Final answer:
The nurse should plan care for a parasitic infection caused by Phthirus pubis, commonly known as the crab louse, which causes itching and irritation due to its bites on the genitals.
Step-by-step explanation:
The patient diagnosed with a parasitic infection caused by close contact with another person's genitals should have care planned for an infection with Phthirus pubis. This parasite is commonly known as the crab louse and causes symptoms such as itching and irritation due to its bites. It is one of the common sexually transmitted parasites, alongside the protozoan Trichomonas vaginalis, which causes trichomoniasis. However, Trichomonas vaginalis is not mentioned as an option in the question. The other options listed, such as Treponema pallidum which causes syphilis, Neisseria gonorrhoeae which causes gonorrhea, and Chlamydia trachomatis which causes chlamydia, are bacterial infections rather than parasitic.
The infection caused by close contact with another person's genitals in this case is due to a parasitic infection. The correct answer for the infection the nurse should plan care for is option A, Phthirus pubis, also known as crab lice. This parasitic infection is commonly transmitted through close contact and results in itching and irritation.