NR 503 Epidemiology midterm questions & answers: <br/>1. The population of a city on February 15, 2005, was 36,600. The city has a passive surveillance <br/>system that collects hospital and private physician reports of influenza cases every month. <br/>During the period between January 1 and April 1, 2005, 2,200 new cases of influenza occurred in <br/>the city. Of these cases, 775 persons were ill with influenza according to surveillance reports on <br/>April 1, 2005. The prevalence rate of active influenza as of April 1, 2005, was: <br/> Correct! 20 per 1,000 population <br/>2. The population of a city on February 15, 2005, was 36,600. The city has a passive surveillance <br/>system that collects hospital and private physician reports of influenza cases every month. <br/>During the period between January 1 and April 1, 2005, 2,200 new cases of influenza occurred in <br/>the city. Of these cases, 775 persons were ill with influenza according to surveillance reports on <br/>April 1, 2005. The monthly incidence rate of active cases of influenza for the 3-month period <br/>was: Correct! 20 per 1,000 population <br/> <br/>3. What would be the effect on age-specific incidence rates of uterine cancer if women with <br/>hysterectomies were excluded from the denominator of incidence calculations assuming that <br/>most women who have had hysterectomies are older than 50 years of age? Correct!: Rates would increase in women older than 50 years of age but may decrease in <br/>younger women as they get older. <br/>4. The ability of a single person to remain free of clinical illness following exposure to an infectious <br/>agent is known as: Correct!: Immunity <br/>5. Which of the following reasons can explain why a person who did not consume the infective <br/>food item got sick? <br/>Correct: All of the above <br/>6. Which of the food items (or combination of items) is most likely to be the infective item(s)? <br/> <br/>Correct!: Ice cream only 7. The case-fatality rate associated with plague is lowest in which community? <br/> Correct Answer: Community C <br/>8. The incidence and prevalence rates of a chronic childhood illness for a specific community are <br/>given below. <br/>Correct Answer: The duration of disease is becoming longer. 9. The following table gives the mean annual age-specific mortality rates from measles during the <br/>first 25 years of life in successive 5-year periods. You may assume that the population is in a <br/>steady state (i.e., migrations out are equal to migrations in). <br/>Based on the information above, one may conclude: Correct Answer: Children ages 5 to 9 had the highest rate of death in all periods 10. In a country with a population of 16 million people, 175,000 deaths occurred during the year <br/>ending December 31, 2005. These included 45,000 deaths from tuberculosis (TB) in 135,000 <br/>persons who were sick with TB. Assume that the population remained constant throughout the <br/>year. Not all 135,000 cases of TB were contracted during 2005. Which of the following <br/>statements is true? Correct Answer: None of the above 11. In 2001, a state enacted a law that required the use of safety seats for all children under 7 years <br/>of age and mandatory seatbelt use for all persons. The table above lists the number of deaths <br/>due to motor vehicle accidents (MVAs) and the total population by age in 2000 (before the law) <br/>and in 2005 (4 years after the law was enacted). Correct Answer: Correct, because both the total and the age-adjusted mortality rates are <br/>higher in 2005 than in 2000 12. Which of the following is an advantage of active surveillance? <br/> <br/>Correct!: More accurate due to reduced reporting burden for health care providers <br/> <br/>13. A disease has an incidence of 10 per 1,000 persons per year, and 80% of those affected will die <br/>within 1 year. Prior to the year 2000, only 50% of cases of the disease were detected by <br/>physician diagnosis prior to death. In the year 2000, a lab test was developed that identified 90% <br/>of cases an average of 6 months prior to symptom onset; however, the prognosis did not <br/>improve after diagnosis. Which statement is true concerning the duration of the disease after <br/>the development of the lab test? Correct Answer: Mean duration of a case of the disease is longer in 2000 14. What is the overall attack rate in persons who did not eat ice cream? <br/>Correct!: 33% 15. The table above describes the number of illnesses and deaths caused by plague in four <br/>communities. The proportionate mortality ratio associated with plague is lowest in which <br/>community? <br/>