At present, there are four known classes of enterovirulent Escherichia coli that trigger gastroenteritis in humans as examined by means of microscopy under the microscope like the binocular compound microscope. Among these is the enterohemorrhagic or EHEC strain nominated Escherichia coli O157:H7. Escherichia coli organism is a typical resident of the intestines of all animals, including humans as observed through microscopy using a microscope such as binocular compound microscope. When aerobic culture techniques are utilized, Escherichia coli is the prevailing species found in stools as examined via microscopy under the microscope such as binocular compound microscope. Naturally Escherichia coli organism performs a helpful task in the body by restraining the growth of injurious bacterial species and by integrating substantial amounts of vitamins as studied through the aid of microscopy using a microscope such as binocular compound microscope. A marginal of Escherichia coli strains are competent of causing human sickness by several varied means. Escherichia coli serotype O157:H7 is a rare diversity of Escherichia coli that generates large amounts of one or more associated, potent toxins that trigger serious destruction to the lining of the intestine. These toxins are also known as verotoxins or shiga-like toxins. They are closely attributed or the same to the toxin generated by Shigella dysenteriae as observed by means of microscopy using a microscope such as binocular compound microscope.

Hemorrhagic colitis is the terminology of the acute disease triggered by Escherichia coli O157:H7. The disease is typified by serious cramping or abdominal pain, and diarrhea that is at first watery but turns grossly bloody. Sporadically vomiting takes place. Fever is either low-grade or none at all. The disease is typically self-limited and lasts for an average of eight days. Certain persons exhibit watery diarrhea only. Infective dose of this organism is not yet known, but based from records of epidemics including the capability of the organism to be transmitted from one person to another person in the day-care areas and nursing homes the dose may be analogous to that of Shigella species, which is as few as ten organisms only.

Hemorrhagic colitis is identified by isolation of Escherichia coli of serotype O157:H7 or other verotoxin-generating Escherichia coli from diarrheal stools with the aid of microscopy using a microscope such as binocular compound microscope. On the other hand, the feces can be examined straightly for the existence of verotoxin. Verification can be acquired by isolation of Escherichia coli of the identical serotype from the implicated food.

Inadequately cooked or raw hamburger or ground beef has been incriminated in many of the reported outbreaks, nevertheless Escherichia coli O157:H7 epidemics have incriminated alfalfa sprouts, non-pasteurized fruit juices and milk, and dry-cured salami as well as lettuce, game meat and cheese curds.

Hemorrhagic colitis contagions are not very common, but this is possibly not reflective of the real frequency. In the Pacific Northwest, Escherichia coli O157:H7 is deemed to be second only to Salmonella as a factor of bacterial diarrhea. Due to the obvious signs of profuse, apparent blood in serious cases, those victims possibly seek medical attention, but less serious cases are possibly more numerous.

Certain victims, specifically the very young, have formed the hemolytic uremic syndrome, typified by renal failure and hemolytic anemia. From none to fifteen percent of hemorrhagic colitis victims may have hemolytic uremic syndrome. The illness can lead to permanent injury of kidney function.

In the elderly, hemolytic uremic syndrome, plus two other indications, fever and neurologic manifestations comprises thrombotic thrombocytopenic purpura. This disease can have a fatality rate in the elderly as high as fifty percent.

All humans are deemed to be vulnerable to hemorrhagic colitis, but young children and the elderly seem to progress to more severe symptoms more often.