Friday, May 2, 2014

MERS-CoV: It was matter of when, not if.

Full disclosure:  I am in no way, shape, or form an expert in any virus let alone the one that causes MERS. Not even a little.  If you want to know all of the available facts about MERS-CoV you'll want to check out Helen Branswell, the Centers for Disease Control and Prevention (CDC) MERS website, the World Health Organization MERS website, and the Center for Infectious Disease Research and Policy.  What I can do is tell you what MERS-CoV stands for and give you a little background.  No quiz at the end....I'd likely fail it anyway.

The reason I'm writing this is because MERS-CoV has landed in the United States.  See the CDC press release here.  MERS stands for Middle East Respiratory Syndrome and refers to the illness caused by a particular coronavirus or CoV.  Look at that, you're smarter already. Coronaviruses are just a group of viruses that can cause mainly respiratory diseases in humans and animals. Some coronaviruses cause mild illness, sort of like a really bad cold, while others can cause quite severe disease and death.  MERS is a pretty gnarly one.  It was first identified in humans in 2012 in Saudi Arabia and, including the case identified here in the US, there have been 401 laboratory-confirmed cases of MERS-CoV as of this afternoon with a fatality rate of approximately 30%.  All confirmed cases have come from 6 countries in the Arabian Peninsula with the vast majority occurring in Saudi Arabia and the United Arab Emirates (UAE).  If you check out any of the experts listed above, you'll note that there has been a massive increase in reported MERS cases in the past few weeks.  Last month gave us more cases than what had been reported in the previous two years. So, it really was only a matter of time before MERS-CoV found its way to the US.  International travel has us within 24 hours of each other, no matter where we live.  Our US case traveled from Riyadh, Saudi Arabia to London, England to Chicago, Illinois by airplane and then by bus to Indiana.  All in a day or maybe a little over a day.  Either way, before the case even began to feel sick.  It's daunting to think about the number of people that may have been exposed to this case.  MERS-CoV adds quite a layer of trouble in this, as we really don't know much about how it's spread.  There's talk of camels and bats and human to human transmission.  And it's all true, but to what extent any one of those routes adds to the spread of MERS-CoV  is unknown.  Sure, there have been cases that had contact with camels, and bats are really good at spreading viruses all over the place.  But not all cases have camel exposure and there have been a number of healthcare workers that have fallen ill after treating a sick patient.  So there's your human to human transmission.  But not everyone, or more accurately, not very many at all, that come into contact with a MERS-CoV infected person get ill themselves.  So it's not like a cold or influenza where the virus is readily passed between people on objects and in cough and sneeze droplets (Sidebar: Get your nerd fix and check out this stunning video of a sneeze courtesy of Science Friday).  We just don't know.  And by "we" I mean the infectious disease community as a whole.  Clearly, I'm not doing research to help answer any outstanding questions.  I'm sitting on my couch sipping wine and writing this post and stopping periodically to make sure I'm not telling you lies. It's nice to be able to lump myself in with the greater community without having to do any of the hard work. That's not to say that I'm out of it completely.  Had this case traveled to Minnesota, I'd likely still be at work helping with the contact investigation.  Thankfully that's being done here in the US by the CDC and Illinois and Indiana state health departments and by similar agencies overseas.

So what do you need to do?  Absolutely nothing.  Calm down, it's all good.  Have you:
1. Traveled to the Arabian Peninsula in the past two weeks?
2. Flown from Riyadh to London and/or London to Chicago in the past week?
3. Taken a bus from Chicago to Indiana in the past week?

If you answered no to these questions, congratulations!  You can go on with your evening, have a great weekend!
If you answered yes to #1, don't panic.  It's unlikely that you'll become ill.  But if you do experience a respiratory illness with high fever, go to a doctor and make sure to let them know of your recent travel.
If you answered yes to #2 and/or #3, also don't panic.  If you were on the travel manifesto of the case patient you will be, or already have been, notified by state or CDC officials.  Again, highly unlikely that you'll also come down with MERS.
If you're a healthcare worker that has had, or could potentially have had contact with the case patient you too have already been notified.  Also, what?!  I'm very happy to have you here at Death by UTI, welcome!

Ok, let's recap:  MERS is a bad respiratory illness caused by MERS-CoV, a virus.  There is a case in the US, but risk to the general public is extremely low.  Diseases in general move easily from one country/region to another.  More needs to be learned about MERS-CoV, but currently it doesn't appear to readily pass between humans.  Sneezes are pretty cool.  I like wine.

Good talk everyone.  Carry on.


Wednesday, March 26, 2014

So there's Listeria in your peanut butter...

I'm writing this in an attempt to quell the fears that have arisen in my fellow Minnesotans as they've read about, heard about, or been called about a recent food recall.  Parkers Farm of Coon Rapids, MN issued a voluntary recall of certain products due to the possibility of Listeria contamination on Friday 3-21-14.  Peanut butter, salsa, cheese, and spreads under a variety of brand names sold at a variety of stores nationwide are part of this particular recall. You can find the MN Department of Agriculture press release with a complete list of products and dates here.

