Echinococcus Measures in Niseko Town

Echinococcus is a type of parasitic worm. There are two types of Echinococcus: unilocular and multilocular. The strain that is problematic in Hokkaido is the multilocular type.
Echinococcus has both adult and larval stages. The adult parasites primarily infect foxes (specifically, the Kita Fox), while the larvae are typically found in wild rodents, such as Ezo Yachi Rats (a species of field mouse).
The adult parasite lays eggs, which are excreted in the fox's feces. If these eggs accidentally enter a human's mouth (for example, through contaminated wild plants, water, or hands), they hatch into larvae in the intestines, which then travel to the liver and cause Echinococcosis.
For more details on Echinococcus, please refer to the page by the Hokkaido Institute of Public Health.

In nature, Echinococcus primarily parasitizes foxes and wild rodents. The cycle works as follows:

1. Adult Parasites live in the intestines of the fox and produce eggs, which are released in the fox's feces.
2. Wild rodents, such as field mice, ingest these eggs along with vegetation, and the eggs hatch into larvae within their bodies, where they parasitize the liver.
3. When a fox eats an infected rodent, the larvae develop into adult parasites within the fox's intestines.

This cycle between foxes and wild rodents maintains the parasite's life cycle.

Humans can become infected with Echinococcus by consuming contaminated wild vegetables, herbs, or water, or by coming into contact with eggs on their hands or objects. Once the parasite enters the human body, the larvae can migrate to the liver and begin to parasitize it, much like in the wild rodents.
Important Note: Echinococcus cannot be transmitted from person to person or from wild rodents to humans.
Echinococcus eggs are microscopic (about 0.03 mm in diameter), and cannot be seen with the naked eye. However, infection can be prevented by washing hands thoroughly or cooking food properly before consumption.
Even after being infected, people may not notice symptoms for several years—usually between 5 to 15 years. Early symptoms may include discomfort or a feeling of fullness in the upper abdomen, followed by fatigue, jaundice, and liver dysfunction. If left untreated, the infection can spread to other organs like the lungs or brain, leading to life-threatening complications.

• Wash your hands thoroughly after coming from outdoors.
• Clean wild plants and berries properly before eating, or cook them to kill any potential parasites.
• Do not feed foxes or touch them, even though they might seem cute. This behavior brings foxes closer to human habitation.
• Properly manage food waste to avoid attracting foxes and other wildlife to your home.
• Let's properly store and dispose of household waste.
• Cover wells properly to prevent contamination by foxes or dogs' feces.

Dogs, like foxes, can become infected with Echinococcus by eating wild rodents that carry the adult parasite.
Therefore, dog owners must be cautious about how they care for their pets—especially by not allowing them to roam freely.
Echinococcosis is a preventable disease, and early detection and treatment are crucial.
If you’ve lived in Hokkaido for over 5 years and haven’t undergone a checkup, or if you haven’t had one for more than 5 years, consider getting a blood test through your local municipality. This is particularly important if you've had direct contact with foxes or if your dog has eaten wild rodents.
For information about Echinococcus screenings in Niseko Town, please contact the Health & Welfare Division, Health Promotion Section.

To monitor Echinococcus infection, fox feces samples are collected and tested for Echinococcus antigens and eggs at specialized laboratories.
Niseko Town began its bait distribution and feces sampling in October 2009.
The results showed a significant reduction in infection rates compared to the tests conducted prior to the introduction of the bait program.

• Antigen-positive: Indicates the fox is infected with Echinococcus.
• Egg-positive: Indicates that Echinococcus eggs are present in the fox’s feces.