Chlamydia trachoma is well-known to attack the reproductive tract to cause infertility, and attacks the eye to cause blindness. Trachoma in the reproductive tract is primarily acquired through sexual activity; and trachoma in the eye may be acquired through flies spreading the infection from one person to another, or self-inoculation to the eye. Trachoma can also infect urine, and can ascend up the urinary system to the bladder and kidney. Chlamydia trachoma increases the risk of cervical cancer, and doubles the risk of ovarian cancer. In men, trachoma acquired through sexual activity is a likely cause of testicular, prostate, and bladder cancer.