Fecal Accidents in Community Swimming Pool Case Study
CDC reference if needed

During June of 2000, several children in Delaware, Ohio, were hospitalized at Grady Memorial General Hospital (GMH) after experiencing watery diarrhea, abdominal cramps, vomiting, and loss of appetite. Dr. McDermott, a new gastroenterologist at GMH, who also had a strong interest in infectious diseases, was asked to examine the children. Their illness lasted from 1 to 44 days, and nearly half of them complained of intermittent bouts of diarrhea. By July 20, over 150 individualsmainly children and young adults between the ages of 20 and 40experienced similar signs or symptoms. Dr. McDermott suspected that their illness was due to a microbial infection and queried the Delaware City County Health Department (DCCHD) to investigate this mysterious outbreak further.

Dr. McDermott helped the DCCHD team in surveying individuals hospitalized for intermittent diarrhea. They questioned individuals about recent travel, their sources of drinking water, visits to pools and lakes, swimming behaviors, contact with sick persons or young animals, and day-care attendance. The DCCHDs investigation reported that the outbreaks were linked to a swimming pool located at a private club in central Ohio. The swimming pool was closed on July 28. A total of 700 clinical cases among residents of Delaware County and three neighboring counties were identified during the entire span of the outbreak that began late June and continued through September. At least five fecal accidents were observed during that time period at the pool. Only one of these accidents was of diarrheal origin. Outbreaks of gastrointestinal distress associated with recreational water activities have increased in recent years, with most being caused by the organism in this case.

Do you know what microorganism might be the cause of the outbreak? How can a single fecal accident contaminate an entire pool and cause so many clinical cases of gastrointestinal distress?

Staining Helps Identify an Infectious Agent Case Study Reference CDC website if needed

A 94-year-old woman went to her local hospital emergency department in mid-November 2001 complaining of a 5-day history of weakness, fever, nonproductive cough, and generalized myalgia (muscle aches). Otherwise, for a person her age she was fairly healthy, although she did suffer from chronic obstructive pulmonary disease, hypertension, and chronic kidney failure.

On physical examination, her heart rate was above normal and she had a fever of 102.3F (39.1C). The rest of her physical examination was normal. Initial laboratory studies of blood cell count, blood chemistries, and chest X ray were also normal except for the chemical urine testing. This finding along with the fever suggested an infection, so the patient was admitted to the hospital. Samples of blood and urine were sent to the microbiology laboratory and set up appropriately.

The next day, microscopic evaluation of the urine culture revealed rod-shaped bacteria that stained red, and the blood culture revealed rods that stained purple. The liquid blood culture was then transferred to appropriate solid media. This finding in the blood was unusual, so a sample culture was sent to the state health department laboratory. Antibiotic therapy was adjusted, yet the patients condition deteriorated. Her most serious symptoms localized to her chest, and she was transferred to the intensive care unit. Four days after admission, the health department announced that the bacteria found in the patients blood were Bacillus anthracis. She was suffering from inhalation anthrax. Further testing showed these bacteria to be of the same strain that had been involved in the recent bioterrorist attack. Despite treatment, the patient died on the fifth day after admission.

What techniques and equipment are used when the bacteria are observed as being purple and red? How are these findings reported? What are the stages of processing a blood sample?