A nurse is investigating a bacterial illness that has caused a health problem in the community. Only some of the people exposed to the bacteria have become ill. Which of the following factors best explains why this would have happened?

Correct Answer: C

Rationale: The correct answer is C: Host factors. Host factors refer to individual characteristics that influence susceptibility to an infection. In this case, some people exposed to the bacteria may have stronger immune systems or other genetic predispositions that make them more resistant to the illness. This explains why only some individuals become ill despite exposure. A: Chemical agent factors are not relevant in this scenario as the question focuses on the individual's response to the bacteria rather than specific chemicals involved. B: Environmental factors may play a role in the spread of the bacteria but do not explain why only some individuals become ill. D: Physical agent factors typically refer to physical forces causing injury, which are not directly applicable to a bacterial illness scenario.

Correct Answer: C

Rationale: The correct answer is C: Cohort study. In a cohort study, participants are followed over time to evaluate the relationship between exposure/lifestyle factors and disease occurrence. This allows for the assessment of causality and temporal sequence. The public health nurse is collecting exposure and lifestyle information to observe how they influence disease development in the future. Cross-sectional studies (B) assess factors and outcomes at a single point in time, not over time like cohort studies. Experimental studies (A) involve interventions and randomization which is not the case here. Case-control studies (D) are retrospective and compare individuals with and without the disease, not following them over time like in a cohort study.

Correct Answer: B

Rationale: The correct answer is B: Subclinical stage. In this stage, the client has elevated blood pressure but no symptoms are present. This stage is characterized by the presence of the disease without noticeable symptoms. It is important for the nurse to identify and monitor clients in the subclinical stage to prevent progression to more severe stages. Choice A: Susceptibility stage refers to the stage where the client is at risk of developing the disease but has not yet been affected. Elevated blood pressure without symptoms indicates that the disease has already manifested, ruling out the susceptibility stage. Choice C: Clinical stage would involve the presence of symptoms, which is not the case with the client in question. Therefore, this choice is incorrect. Choice D: Carrier stage typically refers to individuals who harbor a pathogen without showing symptoms themselves, which is not applicable to a client with elevated blood pressure. Hence, this choice is incorrect.

Correct Answer: A

Rationale: The correct answer is A: Measles. Measles is spread through airborne transmission by respiratory droplets, making it highly contagious. The virus can remain suspended in the air for hours. Influenza (choice B) is also spread through the air but is less contagious than measles. Pertussis (choice C) is primarily spread through respiratory droplets but can also be transmitted through direct contact. Pneumonia (choice D) is not a communicable disease and is typically caused by bacteria or viruses that are not transmitted through the air.

Correct Answer: C

Rationale: The correct answer is C: Dehydration. In mild to moderate food poisoning, dehydration is a common manifestation due to fluid loss from vomiting and diarrhea. Dehydration can lead to complications and requires prompt medical attention. Bloody diarrhea (A) is more indicative of severe cases or specific types of food poisoning. Diarrhea lasting more than 3 days (B) may indicate a more serious infection or underlying condition. Fever less than 102°F (D) is a common symptom, but dehydration is a more critical manifestation that requires immediate focus. Therefore, C is the most appropriate choice to emphasize during community education on mild to moderate food poisoning.