Hundreds of thousands of cases of chlamydia go undiagnosed each year, research by the Centers for Disease Control and Prevention suggests.

The study was conducted through the United States National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention.

Scientists' calculations were formulated by analyzing the information provided within the National Health and Nutrition Examination Survey (NHANES) from 2007 through 2012.

This study involved about 5,000 subjects from across American annually and included both children and adults.

Researchers found that 1.7 percent of men and women ages 14-39 have chlamydia, which works out to about 1.8 million infections each year in the United States.

There are 1.4 million cases reported to the CDC each year. As a reportable disease, all diagnoses of chlamydia are supposed to be reported to the CDC. That discrepancy signifies that as many as 400,000 cases of chlamydia not only go unreported, but likely go undiagnosed every year.

A major reason why chlamydia is so often undiagnosed is that it often produces no symptoms. Unlike other STDs which result in the appearance of symptoms within a matter of days after infection, chlamydia does not. And when symptoms do appear, they may be mild and resolve quickly.

Symptoms can include abnormal discharge from the penis or vagina, a burning sensation during urination, and pain or swelling in the testicles for men.

Along with the revelation of under-reported cases, they also found that young women are at a much greater risk of harboring chlamydia.

The investigators found that the chlamydia infection rate is highest among sexually active girls aged 14-19, at 6.4 percent, HealthDay News reported. The rate among sexually active boys aged 14-19 is 2.4 percent.

Among these female adolescents, chlamydia infection is nearly six times more common in African-Americans than in their white counterparts. The rate found among the African-American girls was 18.6 percent, while the teenage white girls had a much lower rate of 3.2 percent.

These findings show the importance of screening all sexually active teen girls for chlamydia to ensure that all those who are infected get both diagnosis and treatment.

Researchers added that the racial differences they discovered show the need for targeted interventions, particularly among black teen girls, according to HealthDay News.

If caught, chlamydia can be easily cured with antibiotics. Untreated chlamydia, however, can lead to pelvic inflammatory disease, which can in turn cause scarring in a woman’s fallopian tubes and lead to infertility.

Sources:

"400,000 chlamydia infections undiagnosed in US, study finds." Fox News. FOX News Network, 11 June 2014. Web. 4 Aug. 2014.
http://www.foxnews.com/health/2014/06/11/400000-chlamydia-infections-undiagnosed-in-us-study-finds

Kempner, Martha. "This Week in Sex: Hook-Up Apps and STDs, Undiagnosed Chlamydia, and Bears Having Oral Sex." RH Reality Check. N.p., n.d. Web. 4 Aug. 2014.
http://rhrealitycheck.org/article/2014/06/19/week-sex-hook-apps-stds-undiagnosed-chlamydia-bears-oral-sex

Levine, Beth. "Chlamydia Vastly Undiagnosed." Baseline of Health. N.p., n.d. Web. 4 Aug. 2014.
http://jonbarron.org/sexual-health/chlamydia-vastly-undiagnosed#.U9_GPD90xjo

Preidt, Robert. "Many STDs May Go Undiagnosed, U.S. Report Finds." Consumer HealthDay. N.p., n.d. Web. 4 Aug. 2014.
http://consumer.healthday.com/kids-health-information-23/adolescents-and-teen-health-news-719/stds-youth-688668.html

Reviewed August 11, 2014
by Michele Blacksberg RN
Edited by Jody Smith