I first heard about this on 3-22-14 because a friend shared our local CBS affiliate WCCO's Facebook post about the recall, with her personal lament that she eats a brand of salsa on the list.  Sad face.  I assured her that Listeria means her no harm (exceptions to this rule to follow).  Then, earlier this afternoon another friend posted on Facebook.  This time it was peanut butter...that she had eaten most of, much to her dismay.  I figured I ought to write something up.  And clearly my idea of starting a science blog that I was so excited about got lost in the shuffle of life after only one post.  Sheesh.

I would now like to take the opportunity to explain this type of recall.  Listeria is among several microorganisms that have been deemed as adulterants and are part of a zero-tolerance campaign for food safety.  This means that if at any time during an inspection process Listeria bacteria are found, that product and any product produced at the same facility over a certain period of time (of which I know not and am too lazy to find out) cannot be sold for human consumption.  What happened here is that many of these products had already made it to the marketplace and have been sold and likely consumed.  Or in the case of my peanut butter friend, definitely consumed.  The good news is that there haven't been any illnesses and certainly haven't been any outbreaks of illness associated with this recall.

Which brings us to the microbiology lesson portion of this blog!  Get out your pens and paper, there will be a quiz at the end.  Maybe, we'll see how I feel once we get there.  Listeria bacteria are found in soil, water, and some animals, including poultry and cattle, can be carriers.  So one can see how they may come to contaminate your food simply by proximity; pure happenstance.  Most often Listeria are associated with ready-to-eat products like hot dogs, deli meats and cheeses, and unpasteurized milk and milk products.  Listeria are killed by cooking and pasteurization, so how can they still contaminate your hot dog?  Aren't those gems pre-cooked?  Why yes, yes they are.  However, contamination can occur after cooking, but before packaging.  Okay, but refrigeration slows the growth of bacteria right?  True, true.  Well here's a fun fact about Listeria: it thrives at refrigerated temperatures.  Loves it!  Goes bananas!!  Seriously, I used to work in a clinical lab and when we cultured for Listeria we put the specimen in the fridge.  Okay, so it grows in the fridge.  But you've eaten countless sandwiches stacked high with turkey and ham slices and haven't gotten sick right?  Right.  There are several species of Listeria, but only one that causes human illness - Listeria monocytogenesL. monocytogenes can cause an illness called listeriosis.  The reason why you've been able to eat mass quantities of deli meats without coming down with listeriosis is because you're a healthy adult.  Listeriosis in the healthy person may cause a mild, acute febrile gastroenteritis (also known as tummy-ache with a fever; nothing the plop, plop, fizz, fizz of Alka-Seltzer can't alleviate).  Diarrhea is rare and most people that eat food contaminated with L. monocytogenes have no symptoms at all. 

Listeriosis is also quite rare.  Or rather, the manifestation of the illness that put Listeria on the zero-tolerance list is rare.  I was researching listeriosis for a grad school project a few years ago; at that time there were approximately 1600 cases annually.  In comparison to a more well-known foodborne pathogen like Salmonella, that's small potatoes; Salmonella is estimated to cause more than 1 million illnesses each year.  Listeria monocytogenes ranks a lowly 24th of 31 pathogens known to cause foodborne illness in total cases per year, but is 7th when it comes to hospitalizations and 3rd out of 31 in deaths.  Yikes!  So who's at risk?  The elderly, the immunocompromised (due to disease or certain medications), fetuses and newborn babies are at a much higher risk of invasive disease and death.  Invasive disease means that the bacteria get in your blood and/or your spinal fluid where it infects everything and causes your body to effectively shut down.  Invasive listeriosis is a whole other monster from what I described in the previous paragraphs.  Remember when I said there was an exception to the rule that Listeria meant no harm?  I shall now explain.  The following are some relatively recent listeriosis outbreaks:
  • 2010 - 14 illnesses, 7 hospitalizations, 2 deaths; associated with hog head cheese (a meat jelly made from swine heads....ugh.....)
  • 2007 - 5 illnesses, 5 hospitalizations, 3 deaths, 1 stillbirth; associated with consuming pasteurized milk
  • 2002 - multi-state outbreak; 54 illnesses, 8 deaths, 3 miscarriages/stillbirths; associated with sliced turkey deli meat
A pregnant woman with listeriosis may experience a mild, flu-like illness but then might lose the baby or her baby may be born very sick with invasive disease.  Listeriosis can be absolutely devastating.  

So what can you do?  If you are elderly (congrats on making it this far!) or very young (do you have your parent's permission to be online?), pregnant or immune-compromised:  avoid ready-to-eat meats, raw seafood (including smoked), and unpasteurized milk and milk products.  If you really want that deli sammy, you can steam the meat first as cooking does kill that little trouble making bacteria.  If you're a healthy person, Listeria really isn't anything to worry about.  You're far more likely to get sick from touching your computer keyboard.  Look it up.