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In November the Kentucky Department for Public Health identified a spike in Hepatitis A cases beginning in January of last year. These cases were connected to several other statewide outbreaks across the nation this year, spread primarily through person-to-person contact mostly among the homeless and intravenous drug users. As of April 14th, there have been 352 outbreak associated cases with 246 hospitalizations and three deaths.
While Kentucky has been careful to report that this shouldn’t affect people’s travel practices, neighboring states not included in the outbreak are more risk averse and don’t want anyone bringing presents home.
So, with the Derby coming up, let’s do a little risk analysis! Assuming that we want to go see the race and enjoy one of the 60,000 Mint Juleps served each day, what’s our risk of contracting Hepatitis A and ultimately getting sick?
Risk Assessment: Hepatitis A infection via Mint Julep on Kentucky Derby Weekend
Let’s circle back to the criteria I outlined in this post as to what needs to occur for you to get sick:
- The pathogen (or toxin former) needs to get near the food
- The pathogen or toxin needs to get onto/into the food
- The pathogen or toxin needs to proliferate to an infectious dose
- The pathogen or toxin needs to survive any washing/cooking/freezing/processing/storage
- The dangerous food needs to be eaten in a large enough amount
- The food needs to be eaten by someone susceptible to that infectious dose
- That person needs to be susceptible that day
- Available medical treatments have to be unsuccessful
So let’s go through each of these and see what needs to happen.
1. Hepatitis A needs to get near the food…everybody poops
Like most food-borne illness, Hepatitis A is primarily transmitted through the fecal-oral route. Or as I explain to 4th graders and production staff, poop-in-your-mouth. While we don’t have a great way to directly detect fecal material, generally as food safety professionals we assume it can be anywhere that is potentially contacted by people or animals. So, you know, everywhere, especially places where we actually defecate. In 2016 there were an estimated 4,000 cases of Hep-A in the US, so that’s around 1 in 8085 people. If we were not in the middle of an outbreak, then assuming equal distribution there would be an estimated 76 people in Louisville, KY shedding the virus throughout the year.
Once shed from a person, the virus is hardy and capable of surviving months without a host, even in freezing temperatures. While out in the environment it hitches rides on objects, people, flowing water, dust, wherever it’s little microscopic self has the opportunity to go. Obviously people, either through shedding the virus themselves or exposing themselves to contaminated fecal material (wash your damn hands #1), pose an obvious transmission vector. So to get into the area of our drinks the virus could be carried by both customers (less likely to cause an outbreak) or employees (more likely).
Kentucky has the highest concentration of food service workers of any state in the US. 3.65% of all workers in KY are in food service. So…if the labor force in Louisville is 661,400, then there are around 24,000 working in food service. Based on the Hep A rate above, then there are 2-3 of them shedding virus at some point during the year, maybe while I’m there, maybe not. But if they’ve contracted hepatitis A, they can remain infectious for up to two weeks before showing any symptoms that would clue them into going home.
As we’ve discussed before, food safety is a public health game, not a personal risk game. Already I feel pretty good about my own odds of even getting my Julep exposed to hepatitis virus on my weekend. But that’s just the first yes in our flowchart.
2. Hepatitis A needs to get onto/into the food
The helpful folks who made the Derby website gave us explicit instructions on how to make a proper Mint Julep:
The Old Forester Mint Julep Recipe [reprinted from Kentuckyderby.com]
2 cups sugar
2 cups water
Sprigs of fresh mint
Old Forester Straight Bourbon Whisky
Make a simple syrup by boiling sugar and water together for five minutes. Cool and place in a covered container with six or eight sprigs of fresh mint, then refrigerate overnight. Make one julep at a time by filling a julep cup with crushed ice, adding one tablespoon mint syrup and two ounces of Old ForesterKentucky Whisky. Stir rapidly with a spoon to frost the outside of the cup. Garnish with a sprig of fresh mint.
Let’s look at each of these ingredients:
*zeowwwww* QA laser risk assessment eyes locked on:
Sugar: low water activity, highly refined from agricultural raw materials, non-perishable, unlikely to be a microbial risk.
Water/Ice: city tap water supply, already confirmed safe by EPA and other agencies
Bourbon: >40% ABV, likely bactericidal
Fresh mint: Danger Will Robinson, raw agricultural product, likely contaminated at some frequency, may support the growth of pathogens, easily bruised and not likely to be heavily washed or otherwise treated
Mint, as a low-to-the-ground leaf, is succeptible to getting particulates/fecal material from the ground as well as by the hands of pickers/packers. In addition, during preparation, these leaves will need to be handled to remove them from stems, muddle if preferred, and garnish, all possible points where a person carrying Hepatitis A virus may introduce them to the drink (wash your damn hands #2).
More food for thought, transmission rates matter. So even if you were using spoons and tongs to prepare all of the Mint Juleps at your concession stand, the fact remains that the fecal-oral route doesn’t care if the virus ever makes it into the food. If you give your intergluteal cleft a quick scratch and hand me my drink, you will have likely transferred virus to the fancy frosted silver mug, which I will now handle with damp hands and potentially transfer virus to my straw, lip of container, beverage, or teeth as I pick out a piece of steak from earlier.
