Larval Eustrongylides species are large, bright red roundworms or nemotodes, as seen by means of medical microscopy using a microscope, having the length of twenty-five to one hundred and fifty millimeters and a diameter of two millimeters. They come about in freshwater, brackish water and in marine varieties of fish. The larvae typically mature in wading birds like herons, egrets and flamingos as monitored with the help of microscopy. If the larvae are ingested in inadequately cooked or raw fish, they can affix to the wall of the digestive tract as seen by means of medical microscopy using a microscope. In the five instances for which clinical manifestations have been documented, the infiltration into the gut wall was complemented by severe pain. The nematodes can pierce the gut wall and possibly other organs as observed through medical microscopy using a microscope. Elimination of the nematodes by surgical resection or fiber optic tools with forceps is probable with the aid of medical microscopy using a microscope, if the nematodes infiltrate accessible regions of the gut.

One live larva may initiate an illness. In three of the five documented instances, the worms were diagnosed by surgical resection of the intestine with the help of medical microscopy. In one instance, there was no clinical information and in one other, the patient was cared for medically and recuperated in four days. Fish from fresh, brackish or salt water are the foods being implicated on this disease. The illness is very rare. There have been merely five cases documented in America. Septicemia, which is because of the pierced digestive tract, is the usual complication. Those eating whole minnows are at highest risk. One instance was documented from the ingestion of sashimi, and later discovered to be infected by such illness with the help of medical microscopy. These large worms can be apparent even without magnification in the flesh of fish and are typically very active after death of the fish. There have been no major occurrences. There have been reports received regarding the three fishermen in Baltimore, Maryland who ingested live minnows and formed severe abdominal pain within twenty-four hours. Even though information is not complete, contamination by larval Eustrongylides species is prevalent and usual in various species of freshwater fish.

The high rates of contamination for minnows known as Fundulus species may signify a high degree of risk for individuals who prefer to consume these fish without cooking them first. Food and Drug Administration has no particular regulation or activity with regards to these worms. Nevertheless, as pathogens or disease-causing organism, no live Eustrongylides sp. must be present in fish eaten raw or medium raw. So for those who like to eat raw fish, be very alert and very cautious on what you are taking to your mouth. You might not know that the food you are eating or preparing is infected with some larvae of the parasitic organisms that may be the cause of your death or the demised of those you serve.