Outbreak Watch: Exactly as Expected

Summary

Introducing Outbreak Watch by Infectious Dose. Special outbreak update episodes featuring timely updates and systems-focused analysis. Tonight’s outbreak update follows two very different epidemics unfolding in real time: the expanding Bundibugyo Ebola outbreak in eastern Democratic Republic of the Congo and Uganda, and the slow-moving Andes hantavirus cluster linked to the MV Hondius cruise ship.

As official Ebola case counts rapidly catch up to earlier modeling projections, this episode explores why the outbreak is progressing almost exactly as epidemiologists feared. We break down the latest numbers, what genomic and geospatial analyses are revealing about transmission, and why WHO is now describing the situation in eastern DRC as a “catastrophic collision of disease and conflict.”

Then we turn to the Andes hantavirus cruise-ship cluster, where new cases continue emerging across multiple countries weeks after passengers returned home. The pattern is slow, geographically scattered, and entirely consistent with what we know about Andes virus transmission and incubation periods.

Finally, we examine the increasingly controversial U.S. decision to route potentially exposed Americans to a U.S.-run quarantine facility in Kenya instead of utilizing domestic biocontainment units — and what that says about the current state of American public-health infrastructure.

These outbreaks are not behaving unpredictably. They are exposing the vulnerabilities we already knew existed.

Listen here or scroll down to read full episode.

Full Episode

This is the inaugural Outbreak Watch episode. Outbreak Watch are special episodes released in addition to the weekly drop when unfolding outbreaks call for timely updates. Tonight we’re going to catch up on two outbreaks that have been simmering in the background for the last few weeks: the Ebola Bundibugyo virus epidemic in eastern DRC and Uganda, and the Andes hantavirus cluster linked to the MV Hondius cruise ship. Both of these are moving pretty much exactly the way we’d expect, given what we know about how they spread and the conditions on the ground. That doesn’t make them less serious. It just means none of this should be surprising.

For Ebola Bundibugyo, this is basically the scenario we talked about in the first episode on this outbreak: a dangerous virus, no approved vaccine, extremely fragile health systems, and active conflict all stacked on top of each other. For the cruise‑ship hantavirus outbreak, we’re seeing what happens when a virus with limited person‑to‑person transmission and a long incubation period rides home with people from all over the world.

I want to walk through what we know, why it looks the way it does, and what it says about where our public‑health systems are right now—including a decision that, if you’re in the U.S., should make you deeply uncomfortable: sending exposed Americans to Kenya for quarantine instead of bringing them home.

Ebola Bundibugyo: where the numbers are now

Let’s start in northeastern Democratic Republic of the Congo, in Ituri Province, where this outbreak was declared in mid‑May and is classified as a Public Health Emergency of International Concern.

Remember that Imperial College modeling we talked about last week? The one that estimated the true burden was likely sitting between 400 and 800 cases while official counts were still in the double digits? Well, the data have officially caught up. According to the most recent WHO update on the 26th DRC has reported 1077 suspected cases of Bundibugyo virus disease, including 238 suspected deaths. Of the samples tested, 121 came back positive, with 17 confirmed deaths, spread across 13 health zones in three provinces: Ituri, North Kivu, and South Kivu. Neighboring Uganda now has seven confirmed cases and one death, with the response currently centered in Kampala, and those are in people who either travelled from DRC or cared for earlier cases.

WHO and ECDC are both very clear that the risk is “very high” nationally in DRC and Uganda and “high” at the regional level, because transmission is not contained and the contact networks are big, mobile, and hard to see.

If we zoom in a bit, the outbreak is still heavily concentrated in Ituri. About 90% of suspected cases and deaths are coming from three health zones there: Mongbwalu, Bunia, and Rwampara. Among confirmed cases, Ituri accounts for almost 90%, with Rwampara, Bunia, and Mongbwalu again at the top. Early geospatial analysis is highlighting the Mongbwalu–Bunia–Nizi–Fataki corridor as the main transmission spine—a route woven through mining sites, small settlements, and busy roads.

So that’s the picture as of late May: hundreds of suspected cases, more than a hundred confirmed, a double‑digit confirmed death toll, and a growing footprint both within DRC and across the border in Uganda.

Why this is exactly what we expected

As grim as those numbers are, there is nothing here that’s surprising if you look at the virus and the setting.

First, the virus. This is Bundibugyo for which we don’t have a licensed vaccine or proven monoclonal antibody treatments. Experimental antivirals and antibodies exist in freezers and protocols, but nothing you can just roll out with confidence. That means the response leans on classic public‑health tools: find cases early, isolate them, provide intensive supportive care, protect health workers, and bury the dead safely.