3. Hepatitis A needs to proliferate to an infectious dose
This one is a bit of a misnomer because Hepatitis virus is not going to proliferate outside of a host. So what we’re really looking for is how much virus may have gotten transferred to the food when it was contaminated and if it was able to stick around. USDA reports that as few as 10-100 virus particles may be infectious. So while there may be opportunity for bacteria to proliferate on the fresh mint leaves identified above or in the final drink, Hepatitis A is either going to be there in enough concentration to make you sick, or it isn’t. Our handling practices or hot/cold temp controls will be irrelevant for this beverage, though you could kill HAV with cooking.
4. Hepatitis A needs to survive any washing/cooking/freezing/processing/storage
You might think that the whiskey could further reduce the number of virus present in other contaminated materials, but it isn’t like a hand sanitizer, which is typically at least 60% alcohol and won’t be diluted with mint syrup (known in quarantini circles as a Purell Julep). In fact, alcohol is essentially useless at killing Hep A virus. In a study of efficacy of HAV lethality on stainless steel disks, 70% ethanol achieved less than a 90% reduction (1-log) after 60 seconds of contact time. In fact only 3 of 20 chemicals tested achieved a 3 log reduction in 60 seconds. So unless you enjoy your Julep with bleach or toilet bowl cleaner instead of whiskey, don’t expect it to lend you a reduction.
5. The dangerous food needs to be eaten in a large enough amount
Similar to #3 above, not only do there need to be enough viral particles to make me sick, but I actually have to drink them all. This is where transmission rates come in handy again, because while contaminated surfaces may spread the virus, they also dilute it! Listen though, I’ve made the long drive to Louisville for the Derby, I’m going to have…enough Juleps. So let’s assume that we didn’t contaminate a garnish but instead a beverage I plan to consume in it’s entirety.
6. The food needs to be eaten by someone susceptible to that infectious dose
Here’s a relevant one! HAV immunity tends to last for life. This means that if I’ve had it before I’ve got no worries! The best way to prevent HAV infection is by vaccination, either as a child or as an adult, as vaccination can even grant protection after exposure. Kentucky is doing it’s best to make sure vaccine is available for all foodservice workers to prevent further spread of the outbreak as well as at risk populations, but it’s facing a tough battle to get everyone necessary covered. Until recently, CDC only recommended HAV vaccines in states where it was endemic, but now recommends it for all children and at-risk adults.
Nationwide people self-report a vaccination rate of 0.8% at the age of 19, and the Kentucky School Boards Association doesn’t include it on their school vaccine list, so they’re unlikely to be above that average. If you know you’ve had HAV before, or that you were vaccinated (all doses ) at some point, then your risk of infection is extremely low.
7. The person needs to be susceptible that day
Infectious doses and other health “numbers” are tricky things and everyone is different. Maybe I’m somehow immuno-compromised from my Crohn’s disease or another infection, or maybe I’m less susceptible because my continental breakfast included yogurt with competitive probiotics that reduce transmission rates in the gut. The point is that jet lags, hangovers, colds, age, what I ate before, and a million other factors may influence my susceptibility to infection that day.
8. Available medical treatments have to be unsuccessful
Hmmm, I woke up in my hotel and they’re reporting that there was a Hep A outbreak at a Derby concession stand and I’m advised to go get a post-exposure vaccine. Sure! A local doctor will administer the vaccination if I’m between 1 and 40, and Hepatitis A-specific immunoglobulin will be provided to those outside this date range. This is actually similar to how we treat other virus post exposure prophylaxis for HIV or Rabies. However if I don’t get the vaccine, or the HAV happens to have already taken hold, then it’s party time for up to two months (some patients have relapses for up to 6 months) with fever, fatigue, nausea, vomiting, pain, dark urine, clay-colored bowel movements, joint pain, and jaundice. Yee-haw!
Note: from personal experience, the clay colored bowel movements are startling.
So, what’s the risk?
For me personally, I’m feeling pretty good about downing some Juleps at the derby. The odds of encountering a contaminated surface from a random person in the bathroom are probably about about as good as me getting it from my drink, especially if the employees are washing their damn hands (#3). I also know that I’ve likely been vaccinated since HAV is included in Oregon’s required immunization list where I attended grade school. However, it’s certainly not a bad idea to get a vaccine so that you don’t bring any viral souvenirs back to your own state.
As a food operator at the event I might be more nervous in the middle of an outbreak. You have the potential to do a lot of harm if the right circumstances were to arise. I would have a conversation with my existing employees about the outbreak and the possible consequences if they were to spread the virus, how they might not show symptoms, and that vaccination and sanitary practices are the best way to protect our customers. Even more importantly, we would need to find a way to communicate this to any temporary employees that may be coming in just to help for the weekend.
There’s one more thing…oh yeah. Kentuckians, wash your damn hands before going back to make Juleps (#4). If you will only contaminate 1 in 10,000 Mint Juleps, that’s still going to be 12 people potentially exposed over the weekend. Do you think you’re that good?