This Week in Parasitism

TWiP explains research showing that treatment of baby wraps with an insect repellent, and oral dosing with ivermectin, are both effective measures to prevent malaria. Hosts: Vincent Racaniello, Daniel Griffin, and Christina Naula Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server Treated baby wraps prevent malaria (NEJM) Oral ivermectin prevents malaria (NEJM) Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees

TWiP solves the case about the parasite check in summer camp, and presents a new case about a woman who traveled to Brazil and developed furuncles on the back of her head. Hosts: Vincent Racaniello, Daniel Griffin, and Christina Naula Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server Hero: Francesco Redi Wikipedia: https://en.wikipedia.org/wiki/Francesco_Redi Linda Hall Library, Kansas: https://www.lindahall.org/about/news/scientist-of-the-day/francesco-redi/ Habermehl, G., (1994). Francesco Redi—Life and work, Toxicon 32 (4) https://doi.org/10.1016/0041-0101(94)90292-5. Letters read on TWiP 265 New Case From Eyal Leshem, a returning case "provider" 43 years old female who travelled to Brazil on May 2025 for a two week dance class. The dance school is located in a farm two hour drive West of Rio de Janeiro. Upon return to Israel she started feeling pricking and "movements" and under her scalp on the back of her head. She noted three non-healing furuncles on the back of her head A month after she returned movement and pricking in the back of her scalp increased, the furuncles enlarged and produced serous discharge. Several days before her ED visit she thinks an "object" dropped from the back of her scalp, but being outdoors, she could not locate the object. On physical examination she is afebrile and her vitals are normal, and on the back of her head two indurated were detected under the hair on the back of her head. Serous discharge was produced by pushing the furuncles. A non-surgical office procedure led to immediate recovery and confirmed the diagnosis. What was the parasite? What was the procedure? Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees

Vincent and Daniel discuss research showing that Toxoplasma gondii infection of the brain alters extracellular vesicle production and the communication between neurons and astrocytes. Hosts: Vincent Racaniello and Daniel Griffin Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server T. gondii infection of neurons (PLoS Path) Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees

TWiP solves the case of the world travelers with poppy-seed size dots embedded in their skin, then present a new case about parasite check in summer camp. Hosts: Vincent Racaniello, Daniel Griffin, and Christina Naula Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server Hero: Dr Laurence Tetley Letters read on TWiP 263 New Case It is the first day of summer camp and the children are lined up for a parasite check. Some of the children have certificates that allow them to bypass the screening. Some of the parents are upset about this process commenting that this is not required by the state and report this could not be a problem for their children. One by one the children have their scalps examined and 2 of the children are asked to step to the side. The parents of these two children are contacted and told that they must address the identified concern before they can attend the camp. They are treated with a topical therapy on their hair with repeat in 1 week. The upset parents have several questions that hopefully our listeners can address. -what is this all about? -is anyone suggesting this is a hygiene issue? -what is the most sensitive way to look for this problem? -how do we know it is cured? -feel free to talk about the life cycle Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees

TWiP reviews research suggesting that schistosome infection affect behavior through the gut-brain axis, and Chuck Knirsch joins to reminisce about Dickson Despommier. Hosts: Vincent Racaniello, Daniel Griffin, and Christina Naula Guest: Chuck Knirsch Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server Does schistosome infection affect behavior? (PLoS NTD) Hero: Harold Brown (NY Times) Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees

