What Happens if E. coli Goes Untreated

In most infected individuals, symptoms of a Shiga toxin-producing E. coli infection last about a week and resolve without any long-term problems. Antibiotics do not improve the illness, and some medical researchers believe that these medications can increase the risk of developing hemolytic uremic syndrome (HUS). Therefore, apart from supportive care, such as close attention to hydration and nutrition, there is no specific therapy to halt E. coli symptoms. The recent finding that E. coli O157:H7 initially speeds up blood coagulation may lead to future medical therapies that could forestall the most serious consequences. Most individuals who do not develop HUS recover within two weeks.

What occurs during the hospital-stay can range from mild to very severe. Children are generally in the hospital for about two weeks, with the range being from three days to three months. Adults with HUS are typically in the hospital longer, because their course of illness tends to be more severe. Since there is no way to stop HUS with medications or otherwise, patients are provided supportive therapy, which includes meticulous attention to fluid and electrolyte balance. This supportive therapy is the cornerstone of survival.

The inflamed colon is usually non-functional for a week or two, thus total parenteral nutrition (TPN) becomes necessary. TPN is a complete form of nutrition, containing protein, sugar, fat and all needed vitamins and minerals for individuals unable to absorb adequate nutrition through their intestines. TPN is administered through a peripherally inserted central catheter (PICC). This provides access to a large vein in the upper chest that allows infusion of highly concentrated glucose. Even after intestinal function recovers, most patients continue to have a poor appetite for a week or so longer. During this time, nutrients can be given through a nasogastric (NG) tube.

Reduced or absent urine output (oligoanuria) occurs in most cases, and it usually lasts around a week. In some cases, though, oligoanuria can be as brief as two to three days, or a month or greater. Dialysis is required during this time to cleanse the body of uremic toxins, and to maintain fluid and electrolyte balance.

Peritoneal dialysis is usually used for young children unless the colitis is severe. Fortunately, the colitis is often resolving by the time dialysis becomes necessary. Treatment requires placement of a catheter (tube) through the abdominal wall into the peritoneal cavity. Older children and adults are treated with hemodialysis that circulates blood through a hemodialysis machine to filter out (remove) uremic toxins, normalize blood chemistries and correct any edema (swelling). Hemodialysis requires that venous access be established by inserting a temporary catheter into a major vein that returns blood from the upper body to the heart.

Most HUS victims require one or more blood transfusions to treat severe anemia; platelet transfusions are sometimes needed to diminish the risk of bleeding in those with severe thrombocytopenia—that is, platelet counts less than 10,000, to control bleeding, or in preparation for an invasive vascular procedure that can cause hemorrhage—for example, insertion of the hemodialysis catheter.

More than half of HUS patients experience high blood pressure (BP) that is usually mild and labile but may be severe enough to require treatment with anti-hypertensive drugs. This condition usually resolves prior to, or soon after discharge from the hospital.

Treating physicians must remain vigilant for signs of extra renal involvement. Intestinal necrosis and perforation can occur at any time during the acute phase of the disease, and these can be fatal if not promptly diagnosed and surgically treated. Pancreatic damage can cause sugar diabetes, which is almost always temporary, but may require insulin. Heart and lung injury is rare but can be fatal if it occurs. Brain damage can cause stroke or cerebral edema (swelling of the brain) and is the most frequent cause of death in HUS patients.

More frequently, encephalopathy (brain dysfunction) is the result of acute metabolic imbalance (metabolic encephalopathy) and is due to abnormalities in the blood concentrations of sodium, glucose, calcium, or very high levels of metabolic waste products. Since metabolic abnormalities are the result of the acute kidney failure, they can be successfully corrected by dialysis. Twenty-five years ago, the prevalence of metabolic encephalopathy was about 50%. But with earlier diagnosis and more timely treatment, the prevalence is now down to about 25%.

Convulsions are the most dramatic manifestation and are more likely to occur in toddlers (30%) than older children (15%). Unfortunately, structural damage to the brain—through a stroke or swelling—has not decreased over time. When swelling is severe, the pressure strangulates the brain stem, usually causing rapid death.