Second, the geography and politics. This outbreak is unfolding in a part of eastern DRC that has been living in overlapping crises for years: armed conflict, displacement, food insecurity, gender‑based violence, and chronic under‑investment in health services. Mining is a huge driver of local economies and mobility in Ituri. Artisanal and industrial mining sites bring in workers from other regions, spin up informal settlements, and keep people moving along long, porous corridors. Early geospatial work suggests those mining‑linked routes probably facilitated undetected transmission before the outbreak was formally recognized. We know from the genomic sequencing we discussed last week that this outbreak started as a fresh spillover from nature, not a smoldering human chain left over from years ago. But what the latest geospatial mapping tells us is how that single spillover turned into a regional emergency: it hitched a ride on the highly mobile, informal transit corridors feeding the local mining economy.

Third, the operational reality. As of 24 May, DRC had identified 2 231 contacts, but only about 19% of them were actually seen in the 24 hours before that May 24th report. That contact‑tracing failure isn’t because people don’t know how to do contact tracing; it’s because insecurity, roadblocks, burned treatment tents, and community attacks on health facilities make it almost impossible. In Mongbwalu, a security incident led to part of an Ebola treatment center being burned and 18 suspected patients leaving on their own, while at least one confirmed patient was released under community pressure despite efforts to keep them in care.

So when we see more suspected cases, more deaths, expansion into new health zones, and confirmed cases popping up in Kampala among drivers, health workers, and patients, that’s not an unexpected twist. It’s exactly what you’d predict if you took a virus that spreads through close contact with bodily fluids, dropped it into a conflict‑affected mining corridor, and gave responders limited access and no vaccine.

That doesn’t make it “fine.” Last week, I said the situation in DRC was bad and would get worse. Nothing in the latest reports contradicts that; if anything, they underline it. You cannot do good community engagement, meticulous contact tracing, or safe, dignified burials while the people doing that work are being threatened, attacked, or displaced alongside everyone else.

WHO’s own language in a 27 May statement is unusually blunt: they describe a “catastrophic collision of disease and conflict” in eastern DRC, with Ebola outpacing the response, health facilities under attack, and exposed contacts pushed into overcrowded camps. They say, very plainly, “we cannot build community trust or isolate the sick while bombs are falling,” and they are urging all parties to agree to an immediate ceasefire so that teams can get safe, sustained access. That is not a technical problem. It’s a political choice.

What the response looks like on the ground

At the same time, it’s worth noting that a lot is happening, even if it’s not enough to completely turn the tide yet.

A continental Incident Management Support Team has been set up involving WHO, Africa CDC, and multiple partners to coordinate across DRC, Uganda, and at‑risk neighbors like South Sudan, Kenya, and Tanzania. Kampala is being used as a regional operational hub, and a six‑month response plan is under development. High‑level meetings between DRC, Uganda, and South Sudan in late May focused on cross‑border surveillance, joint contact tracing, and harmonizing how these countries screen travelers and share lab data.

On the logistics side, WHO reports that 52 surge staff have been deployed to DRC, and supply corridors from Kinshasa, Nairobi, and Dakar are pushing personal protective equipment, treatment‑center materials, lab reagents, and even specialized isolation transport systems into the region. In Bunia, earthworks are underway to expand Ebola treatment capacity, and warehouse and supply‑chain assessments are trying to make sure material doesn’t sit in a port while patients go without.

Surveillance is being scaled up in both countries: in DRC, that includes active case finding, retrospective reviews of deaths, and contact tracing, while Uganda is layering in digital tools and experience from previous Ebola responses. Formal points of entry are screening tens of thousands of travelers; one recent day in DRC saw about 11 000 people screened, with similar numbers in Uganda.

Laboratories are under strain but functioning: Last week, I talked about the diagnostic bottleneck of having to ship local samples all the way to Kinshasa just to see what Ebola species we were dealing with. We have some operational progress on that front: the Bunia Provincial Laboratory is now actively on the frontline, and had received 431 samples as of 24 May and tested 295, with a positivity rate around 36%. Additional RT‑PCR capacity and test kits are being pushed in, and both DRC and Uganda are doing confirmatory testing and sequencing at their national reference labs to better understand transmission chains.

If you step back, you can see the familiar outlines of an Ebola response: treatment centers being expanded, IPC training for health workers, safe burial teams working under impossible conditions, anthropologists and risk‑communication teams trying to understand and shift local perceptions, and a ring of neighboring countries quietly cranking up their preparedness. The problem is not that none of this is happening. It’s that it’s happening in a place where armed groups, fear, misinformation, and sheer exhaustion keep cutting the response off at the knees.

Andes hantavirus on a cruise ship: slow‑motion spread

Now, let’s step back into the cruise ship cluster. According to the latest update from WHO Director-General Dr. Tedros on May 27, a new case reported in Spain among quarantined passengers has brought the total to 13 cases, with the total number of deaths holding steady at three.

The important thing here is the pattern, which is exactly what you’d expect from Andes virus in this setting. The incubation period can be long, and some exposures may have happened on board late in the voyage, so health agencies fully anticipate that additional cases may show up after passengers and crew have gone home. WHO and ECDC both assess the risk to the general public as low because this virus does not spread like influenza or SARS‑CoV‑2; you don’t get community‑wide airborne transmission from a single cluster.

