After talking about parasites in a former post, now it’s time to talk bacteria. Could your sushi carry bugs that could make you sick?
If you eat sushi in the U.S. and then get sick, it’s more likely you’re suffering from a viral or bacterial infection than parasites. Since 1998, these infections were responsible for all the foodborne illness outbreaks reported to the Centers for Disease Control and Prevention (CDC).
Fish carries the same risk of microorganisms as does chicken, red meat, and eggs, and eating it undercooked, as is the case with most sushi, increases those risks. Here’s more about the types of bugs you may encounter, and how to increase your chances of enjoying your sushi bacteria-free.
Health Risk #2: Bacteria (and Viruses)
There are a number of bacteria and viruses that can cause you problems when eating sushi. Here’s a glance at a few of them:
- Salmonella: You’ve heard of this one. It’s a common bacterium that can contaminate a number of foods, and sushi is one of them. In 2012, there was a sushi-salmonella outbreak, affecting people in 20 states. Yellowfin tuna was flagged as the culprit, sickening over 100 people. The outbreak resulted in a recall of nearly 59,000 pounds of a frozen yellowfin tuna product that had been sold to restaurants and grocery store chains. Symptoms of the infection included diarrhea, fever, and abdominal cramps within 72 hours of exposure. The infection lasted between 4-7 days.
- Vibrio parahaemolyticus: This bacteria has been associated with the consumption of raw or undercooked fish and shellfish, particularly oysters. A related bacterium called Vibrio vulnificus has also been found in oysters, clams, and crab. Symptoms of food poisoning with these bacteria are similar to those with salmonella—vomiting, diarrhea, and abdominal pain. Usually the infection goes away on its own, but those with weakened immune systems may suffer complications.
- Staphylococcus aureas: You’ve heard of this bug too, but in relation to sushi? Turns out this one comes from the rice, not the fish. The rice can grow this bacterium quickly if it’s not chilled soon after cooking. Watch out for grocery stores and restaurants that do not keep prepared sushi cool. Symptoms include vomiting, nausea, loss of appetite, mild fever, and diarrhea that lasts about two days.
- Hepatitis A: This virus can be transmitted when cold or uncooked foods are handled by people who haven’t washed their hands after using the bathroom. In 2011, there was a hepatitis A outbreak in Japan associated with a revolving sushi bar in Chiba, Japan. Hepatitis A can inflame and damage the liver, and also weakens the immune system. Symptoms include fever, nausea, and loss of appetite. Shellfish, like crab and shrimp, have been associated with hepatitis A infections. The disease can be prevented by a vaccine, or treated with medications.
A number of other bacterial contaminations are possible with sushi, including e-coli, listeria monocytogenes, and human and animal waste bacteria (from not washing hands before handling). The key is to find out how the fish is handled before it comes to you.
How to Protect Yourself
In 2011, CBS News reported that many sushi restaurants “fail to follow the most basic requirement to keep sushi safe,” even though it’s one of the riskiest fish dishes to eat. Investigators found that restaurants were thawing the fish at a higher temperature than was recommended, and were also storing at temps too high for safety.
Here are seven tips to help you protect yourself from bugs when enjoying your sushi:
- Smell: The fish should not smell “fishy.” If it smells bad, you have bad fish that could be contaminated.
- Color: There shouldn’t be any dark spots on the fish, and it should also look soft and tender—not too dry.
- Trust: Buy from a trusted source that you know adheres to proper handling recommendations.
- Cleanliness: Check out the preparation area, the equipment, and the personnel. Do they look clean to you? What about the restaurant as a whole? The restrooms? A clean location means the management is likely careful about clean food, as well.
- Storage: Is the sushi stored in a refrigerated environment, or is it left sitting out at room temperature? The longer it sits out, the greater the risk of contamination.
- Location: Sushi bars offer you the opportunity to interact with the sushi chef and watch how he handles and prepares the fish. You should also be able to inspect the fish before preparation. This gives you a number of opportunities to check for safety. Sushi stored in a container at the airport, on the other hand, contains a lot of secrets. How long has it been there? How was it stored before it was displayed? Choose to eat your sushi at locations where there is a lot of transparency in preparation.
- Chef? If there is no sushi chef preparing the sushi, likely the establishment is getting it shipped in already prepared. Fuji Food Products, for example, ships sushi to some Target, Walgreen’s, and Trader Joe’s stores. Shipped-in sushi isn’t necessarily contaminated, but watching the chef prepare your sushi is the best way to avoid foodborne illness.
- Ask for the freshest: Ask the chef what he recommends—what is the freshest? You’ll be more likely to get fresh sushi if you’re a little less picky about the kind you want.
- Wash: Remember that your hands can also carry germs, especially if you’ve been out and about or even worse, if you’re traveling. Always wash your hands thoroughly before eating sushi.
- Think twice about rolls: Things like the California roll are made up of chipped fish, which requires more handling—and thus carries a higher risk of contamination, especially if the handler didn’t wash his or her hands.
How do you avoid contamination when enjoying sushi? Please share any tips you may have.
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“2 Investigators: Is Your Sushi Safe?” CBS News, October 27, 2011, http://chicago.cbslocal.com/2011/10/27/2-investigators-is-your-sushi-safe/.
Christina Frangou, “An Informal Poll of Gastroenterologists on Sushi: Do Those Who Treat Also Eat?” Gastroenterology & Endoscopy News, April 2006, http://www.gastroendonews.com/ViewArticle.aspx?d_id=187&a_id=6700.
“Sushi Health Risks—Risks of Sushi such as Parasites, Heavy Metals, & Bacteria,” http://www.articlesbase.com/health-articles/sushi-health-risks-risks-of-sushi-such-as-parasites-heavy-metals-bacteria-1132521.html.
Ryan Jaslow, “Sushi-linked salmonella outbreak reaches 20 states, yellowfin tuna recalled,” CBS News, April 16, 2012, http://www.cbsnews.com/8301-504763_162-57414609-10391704/sushi-linked-salmonella-outbreak-reaches-20-states-yellowfin-tuna-recalled/.
“Sushi Safety,” Health.qld.gov.au, http://www.health.qld.gov.au/foodsafety/documents/fs-35-sushi.pdf.
Tominaga A, et al., “Hepatitis A outbreak associated with a revolving sushi bar in Chiba, Japan: Application of molecular epidemiology,” Hepatol Res. 2012 Aug; 42(8): 828-34, http://www.ncbi.nlm.nih.gov/pubmed/22776552.
Kate Lowenstein, “Is that sushi safe?” Fox News, August 21, 2012, http://www.foxnews.com/health/2012/08/20/is-that-sushi-safe/.