Which of the following are portals of entry for disease? Select all that apply.

Rationale:
A. Asking affected adults to keep a diary of food intake is incorrect because this intervention targets individual behavior, not the broader environment. It focuses on personal monitoring and self-awareness rather than modifying environmental factors that influence obesity.

B. Determining whether clients have a family history of obesity is incorrect because this addresses host factors, specifically genetic predisposition, rather than environmental influences. It helps identify risk but does not change the environment to prevent obesity.

C. Providing low-fat meal options at public school is correct because it targets the environmental component of the epidemiological triad. By modifying the availability of healthier food options in schools, the intervention reduces environmental risk factors that contribute to obesity at a population level. Environmental interventions aim to make healthy choices easier and more accessible for the community.

D. Measuring a client’s body mass index (BMI) is incorrect because this is a screening and assessment tool that identifies individuals at risk or affected by obesity. It does not alter the environment or reduce incidence; it only monitors the host’s condition.

Rationale:

A. Cholera is caused by the bacterium Vibrio cholerae and is a classic example of a waterborne disease. Transmission occurs when individuals consume water or food contaminated with fecal matter containing the bacteria. Cholera primarily spreads in areas with poor sanitation, inadequate sewage systems, or contaminated drinking water. The disease can lead to profuse watery diarrhea, severe dehydration, and electrolyte imbalances, which can be fatal if untreated. Public health measures such as ensuring safe drinking water, proper sanitation, and hygiene education are essential to prevent outbreaks.

B. Malaria is a vector-borne disease, transmitted through the bite of an infected female Anopheles mosquito. The mosquito carries Plasmodium parasites, which enter the human bloodstream. Malaria is not spread through water consumption, although mosquito breeding often occurs in stagnant water. Preventive strategies focus on mosquito control, use of insecticide-treated nets, and prophylactic medications.

C. Influenza spreads via airborne droplets, generated when an infected person coughs, sneezes, or talks. It can also be spread by touching surfaces contaminated with the virus. Influenza is not transmitted through water, so preventive strategies include vaccination, hand hygiene, and respiratory etiquette.

D. Chickenpox (varicella) is another airborne disease, transmitted through respiratory droplets or direct contact with lesion fluid from an infected person. It does not spread through contaminated water. Prevention relies on varicella vaccination and isolation of infected individuals.