Final answer:
The primary syphilis stage is characterized by a genital chancre— a firm, round, painless sore that appears where the bacteria entered the body and is highly infectious.
Step-by-step explanation:
The client diagnosed with primary syphilis would most likely display a genital chancre, which is the correct finding associated with this stage of the infection. This chancre is a firm, round, and generally painless sore that occurs at the site where the syphilis bacteria entered the body. The chancre, highly infectious and containing many Treponema pallidum (T. pallidum) cells, typically appears within 10 to 90 days after transmission and heals on its own in two to six weeks.
Other stages of syphilis present different symptoms: the secondary stage commonly leads to a palmar rash and other systemic indicators such as fever and swollen lymph nodes; the tertiary stage may lead to the development of gummas, cardiovascular problems, or central nervous system lesions. It is vital to recognize the different stages and associated symptoms to provide appropriate treatment and prevent the infection's progression.