Consumers must choose fresh, clean, unblemished food of clear origin; practice cooked food, and boiled water; carefully wash fresh vegetables and fruits, wash vegetables under running water, and soak them in salt water, Phong said.

He emphasized that cooked food should be carefully preserved, and eaten immediately after cooking, used food should be thoroughly cooked before being eaten again, and raw and cooked food should not be mixed.

"People must wash their hands before processing food, before eating, and after using the toilet; keep the kitchen, utensils, and processing area clean, tidy, and dry; not eat spoiled, moldy food; and use clean water to process food and drink," Phong told The Hanoi Times.

People should also be regularly dewormed every six months. In particular, people living in high-risk areas (or working in livestock and agricultural environments) should have regular health checks and parasite testing to prevent and detect liver flukes and other parasites early for timely treatment.

The dissemination of principles has been made following the consumption of raw vegetables (some kinds of Vietnamese herbs that can be used as dessert) and undercooked meals by many people. Those habits do not ensure food safety and expose them to parasite infections and other diseases, according to health experts in Hanoi.

They said that once infected, these diseases are very difficult to treat and can even be life-threatening.

Many cases of liver flukes and parasitic infections caused by eating uncooked food have recently been reported in Hanoi hospitals.

The latest was a 43-year-old man from the outskirts of Hanoi's Dan Phuong district who had itchy red rashes all over his body. Although he has been administered antibiotics several times, there has been no improvement. The patient has lost his appetite and his itchy rash has recently gotten worse. Concerned about these strange symptoms, he sought medical attention at Dang Van Ngu Hospital, which specializes in entomology, parasitology, and malaria.

"I was diagnosed with visceral dog roundworm after the doctors took me for blood tests. I think it was because I often eat raw vegetables," he told The Hanoi Times.

Raw vegetables carry the risk of parasitic infections. Photos: Ha Linh/The Hanoi Times

A 27-year-old woman from the northern province of Lang Son was diagnosed with large liver flukes by doctors at Dang Van Ngu Hospital. She said she often eats raw vegetables, especially fish mint, and lettuce.

"I often wash and soak raw veggies in salt water before eating them. I cleaned the vegetables thoroughly, so I was shocked when the doctors told me I had parasites," the patient told The Hanoi Times.

When doctors at Medlatec General Hospital in Hanoi told a 38-year-old woman who was there for a routine check-up that she had parasites and that her daily eating habits were the cause of her illness, she was taken aback.

The patient, who reported occasional pain in her calves, has a habit of eating raw vegetables and is often in contact with dogs and cats. Testing was positive for roundworms, eelworms, dog and cat roundworms, large liver flukes, and small liver flukes. 

Dr. Tran Huy Tho, Deputy Director of Dang Van Ngu Hospital, said that liver flukes can cause liver abscesses, which are quite common in Vietnam.

Raw fish salad if unproperly made is unsafe for health.

"Currently, many people inadvertently ingest liver flukes simply by eating their favorite uncooked foods. Patients with liver flukes often have symptoms of pain in the liver area, rash, digestive disorders, even bile obstruction, cholestasis, and jaundice. If not diagnosed and treated promptly, the patient will suffer from anemia, liver fibrosis, portal hypertension, and gradual exhaustion," Tho told The Hanoi Times.

He said many people have the habit of soaking raw vegetables in salt water because they think it kills worms and parasites. But this is a misconception. Saltwater is not used to sterilize vegetables, but rather to screen out worm and parasite eggs.

Le Van Thieu, a doctor at the Facility of General Infection under the National Hospital for Tropical Diseases, said the hospital regularly treats patients with abdominal pain, weight loss, fatigue, and itching, whose test results were positive for many types of worms and parasites at the same time.

"Some types of worms and parasites enter the human body through skin contact. Some worms and parasites are transmitted through food, such as eating raw, uncooked, or unhygienic food that contains worm larvae," Thieu said.

When the worms are in the brain (generally found in 60-96% of cases), they can cause neurological disorders such as headaches (48.4%), epilepsy (6.2%), mental disorders (5.2%), visual disturbances (15.6%), physical weakness and memory loss (28.1%), muscle spasms (34.3%). 

Medical experts also believe that fascioliasis is caused by a large liver fluke (Fasciola hepatica or Fasciola gigantica). This fluke lives as a parasite mainly in herbivores such as cows and buffaloes. 

"While parasitizing in the bile duct, fascioliasis destroys liver tissue and causes lesions in the liver. Especially if liver fluke disease is not thoroughly detected and treated, it can cause liver abscess, cholangitis, cholestasis, and even bile duct cancer," the doctor said.

An interdisciplinary team from Hanoi inspects a vegetable farm in Thanh Tri District.

People infected with liver flukes often have symptoms of dull pain in the abdomen (liver location), then the pain spreads to the back or epigastric region. The symptoms cause patients bloating, nausea, digestive disorders, pale skin, jaundice, hives, fatigue, anorexia, weight loss, and so on.

Dr. Nguyen Trung Nguyen, Director of the Poison Control Center at Hanoi's Bach Mai Hospital, warned that raw foods have many potential health risks, such as being infected with bacteria that cause poisoning.

Moreover, when eating raw foods, people will get diseases transmitted through the digestive tract, such as HP bacteria infection (which can cause stomach cancer), and hepatitis E. 

“Eating unprocessed foods also makes us a target for the hepatitis A virus, worms, and many other parasites that stealthily destroy the body," Nguyen told The Hanoi Times.