Been awhile since I've seen an article about infections diseases that actually made me feel better by the end of it.
Been awhile since I've seen an article about infections diseases that actually made me feel better by the end of it.
For the past 10 years, I've been a global health reporter at NPR. That whole time, I've heard the same idea repeated over and over again about spillovers: They are extremely rare. Animal viruses tend to stay in their animal host. One way scientists have described it is that a virus spilling over is, in a way, winning the lottery: The virus is in the right place at the right time, and on top of that, it has special, rare characteristics that allow it to infect people.
Altogether, these clusters of studies paint a clear and striking picture of spillovers: Spillovers aren't like needles in a haystack. They're more like a rake sticking out of the side of the haystack. Once you start looking, you find them — everywhere. The barriers for some animal viruses to jump into humans are likely much lower than previously thought.
On top of that, if spillovers aren't rare, then why don't we have more outbreaks and pandemics? What's holding these viruses back?
First off, the vast majority of these spillovers don't harm anyone, Salemi says. Most people's immune systems fight off the pathogen without having symptoms at all. When a virus does trigger symptoms, the illness masquerades as a cold, flu or stomach bug.
What scientists don't always realize, says Dr. Gray at UTMB, is that viruses don't jump from an animal into people and then trigger a pandemic right away. "It takes time — many years — for pathogens to adapt to humans," he says.
Been awhile since I've seen an article about infections diseases that actually made me feel better by the end of it.