The World Health Organization has declared an Ebola outbreak in the Democratic Republic of Congo to be a "public health emergency of international concern". Officials say at least 91 people have died in the central African country, and there are more than 350 suspected cases. The current outbreak of Ebola is caused by the Bundibugyo virus, for which there are no approved drugs or vaccines.

We ask the BBC's health and science correspondent James Gallager how worried the world should be about the spread of Ebola.

The WHO chief Tedros Adhanom Ghebreyesus has said there are "significant uncertainties" about the scale of the outbreak. At least one person has died of Ebola in Uganda - the DRC's neighbour to the northeast. Another neighbour, Rwanda, has increased screening at the border. And at least six Americans who were exposed to the Ebola virus in the DRC may be taken to a US military base in Germany for treatment.

Three poisoned by mushrooms foraged in California wine country amid ‘unprecedented’ outbreak

The CDC is having people isolating in their homes wear a respirator if they are near others in the house. Also and most importantly they say a health department worker will come to the house twice a day in person to check on them. This is crucial and actually allows the initial rise in temperature which is believed to be the most contagious time to be caught before household members are exposed. This is a huge change from the scouts honor of taking one's own temperature and not wearing a respirator when out of the room.

https://www.cdc.gov/hantavirus/php/emergency-guidance/index.html#:~:text=Coordinate%20any%20urgent%20or%20necessary,home%20and%20away%20from%20others

General precautions

Health departments should advise all individuals with high-risk exposure to modify their activities during the monitoring period to protect their household members and communities as follows:

• Practice good hand hygiene
• Ensure good ventilation
• Wear a respirator or well-fitting mask that covers the mouth and nose, if indoors with others
• Maintain distance
  • Avoid kissing, hugging, or other intimate contact
  • Avoid sharing a bedroom with anyone
• Avoid exposing others to bodily fluids
  • Avoid sharing items that may be contaminated (e.g., toothbrushes, cigarettes/vapes/hookah, or unwashed towels, bedding, or clothing, etc.)
  • Avoid sharing food out of the same plate or bowl, eating from the same utensil, or sharing beverages
• Delay nonessential medical or dental appointments
  • Coordinate any urgent or necessary care with the health department in advance and notify the healthcare facility

Monitoring

• Monitoring by the health department should occur twice daily, in person

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In outbreak investigations, health officials often describe infections in “generations”:

• First-generation cases are the original infected individuals.
• Second-generation cases are people infected directly by the first group.
• Third-generation cases are people infected by the second group, meaning the virus has moved beyond the original cluster into the wider community.

At the moment, health authorities are closely watching for possible third-generation hantavirus cases linked to the cruise ship outbreak.

Key Dates in the Timeline

April 24
This is considered the most important starting date in the outbreak timeline. Twenty-nine passengers left the cruise ship before the hantavirus risk was fully understood. Because these passengers traveled internationally, officials began monitoring for possible infections from this point onward.

May 12
As of this date, all confirmed cases were still connected directly to the ship. No confirmed wider community transmission had been identified.

May 15 to Late May
This period is considered the earliest likely window for new symptomatic cases to appear among passengers who left the ship earlier, or among people they may have infected before showing symptoms themselves.

If unrelated people begin developing symptoms during this period, it could indicate that the virus spread before infected passengers became visibly ill.

May 19
Public health experts identified this as an important checkpoint date. By around this time:

• Additional passengers infected on the ship would likely begin showing symptoms.
• The earliest potential third-generation cases could also start appearing.

A significant rise in cases around this date would suggest the virus spreads more easily between humans than initially hoped.

June 5
This is considered a more likely timeframe for third-generation cases if symptomatic passengers infected household members or close contacts after leaving the ship.

For example:

1. A passenger becomes sick.
2. They infect a family member or partner.
3. That person develops symptoms several weeks later.

End of June
Officials believe the end of June is the point at which they could confidently say the outbreak has likely ended, assuming no new cases appear.

Because hantavirus can have a long incubation period, health authorities may need several weeks of no new infections before declaring the situation contained.

The leading hypothesis A landfill site on the outskirts of Ushuaia where tourists watch birds — waste attracts rodents, rodents carry Andes virus. Anonymous Argentinian officials have floated this as their primary theory. Locally it has gone down like a cup of cold sick.

Ushuaia's defence The provincial epidemiologist makes a genuinely substantive case, not just political deflection. Zero recorded hantavirus cases in Tierra del Fuego since 1996. Wrong climate, wrong humidity, wrong rodent subspecies — the long-tailed pygmy rice rat's endemic zone (a geographic area where a particular disease or organism is consistently present at a baseline level) is 1,500km north. Being an island with the Strait of Magellan as a barrier adds another layer of difficulty for rodent migration.

The actual likely origin The epidemiological reconstruction points to the Dutch couple — almost certainly patient zero — having contracted it two to four weeks before boarding, probably in the Patagonian provinces of Neuquén, Río Negro or Chubut. That's the established endemic zone. Their four-month road trip through Argentina, Chile and Uruguay before boarding on April 1st is the exposure window investigators are working through.

