Chlamydia testing is best performed at a regular hospital. If the chlamydia test is negative at this time, the general interpretation of the test results is that the patient does not have an associated infection caused by chlamydia, but it must be reminded that a negative chlamydia test does not completely rule out the possibility of a chlamydial infection. For example, if the patient has been treated with systemic erythromycin for neonatal ophthalmia caused by Chlamydia trachomatis prior to testing, this can affect the test result. Therefore, if the chlamydia test result is negative, the clinical consideration is usually combined with the patient’s condition, clinical diagnosis and imaging results. In such cases, if the patient is on antibiotics, the clinician will prompt the patient to stop the antibiotics for 1 week or more before performing the chlamydia test.