Are the long, thin worms found in Sichuan dragon worms?

Recently, some netizens took photos of long white worms several meters long appearing in the waters near Chengdu and Leshan scenic spots in Sichuan. The worms were swimming very fast and were suspected to be African dragon worms.

The matter has been reported to the local disease control department and the specific circumstances need to be further verified.

Today, I will first tell you about the dragon worm and its related knowledge, and then talk about this worm in Sichuan (there is no warning picture in this article)

01. What is guinea worm?

The guinea worm, scientifically known as Dracunculus medinensis, is also known as the guinea worm. It is a large nematode that can parasitize deep inside the body of mammals. It is mostly found in tropical and subtropical areas.

This type of worm usually infects humans as females, and the females can grow from dozens of centimeters to more than one meter long, making them one of the longest nematodes that infect humans. The male worm can only grow about 4 centimeters, or about an inch.

02. The infection route of guinea worm

The infection route of guinea worm is as follows:

Specifically:

1. Humans become infected by drinking unfiltered water that contains copepods (small crustaceans) that harbor the larvae of the worm.

2. After being ingested by humans, copepods die and release larvae, which begin to reproduce in the human body. During this period, the larvae migrate along the intestines and enter the abdominal cavity.

3. After maturing into adults and mating, the male worms die and the female adults begin to move along the skin, from the subcutaneous tissue to the skin surface.

4. Blisters form on the skin surface, and then wait for the blisters to burst before coming out of the blisters. Holes usually appear mainly on the feet.

5. When the lesions come into contact with water, female worms emerge and release larvae.

6. The larvae are ingested by copepods and develop into infective larvae.

When it passes through the human body, it leaves holes, which can easily lead to infection by other microorganisms.

03. About Guinea worm

The guinea worm originated in Africa. It once wreaked havoc for a long time and its population was so great that some people even believed that the snake staff in medicine might not actually be a snake, but a guinea worm.

Dracunculus medinensis ("little dragon from Medina") was described in Egypt as early as the 15th century BC and possibly was the "fiery serpent" of the Israelites described in the Bible.

It has been basically eliminated in recent years.

Both the geographical area of ​​infection and the overall number of infections have decreased.

But it is worth mentioning that people once believed that this insect only parasitized humans, but now it is discovered that it seems to have many hosts, such as some wild animals and dogs.

This also makes it more difficult to completely eliminate the parasite.

04. Is the nematode found in Sichuan the dragon worm?

The Sichuan case may not be the guinea worm. Zhao Li, curator of Chengdu Huaxi Insect Museum, has ruled out the possibility that it is the guinea worm. Because the guinea worm itself originated in Africa, so far only one case has been reported in Anhui, my country.

Judging from the multiple locations mentioned in the report, they should be other nematodes.

"When I was playing in the river near the Heizhugou Scenic Area in Leshan City, it was so densely packed that it gave me goose bumps."

According to this description, given that it appeared in such a large area in multiple places in the scenic area, if it was guinea worm, theoretically it would have caused a certain epidemic long ago (well, parasites are also considered infectious diseases).

Finally, I would like to remind you again that you should never drink untreated water in the wild. No matter how clean the water looks, there is a risk of parasites.

Just like guinea worm, it is caused by people drinking contaminated water directly.