microbiology case study chapter22?

On October 15, a 40-year-old man was admitted to the hospital. He had a "splitting" headache, his
legs were unsteady, and his vision was blurred. During examination, it was apparent that there
was something wrong with his throat. It wasn't sore, but it felt stiff and tight, and it was almost
impossible for him to speak.

Over the next seven days, 28 persons with similar symptoms were admitted to the hospital.
Twelve of these patients required ventilatory support; no deaths were reported. During the
investigation, it became apparent that the illnesses were due to meals consumed between October
14 and 16 at one restaurant. Detailed food histories were obtained from the patients. An additional
case-control study was conducted on well people who had consumed food at the restaurant during
the same three-day period. Repeated news media announcements aided health personnel in
locating 18 other people who had eaten virtually the same foods at the restaurant.

The meals consisted of the following foods:

Patty Melt. Frozen hamburger patties purchased from a restaurant distributor. Patties were
removed from the freezer and fried as ordered. Presliced pasteurized American cheese purchased
from a distributor was kept refrigerated, and a slice was melted on each cooked hamburger patty.
Meat and cheese were served on rye bread purchased from a local bakery.

Sauteed Onions. Onions were purchased fresh from a farmer. Fresh whole onions were sliced and
then sauteed with margarine, paprika, garlic salt, and a chicken-based powder. After the initial
cooking, the onions were held uncovered in a pan on a warm stove (<60°C) along with a large
volume of melted margarine; they were not reheated before serving.

French-Fried Potatoes. Precut frozen potatoes were deep-fried in two- or three-serving batches
as needed.

Potato Salad. Potatoes were purchased from a farmer. They had been stored in a root cellar and
were transported loose in a pickup truck. The potatoes were washed, peeled, diced, and boiled.
Cooled, drained potato cubes were mixed with oil, vinegar, dry mustard, and garlic salt, and kept
refrigerated. Individual servings were removed from the container as needed.

Lettuce and Tomato Salad. Produce was delivered every other day. Lettuce and tomatoes were
cut in the morning, refrigerated, and mixed with oil and vinegar for serving.

 

1-On one page, identify the etiologic agent of this outbreak of food poisoning.

 

2-Was it food infection or intoxication?

 

3-What item was contaminated, and how did it become contaminated?

 

4-Briefly explain how you arrived at your conclusion. How did you eliminate the
other major causes of food poisoning?