Lo and behold! Middle East Respiratory Syndrome has landed in America. Here are some quick facts if you’re playing catch up:
1. MERS is an infectious respiratory illness caused by the MERS coronavirus (MERS-CoV). It was first discovered about two years ago… In the Middle East.
2. Because of its novelty, we don’t know a lot about its transmission pathways. What we think we know for the time being is: (A) MERS-CoV is zoonotic, likely spreading to humans first from camels; and (B) the virus can spread via respiratory fluid droplets – either on fomites (like doorknobs, elevator buttons, etc.) or human-to-human. [So, you know – don’t kiss the sick and wash your hands regularly!]
3. There’s been an outbreak of MERS going on in Saudi Arabia for the past 40 days or so. 40% or more of cases had contact with previously lab-confirmed cases. While this seems to suggest that human-to-human transmission might be a significant pathway for MERS-CoV, let’s remember that correlation ≠ causation!
4. People with pre-existing conditions – such as diabetes, heart disease, etc. – are more likely to die from MERS than those without. Since the disease was first discovered, the average rate of death in otherwise healthy people has been around 20% (compared to ~35% in people with pre-existing conditions). However, since the most recent outbreak began, these numbers have dropped to 12% and 16%, respectively. Though we don’t yet know why this has been the case, it may somehow be related to the observation that otherwise people have been getting MERS more frequently during this outbreak than prior to it.
5. In the latest outbreak, a lot of asymptomatic cases have been diagnosed – especially in individuals without pre-existing conditions. It remains unclear whether asymptomatic individuals can transmit MERS-CoV, though we do know that asymptomatic camels can.
Reality is that an exported case to the United States was bound to happen eventually; the current outbreak in Saudi Arabia has been actively growing since March 2014! Whether or not it spreads to anyone else now that it’s here, we’ll have to wait and see. However, given the low rate of tertiary (person-to-person-to-person) transmission we’ve seen historically, it seems fairly unlikely. So please, don’t panic! But do keep your eyes peeled for the time being. (Personally, I’m curious to see how this influences the USA-KSA dynamic and how the CDC manages the situation. Needless to say, things are about to get interesting!)