Latent syphilis is defined as the asymptomatic period more than 1 year after primary infection with no clinical manifestations but positive serologic tests 

-it is a diagnosis of exclusion after primary, secondary, tertiary and neurosyphilis have been ruled out 

-Patient can be infectious during this period 

-Secondary syphilis relapses often interrupt latent syphilis 

-it can last 20-30 years 

-It should be treated with benzathine penicillin or doxycycline