In the age of media-induced panics over every possible issue, several patients have recently asked my thoughts on the recent Hantavirus outbreak onboard the cruise ship MV Hondius. The quick punchline: I think it’s very unlikely that this will become a major pandemic ala COVID.
Here’s a brief FAQ I’ve prepared that breaks this down a bit more:
What is Hantavirus? Hantaviruses are a family of viruses that typically spread from rodent droppings to humans, and hence are very rare. In a normal year, there might be only a dozen or so cases in the United States. It is not a new virus – Hantaviruses have been known since the 1960s. Among the many Hantavirus strains, there is only one – known as the Andes strain – that is able to spread from person to person (as opposed to from rodent to person). Every year in South America, there are small outbreaks of this strain, and this is the current strain of concern. It appears that somebody who was infected with Andes strain Hantavirus boarded the cruise ship MS Hondius in Argentina back in April, and subsequently 11 of the 175 people on board the ship (so far) have become infected, with 3 of them dying. Given that the incubation period for Hantavirus can be more than a month, it is likely that there will be some additional cases before this ordeal is over (that is to say, there are probably some additional passengers or crew on board the ship that have contracted the virus but are not yet showing any signs of it). At this point in time, the remaining passengers have been disembarked and flown back to their home countries, where they are being closely monitored by health officials for any signs or symptoms of the disease.
How deadly is Hantavirus? This is the terrifying part. Hantavirus can cause massive pulmonary (lung) hemorrhaging, leading to respiratory failure and death. While not every infection will lead to this, it happens often enough that approximately one-third of those infected will die.
Is there any cure or treatment? The only treatment is supportive, meaning putting a patient on a breathing machine if they are having severe lung hemorrhaging and waiting until the worse of the disease passes (even this is not a guarantee of survival, though it considerably improves the odds). Clearly this is doable with adequate medical capacity, but if a true pandemic broke out and tens of thousands of Americans were sickened, the ICUs would quickly be overfilled and there would be no available treatment for most patients.
OK then, if this virus is so deadly and there is little treatment for it, why are you not worried? For one simple reason: Hantavirus does not spread easily. Unlike measles, flu, or COVID, you are very unlikely to catch Hantavirus unless you have prolonged close contact with a patient who is actively sick. There is always the slim chance that the virus will mutate of course, so I wouldn’t advise complete and total complacence, but as long as the virus continues to behave as it always has (and so far all of the gene sequencing shows that we are dealing with a non-mutated strain that should behave as expected), Hantavirus is just very unlikely to spread far and wide. The slow spread also means that public health authorities will have a much easier time tracking and quarantining cases and that – if God forbid things really got out of hand – a short-term lockdown, masks, and social distancing measures would, unlike with COVID, actually create a major reduction in new cases. (Please note: I’m not advocating for such measures and highly doubt they will be needed – I’m just pointing out that trying to contain COVID was always a fool’s errand, whereas this virus actually could be contained by extreme measures if it became absolutely necessary to do so).
The news will likely report additional cases of the virus in the coming weeks as at least a few of the remaining passengers from the ship come down with infection, and no doubt they will do so in the most panicked tone possible. But the reality is that while we remain very vulnerable to a future pandemic, this one is almost certainly not it.
