Final answer:
Late latent syphilis is a symptom-free stage after secondary syphilis, with the bacteria remaining in the body. It precedes tertiary syphilis, which can cause severe and potentially fatal symptoms affecting the nervous and cardiovascular systems. Diagnosis during this stage relies on serologic testing for the presence of antibodies.
Step-by-step explanation:
Late latent syphilis is a stage of syphilis that follows secondary syphilis and is characterized by the absence of symptoms while the bacteria Treponema pallidum remains in the body. This phase can persist for years and precedes the potentially fatal tertiary stage. During the tertiary stage, severe symptoms may manifest, including neurosyphilis with effects such as paralysis, dementia, or blindness, and cardiovascular syphilis that can lead to a fatal aortic aneurysm or coronary stenosis. The latent stage itself does not present symptoms; however, blood tests are still able to detect the presence of T. pallidum.
The progression from primary syphilis, with a hard, painless chancre, to secondary syphilis, marked by a rash and systemic symptoms such as fever and swollen lymph nodes, indicates the systemic spread of the bacteria. The primary chancre and secondary symptoms generally resolve even without treatment. After which, syphilis can enter the latent phase, including latent syphilis. It is during the tertiary stage that the most severe damage occurs, with the development of gummas and serious infections of internal organs.
Diagnosis of syphilis in the latent and tertiary stages relies on serologic tests, which include both non-treponemal and treponemal tests to detect antibodies associated with infection. The presence of these antibodies indicates the infection has occurred and persists, despite the lack of symptoms in late latent syphilis.