Basics of Epidemiology, Disease Transmission, and Control
1. What is epidemiology primarily concerned with?
A. Studying the economic impact of diseases
B. Investigating the distribution and determinants of health-related events
C. Treating individual patients with infectious diseases
D. Manufacturing vaccines for public use
Answer: B
Explanation: Epidemiology is the study of the distribution and determinants of diseases in populations to help control and prevent health issues.
2. Which of the following is NOT a mode of disease transmission?
A. Direct contact
B. Vector-borne
C. Cloud formation
D. Airborne
Answer: C
Explanation: Disease transmission occurs through direct contact, vector-borne (e.g., mosquitoes), airborne, waterborne, and foodborne routes—not via clouds.
3. What is the incubation period of a disease?
A. The period when symptoms appear and peak
B. The time between exposure to an infectious agent and the appearance of symptoms
C. The period when the disease is most contagious
D. The duration of disease recovery
Answer: B
Explanation: The incubation period is the time between infection and symptom onset, varying for different diseases.
4. Which term refers to the constant presence of a disease in a population?
A. Epidemic
B. Endemic
C. Pandemic
D. Sporadic
Answer: B
Explanation: A disease that is regularly found in a population, such as malaria in tropical regions, is considered endemic.
5. Which of the following is an example of a vector-borne disease?
A. Tuberculosis
B. COVID-19
C. Dengue fever
D. Food poisoning
Answer: C
Explanation: Dengue fever is transmitted by mosquitoes, making it a vector-borne disease.
6. What does herd immunity refer to?
A. A group of people who avoid vaccines
B. Immunity gained from multiple infections
C. When a significant portion of a population is immune, reducing disease spread
D. The ability of a virus to mutate rapidly
Answer: C
Explanation: Herd immunity occurs when a large portion of the population is immune (via vaccination or prior infection), protecting vulnerable individuals.
7. What is the main goal of disease surveillance?
A. To monitor and predict disease outbreaks
B. To identify new antibiotics
C. To test vaccines
D. To count the number of hospitals in an area
Answer: A
Explanation: Disease surveillance helps in early detection, monitoring, and prevention of outbreaks.
8. Which of the following is an example of primary prevention in public health?
A. Early disease detection through screening
B. Surgery to remove a tumor
C. Vaccination against polio
D. Physical therapy after an injury
Answer: C
Explanation: Primary prevention aims to stop diseases before they occur, such as through vaccination.
9. Which epidemiological study design is used to investigate the cause of an outbreak?
A. Cross-sectional study
B. Case-control study
C. Cohort study
D. Experimental study
Answer: B
Explanation: A case-control study compares people with and without a disease to identify potential risk factors.
10. Which global organization is responsible for monitoring disease outbreaks?
A. UNICEF
B. Red Cross
C. Centers for Disease Control and Prevention (CDC)
D. World Health Organization (WHO)
Answer: D
Explanation: The WHO is the leading international health agency responsible for tracking and responding to global disease outbreaks.
Application of Biostatistics in Public Health Studies
11. What is the primary role of biostatistics in public health?
A. To study the financial impact of diseases
B. To analyze and interpret health data for decision-making
C. To treat patients with infectious diseases
D. To manufacture vaccines
Answer: B
Explanation: Biostatistics is used to analyze and interpret data to guide public health policies and decision-making.
12. Which of the following measures is used to describe the central tendency of a dataset?
A. Range
B. Standard deviation
C. Mean
D. Variance
Answer: C
Explanation: The mean (average) is a key measure of central tendency, summarizing a dataset.
13. Which biostatistical tool is most appropriate for analyzing the effectiveness of a new vaccine?
A. T-test
B. Chi-square test
C. Regression analysis
D. ANOVA
Answer: A
Explanation: A T-test is commonly used to compare two groups, such as vaccinated vs. unvaccinated individuals.
14. What does a p-value of less than 0.05 indicate in a statistical test?
A. The result is not significant
B. There is strong evidence against the null hypothesis
C. The study was poorly designed
D. The data is incorrect
Answer: B
Explanation: A p-value < 0.05 means there is strong statistical evidence to reject the null hypothesis.
