Chlamydia Infection Common but Controversy Arises About Screening Programs

Chlamydia may not be as well known as gonorrhea or syphilis but it 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 according to the CDC. I have posted previous notes about this problem (see: Chlamydia Reports to CDC Hit All Time High, Direct Access Testing for STDs). Now comes the news that screening for chlamydia in the U.S. is inadequate (see: Fewer than half of U.S. women screened for chlamydia). Below is the story with boldface emphasis mine:

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....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...."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," [according to CDC researchers]. "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.

It turns out that there is controversy in public health circles about what constitutes an optimal chlamydia screening program. Population-wide screening programs for chlamydia may not actually work, according to Dr. Nicola Low, an epidemiologist at the University of Bern. According to her, this opinion is particularly relevant for so-called "opportunistic" programs whereby patients are routinely tested for chlamydia whenever they seek medical care (see: Chlamydia Screening Programs Don't Work: Expert). Here's how she distinguishes between screening and a screening program:

"There is a difference between 'screening' and a 'screening program,' " Low said. "Any benefits of screening in a population will only be achieved if screening is implemented as a program. This means regular repeated screening of all those in the target population. Opportunistic screening as usually practiced does not ensure that people who have been screened once are invited for subsequent screening tests."The bottom line, according to the Swiss expert: "Low overall coverage and infrequent screening will not control the spread of an asymptomatic, infectious disease."

I am certainly no expert in this area but it strikes me as unusual that there is no unanimity of opinion among public health experts about a topic as basic as the optimal way to screen populations for an STD.

:: Update on 6/30/2009 @ 3:20 p.m.

See: Chlamydia, the Silent STD That Can Cause Infertility