Question 1

Vaccine-preventable diseases include Haemophilus influenzae type b (Hib).

Accepted Answer

Haemophilus influenzae type b (Hib) is a vaccine-preventable disease, as there is an effective vaccine available to protect against infections caused by this bacterium.

Question 2

A major resurgence of measles occurred during the period 1989 to 1990.

Accepted Answer

A major resurgence of measles occurred in the United States during 1989-1990, largely due to low vaccination rates and the accumulation of susceptible individuals.

Question 3

Reasons for the resurgence of tuberculosis include the increasing prevalence of HIV infection.

Accepted Answer

The resurgence of tuberculosis is partly due to the increasing prevalence of HIV, as HIV weakens the immune system, making individuals more susceptible to TB infections.

Question 4

In 2017, the groups in the United States most affected by tuberculosis were foreign-born individuals and racial and ethnic minorities.

Accepted Answer

In 2017, data from the CDC indicated that tuberculosis disproportionately affected foreign-born individuals and racial and ethnic minorities in the United States.

Question 5

An enzootic disease among animals is similar to an endemic disease among humans.

Accepted Answer

An enzootic disease is consistently present in a particular animal population, similar to how an endemic disease is consistently present in a human population.

Question 6

The reservoir for Q fever is infected livestock, such as cattle, sheep, or goats.

Accepted Answer

Q fever is primarily transmitted to humans from infected livestock, including cattle, sheep, and goats, which serve as the main reservoirs for the bacteria Coxiella burnetii.

Question 7

Lyme disease is an example of a disease transmitted by arthropod vectors.

Accepted Answer

Lyme disease is transmitted by ticks, which are arthropods, specifically the Ixodes species.

Question 8

A person with an inapparent infection:

Accepted Answer

A person with an inapparent infection can still transmit the infection to others, even if they do not show symptoms themselves.

Question 9

You have just finished administering a food/drink questionnaire to ill and non-ill participants in a Minnesota summer picnic party. The ill individuals developed moderate to severe diarrhea 16 to 46 hours after the picnic. Six persons experienced vomiting. The following data were collected:

Which food item appears to be the most probable vehicle for the salmonella (agent) infection associated with the illness?

Accepted Answer

The answer of You have just finished administering a food/drink...

Question 10

In two communities of similar size and age structure (A and B), there were outbreaks of viral illnesses (virus A in community A, and virus B in community B), both of which were traced back to a single source. Exposure to these viruses in each community confers permanent immunity. In community A, 200 susceptible people were exposed to an index case, 150 people were infected (not including the index case), 75 people became ill, and 40 people died. In community B, pathogenicity was 40%, infectivity was 90%, and virulence was 60%. Which virus had the greatest infectivity?

Accepted Answer

Infectivity is the proportion of susceptible individuals who become infected after exposure to a pathogen. In community B, 90% of susceptible individuals were infected, while in community A, only 75% of susceptible individuals were infected. Therefore, virus B had the greater infectivity.

Question 11

In two communities of similar size and age structure (A and B), there were outbreaks of viral illnesses (virus A in community A, and virus B in community B), both of which were traced back to a single source. Exposure to these viruses in each community confers permanent immunity. In community A, 200 susceptible people were exposed to an index case, 150 people were infected (not including the index case), 75 people became ill, and 40 people died. In community B, pathogenicity was 40%, infectivity was 90%, and virulence was 60%. Which virus was most pathogenic?

Accepted Answer

The answer of In two communities of similar size and...

Question 12

In two communities of similar size and age structure (A and B), there were outbreaks of viral illnesses (virus A in community A, and virus B in community B), both of which were traced back to a single source. Exposure to these viruses in each community confers permanent immunity. In community A, 200 susceptible people were exposed to an index case, 150 people were infected (not including the index case), 75 people became ill, and 40 people died. In community B, pathogenicity was 40%, infectivity was 90%, and virulence was 60%. Which virus was most virulent?

Accepted Answer

Virulence is the degree of pathogenicity, which is the ability of a pathogen to cause disease. In community B, the virulence is 60%, which means that 60% of those infected became ill. In community A, the virulence is not explicitly stated, but it can be calculated as the number of people who became ill divided by the number of people who were infected. This is 75/150 = 50%. Therefore, virus B is more virulent than virus A.

Question 13

Community A receives its water from several sources. The water source responsible for causing an outbreak of disease X is unknown. The best evidence to determine which suspected water supply is responsible would be:

Accepted Answer

Comparing attack rates for disease X in those who did and did not drink from each water supply would help identify the source responsible for the outbreak by showing a higher rate of disease among those who consumed water from the contaminated source.

Question 14

The Centers for Disease Control and Prevention published an article concerning the high rate of foot fungal disease in New Orleans. The article explains that there has been a high rate of foot fungal disease in New Orleans for decades. Foot fungal disease in New Orleans is best described as:

Accepted Answer

An endemic refers to a disease or condition regularly found and consistently present in a particular geographic area or population, which aligns with the description of foot fungal disease in New Orleans being present for decades.

Question 15

An attack rate is an alternative incidence rate that is used:

Accepted Answer

An attack rate is used in all these scenarios: foodborne illness, sudden increases in disease occurrence, and acute health-related events.

Question 16

An important point about the agent-host-environment model (the epidemiologic triangle) of epidemiologic investigation is that:

Accepted Answer

The etiology of infectious disease involves more complex multivariate causality as well.

Question 17

The following table shows the mumps experience of children in 390 families exposed to mumps by a primary case within the family:

The secondary attack rate among children aged two to four years is:

Accepted Answer

The answer of The following table shows the mumps experience...

Question 18

An outbreak of salmonellosis occurred after an epidemiology department luncheon, which was attended by 485 faculty and staff. Assume everyone ate the same food items. Sixty-five people had fever and diarrhea; five of these people were severely affected. Subsequent laboratory tests on everyone who attended the luncheon revealed an additional 72 cases. The attack rate of salmonellosis was:

Accepted Answer

The answer of An outbreak of salmonellosis occurred after an...

Question 19

An outbreak of salmonellosis occurred after an epidemiology department luncheon, which was attended by 485 faculty and staff. Assume everyone ate the same food items. Sixty-five people had fever and diarrhea; five of these people were severely affected. Subsequent laboratory tests on everyone who attended the luncheon revealed an additional 72 cases. The ratio of severe cases to other clinically apparent cases was:

Accepted Answer

The ratio of severe cases (5) to other clinically apparent cases (60, which is 65 total cases minus the 5 severe cases) is 5/60.

Question 20

An outbreak of salmonellosis occurred after an epidemiology department luncheon, which was attended by 485 faculty and staff. Assume everyone ate the same food items. Sixty-five people had fever and diarrhea; five of these people were severely affected. Subsequent laboratory tests on everyone who attended the luncheon revealed an additional 72 cases. The virulence of salmonellosis was:

Accepted Answer