Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
About 10% of all persons infected with E. coli 0157:H7 develop some
complication. These complications may lead to disability or death.
The major complications are as follows:
Hemorrhagic (bloody) diarrhea: This complication can prolong the disease
by about a week, and cause severe
abdominal pain. The
individual may also develop
dehydration and anemia.
Hemolytic-uremic syndrome (HUS): This condition also prolongs the disease
as it usually becomes apparent about 7 to 10 days after the onset of symptoms.
Children under 10 years of age are the most likely to get this complication; HUS is the most
common cause of renal failure in children. The toxin produced by E. coli 0157:H7
enters the blood, causing blood cells to be damaged and small clots to form. The
toxin can lodge in the kidneys and eventually destroy renal tissue; sometimes
the damage is severe enough to cause kidney failure.
Thrombotic thrombocytopenic purpura (TTP): This complication is a
variation of HUS that usually occurs in the elderly. The same mechanisms as
those for HUS are responsible for TTP. However, the elderly develop more
clotting problems and use up more platelets resulting in easy or "spontaneous"
bruising over the body. The elderly experience more fever and neurologic
changes, in addition to kidney damage. Until the 1980's, TTP was considered a
fatal disease. However, treatment with plasma exchange and infusion techniques
has reduced the mortality rate (deaths) to about 10%.