Infectious Dose

Infectious Dose
  • 5.0 (9)
  • LIFE SCIENCES
  • UPDATED WEEKLY

Infectious dose is the shot of science you need to protect yourself from misinformation. Heather McSharry, PhD, an expert in viral pathogenesis, brings her blog to the airwaves to help bridge the dangerous gap between the science of infectious diseases and public misperception. On the podcast website, infectiousdose.com, all episodes have corresponding blog posts with the information contained in the episode along with links or PDFs for all sources used. To prevent unwelcome surprises, episodes with limited, mild profanity are marked as explicit. *Podcast intro and outro music are adapted from Heather Nova’s song, I Miss My Sky. Used with permission.

  1. 4D AGO

    S2E19 Hantavirus on the High Seas Part 2: What Changed, What Didn’t, and Why the Conversation Got So Messy

    Last week, the central question surrounding the MV Hondius outbreak was whether Andes virus was spreading person-to-person at all. This week, the evidence shifted. In Part 2 of Hantavirus on the High Seas, we revisit the major questions from last week’s episode and examine what new genomic data, case timelines, and public-health guidance now suggest about the outbreak. We break down what changed, what remains uncertain, and why the public conversation around “airborne” spread, “prolonged close contact,” and precautionary public-health measures became so messy in real time. Topics include: Updated case timeline and international spread New genomic sequencing analysis Evidence supporting likely person-to-person transmission Why “person-to-person” does not automatically mean “pandemic-level spread” The difference between scientific evidence and public-health operations WHO’s new technical guidance for disembarkation and quarantine The Tristan da Cunha military medical deployment The International Hantavirus Society’s updated statement Why outbreak language became so contentious after COVID This episode is less about headlines and more about learning how scientific understanding evolves while an outbreak is still unfolding. Subscribe to weekly Field Notes to continue the conversation Companion blog post with annotated citations at infectiousdose.com

    36 min

  2. MAY 6

    S2E18 Hantavirus on the High Seas: How We Talk About Outbreaks When the Evidence Is Still Coming In

    A hantavirus outbreak linked to a cruise ship has triggered fear, speculation, and growing debate online about whether the virus could be spreading person-to-person. But what do we actually know right now? In this episode, Heather breaks down the current hantavirus cruise cluster through the lens of science communication and uncertainty. Rather than focusing only on the facts of the outbreak, this episode explores a bigger question: What does trustworthy, imperfect outbreak communication sound like when the evidence is still coming in? Topics include: the timeline of the current cruise ship cases why the first infection almost certainly occurred before boarding the difference between hantavirus “airborne” transmission and viruses like measles what we know about Andes virus and rare person-to-person spread how outbreak investigations work in real time and why “we haven’t ruled it out” is not the same thing as “this is happening” Heather also introduces a practical framework for understanding outbreak communication. This episode is about resisting panic, avoiding false certainty, and rebuilding a clearer understanding of how science works when the story is still unfolding. Heather will also be following the outbreak with updates in her free, weekly newsletter, Field Notes. Subscribe at the link if you want to join the conversation. All citations in the companion blog post at infectiousdose.com

    18 min

  3. APR 29

    S2E17 Remedies and Regrets: The Worst Infection Treatments in History

    Imagine getting sick in the 1700s—before microbes were discovered, before antibiotics, and before infection had a clear cause. In this Outbreak After Dark episode, we explore the strange, unsettling, and sometimes surprisingly insightful treatments used to fight disease in the pre-germ theory era. From bloodletting and mercury to tobacco smoke enemas and malariotherapy, these practices reflect a time when medicine was working without seeing the real enemy. Along the way, we also uncover the rare moments when history got it almost right—and how those moments helped shape the science we trust today. Don't forget to sign up for my free weekly newsletter Field Notes, to continue the conversation around each episode. Transcript and annotated citations in companion blog post at infectiousdose.com

    43 min

  4. APR 22

    S2E16 The Call Came From Inside: Epstein–Barr virus and the biology of persistence

    There’s a virus you probably already have. Epstein–Barr virus infects nearly 95% of adults worldwide. For many, it shows up once—fatigue, a sore throat, maybe a diagnosis of mononucleosis—and then disappears. But EBV doesn’t disappear. It stays, establishing lifelong infection inside B cells—the very cells responsible for immune memory. Most of the time, the immune system keeps it under control. But EBV is not passive. It shifts between latency and reactivation, adapts to immune pressure, and in some cases contributes to cancer and chronic disease. In this episode, we explore: How EBV infects epithelial cells and B cells The molecular mechanisms that allow it to persist for life Latency, reactivation, and immune system control Why EBV is linked to cancers like Hodgkin lymphoma and nasopharyngeal carcinoma How host genetics and viral variation shape disease risk And what new research suggests about finally preventing infection This isn’t just a story about a virus. It’s a story about what happens when infection never truly ends. Want to go deeper? Field Notes is my free, weekly newsletter where I expand on one key idea from each episode. It’s not a summary—it’s a shift in perspective. Subscribe here. Annotated citations are in the companion blog post at infectiousdose.com

