FREE Bachelor of Health Science Epidemiology Questions and Answers
The epidemiologic triad of disease causation involves: (Select one best option)
The epidemiologic triad of disease causation encompasses the elements of agent-host-environment.
In Figure 1.27, the timeline illustrates the natural history of disease. Item "A" takes place between the stage of susceptibility and the stage of subclinical disease. Item "B" occurs during the stage of subclinical disease. Item "C" happens between the stage of subclinical disease and the stage of clinical disease. Item "D" occurs shortly after the stage of clinical disease begins, and item "E" occurs at the end of the stage of clinical disease. Determine the appropriate letter from the time line in Figure 1.27 to each of the following stages representing the natural history of disease. Choose the correct answer.
Figure 1.27 illustrates the natural history of disease with distinct items marked on the timeline. "A" represents the period of exposure between susceptibility and subclinical disease stages. "C" indicates the onset of symptoms between subclinical and clinical disease stages, and "D" reflects the usual time of diagnosis shortly after the clinical disease stage begins. Understanding these key points on the timeline helps epidemiologists comprehend the development and evolution of diseases.
People with new-onset Lyme disease were asked how often they walked in the forest, used repellents, and wore short sleeves as well as pants. The same questions were asked of twice as many people without Lyme disease from the same doctor's office. Then, the results from people with and without lyme disease were compared.
The answer, "Observational case study," is correct because the study involves observing and comparing individuals diagnosed with new-onset Lyme disease and those without the disease based on their behaviors related to walking through the woods, using insect repellent, and clothing choices. It is an observational design as researchers are not manipulating any variables but rather gathering data through interviews to study the association between the potential risk factors and the presence of Lyme disease in the two groups.
In a cross-sectional study, a prominent characteristic is that:
A cross-sectional study or survey offers a snapshot of a population's health, focusing on prevalence rather than incidence. While it may not be as valuable as a cohort or case-control study for analytic epidemiology, it can effectively measure the prevalence of exposures and outcomes.
The people who have been studied were children whom are part of a health maintenance organization. At 2 months, each child was given one of the two vaccines against rotavirus infection based on a chance draw. After two weeks, a nurse reached out to the parents and asked if their children had any of a list of side effects.
In this study, children were randomly assigned to receive one of the two types of rotavirus vaccines. This random allocation of the vaccine types is a key characteristic of experimental design, where researchers manipulate the independent variable (type of vaccine) to observe its effects on the dependent variable (side effects experienced by the children). The study involves an intervention (administration of vaccines) and a comparison between groups, which are the defining features of an experimental study.
In most cases, "determinants" in the definition of epidemiology means:
In epidemiology, "determinants" typically encompass causes (including agents), risk factors (including exposure to sources), and modes of transmission, but they do not encompass the resulting public health action.
On a cruise ship from Puerto Rico to the Panama Canal, a group of passengers has recently developed a gastrointestinal illness compatible with norovirus (formerly known as Norwalk-like virus). Norovirus testing is not readily accessible on nearby islands, and even where available, it takes several days to obtain results. What variables might be included in characterizing the outbreak by person?
In this context, "person" refers to demographic information, such as age, gender, nationality, etc. It typically does not involve specific medical details or factors that may have caused the illness, like clinical features or exposures.
When examining surveillance data based on age, which of the following age groups is favored? (Select one best option)
Epidemiologists customize descriptive epidemiology to effectively depict the available data. As diseases exhibit distinct age patterns, epidemiologists adopt specific age groupings suitable for the particular disease they are studying.
"Distribution" in the definition of epidemiology means:
In epidemiology, "distribution" pertains to descriptive epidemiology and encompasses time (when), place (where), and person (who). On the other hand, "determinants" relates to analytic epidemiology, focusing on the factors that influence the occurrence and patterns of health events in populations.
When comparing the number of sick people in a community to the rate of illness, rates are better for: (Choose one best answer)
Rates are used to measure risk, while numbers are often better for finding individual cases and planning resources.
Several people on a cruise ship that went from Puerto Rico to the Panama Canal recently got sick with a virus that is similar to norovirus (formerly called Norwalk-like virus). On any nearby island, it is hard to test for norovirus, and when it is possible, the test takes several days. If you are the epidemiologist who has been asked to go on the ship and look into this possible outbreak, how would you illustrate the time course of the outbreak? (Select one best answer)
The classic graph for displaying the time course of an epidemic is an epidemic curve, where the x-axis represents the date or time of onset, and the y-axis represents the number of cases.
What type of exposure typically leads to a propagated epidemic?
In a propagated epidemic, the infection is transmitted from one person to another.
How does a cohort study differ from a case-control study?
The main distinction between a cohort study and a case-control study lies in the way subjects are enrolled. In a cohort study, participants are selected based on their exposure to a specific factor, whereas in a case-control study, participants are chosen based on whether they have the disease under investigation or not. Both types of studies examine exposure and disease status and can be employed to investigate various health issues, including infectious and non-infectious conditions, with some cohort studies spanning several years and others, particularly outbreak-related studies, being completed in a matter of days.
Several people on a cruise ship that went from Puerto Rico to the Panama Canal recently got sick with an illness that is similar to norovirus (formerly called Norwalk-like virus). Testing for norovirus is not easy to do on any nearby island, and even when it is possible, the test takes several days. If you are the epidemiologist who has been asked to go on the ship and look into this possible outbreak, your case definition should at least include: (Select one best answer)
For a field investigation, a comprehensive case definition should include clinical criteria and specify the time, place, and person related to the illness or condition being studied. The case definition should remain independent of the exposure being evaluated. Whether a case definition is developed for suspect cases depends on factors like laboratory confirmation availability and diagnosis certainty. Typically, the nationally agreed standard case definition for disease reporting is highly specific and may not encompass suspect or possible cases.
What can serve as a reservoir for an infectious agent?
The reservoir of an infectious agent refers to the natural environment where the agent resides, thrives, and reproduces. This reservoir can encompass humans, animals, and the surrounding environment.
This is an example of conducting a survey with a representative sample of residents to inquire about their weekly exercise habits and whether they have been diagnosed with heart disease or not.
This is known as an observational cross-sectional study, as it provides a snapshot of the population's characteristics and associations between variables at a specific moment without manipulating any factors or following participants over time.