Final answer:
The secondary stage of syphilis occurs 4 to 10 weeks after the initial infection and lasts 3 to 6 weeks.
Step-by-step explanation:
The secondary stage of syphilis occurs 4 to 10 weeks after the initial infection. During this stage, the bacteria spread throughout the body, causing systemic symptoms such as skin rashes, sores on the mucous membranes, fever, and swollen lymph glands. This stage typically lasts 3 to 6 weeks.