Final answer:
Early latent secondary syphilis is symptom-free after secondary symptoms resolve and requires treatment to prevent progression. Late latent syphilis is asymptomatic, may last years, and can progress to serious tertiary syphilis without treatment.
Step-by-step explanation:
Early latent secondary syphilis is characterized by the absence of symptoms despite the recent history of secondary syphilis. During this phase, the bacteria are still alive and can be detected by blood tests but are not causing noticeable symptoms. Treatment at this stage, usually with penicillin, can prevent the disease from progressing. In contrast, late latent syphilis also has no symptoms, but it occurs after the early latent phase and may persist for years. At this point, the bacteria remain in the body but the risk of transmission is lower. However, without proper treatment, late latent syphilis may advance to the tertiary stage, which could result in serious and possibly fatal damage to internal organs, such as the brain, heart, and liver.