90-Second Read: Hantavirus likely to be fully contained but may take time, Hanage says

Hantavirus is deadlier, case-by-case, than COVID, but is significantly harder to spread, according to William Hanage, professor of epidemiology at the Harvard T.H. In this edited conversation, the Gazette spoke with Hanage, who is also associate director of the Chan School's Center for Communicable Disease Dynamics, about the outbreak and his expectation that it will be fully contained, though that will likely take some time. It does indicate, however, that healthcare staff should take care while treating people who have Hantavirus to minimize the potential for transmission. The World Health Organization reports eight cases and three deaths as of May 8. But it's always difficult to be sure, because there could be milder cases that we don't recognize amid the chaos of an outbreak.

That's a weird cruise ship." Then I heard it came from Argentina, and it made more sense, because the only Hantavirus we know of that's capable of human-to-human spread is the Andes strain. For instance, when you would see cases of COVID-like symptoms developing four or five days apart, you would think, "That's a transmission chain." But in the case of Hantaviruses, it can be weeks. That's one of the reasons why you're hearing about people with symptoms who are being treated as potential cases but which on further investigation turn out to not be caused by Hantavirus. There have been three deaths so far, which sounds like a lot for the number of exposures we know about. What we know is that it seems to require reasonably extended contact.

Before vaccines and widespread immunity, COVID had the capacity to flatten healthcare systems provided it's given free reign, but the number of severe cases would be dependent on how many old people there are in the population. I know that Hantaviruses spread among rats, but what else is important to know about the virus? Another thing that is important here is that everything we know indicates that people are infectious and most likely transmit as they develop symptoms and once they've developed symptoms. If you have Hantavirus pulmonary syndrome, then you have very severe, rapidly progressing respiratory symptoms. The numbers that float about are around 40 percent base fatality.

One thing which I'm going to say right now is that I'm absolutely confident that this is going to be limited and contained. The number of people in the world who should be worried about this now is in the low hundreds, if not less. One of the cases of transmission was to the doctor on the cruise ship who was attending the index case. What does the transmission pattern, starting on a cruise ship, people getting onto airplanes, and then to different countries, illustrate about the potential health consequences of our connectedness today? Infectious diseases are our companions, and their spread reflects the contacts that we make between us.