This TWiP (This Week in Parasitism) episode, number 261, centers on solving a clinical case involving a 32-year-old pregnant woman from rural Tanzania presenting with dehydration and three weeks of bloody, sticky diarrhea. The hosts and listeners leverage "Hickam's dictum" to consider multiple co-infections, ultimately diagnosing Giardia and Entamoeba based on stool microscopy. The patient successfully responded to metronidazole treatment. The episode also features Dame Bridget Ogilvie as a "parasitology hero," celebrating her pioneering work on IgE in helminth immunity and her impactful career in science and global health. A new, intriguing case of a family with mysterious skin-embedded objects following extensive travel is introduced, setting the stage for future discussions.
Solving the Case: Dual Parasitic Infections and a New Skin Mystery
0:00 Introduction & Podcast Support: Hosts Vincent Racaniello, Daniel Griffin, and Christina Naula open the episode, highlighting the podcast's commitment to unadulterated science, supported by listener donations. Christina shares a personal anecdote of meeting TWiP listeners at a malaria diagnosis course in London.
3:20 The Case of the Pregnant Woman from Tanzania: Daniel Griffin presents a clinical case: a 32-year-old pregnant woman in her second trimester from northern Tanzania, experiencing dehydration and three weeks of bloody, sticky diarrhea. Her water source is a nearby river, and initial bloodwork shows low hemoglobin and elevated creatinine. A key hint is provided: "Ockham would be confused but Dr. Hickam would know what to do," implying multiple causative factors.
33:20 Diagnosis and Treatment: Stool examination reveals the presence of both Giardia (explaining the sticky stool) and Entamoeba (accounting for the bloody stool). The patient is successfully treated with metronidazole, considered safe during the second trimester of pregnancy. The discussion emphasizes the importance of accurate laboratory diagnosis and promoting safer water sources.
41:40 Bonus Case: Hemorrhagic Gastroenteritis in a Puppy: Vincent introduces a bonus case about a 6-month-old puppy with bloody diarrhea post-spay that resolved after metronidazole treatment. Daniel suggests Hemorrhagic Gastroenteritis (HGE) as a likely diagnosis. Vincent also shares the puppy's inspiring story of rescue and successful surgery for a congenital heart defect (patent ductus arteriosus).
52:53 Parasitology Hero: Dame Bridget Ogilvie: Christina Naula features Dame Bridget Ogilvie, an influential Australian parasitologist. Her contributions include growing up on a farm with early exposure to parasites, pioneering research demonstrating the role of IgE antibodies in helminth immunity (published in Nature in 1964), and serving as the first director of the Wellcome Trust. She is highly acclaimed for her scientific achievements and advocacy for science education and global health.
53:00 New Case Introduced: The Skin-Embedded Objects Mystery: A new, multi-part case for listeners to solve is unveiled. It involves a family (mom, daughter, son) who discovered small, dark, "poppy seed"-sized objects embedded in their skin—with one even described as mobile—after extensive hiking trips across Scotland and the U.S. (Long Island, Cape Cod). This mystery prompts questions about the objects' identity, their relevance to the travel history, removal methods, and necessary testing/treatment.
General Discussions & Listener Engagement: The episode integrates diverse topics from listener emails, including the efficacy of metronidazole for anaerobic bacterial infections, the historical eradication of Schistosoma japonica in Japan, the potential of papaya seeds as a natural dewormer, and the limitations of mice as models for the human gut microbiome. Tributes to the late Dixon de Pomeier and his lasting legacy, including the new 8th edition of his "Parasitic Diseases" textbook, are also shared.