Hantavirus update
Steady heads, good news, and some questions
Well, this was a week in global public health. The Andes hantavirus outbreak has been evolving quickly, and there is a lot of information swirling on social and mass media. I figured it may be helpful to take you along for the scientific ride.
Here’s the latest.
Note: If you missed it, this post builds on the live briefing from Wednesday. You can find it here.
Situation report
Case count has remained stable. There are still three deaths and five cases. I hope it stays this way, but there is a chance (and I expect) it will increase over the next six weeks. This virus has a long incubation period, up to 45 days (median 18 days), during which it can enter the body, latch on, and wreak havoc. Unfortunately, we are at the mercy of time and biology.
Risk to the general public remains low, per the WHO. I agree with this assessment. Risk is probabilistic: what’s possible isn’t what’s probable. The odds of this escalating are low for several reasons:
This isn’t a novel virus. We’ve known about Andes hantavirus since the 1990s. We have prior data about how it spreads, where it’s located, and how it acts. That’s different from Covid-19.
Past Andes hantavirus outbreaks typically involve close-contact settings, such as caring for a sick person or sleeping in the same bed. To our knowledge, this isn’t spread asymptotically. Some research shows spread through more casual contact, but all prior outbreaks have been contained successfully. In this outbreak, all cases so far are linked to close contact. This helps with containment.
Like many viruses, Andes can mutate randomly or reassert, but it doesn’t have a track record of rapid mutation, making it hard to change the circumstances quickly. WHO has confirmed that this holds here—the sample in South Africa is nearly identical to the version seen in Argentina.
Off the boat, there is extensive contact tracing. Thirty people got off the boat after the first death (and before officials knew this was an outbreak). They are now being contact-traced by epidemiologists. This means alerting those passengers, monitoring for any symptoms, tracing their steps (such as boarding a plane), and alerting those who are near them for an extended period. None of these passengers has symptoms so far. Six are Americans and live in California, Georgia, Virginia, and Arizona.
Note: Because there is a lot of contact tracing, you may start hearing rumors about more positive cases, like a flight attendant. These may turn out to be truly positive, but importantly, having symptoms does not mean it’s hantavirus. Epidemiologists discern correlation from causation by understanding risk (like where contacts are relative to the patient) and by sending the test to confirm. This takes time.On the boat, people will get relief soon. Three sick passengers were evacuated from the ship to a hospital yesterday, which is excellent news. Hospitals have specialized airborne isolation units designed exactly for situations like this. The ship is now heading toward islands near Spain, which have agreed to allow it to dock. It should reach there by Monday. It’s still unclear what the long-term plan is, but I hope passengers will be able to safely isolate closer to home and near their families.
The international response has been fantastic so far. I continue to be impressed by WHO’s coordination across multiple countries, their public briefings, the swiftness of contact tracing and testing, and their success in negotiating with Spain to allow the boat to dock.
This is an evolving situation, and we will learn more in the days ahead. It’s possible that some early information may be inaccurate, and we will learn new things about this virus that we didn’t know before. That uncertainty is uncomfortable, but it’s also a normal part of the scientific process.
There’s understandably a lot of fear around this outbreak. This is a really scary virus, like one you would expect to see in a movie. We are also on the heels of the pandemic, and there are some similar vibes (e.g., cruise ships, quarantining, WHO briefings, scientists speaking out). And we’re living in an incredibly low-trust environment, both with our government and amongst ourselves.
Is our government responding appropriately?
Public health scientists are on it. CDC scientists are actively involved behind the scenes, including standing up an Emergency Operations Center and coordinating with the WHO. (They are allowed to talk to WHO for this situation.) States are also activated and have initiated contact tracing and coordination. This is exactly what we train for, and these guys are working incredibly hard under difficult circumstances: significant funding cuts, a workforce that’s lost roughly a third of its people, research on Hantavirus halted, and institutions under enormous strain for the past 14 months.
That said, I do have some major questions for CDC leadership and the administration. I want to know:
Why haven’t they deployed a team to help with the international response?
Why haven’t physicians been alerted through the Health Alert Network (HAN) as they typically would?
Why is there zero communication with the public or updates to the website?
This is abnormal. The muffling of scientists and the lack of transparency are unacceptable for Americans’ safety and security.
What this means for you
To the general population, your risk is close to zero. I loved this graphic that my friend Dr. Caitlin Rivers put together in the New York Times.
Right now, people are focused on this outbreak and want to take action. This is an understandable response. The most important thing you can do is help spread accurate information. This means:
Triple-check sources, and don’t spread unverified rumors. There are a lot of rumors and speculation right now, but often they turn out not to be true. (The flight attendant is a great example; many assumed she had already tested positive, which wasn’t true.) Not sharing or spreading something until it’s verified helps prevent the spread of inaccurate information and keeps our stress levels down.
DO share reputable and verified information. This includes information from the WHO, local health departments, and reputable public health leaders.
This is also a reminder that a type of hantavirus does live in the U.S. It’s also very rare and does not spread person to person, but we can take action in rodent-infested areas, like barns.
Bottom line
This is a serious, unique international outbreak. Things are moving quickly, but this virus is behaving as we expect so far, and it’s a low-risk situation for the general public.
This is public health in action. Let it be a reminder of why we need these systems in place, from local to state to global health.
Love, YLE
Your Local Epidemiologist (YLE) is founded and operated by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE reaches over 425,000 people in over 132 countries with one goal: “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:
This outbreak is also a reminder of something painfully obvious: global public health systems matter.
WHO coordination appears to have been effective, organized, and scientifically grounded during a rapidly evolving international situation involving multiple countries, quarantine logistics, contact tracing, and public communication.
At the same time, the weakening of the CDC through staffing cuts, funding reductions, and the broader political undermining of public health expertise looks increasingly reckless and shortsighted.
You do not dismantle fire departments because there isn’t currently a fire.
You do not weaken epidemiologic infrastructure because outbreaks are uncommon.
You maintain these systems precisely because when serious events occur, competence, coordination, and trust suddenly become indispensable.
What we are seeing now is public health professionals working hard despite political dysfunction above them, not because that dysfunction was harmless.
Thank you for this calm, fact-based report. I knew we could count on you for the information we need!