Region I Infertility Prevention Project

Chlamydia FAQ

Chlamydia is a sexually transmitted disease (STD) that is caused by the bacterium Chlamydia trachomatis. According to the Centers for Disease Control and Prevention, chlamydia is the most frequently reported communicable disease in the United States and may be one of the most dangerous sexually transmitted diseases among women today.

Approximately 75% of women and 50% of men have no symptoms. Therefore, most people infected with chlamydia are not aware of their infections and may not seek healthcare. As a result, the number of reported cases, about 660,000 in 1999, is a gross underestimate. The CDC estimates that 3 million people are newly infected with chlamydia each year in the United States (Tracking the Hidden Epidemics: Trends in STDs in the United States 2000, CDC). Most of these infections are common in sexually active adolescents and young adults.

Teenage girls have the highest rates of chlamydia infection. It is estimated that 1 in 10 adolescent girls tested for chlamydia is infected. Forty percent of cases are among people 15-19 years old (Tracking the Hidden Epidemics: Trends in STDs in the United States 2000, CDC).

When diagnosed, chlamydia can be easily treated and cured. Untreated, chlamydia can cause severe, costly reproductive and other health problems that include both short- and long-term consequences. Up to 40% of women with untreated chlamydia will develop pelvic inflammatory disease (PID). Of those with PID, 20% will become infertile; 18% will experience debilitating, chronic pain; and 9% will have a life-threatening tubal pregnancy.

For more information visit the CDC's STD Fact Sheet on Chlamydia


From 1995-2012, JSI Research & Training Institute, Inc. successfully served as the coordinator of the Region I Infertility Prevention Project (IPP). Further information about the Region I Infertility Prevention Project can be obtained on