A city that depended on tourist dollars had feedback that tourists were saying they were never returning because of the constant mosquito bites. Which action should be taken by the city?

Correct Answer: B

Rationale: Knowing the reservoirs for infectious agents is important, because, in some cases, transmission can be controlled by eliminating the reservoir, such as eliminating the standing water where mosquitoes breed. The other interventions, not having events at dusk or dawn, providing bug repellent, and wearing bright colors are ways the tourists can cope with the mosquitos that are present, but they do not eliminate the breeding and presence of the mosquitos.

Correct Answer: A

Rationale: Morbidity rates (incidence and prevalence rates) are not available for many conditions because surveillance of many chronic diseases is not widely conducted. Furthermore, morbidity rates may be subject to underreporting when they are available. In other words, there is no responsibility to report cases of most diseases, including gonorrhea. Information is only available related to conditions where care providers are required to report that specific condition or where those affected die and mortality data are available.

Correct Answer: D

Rationale: Because longitudinal, cohort, or incidence studies are costly in terms of resources and staff and often lose subjects over time, a retrospective study may be used because it is faster and less demanding of resources.

Correct Answer: B

Rationale: Information bias (e.g., recall bias) occurs when data is misreported. Collecting dietary data before disease onset (B) reduces recall bias, as participants aren’t influenced by symptoms (e.g., cancer patients over-reporting fat intake). A may increase detail but not reduce bias. C addresses confounding, not information bias. D ensures generalizability, not accuracy of intake data.

Correct Answer: C

Rationale: The epidemiological triad is host (A), agent (B), and environment (C). Pathogen (D) is a type of agent, not a separate component.