An ELISA (Enzyme-Linked Immunosorbent Assay)-based test called Chlamydia trachomatis IgA, commonly known as anti-Chlamydia trachomatis IgA, looks for IgA antibodies produced against Chlamydia trachomatis in serum (blood). One of the most common causes of STDs (sexually transmitted diseases) worldwide is the bacteria Chlamydia trachomatis. The existence of certain IgA antibodies indicates that the body is still actively infected with Chlamydia. This test looks for the IgG antibody the body produces to fight Chlamydia infection. Many different types of human infections have been linked to Chlamydia trachomatis. It frequently causes cervicitis and non-gonococcal urethritis. It causes endometritis, salpingitis, and pelvic inflammatory disease in females. It causes epididymitis and Reiter's syndrome in men. Chlamydia trachomatis is the source of the sexually transmitted infection known as lymphogranuloma venereum (LGV). Additionally, it can result in ophthalmologic illnesses like inclusion conjunctivitis and trachoma.