Fewer than half of U.S. women screened for chlamydia

WASHINGTON (Reuters) - Fewer than half of vulnerable U.S. women are being screened for chlamydia, a common sexually transmitted disease that often causes few symptoms but can lead to infertility, researchers reported on Thursday.

A colorized transmission electron micrograph of Chlamydia trachomatis is seen in this undated handout photo. (REUTERS/Newscom)

Screening rates have spiked up from 25 percent in 2000 to nearly 42 percent in 2007, but that is still far too few women being screened, the team at the U.S. Centers for Disease Control and Prevention reported.

The CDC’s Dr. Karen Hoover and colleagues looked at the records of public and private health plans representing more than 40 percent of the U.S. population for the study.

“Nationally, the annual screening rate increased from 25.3 percent in 2000 to 43.6 percent in 2006, and then decreased slightly to 41.6 percent in 2007,” the researchers wrote in the CDC’s weekly report on death and disease.

“Chlamydia trachomatis infection is the most common bacterial sexually transmitted disease (STD) in the United States, with more than 2.8 million new cases estimated to occur each year,” they wrote.

“During 2007, approximately 1.1 million cases of chlamydia were reported to CDC; more than half of these were in females aged 15 to 25 years.”

It often causes few or no symptoms and if not treated with antibiotics can cause pelvic inflammatory disease, infertility, chronic pain and ectopic pregnancy, which is a pregnancy outside the uterus -- something that can kill the mother or the baby.

Men and women alike can be infected with chlamydia and can re-infect one another if only one sexual partner is treated. It can make men sterile, too, but only rarely.

Chlamydia can be passed to a newborn and can cause pneumonia and conjunctivitis, or pink eye.

The CDC recommends yearly chlamydia testing of all sexually active women 25 or younger, older women who have a new sex partner or multiple sex partners, and all pregnant women.

Reporting by Maggie Fox; Editing by Will Dunham