Chapters 2-4
Which of the following is a condition which may occur during the incubation period?
Transmission of infection
Chicken pox is a highly
... [Show More] communicable disease. It may be transmitted by direct contact with a person
infected with the varicella-zoster virus (VZV). The typical incubation time is between 10 to 20 days. A
boy started school 2 weeks after showing symptoms of chicken pox including mild fever, skin rash, &
fluid-filled blisters. One month after the boy returned to school, none of his classmates had been
infected by VZV. The main reason was:
Contact was after infectious period
The ability of a single person to remain free of clinical illness following exposure to an infectious agent
is known as:
Immunity
Which of the following is characteristic of a single-exposure, common-vehicle outbreak?
The epidemic curve has a normal distribution when plotted against the logarithm of
time
What is the diarrhea attack rate in persons who ate both ice cream & pizza?
39/52
What is the overall attack rate in persons who did not eat ice cream?
33%
Which of the food items (or combination of items) is most likely to be the infective item(s)?
Ice cream only
Which of the following reasons can explain why a person who did not consume the infective food item
got sick?
They were directly exposed to persons who did eat the infective food item
Diarrhea is a general symptom consistent with a number of illnesses
There may have been an inaccurate recall of which foods were eaten (all of the
above)
An outbreak of gastroenteritis occurred at a boarding school with a student enrollment of 846. Fiftyseven students reported symptoms including vomiting, diarrhea, nausea, & low-grade fever between
10 p.m. on September 24 & 8 p.m. on September 25. The ill students lived in dormitories that housed
723 of the students. The table below provides information on the number of students per type of
residence & the number reporting illnesses consistent with the described symptoms & onset time.
Calculate the attack rate among all students at the boarding school.
The answer is found by dividing the total number of cases (57) by the total number of students (846).
This equals 6.7%.
An outbreak of gastroenteritis occurred at a boarding school with a student enrollment of 846. Fiftyseven students reported symptoms including vomiting, diarrhea, nausea, & low-grade fever between
10 p.m. on September 24 & 8 p.m. on S [Show Less]