The symptoms from such infections vary depending on the kinds of parasite. Among the most common infections are those caused by the worms, known as anisakiasis, among others, caused by the worms Anisakis. The parasite often causes severe abdominal pain, nausea, vomiting, and diarrhoea within a few hours or up to one day after ingestion of the infected fish. Sometimes, the parasite can penetrate the stomach or wall of the intestines, leading to inflammation and fever. The parasite may also cause allergic reaction from rashes to anaphylaxis. In general, symptoms appear very quickly and therefore there are reasons to find a hospital facility shortly after infection.
Another type of worm that infects a person with the disease diphyllobothriasis is known as fish tapeworm. This parasite develops much more slowly than the first three above, but it does so with abdominal pain, nausea, diarrhea, weight loss. Its signs and symptoms occur weeks to months following the ingestion of infected freshwater fish. In long-standing infections, a deficiency in vitamin B12 has led to secondary anemia and fatigue. Other fluke infections are caused by liver flukes and lead to opisthorchiasis or clonorchiasis, perhaps with an even longer incubation; years may elapse before this disease will present such manifestations as inflammation of the liver and jaundice. Medical consultation is thus advisable immediately if symptoms occur following the consumption of undercooked or raw fish.
1. Anisakiasis
Cause:
Raw or undercooked marine fish containing the Anisakis worm
Symptoms:
Later:
Symptoms:
- Hours after ingestion up to the following day
- Severe abdominal pain, nausea, vomiting, and diarrhea.
Later:
In case the worm attaches to the stomach or intestines, then inflammation and fever occur with allergic reactions in the form of rash or anaphylaxis.
Timeline: Symptoms usually come after hours of eating but could take a day.
Cause: Freshwater fish tapeworms by Diphyllobothrium.
Symptoms:
Mild: Some gastroenteritis complaints like abdominal pain, diarrhea, nausea, and sometimes weight loss.
Severe: Like all other chronic infections, there will be anemia and fatigue due to a resultant vitamin B12 deficiency.
Timeline: Signs and symptoms may not occur until weeks to months after ingesting the contaminated fish since the tapeworm takes several weeks to replicate within the intestines.
Opisthorchiasis or Clonorchiasis: The freshwater fish-born liver flukes may manifest signs and symptoms of which include inflammation in the liver, jaundice, and digestive malfunctions even months or years later.
Hours to days: Anisakiasis (symptoms will be immediate).
Weeks to months: Diphyllobothriasis or other parasitic diseases (with late onset due to incubation periods being longer).
If you suspect any parasitic disease, always see the diagnosis of a medical doctor since they have resulted from consuming raw fish.
Timeline: Symptoms usually come after hours of eating but could take a day.
2. Diphyllobothriasis:
Cause: Freshwater fish tapeworms by Diphyllobothrium.
Symptoms:
Mild: Some gastroenteritis complaints like abdominal pain, diarrhea, nausea, and sometimes weight loss.
Severe: Like all other chronic infections, there will be anemia and fatigue due to a resultant vitamin B12 deficiency.
Timeline: Signs and symptoms may not occur until weeks to months after ingesting the contaminated fish since the tapeworm takes several weeks to replicate within the intestines.
3. Other Possible Worms:
Opisthorchiasis or Clonorchiasis: The freshwater fish-born liver flukes may manifest signs and symptoms of which include inflammation in the liver, jaundice, and digestive malfunctions even months or years later.
General Timeline:
Hours to days: Anisakiasis (symptoms will be immediate).
Weeks to months: Diphyllobothriasis or other parasitic diseases (with late onset due to incubation periods being longer).
If you suspect any parasitic disease, always see the diagnosis of a medical doctor since they have resulted from consuming raw fish.