E. coli is short for Escherichia coli, a very common bacterium. The E. coli bacterium has hundreds of strains or types. Most of these strains are harmless to humans and some normally inhabit the intestines of healthy humans and animals. But a few are pathogenic (i.e., disease-causing) and can cause illnesses of varying severity.
Pathogenic E. coli strains occasionally bring about outbreaks of diarrhea in hospital nurseries. Enterotoxigenic Escherichia coli (ETEC), on the other hand, are the most common causative agents of travelers’ diarrhea – watery diarrhea, often associated with cramps and low-grade fever that affect travelers from industrialized countries to developing countries. As a rule, though, travelers’ diarrhea is a benign, self-limited condition that occurs during travel or soon after returning home.
The deadly E. coli strain that struck Ciara Marie Abalos is, according to her doctors, Escherichia coli O157:H7. This strain of E. coli was first identified in 1982 after it caused an outbreak of bloody diarrhea following consumption of contaminated hamburgers. This newly emerged pathogen has since been recognized as the causative agent of countless cases of severe diarrhea all over the world, although most of the reported cases are from the US, UK and Canada. In the US, it is estimated that at present, 73,000 cases of the infection that result in 61 deaths occur annually.
E. coli O157:H7 (the letters and numbers in the name of the bacterium denote the specific markers found on the surface of the E. coli that differentiates it from other strains) inhabit the intestines of some healthy cattle. It is thus present in feces of these cattle. Humans get infected with the pathogen when they consume undercooked ground beef that has been contaminated during slaughter, contaminated drinking water and improperly washed contaminated fruits and vegetables. The germ can also be transmitted from human to human through unsanitary practices.
The diarrhea that characterizes E. coli O157:H7 infection usually starts three to four days after exposure. Sometimes, the diarrhea is mild and the illness resolves spontaneously in 5-10 days, but often it worsens (becomes bloody) and is accompanied by abdominal cramps and low grade fever.
About two to seven percent of people who get infected with E. coli O157:H7 develop life-threatening complications. The most common of these complications is hemolytic uremic syndrome (HUS), a condition marked by destruction of red blood cells and kidney failure. HUS often affects the nervous system and causes seizures and eventually coma. With good hospital intensive care, most patients recover from HUS, but a few do not. In about a third of those who recover, normal kidney function is not fully restored resulting in kidney failure years later.
Treatment of mild forms of E. coli O157:H7 infection consists simply of liberal fluid intake to replace the fluid that is lost by frequent bowel movement. But the moment the diarrhea becomes bloody, the patient should be brought to the hospital where better supportive care can be given. By the way, antibiotics are not routinely used in the treatment of E. coli O157:H7 infection, because, according to some experts, they may even precipitate kidney failure.
E. coli O157:H7 infection can be prevented by: Cooking ground beef (e.g., hamburger patties) thoroughly, washing fruits and vegetables adequately, not drinking milk, milk products and juices that have not been pasteurized, making sure drinking water is safe, observing good personal hygiene and sanitary practices (e.g., wash hands with soap and water after using the toilet and before preparing food).
