Question

which is the best example of a healthcare - associated infection?

having an allergic reaction to a medication

developing cancer after long term exposure to the sun
experiencing a headache prior to visiting the doctor

contracting an illness from a needle while delivering a baby

Explanation:

A healthcare - associated infection (HAI) is an infection acquired in a healthcare setting. Contracting an illness from a needle while delivering a baby occurs in a healthcare setting (during childbirth, which is a healthcare procedure) and is related to the use of a medical device (needle) in that setting. An allergic reaction to a medication is an adverse drug reaction, not an HAI. Developing cancer from sun exposure is a non - healthcare - related environmental risk. A headache prior to a doctor's visit is not an infection and not acquired in a healthcare setting.

Answer:

contracting an illness from a needle while delivering a baby