 [ Symptoms ] how long after chlamydia treatment are you contagious i took a one dose treatment of azithromycin for chlamydia on tuesday later that night i vomited a little i called the doctor and repeated the treatment on wednesday am i still contagious to spread chlamydia [ Disease ] this is caused by the rheumatoid activity you have developed degenerative changes in your neck see your doctor and an xray will show what is going on