Pathogen Perspectives

Outbreak Watch returns with updates on three unfolding biological events and the systems responding to them. This week: • The Bundibugyo Ebola outbreak in the Democratic Republic of the Congo becomes the largest on record as contact tracing, clean water access, and response operations face growing challenges. • The Andes hantavirus outbreak linked to the MV Hondius cruise ship is behaving as expected, providing an important lesson in what successful containment looks like. • New World screwworm detections in the United States highlight ongoing debates about surveillance, preparedness, and the challenges of responding to an emerging threat when critical systems must be rebuilt. In this episode, we explore visibility, uncertainty, and the operational realities that shape outbreak response long before most people hear about it. For weekly outbreak updates, subscribe to the free Infectious Dose newsletter, Field Notes, at infectiousdose.com

In this episode of Infectious Dose, Heather explores one of the strangest allergic conditions modern medicine has ever identified: a syndrome in which a tick bite can trigger an allergy to mammalian meat weeks, months, or even years later. Why do symptoms often appear in the middle of the night instead of immediately after a meal? How did a cancer drug help scientists solve the mystery? Where does the alpha-gal molecule come from, and why do ticks seem uniquely capable of triggering this unusual immune response? Join us as we follow the trail from the woods to the dinner table and unravel the science behind alpha-gal syndrome. In this episode: • What alpha-gal syndrome is and how it develops• The surprising role of the Lone Star tick• The cancer drug clue that helped solve the mystery• Why reactions are delayed for hours after eating• Diagnosis, testing, and common misconceptions• Living with AGS and preventing future tick bites• Separating evidence from conspiracy theories Part of our June series, Stories of Summer Rain, this episode explores how warm, wet environments shape the ecosystems around us—and how those ecosystems can unexpectedly shape our health. Referenced resources and scientific citations are available at InfectiousDose.com. Subscribe to Field Notes, the free Infectious Dose newsletter, for weekly Outbreak Watch updates and additional resources.

Introducing Outbreak Watch by Infectious Dose. When major outbreaks evolve quickly, Heather will occasionally release these extra episodes featuring timely updates and systems-focused analysis. In this first Outbreak Watch episode, we examine the rapidly escalating Bundibugyo Ebola outbreak in eastern DRC and Uganda alongside the continuing Andes hantavirus cluster linked to the MV Hondius cruise ship. We break down the latest WHO numbers, why Ebola transmission is accelerating through conflict-affected mining corridors, what new genomic and geospatial analyses reveal about the outbreak’s spread, and why public-health responders are struggling to contain it amid violence and instability. We also discuss the newest hantavirus cases emerging internationally weeks after passengers returned home, why the slow appearance of additional cases is expected for Andes virus, and how this cluster has already affected global biocontainment logistics. Finally, we look at the U.S. decision to send exposed Americans to a quarantine facility in Kenya instead of bringing them home for monitoring and treatment — and what that reveals about confidence in domestic public-health systems. Pathogens don’t create emergencies in isolation. They exploit the vulnerabilities we leave open for them.

A new Ebola outbreak is unfolding in Central Africa — this time caused by Bundibugyo ebolavirus. As cases rise in the Democratic Republic of the Congo and Uganda, fear and misinformation are spreading too. In this episode, we break down: What Ebola actually is How Ebola spreads — and how it doesn’t Why healthcare workers and caregivers are at highest risk What happens inside the body during Ebola infection Why Ebola outbreaks amplify through strained systems The latest updates on the 2026 Bundibugyo outbreak Newly released genomic data suggesting a possible new spillover event Hot Zone Hotline for listener questions This episode also explores the human side of Ebola outbreaks: caregiving, fear, stigma, survival, and the difficult realities faced by affected communities. Companion blog post with transcript, references, outbreak updates, and photographs from the 1995 Kikwit outbreak: Infectious Dose Subscribe to the free weekly newsletter, Field Notes, for outbreak updates and behind-the-scenes context.

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

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

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

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

When we talk about misinformation in public health, we usually imagine social media, conspiracy theories, or individuals misunderstanding science. But what if some of the most influential misinformation starts somewhere else? In this episode of Infectious Dose, Heather speaks with biomedical researcher Dr. Mark Ungrin about how scientific ideas move through institutional systems and why correcting errors can be surprisingly difficult once they become embedded in policy. They discuss: Why “human error” is often a misleading explanation for systemic failures How flawed studies can shape public health guidance Why institutional hierarchies can make correcting mistakes difficult The role of evidence-based medicine in shaping policy decisions Why transparency and accountability are essential for rebuilding public trust This conversation explores how misinformation can emerge from institutional processes themselves — and why understanding those systems is critical for responding more effectively to future pandemics and biological threats. 👉Dr. Ungrin's Talk: Science, Pseudoscience and Public Policy https://whn.global/science-pseudoscience-and-public-policy/ Transcript and sources at infectiousdose.com

What if attraction isn’t entirely yours? In this Outbreak After Dark episode, Heather, Kate, and Sam gather around the campfire to explore the parasites, fungi, and viruses that manipulate behavior in the name of survival. We’re talking: Toxoplasma gondii, the parasite that dampens rodents’ fear of cats The lancet liver fluke, which turns ants into grazing bait Ophiocordyceps, the real-life “zombie ant” fungus Baculoviruses that liquefy caterpillars from the treetops Hairworms that drive crickets into water Limb-altering trematodes that make frogs easier prey Insect viruses that disrupt courtship songs and pheromones And the global rise of antifungal-resistant Candidozyma (Candida) auris Then we turn the lens toward humans. Do gut microbes influence mood and attraction? Are pheromones real? What happens to your microbiome when you kiss someone? (Answer: about 80 million bacteria exchange in ten seconds.) This episode blends behavioral ecology, evolutionary strategy, fungal cautionary tales, and just enough snack-fueled chaos to keep it campfire-worthy. Because love isn’t always sweet. Sometimes it’s optimized. 🔥 Recipes for Parasite Punch, Symbiosis Spritz, Zombie Ant Tapenade Toasts, and Courtship Clusters are available on infectiousdose.com.

Syphilis is back—and it never really left. In this episode, we break down how a curable, preventable infection is resurging to cause a public health crisis across the U.S., and globally, especially among pregnant people and newborns. We unpack the science behind Treponema pallidum, the public health failures driving the crisis, and why trust in health systems is still broken—from Tuskegee to today. Plus: what you need to know about testing, treatment, and why a shot of penicillin makes all the difference. Sources at Infectiousdose.com

RSV is one of the most common respiratory viruses — and a leading cause of hospitalization in young children worldwide. In this solo episode, I explain what RSV is, how it spreads, and what illness typically looks like in babies, children, and adults. We cover when RSV can be managed at home, how to recognize breathing-related red flags, when to go to the ER or call an ambulance, and what supportive care actually helps. The episode also looks at the current RSV landscape, including rising cases in parts of the U.S. and new prevention tools — maternal vaccination and long-acting monoclonal antibodies — that are dramatically reducing severe RSV disease in infants. Clear, practical, and evidence-based. https://www.healthychildren.org/English/health-issues/conditions/chest-lungs/Pages/RSV-When-Its-More-Than-Just-a-Cold.aspx