The public health nurse understands that which of the following is the number one cause of death worldwide?

A. Hepatitis B: Hepatitis B is a bloodborne disease, primarily spread through contact with infected bodily fluids, not through a vector.

B. Rocky Mountain spotted fever: Rocky Mountain spotted fever is a vector-borne disease transmitted by tick bites. Vectors are living organisms, such as mosquitoes or ticks, that carry infectious agents.

C. E. coli O157:H7: E. coli is a foodborne illness that spreads through contaminated food or water, not via a vector.

D. Anthrax: Anthrax is a bacterial infection that spreads through direct contact, ingestion, or inhalation of spores, not through a vector.

A. Putting students on a diet if they weigh greater than 20% of their ideal weight: This is a tertiary prevention strategy, as it focuses on managing obesity after it has been diagnosed rather than early detection.

B. Weighing students to identify those who are overweight: Secondary prevention focuses on early detection and intervention to prevent disease progression. Weighing students allows for early identification of obesity and timely interventions.

C. Giving a presentation on the importance of exercise and physical fitness: This is primary prevention, which aims to prevent obesity before it occurs by promoting healthy habits.

D. Designing a game in which students select healthy food choices: This is also primary prevention, as it promotes healthy behaviors rather than identifying or managing existing obesity.