15. Which statistical method is used to predict disease outbreaks?
A. Regression analysis
B. Standard deviation
C. Median calculation
D. Mean calculation
Answer: A
Explanation: Regression analysis helps in predicting trends and future disease outbreaks based on past data.
16. Which graph is most commonly used to display the frequency distribution of disease cases?
A. Pie chart
B. Histogram
C. Line graph
D. Scatter plot
Answer: B
Explanation: A histogram effectively displays the distribution of disease cases over time.
17. Which of the following is a measure of disease frequency?
A. Standard deviation
B. Incidence rate
C. Median
D. Mode
Answer: B
Explanation: The incidence rate measures new cases of a disease in a population over a specific period.
18. What type of variable is "number of hospital visits in a year"?
A. Nominal
B. Ordinal
C. Discrete
D. Continuous
Answer: C
Explanation: Discrete variables take whole number values, such as number of hospital visits.
19. Which biostatistical test is best suited for analyzing categorical data?
A. T-test
B. Chi-square test
C. ANOVA
D. Regression analysis
Answer: B
Explanation: The Chi-square test is used for analyzing categorical (qualitative) data.
20. What does an odds ratio (OR) greater than 1 indicate?
A. No association
B. Increased likelihood of disease
C. Decreased likelihood of disease
D. Invalid result
Answer: B
Explanation: An OR > 1 suggests an increased association between a risk factor and a disease.
Analysis and Interpretation of Public Health Data
21. What is the first step in analyzing public health data?
A. Collecting raw data
B. Interpreting results
C. Applying statistical tests
D. Identifying trends
Answer: A
Explanation: The first step in data analysis is to collect accurate and reliable data before applying statistical methods.
22. Which type of study is most effective in determining the cause of an outbreak?
A. Cross-sectional study
B. Case-control study
C. Descriptive study
D. Randomized controlled trial
Answer: B
Explanation: A case-control study compares affected and unaffected groups to identify potential causes of an outbreak.
23. What does a high prevalence rate of a disease indicate?
A. A rapid increase in new cases
B. A low mortality rate
C. A recent outbreak
D. A large number of existing cases in a population
Answer: D
Explanation: Prevalence measures all existing cases (new + old) of a disease in a population at a specific time.
24. What does a confidence interval (CI) represent in public health studies?
A. The margin of error in a study
B. The range within which the true population parameter is likely to fall
C. The time frame for data collection
D. The total number of cases in a study
Answer: B
Explanation: A confidence interval (CI) provides a range within which the true value of a population parameter is likely to be found.
25. Which statistical test is most commonly used to compare the means of two independent groups in public health research?
A. Chi-square test
B. T-test
C. ANOVA
D. Regression analysis
Answer: B
Explanation: A T-test is used to compare the means of two groups, such as vaccinated vs. unvaccinated individuals.
26. Which measure is best for identifying disease trends over time?
A. Mean
B. Median
C. Incidence rate
D. Prevalence rate
Answer: C
Explanation: The incidence rate measures new cases over time, making it useful for tracking disease trends.
27. What does a p-value of 0.01 in a statistical test suggest?
A. The study results are not statistically significant
B. There is a 1% chance the results occurred by random chance
C. The results are invalid
D. The hypothesis must be rejected
Answer: B
Explanation: A p-value of 0.01 means there is only a 1% probability that the results happened by chance.
28. Which visualization is best for showing disease trends over multiple years?
A. Pie chart
B. Histogram
C. Line graph
D. Bar graph
Answer: C
Explanation: Line graphs effectively show trends in disease cases over time.
29. If a study finds a relative risk (RR) of 2.0 for a disease, what does this mean?
A. The disease is twice as likely to occur in the exposed group
B. The disease will occur in everyone
C. There is no association between exposure and disease
D. The exposure prevents the disease
Answer: A
Explanation: A relative risk (RR) of 2.0 means that those exposed to a risk factor are twice as likely to develop the disease compared to those unexposed.
30. Which factor should be considered when interpreting public health data?
A. Sample size
B. Data source reliability
C. Statistical significance
D. All of the above
Answer: D
Explanation: Sample size, data reliability, and statistical significance all affect the accuracy and interpretation of public health data.