    21 min

  5. APR 15

    S2E15 Scratching the Surface: How We Miss Murine Typhus

    Murine typhus is a flea-borne bacterial infection that continues to circulate in parts of the United States, particularly in urban and suburban environments. But it’s often missed—because its symptoms are nonspecific, its rash may be subtle or absent, and it doesn’t fit the diagnostic patterns clinicians expect. In this episode, we explore: How murine typhus is transmitted (and why fleas matter more than you think) The role of urban ecology, including opossums, rodents, and flea vectors What happens biologically when Rickettsia typhi infects endothelial cells Why these infections are frequently misdiagnosed or overlooked This is not just an episode about typhus—it’s about how recognition fails, and what that means for the diseases hiding in plain sight. Also in this episode, introducing Field Notes, the new, free email newsletter companion to the episodes - not a recap, but what stays with Heather after the episodes. Issues are sent mid-morning after episodes drop. Sign up on the website if you want to receive Field Notes.  Companion blog post with transcript and all citations is at infectiousdose.com

    25 min

  6. APR 8

    S2E14 In the Quiet Hours: A Year of Science and Storytelling

    One year in, Heather steps back to reflect on what this podcast has become—and what changed along the way. What started as a focus on clear, accurate science grew into something more layered: an exploration of how trust, systems, and lived experience shape the way people understand infectious disease. It also opened the door to creative storytelling, immersive formats, and conversations that challenged her own assumptions. This episode includes a few short clips from the past year—moments that capture the range of the show, from unsettling to unexpected to quietly funny. If you want to keep following those threads a little further, Heather is starting a free, weekly companion called Field Notes—a place to sit with one idea from each episode and see where it leads. The first issue arrives with next week's episode.  Whether you’ve been listening from the beginning or just found your way here, thank you so much for listening. We're glad you’re here. Companion blog post at Infectiousdose.com

    20 min

  7. APR 1

    S2E13 Inside the Suit: An immersive walk through a BSL-4 lab

    You’re about to step inside a BSL-4 lab. Not a tour. Not an explanation. An experience. You’ll move through clearance. Suit up. Connect to air. And cross the threshold into one of the most controlled environments in the world. Inside, the work is methodical. Quiet. Precise. And everything you think you know about these labs… starts to shift. Put your headphones on. And step inside. More information and resources can be found at infectiousdose.com.

    35 min

  8. MAR 25

    S2E12 The Bell, the Beak, and the Mark: Plague Doctors and the Fear of Contagion

    The plague doctor: a symbol of fear, medicine, and mystery. But were they really the heroes we imagine—or something more complicated? In this Outbreak After Dark episode, we explore the real history behind the iconic beaked mask. From medieval theories of “bad air” to the rise of quarantine systems and early public health policy, we follow the evolution of plague response—and the role of the doctors at its center. Along the way, we unpack: What plague doctors actually did (and didn’t do) Why their treatments were mostly ineffective How quarantine emerged as one of the few strategies that worked The rise of epidemic bureaucracy—and what it meant for ordinary people Why the plague doctor image still resonates today This episode also explores the emotional reality behind the mask—both in the past and in modern medicine—and asks a deeper question: What does care look like when distance becomes necessary? 🔥 Plus: our themed Masks & Miasma snack break, with recipes and all citations in the blog post at infectiousdose.com

    39 min
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5
out of 5
9 Ratings

About

Infectious dose is the shot of science you need to protect yourself from misinformation. Heather McSharry, PhD, an expert in viral pathogenesis, brings her blog to the airwaves to help bridge the dangerous gap between the science of infectious diseases and public misperception. On the podcast website, infectiousdose.com, all episodes have corresponding blog posts with the information contained in the episode along with links or PDFs for all sources used. To prevent unwelcome surprises, episodes with limited, mild profanity are marked as explicit. *Podcast intro and outro music are adapted from Heather Nova’s song, I Miss My Sky. Used with permission.

Information

  • Creator
    Infectious Dose
  • Years Active
    2020 - 2026
  • Episodes
    64
  • Rating
    Explicit
  • Copyright
    © Copyright 2020 All rights reserved.
  • Show Website
    Infectious Dose

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