin because he is infected with cryptosporidium. 4% (3/67) 3 No treatment, as he is not currently infected with any organisms. 3% (2/67) 4 No treatment because he is not experiencing any symptoms. 37% (25/67) 5 No treatment because there is no effective treatment for his current pathologic state. 7% (5/67) M 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (M1.MC.15.74) A 17-year-old male returns from a camping trip. He complains of abdominal bloating and flatulence. On further review, he reports foul-smelling diarrhea, which is difficult to flush. The results of staining a stool specimen with iodine are shown in Figure A. Which of the following treatment options is most appropriate? Tested Concept QID: 106700 FIGURES: A Type & Select Correct Answer 1 Penicillin 1% (4/270) 2 Azithromycin 2% (6/270) 3 Metronidazole 89% (239/270) 4 Trimethoprim-sulfamethoxazole 5% (14/270) 5 Ribavirin 0% (1/270) M 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review tested concept (M1.MC.15.74) A 5 year-old-boy with a history of severe allergies and recurrent sinusitis presents with foul-smelling, fatty diarrhea. He is at the 50th percentile for height and weight. The boy's mother reports that he has had several such episodes of diarrhea over the years. He does not have any known history of fungal infections or severe viral infections. Which of the following is the most likely underlying cause of this boy's presentation? Tested Concept QID: 106684 Type & Select Correct Answer 1 Thymic aplasia 2% (1/59) 2 Hyper IgE syndrome 14% (8/59) 3 Severe combined immune deficiency 8% (5/59) 4 Wiskott-Aldrich Syndrome 3% (2/59) 5 IgA deficiency 69% (41/59) M 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK
All Videos (2) Login to View Community Videos Login to View Community Videos Giardia Lamblia Chris Robinson Microbiology - GI Infections: Protozoa D 2/14/2015 53 views 5.0 (3) Login to View Community Videos Login to View Community Videos Entamoeba Histolytica Chris Robinson Microbiology - GI Infections: Protozoa D 2/14/2015 62 views 5.0 (3)