Foods That Commonly Contain Worms and Parasites

Particularly for pregnant women and children with weaker immune systems, it’s important to avoid these foods, as their bodies are less capable of fighting infections.

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Raw Pig’s Blood (Tiết canh)

Raw pig’s blood pudding is extremely dangerous, especially when it comes from pigs infected with Streptococcus suis bacteria, which typically reside in the pig’s throat and can be directly transmitted to humans.

Those who consume pig’s blood are at risk of developing cysticercosis (tapeworm infection) or roundworm infestations, with infection rates as high as 80%. Once inside the intestines, these parasites attach to the intestinal lining, multiply, and mature into adult worms within a few months. Mature larvae release toxins that can cause severe blood infections, leading to symptoms such as high fever, widespread subcutaneous bleeding, and septic shock.

In some cases, worms from raw blood can migrate to the brain, causing dizziness, headaches, malnutrition, and anemia. If left untreated, these conditions may cause serious damage to the nervous system.

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Fermented Pork Roll (Nem chua)

Nem chua, a traditional delicacy of northern and central Vietnam, is popular but carries many health risks. It can cause digestive disorders and transmit parasites such as roundworms and liver flukes.

Children and individuals with weak digestive systems are especially vulnerable. Eating contaminated nem chua may lead to trichinosis, liver fluke infections, and in severe cases, respiratory failure, mental disturbances, or low blood pressure.

Many commercially available nem chua products today are made with unknown origins, questionable preservation, and poor hygiene. Spoiled ingredients and even chemicals are sometimes used to reduce costs, encouraging mold and parasite growth. This can result in abdominal bloating, indigestion, and diarrhea. Additionally, contaminated production environments—unclean hands, dirty utensils, and unsanitary wrapping leaves—increase the risk of food poisoning.

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Rare or Undercooked Beef

Raw or undercooked meat often harbors harmful bacteria and parasites. If not thoroughly cooked, these pathogens can survive and multiply inside the human body, causing not only worm infestations but even cancer in the long term.

Beef dishes such as rare beef salad, rare beef pho, or seared beef are popular but significantly increase the risk of parasitic infections, including tapeworms (Taenia saginata) and liver flukes. To ensure both nutrition and safety, beef should always be well-cooked before consumption.

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Raw Vegetables

While raw vegetables retain more nutrients than cooked ones, they also pose serious health risks if not properly washed. Studies show that 92–100% of raw vegetables may contain parasites harmful to the digestive system. Consuming unwashed vegetables can easily lead to intestinal worm infections and diarrhea.

Over 10% of parasitic infections are linked to eating raw vegetables of unclear origin or those not cleaned and soaked properly in salt water. To minimize risks, vegetables should be carefully picked, rinsed leaf by leaf under running water, and then soaked in salt water for 1–2 minutes before eating.

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Snails

Snails are a popular street food and drinking snack but are known hosts to many parasites such as threadworms, liver flukes, intestinal flukes, and blood flukes. Eating contaminated snails can cause dangerous diseases, including cholera and diarrhea.

Snails serve as intermediate hosts for numerous parasites, which survive stubbornly inside their shells and can only be killed by high heat over a long period. Once inside the human body, they release toxins that may trigger severe allergic reactions, cancer, or organ failure.

Before cooking, snails should be soaked in rice water, vinegar, or salt mixed with lemon for about an hour to purge dirt and toxins. After thorough cleaning, they must be fully cooked to ensure safety.