by Bob Thomas
Roundworms, better called nematodes, are among the most common critters on earth. It is said that if one could remove every speck of living and non-living material from the earth, leaving only nematodes, that one would still see a perfect outline of the planet, its mountains and valleys, and its inhabitants.
Nematodes may be free-living or parasitic; they may be fierce predators or they may feed on detritus. Nematodes range is size from microscopic to seven meters long (the largest are parasitic in whales). People are probably most aware of the nematodes we call pinworms, tiny thin roundworms that may infest our bodies, especially in small children.
In America’s WETLAND, there is another nematode that may be quite bothersome. Humans who work or recreate in the marsh may get an occasional case of nutria itch, a condition resulting in severe itching and swelling. It is caused by a small nematode of the genus Strongyloides (pronounced “strong eh loy’ dees”) that is parasitic in nutria intestines.
Nematode eggs leave the nutria in its feces, and they hatch into tiny larvae that swim about in the water. Normally, these larvae burrow into a nutria’s skin, become adults, and the cycle begins again.
Woe is to the hapless human who has skin contact with the nematode larvae. This may happen wading around, sitting in a blind, or crawling around under a camp repairing the foundation. The larvae instinctively burrow into the person’s skin.
Since humans are not the normal host, the larvae burrow about until they die. The whole process can cause several weeks of unmitigated agony!