Disease superspreaders and the new coronavirus

Coronavirus — characterized by the halo of protein spikes that surround each individual virus particle — is the family that gave birth to SARS. Today, there's a new coronavirus stalking humans, especially in the Middle East. Scientists have documented 16 infections, and 10 fatalities. The good news is that there are probably lots of non-serious infections that aren't being reported, meaning the fatality rate probably isn't as high as it looks. Also, this coronavirus seems to have trouble spreading from person to person. But, in regards to that last factor, it's important to pay attention to a detail from the SARS outbreak that we still don't totally understand. Turns out, a handful of people were responsible for most of those infections. The Canadian Press' Helen Branswell writes about superspreaders and the scientists trying to understand how individuals can alter the course of an outbreak. (BTW: If you don't follow Helen Branswell on Twitter, you're missing some of the best infectious disease reporting out there.)

New respiratory virus identified in the Middle East: What you need to know

Coronaviruses are a family of relatively large viruses. The name comes from the fact that, under a microscope, coronaviruses all look like they are surrounded by little halos. Those "coronas" are actually little proteins that cover the surface of the viruses and help them gain access to the cells they invade.

Although scientists think that coronaviruses are actually responsible for a significant percentage of the illnesses that we call the "common cold", the most famous coronavirus is SARS, which killed almost 1000 people in 2003. That doesn't sound like many, but comparing deaths to diagnosed cases reveals a fatality rate of 10%. (There's a good chance this number doesn't give you the full picture. It's likely more people contracted SARS than ended up diagnosed with it, simply because, if your illness isn't severe, you don't usually bother to get diagnosed. To provide some context, the 1918 flu pandemic had an estimated fatality rate of 2.5%.)

All of this explains why a newly identified coronavirus — which may be the cause of two deaths and a couple of outbreaks of respiratory illness in the Middle East — is getting so much attention and causing people to freak out a little. The virus (which doesn't actually have a name yet) is part of the same family as SARS. SARS was a scary virus. So this new virus has everyone a little on edge, too.

The key thing to remember, though, is that this new virus is not SARS. And there's a lot we don't yet know about it.

Read the rest