Winn is correct. Poop unlikely to be a good test or catch the chlamydia.
Its a weird disease. Periods of hiding in organs and dormancy and intermittent shedding. Some burds are carriers and never show clinical signs. Some birds its dormant for years, then a stress on the burds body , changing homes, a bad molt, another illness, nutritional stress, and it can activate and make the bird sick. Hits hardest on just weaned chicks, or sudden death in young chick's, and older birds. But can be deadly at any age. But chronic low grade is also common. People who have burds get "sinus infections" every winter should consider this as possibility.