Infectious Dose

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 nurse in Louisiana receives an HIV diagnosis that doesn’t make sense.

No clear exposure. No obvious source. And eventually, investigators begin to suspect something far more disturbing.

In this episode of Outbreak After Dark, Heather and Kate explore the real case that brought forensic virology into the courtroom for the first time. Through genetic sequencing and phylogenetic analysis, scientists traced the relationships between viruses to help prosecutors build a criminal case against a physician accused of intentionally infecting his former partner.

How can a virus become evidence?
What can viral evolution reveal?
And how do you explain that science to a jury?

This is the story of the case that asked whether a virus could testify.

Topics include:

• Forensic virology
• Viral mutation and transmission
• Scientific evidence in criminal court
• Daubert standards
• The Richard Schmidt case

And because this is Outbreak After Dark, there’s also a menu:
• Chain of Custody cocktail
• Cold Case File mocktail
• Trace Evidence Bites
• Gel Run Layers dessert

All recipes and citations in the companion blog post at infectiousdose.com

Subscribe to the free weekly newsletter, Field Notes, to continue the conversation.

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.

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

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

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 

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

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

 

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

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.