Concerns About Parasite Infection After Eating Raw Crab in Korea

After eating raw crab in South Korea, experiencing discomfort?

Hello Doctor, I had several servings of raw crab in Korea on the night of March 4th this year, but I did not experience any discomfort at that time.
After returning home, I developed a fever and gastrointestinal discomfort for the first time on March 11th, and the doctor diagnosed it as a gastroenteritis.
After taking medication, I recovered.
However, on the night of March 28th, I experienced a second fever.
Since I had no other symptoms at that time, I only rested and did not see a doctor.
Although the fever subsided the next day, I began to experience continuous headaches for two days.
On the second day of the headache, I consulted a doctor, who also diagnosed it as gastroenteritis (I specifically informed the doctor about eating raw crab in early March).
I have never had such frequent fevers within a month, and later I realized that consuming raw crab could pose risks of parasitic infections or other issues.
I also found that the incubation period for parasites can be quite long, and that Koreans regularly take deworming medications.
Therefore, I am very concerned that I might have a parasitic infection, which could explain the frequent fevers and headaches.

As a note, my brother, who traveled with me, also consumed a similar amount of raw crab.
He experienced discomfort on the night of March 4th, with symptoms of fever and diarrhea from that night until noon on March 5th.
He took some over-the-counter medication for his stomach, which helped alleviate his symptoms and reduce the fever.
After enduring the flight back home on March 5th, he immediately visited a clinic, where the doctor diagnosed him with gastroenteritis.
He took medication and rested for a few days before recovering, and he has not experienced any further symptoms since then.

Ms. Wu, 20~29 year old female. Ask Date: 2024/03/30

Dr. Ye Qianyu reply Family Medicine

Hello! Since the symptoms of lung fluke infection are similar to those of gastroenteritis, and the incubation period can last from 6 to 10 weeks, if you are concerned, you may want to undergo a stool examination and seek medical attention at a healthcare facility.

Reply Date: 2024/03/30

More Info

Eating raw or undercooked seafood, including crab, can pose a risk for various parasitic infections, particularly in regions where such practices are common. In your case, consuming raw crab in Korea raises valid concerns about potential infections, especially given your subsequent health issues.

Parasites such as Anisakis, which can be found in raw or undercooked fish and seafood, are known to cause gastrointestinal symptoms. Symptoms of Anisakis infection can include abdominal pain, nausea, vomiting, and diarrhea, typically occurring shortly after consumption. However, the symptoms you described—fever and gastrointestinal discomfort—are more indicative of a viral or bacterial infection, such as gastroenteritis, rather than a parasitic infection.
The incubation period for parasitic infections can vary significantly. For example, Anisakis typically causes symptoms within hours to a few days after ingestion, while other parasites like Giardia or Cryptosporidium can take longer to manifest symptoms, sometimes up to weeks. However, the fact that you experienced symptoms shortly after eating the crab suggests that if a parasite was involved, it would likely be one with a shorter incubation period.

Your brother's experience also supports the idea that the symptoms you both experienced may be related to a common infectious agent rather than a parasitic infection. Gastroenteritis, often caused by viruses such as norovirus or rotavirus, can spread easily, especially in close quarters or through contaminated food. Given that your brother had similar symptoms shortly after consuming the same food, it is plausible that you both contracted a viral infection rather than a parasitic one.

In terms of your health concerns, it is essential to monitor your symptoms. If you experience persistent fever, severe abdominal pain, or any new symptoms, it would be prudent to seek medical attention. A healthcare provider may recommend specific tests, such as stool tests, to check for parasites or other infectious agents.
Additionally, it's worth noting that while the risk of parasitic infection from raw crab exists, proper cooking methods can effectively eliminate these risks. Cooking seafood to an internal temperature of 145°F (63°C) is recommended to kill harmful organisms. If you plan to consume raw seafood in the future, ensure it comes from reputable sources that follow safe handling practices.

In conclusion, while your concerns about parasitic infections are valid, the symptoms you experienced are more likely related to a viral or bacterial infection rather than a parasite. Continue to monitor your health, and don't hesitate to consult a healthcare professional if you have further concerns or if your symptoms persist.

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