A nurse is teaching a client about primary syphilis. Which of the following information should the nurse include in the teaching?

Brief Introduction: Primary syphilis is characterized by the appearance of a painless chancre at the site of inoculation, caused by the spirochete Treponema pallidum. Without prompt antibiotic intervention, the pathogen undergoes systemic dissemination through the lymphatic and hematogenous routes, progressing into secondary and tertiary stages marked by multisystem involvement. Rationale: A. Syphilis is a bacterial infection, not viral, and must be treated with parenteral penicillin G. Antiviral medications are ineffective against spirochetes; the gold standard is a single intramuscular injection of benzathine penicillin, which targets the bacterial cell wall synthesis to eradicate the pathogen. B. Although the primary chancre will heal spontaneously within 3 to 6 weeks, the underlying infection remains clinically latent. Failure to treat the infection at this stage allows the bacteria to multiply, leading to secondary syphilis characterized by a diffuse maculopapular rash on the palms and soles. C. Tertiary syphilis can develop years after the initial infection, causing irreversible damage to the central nervous system and the aorta. This stage, known as neurosyphilis or cardiovascular syphilis, results in tabes dorsalis, aneurysms, or gummatous lesions that significantly increase morbidity and mortality risks. D. Syphilis is highly contagious and is transmitted through direct contact with infectious lesions during any form of sexual activity. This includes vaginal, anal, and oral sex, as the spirochete can easily penetrate mucous membranes or micro-abrasions in the oral cavity, leading to extragenital chancres.