Nov 16 2008
Escherichia coli
Escherichia coli
Description: Escherichia coli is one of the predominant bacterial species found in human and animal intestinal trac
ts. The bacterium is a GRAM-NEGATIVE rod. The species often is subdivided into strains by virulence (disease-causing) factors (O= cell; H = flagella; K = capsule). The strains forming part of the normal human gut microbiota are not pathogenic.
On October 6, the McAuliffe family from a large city in Connecticut decided to take a Sunday drive in the country. It was such a nice day that the family decided to have a picnic. They stopped to purchase a picnic lunch at a general store along the highway. The family purchased a complete picnic lunch that included chicken sandwiches, potato salad, and ice cream for desert. The father and two daughters had apple cider, while the mother had a soda to drink. After lunch the family continued on their drive and returned safely home that night.
On Wednesday, the two daughters woke up with abdominal pains and vomiting. Moreover, there was blood in their stools. That night, their father also experienced similar symptoms. The mother had no symptoms.
One of the daughters, Vicki, became worse and had to be admitted to the emergency room at the local hospital at 2 AM on Thursday. The presence of bloody diarrhea was noted by the attending ER doctor.
On interviewing the rest of the family, it was evident to the attending ER physician that some type of food poisoning had occurred among the three family members. Therefore, later Thursday morning, the physician contacted the Connecticut Department of Public Health (CDPH) to report the cases. The CDPH informed the physician they already had been notified of the five additional cases among local residences all with disease onset during the same period.
Of the eight case-patients, six were female, and ages of all eight ranged from 2 to 73 years (mean: 25 years). Case-patients resided in six near-by towns within the county. Symptoms included bloody diarrhea and abdominal pain (eight patients), vomiting (five), and fever (four). Duration of illness ranged from 3 to 11 days (median 7 days). Five patients were hospitalized, including one with hemolytic uremic syndrome (HUS).
The CDPH produced a case definition, which was defined as:
An infection of variable severity with bloody diarrhea (three or more loose stools per day) and cramps lasting less than seven days.
A stool sample from the McAuliffe’s daughter Vicki was sent to the clinical lab to identify the infectious agent. Meanwhile, her kidneys began to fail so the doctor transferred her to intensive care and advised dialysis to assist the kidney function.
The laboratory results identified and confirmed the presence of gram-negative rods as the cause of infection. Further tests were ordered to identify the specific bacterial species - it was Escherichia coli O157:H7.
After CDPH officials were notified of the lab results, they began a telephone survey to find out if anyone else were similarly infected. Over two dozen cases were found. All were asked about food consumption during the seven days preceding the illness.
Based on the interviews, increased risk of illness was associated with drinking fresh apple cider from cider mill A.
When inspectors visited cider mill A, which was located across the street from a dairy farm, the inspectors were told that the apples were purchased from one apple orchard in New York state, and then the apples were washed and brushed using water from the mill’s 45-foot drilled well. Inspectors then interviewed the owner of the orchard. He stated that the apples were picked directly from the trees; no apples were picked up from the ground.
Further testing identified E. coli O157: H7 in the well water at cider mill A. Appropriate control measures were instituted immediately to prevent further cases. Vicki McAuliffe recovered as did all the affect patients.
-Dr. Pommerville-