That doesn’t make it benign. Andes hantavirus can cause severe hantavirus pulmonary syndrome, and the fact that person‑to‑person spread is possible means you have to think carefully about how you manage close contacts of confirmed cases. But again, if you know the virus and the setting—a crowded ship, people from different countries, a long incubation—you would predict exactly this slow‑motion unveiling of cases, and that’s what we’re seeing. For more on hantaviruses check out my episodes on this outbreak (one and two) and my episode on Sin Nombre, that North American hantavirus that's usully the cause of HPS in the US.

This cruise ship hantavirus cluster isn't just a slow-moving maritime story; it has direct operational overlap with the Ebola response. Remember, it was the domestic isolation footprint of this very hantavirus cluster that initially maxed out U.S. containment capacity, forcing an exposed American scientist to be evacuated to Germany instead of the U.S. last week. As Dr. Tedros noted today that the hantavirus denominator has crept up to 13 cases, the domino effects on global containment logistics continue.

The U.S., Ebola, and why patients are going to Kenya

The last piece I want to talk about is where U.S. citizens who might be exposed to this Ebola Bundibugyo outbreak are being sent.

Last week, we talked about the administration's blunt Title 42 travel ban—an architectural panic move that historically does more epidemiological harm than good. Now, that isolationist approach has evolved into something even more ethically fraught: rather than using our own state-of-the-art biocontainment units to monitor exposed or positive American personnel, the plan is to route them to a U.S.-run facility on Kenyan soil.” The facility would not just monitor exposed people—it could also hold individuals who test positive and prevent them from returning to the U.S., with onward transfer for treatment in Europe if they become ill.

If you’ve followed previous Ebola responses, you’ll notice how different that is from what we’ve done before. In earlier outbreaks, including the 2014–16 West Africa epidemic, U.S. citizens and health‑care workers who were exposed were typically flown back to specialized biocontainment units in the U.S.—places like Emory, Nebraska, and NIH—which were designed precisely for this purpose. Those centers proved they could care for Ebola patients safely, protect staff, and prevent onward spread.

So why route people to Kenya now? They say it's to prevent ebola from being released in the US. So if the only way they think they can do that is by not sending them here at all then they have zero trust in U.S. public‑health capacity. Now this administration including rfkjr has gutted US public health. We've lost funding, staff, experts and had extreme political interference in NIH, CDC, FDA, and HHS. They are right now asking for volunteers to screen people for Ebola at US airports because they have no staff. They fired everyone. So they aren't entirely wrong to question what we can handle but the bigger issue here is this: If your own administration does not believe your domestic health‑care system can safely manage a small number of Ebola patients in high‑containment units, that is an absolute indictment of their own public health policies.

You’re effectively outsourcing risk and responsibility to a country that is already a regional hub for outbreak response, and you’re doing it in the middle of a crisis centered in its neighborhood. Even if the facility is technically run by U.S. staff, it sits on Kenyan soil, under Kenyan regulatory and political realities, and it sends a very clear message about who is considered safe to bring home.

And just like with the rest of this episode, none of that is truly surprising if you look at the trajectory of U.S. public health under trump. When you hollow out your own systems, sideline your own experts, and treat serious outbreaks primarily as political problems, you eventually get to a point where, faced with a high‑consequence pathogen, you decide the safest thing to do is send your citizens somewhere else.

That’s not where the story has to end—but it's exactly where we are right now.

Closing

Ebola and hantavirus became fixtures of our public imagination before most people understood how they actually function. But as we’ve seen today, once you strip away the cinematic mythology, these outbreaks unfold along highly predictable lines. Pathogens don't create emergencies in a vacuum; they exploit the cracks we leave open for them—whether that’s a mobile mining corridor in a conflict zone, a crowded cruise ship with a long incubation window, or a domestic public health system hollowed out by political choices.

None of this is truly unexpected when you understand the biology of these viruses and the vulnerabilities of the human systems they move through. The question we have to confront is what we are actually willing to change so that “exactly as expected” doesn’t always mean “and many more people will die.”

Thanks for being here. If you want these weekly outbreak updates delivered straight to your inbox, make sure to subscribe to my newsletter, Field Notes. Every Wednesday morning, I pull a single thread from that week’s episode to see exactly where it leads, give you a raw look behind the scenes, and provide the latest updates on ongoing outbreaks so you can stay ahead of the curve.

Next week, we are pivoting to a threat that hits incredibly close to home for me. Living here on the Texas Gulf Coast, we are at the doorstep of hurricane season. But we aren’t just talking about high winds and evacuation routes. We are diving into the aftermath—specifically, how extreme precipitation events and catastrophic flooding fundamentally alter the local environment to trigger infectious disease outbreaks. Plus, I’m going to walk you through how to build a practical, scientist-approved infectious disease emergency prep kit so you’re ready for whatever the season throws at us. You won't want to miss it.

Until then, stay healthy, stay informed, and spread knowledge not diseases.