Dangerous Potential

What am I looking at?

The circular and oval shapes in the center of this image are a group of larvae (1) from a parasitic worm known as a schistosome, or blood fluke. They are shown developing within their host, a freshwater snail, whose muscles are visible around the edges of the image (2). This image is color-coded for depth, with warmer colors such as red and yellow being closer to the viewer and cooler colors such as violet, blue, and green being farther from the viewer.

Biology in the background

Schistosomes, or blood flukes, are a type of parasitic flatworm that can infect multiple different hosts during their life cycle. Their eggs are produced in a mammalian host and hatch in fresh water. After hatching, the parasites seek out freshwater snails to support their growth and development. The larvae grow into their infectious stage while inside the snail.

Once they become infectious, the larvae exit the snail and reenter the water. These free-swimming larvae can invade humans and many other mammals through their skin. The larvae then enter the host’s bloodstream and develop into adult worms. These worms can live in a host’s bloodstream for decades.

Schistosomiasis is the name of the disease caused by these worms once they infect a host’s bloodstream. Symptoms occur when female worms release their eggs, which enter the digestive system and cause abdominal pain, diarrhea, and blood in the host’s stool. In nature, these symptoms allow the eggs to be deposited back into bodies of fresh water through the feces of the infected host.

At the larval stage of their life cycle, a schistosome can reach 200 micrometers long, or roughly 2.5 times the width of a human hair.

Technique

This image was created using confocal microscopy.