The investigation on the ground Argentina announced a team of experts to trap and test rodents at the landfill. Two days later they still hadn't shown up. The BBC visited the site and found birds circling piles of waste and no active investigation. Vintage.

The economic stakes 95% of Antarctic cruises depart from Ushuaia. Over 500 port calls annually. No cancellations yet but the season just ended — the real damage assessment comes later.

The Dutch couple can't fill in the gaps because they're dead. That's the brutal epistemological problem at the centre of this entire origin investigation.

Twelve hospital staff at Radboud University Medical Centre will be in isolation for six weeks after failing to follow strict PPE protocols when treating a hantavirus-infected patient evacuated from the cruise ship MV Hondius

Harvard Professor Contradicts Official CDC Messaging on Andes Virus Transmission

Professor Joseph Allen, an Exposure Assessment Scientist at Harvard University, is publicly challenging the official public health messaging around Andes hantavirus transmission — and he's backing it with published literature and first-hand accounts from the ship.

What officials are saying That transmission requires prolonged close contact and is very difficult to pass between people.

What the science actually says Allen went to the primary literature expecting to find support for that claim. He didn't find it. The best available paper on Andes transmission does not support the prolonged close contact requirement.

What happened on the ship Initial cases involved close contact with treating medical staff — expected. But subsequent cases occurred among passengers who only shared a dining room or lecture hall with no close physical contact. The ship's doctor contracted it and had to be evacuated.

The birthday party precedent In a prior land-based Andes outbreak, transmission occurred between people who briefly said hello in passing at a 90-minute gathering. People at separate tables got sick. One attendee later died and passed it to his wife at his funeral — she then transmitted it to ten other people.

His bottom line Overall public risk remains low and this is not a COVID-scale event. However people currently in quarantine need accurate transmission information because if they believe only intense close contact matters, they will inadvertently create secondary transmission chains within their own households.

Ventilation and air filtration are relevant if airborne spread is confirmed — same principles that applied during COVID.

Welcome to r/Outbreak

Good to have you here.

If you've landed here, you're probably the type who reads past the headline, wonders how these things actually spread, and finds the intersection of biology, human behaviour, and global events genuinely fascinating. You might also be the type who binges pandemic films but spends half the runtime muttering about implausible transmission vectors. The world is stranger and more complex than the news cycle suggests, and outbreaks have a way of making that very clear very fast.

What we're here for

Tracking and discussing outbreaks as they happen around the world, with enough context to actually understand them. New pathogens, historical parallels, the occasional "wait, that's spreading where?" moment. We follow the evidence, favour credible sources, and try to generate more light than heat.

What good posting looks like here

Interesting links, genuine questions, informed discussion, dark humour. You don't need a science degree to contribute, just curiosity and a willingness to engage seriously with the material. If you're posting a video, a short summary in the comments isn't required but will earn you serious brownie points. Not everyone has the time or bandwidth to commit to a full watch. Personal anecdotes and inside scoops are genuinely welcome too. If you're a nurse who noticed something unusual, a traveller who just returned from somewhere interesting, or someone with a view from the ground that the media isn't capturing, that's exactly the kind of thing this community exists for.

What we're not

A panic feed. Or a place where fear substitutes for understanding. Fringe and contrarian takes are not automatically unwelcome here. Sometimes the heterodox position turns out to be correct, and groupthink has burned us before.

Getting started

Read the rules, then jump in.

Remember to wash your hands before posting.

With your help, we can make this subreddit go viral.

Hantavirus isn't new. It's an ancient rodent-borne pathogen that simply wasn't on Western medicine's radar until the Korean War, when roughly 3,000 UN troops developed a mysterious hemorrhagic fever near the Hantan River (the virus's namesake). Military activity disturbed local rodent habitats, stressing the animal population and increasing viral shedding, which exposed a vulnerable and immunologically naive troop population. Critically, it's believed that returning American troops may have carried the infection back to the United States, meaning the virus's presence in the Americas may itself be a legacy of that conflict.

What appeared to be a new disease was anything but. It was already ancient in that part of Korea, circulating silently in the local rodent population for who knows how long before a large vulnerable human population stumbled into it.

Hantavirus is a family of viruses with geographically distinct strains. The strain relevant to the current cruise ship situation is Andes Virus, originating in South America, and it has one characteristic that sets it apart from most hantaviruses: a demonstrated capacity for person to person transmission. Most strains require direct exposure to infected rodent material. Andes Virus doesn't strictly need that chain.

That said, it remains an inefficient transmitter with no current evidence of mutation toward greater infectivity, which is why pandemic risk is assessed as low.

Severity variation between individuals remains incompletely understood. Immune status, general health, and genetics all contribute. The cruise ship context compounds vulnerability: these voyages attract older passengers with greater baseline immune susceptibility, and prolonged time in a cold, poorly ventilated enclosed environment provided ideal conditions for slow cumulative exposure rather than explosive outbreak.

Returning passengers pose minimal risk to the broader public but warrant close individual monitoring given their age profile and a potential incubation period still running.