5/19/2016 – Meg Withers

Don’t Be Scared, Be Safe

We are officially two days away from lift-off to St. Croix!  Today, when we weren’t practicing our interviewing skills, we were learning about two diseases we will be dealing with when on the island: Zika and Ciguatera.

Zika

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According to The Centers for Disease Control and Prevention (“CDC”), “Zika virus disease (Zika) is a disease caused by the Zika virus, which is spread to people primarily through the bite of an infected Aedes species mosquito.”  Zika has received a great deal of attention recently, especially concerning its effect on the head size of children born to women with the virus.  However, not all of the disease’s symptoms are as drastic and long-lasting.  The most common symptoms are fever, rash, joint pain, and conjunctivitis.  Additionally, only 20% of those infected display symptoms.  However, this fact can be both a blessing and a curse.  If you aren’t aware you have the virus, you may be less likely to take the proper precautionary measures and accidently spread the virus to someone else.

The common modes of Zika transmission are mosquito bites, an infected woman to a fetus, sexual contact, and blood transfusion.  These and many other forms of transmission have become much easier with globalization.  Someone can be in the Caribbean one day and in almost any other part of the world the next.  Thus, the rate at which a disease like Zika propagates is faster than it would have in the past.  This does not mean that we should all go buy hazmat suits and never travel again, but Liam Neeson may have the right idea!

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Today, we had the privilege of learning about the virus from Dr. Gonzalo Vazquez-Prokopec, one of the world’s leaders on the issue.  He told us, “Don’t be scared, be safe.”  Risk of infection can be greatly reduced when the proper protective measures are used.  Dr. Vazquez-Prokopec recommends covering as much skin as possible and using strong bug repellent on whatever skin is exposed.  The idea of wearing long pants and a long-sleeved shirt while surveying in the hot Caribbean sun is not something which one likes to contemplate, but the recommendation is probably worth following.  While we will not be in St. Croix during peak mosquito season, we are still well within range of the virus.

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Ciguatera

The second disease we discussed today was Ciguatera, also known as “fish poisoning.”  It is the “main cause of non-bacterial illness associated with seafood consumption.”  Research is currently underway to determine the level of risk associated with eating lionfish as a result of the disease.  The toxin accumulates in predators that eat toxic prey. Thus, those species that are high on the food chain are more likely to have the disease.  Because lionfish are top predators and consume such a wide range of other fish, this species may have a higher probability of carrying the toxin.

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As of yet, there is no way to test for Ciguatera outside of a lab.  The toxin is odorless, tasteless, and colorless so the only definitive way to determine if Ciguatera is present in a fish is to put it through a complicated and expensive chemical test.  So this leaves us with two options: don’t examine the fish and possibly risk the health of consumers or perform costly and time intensive chemical tests.  Neither of these are great.  But wait!  There is a third option.  Ciguatera is a localized disease.  It doesn’t spread out equally throughout the ocean.  Experienced fishermen make sure to monitor where Ciguatera has been found and avoid those areas.  Thus, researchers are hoping to create a map of Ciguatera “hot-spots” and encourage the harvesting of lionfish in those areas alone.

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However, it’s not quite that simple.  With global climate change, sea temperatures are going to rise and the area available to top predators like the lionfish is going to increase.  Research shows that Ciguatera levels increase with rising sea temperatures.  Also, lionfish eat so much so quickly that they may exhaust resources in a certain region and move to another.  In either case, the “hot-spot” map would become unhelpful.

Lionfish is not the only species that carries Ciguatera.  A whole host of other species like Grouper and Barracuda have it as well.  Researchers are trying to determine if lionfish have a higher probability of containing the toxin at concentrations above the 0.1 µg/kg limit set by the Food and Drug Administration. One study found that 12% of the lionfish tested had Ciguatera levels greater than the set limit, but this value is similar to Ciguatera percentages for other species.  So far, it doesn’t look like there is a heightened risk associated with eating lionfish. More good news is that as of January 2013, there have been no reports of fish poisoning from lionfish. The hope is that via proper management and smart fishing practices, this number can remain zero for a very long time.

A common theme ran through today’s class, “Don’t be scared, be safe.”  Yes, these diseases pose a threat.  And yes, people need to practice risk management.  But this does not mean that we should be terrified of eating seafood or taking a trip to the Caribbean.  Understanding the mechanisms at work behind these diseases can be extremely helpful in preventing or mitigating their affects.  A little information can go a long way.

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