TWiP solves the case of the pregnant woman from Tanzania with dehydration and 3 weeks of bloody stool, a situation that would confuse Ockam but not Dr. Hickam. Hosts: Vincent Racaniello, Daniel Griffin, and Christina Naula Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server Hero: Dame Bridget Ogilvie (Interview and Wiki) Letters read on TWiP 261 New Case I feel like the back section of our book has been a bit neglected. The new PD 8th Edition is posted on our website so please download a copy and extra points to anyone who can tell us what that is on the cover. Three individuals are involved here with a rather impressive travel history. We have a mom, a daughter and a son who reach out for guidance. Initially one of them found something small dark and about the size of a poppy seed embedded in their skin. This led to a more involved investigation where they found that all three had similar findings but some of these were larger, some a bit larger, one was actually described as mobile. They all feel fine and report no skin rashes. They have a number of concerns about what these are, if they might carry disease, what to do about removing them and should there be testing or treatment. The interesting travel and exposure history. They report that just prior to this they spent a week on a remote island off the coast of Scotland with extensive hiking in tall grass and boggy areas with deer, rabbits, and lots of sheep. An Island called Harris and Lewis and then just that Saturday hiking in wooded areas around Loch Ness and in the Cairngorns. Sunday out hiking and running on Long Island and then Wednesday when these mystery objects were found they had just been hiking and going for a run in Cape Cod. They report on Cape Cod the trail they followed had a fallen tree and they had to crawl underneath it prompting this skin inspection. -lots of questions here… What might these be and how do we identify them? Is the travel history relevant? Are there any timing issues that impact what we do? Should we try to remove these and if so how? Any testing or treatment indicated? Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees

TWiP explains how circadian clocks of parasite and vector circadian mediate efficient malaria transmission. Hosts: Vincent Racaniello, Daniel Griffin, and Christina Naula Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server Clocks mediate malaria transmission (Nat Micro) Hero: Dame Bridget Ogilvie (Wiki) Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees

TWiP solves the case of the man in the Malaysian city of Kucheng who presents with daily fevers and shaking chills, and serve a new clinical puzzle for you to solve. Hosts: Vincent Racaniello, Daniel Griffin, and Christina Naula Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server Letters read on TWiP 259 New Case Another case from Northern Tanzania, up by the border of Kenya. 32 yo pregnant woman admitted to the hospital, dehydrated, reporting 3+ weeks of diarrhea. Second trimester, second pregnancy, reports stools are sticky and it is hard to get herself clean. She also noticed blood mixed in the stool. No fever, no chills, but she feels weak. While many in the area get their water from boreholes, rivers and rainfall she reports getting hers from a nearby river. She lives with her husband and one child who is 2 years old. She is HIV negative and reports she had been in good health otherwise. She looked tired and worn down when she arrived in the hospital but is already feeling better. Her blood work is notable for a low hemoglobin and elevated creatinine. Stool studies are sent and Ockam would be confused but Dr Hickam would know what to do. Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees

TWiP describes how a gut commensal protozoan influences respiratory disease outcomes by shaping pulmonary immunity, and body shape variation in lice that parasitize diving hosts. Hosts: Vincent Racaniello, Daniel Griffin, and Christina Naula Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server Gut commensal shapes pulmonary immunity (Cell) The deeper the rounder (Sci Rep) Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees

TWiP solves the case of the man in the Malaysian city of Kucheng who presents with left arm swelling, and presents a new case for you to decipher. Hosts: Vincent Racaniello, Daniel Griffin, and Christina Naula Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Links for this episode Join the MicrobeTV Discord server Letters read on TWiP 257 New Case We are still in Kuching, Malaysia in the northern part of the Island of Borneo. This is the Sarawak portion of Malaysia. A man in his late 30s is admitted to the hospital in December with daily fevers that last for several hours and shaking chills. He had previously been healthy with no medical problems. He lives in the city and works in an office, however, in the few weeks prior to getting admitted he was visiting the jungle. Apparently not too far outside of Kuching, one can go up into the jungle and see Orangutans. He had gone into the jungle but this was 2 weeks prior to the onset of symptoms. Since then he reports no unusual exposures. He lives with his wife and children and they are all healthy. A few days prior to admission he noted fever, chills, and a headache. He is a little nauseated but no vomiting. On exam he has a fast heart rate and appears ill. His respiratory rate is increased and he is not febrile on admission but later does have fever. No enlargement of the liver or spleen on exam. Otherwise unremarkable. His labs are notable for low white blood cells, anemia, and a platelet count of less than 50k per microL. His coagulation studies are abnormal, serum creatinine is elevated, and there is elevation of his serum aminotransferases. Become a patron of TWiP Send your questions and comments to twip@microbe.tv Music by Ronald Jenkees