Chlamydia – commonly known as “the clam” – is the most common sexually transmitted infection in the military community, military health data shows.

And the rates for Chlamydia, among both men and women, have been rising in recent years, according to a 2021 report on sexually transmitted infections, or STIs, from the Defense Health Agency’s Armed Forces Health Surveillance Branch.

“Annual rates among all active component members increased 64% between 2013 and 2019,” according to the report, which is based on a study of medical records between 2012 and 2020.

Chlamydia can cause permanent damage that can make it difficult or impossible for women to get pregnant. It often shows no symptoms at all but in some cases, it can cause a burning sensation when peeing in both men and women.

Chlamydia is by far the most common STI in the military. Rates of chlamydia were greater than the sum of the other four most common STIs combined, according to the report.

Why is Chlamydia so Prevalent?

The problem is not unique to the military. The “rates of chlamydia have been steadily increasing in the general U.S. population among both females and males since 2000,” according to the report.

“Cases of chlamydial infections are increasing both in the military and throughout the United States,” said Navy Lt. (Dr.) Karli Woollens, a family medicine specialist at the Navy Medicine Readiness and Training Command Bremerton supporting Naval Hospital Bremerton, in Washington.

“In the U.S., chlamydial infections increased by 19% between 2015 and 2019, according to the Centers for Disease Control and Prevention,” Woollens said.

And while “females statistically show higher incidences of chlamydia,” this could be because “they are also more likely to be screened and therefore diagnosed with STIs due to recommended screening programs for all asymptomatic sexually active young women and pregnant women,” she said.

Woollens said one of the big reasons chlamydia is so prevalent is that there’s a large patient population that is infected with chlamydia without any symptoms, “providing an ongoing source for disease transmission.”

When chlamydia does show symptoms, they can vary.

“It can be entirely asymptomatic but still transmissible, or it can cause infection of specific anatomic sites depending on the type of intercourse practiced (oral, rectal, or vaginal),” Woollens said.

The most common clinical symptoms in males are infections of the urethra, which can cause burning and pain during urination, she said.

“Males can also get infection of the epididymis [a duct behind the testis], causing testicular pain and tenderness, or prostate infection causing painful urination, painful ejaculation, and pelvic pain,” Woollens said.

“In females, the most common clinical finding is cervical infection, which can result in abnormal vaginal discharge, vaginal bleeding, or bleeding and pain with intercourse,” said Woollens. “Females can also get infection of the urethra, causing painful and frequent urination.”

Women can also develop pelvic inflammatory disease, “which is an infection of the upper reproductive tracts causing abdominal and pelvic pain and even inflammation of the liver capsule, causing pain in the right upper quadrant of the abdomen,” she said.

In both men and women, chlamydia can also affect different organs that come in contact with infected genital secretions, for example the rectum or the throat if engaging in anal or oral sexual activity, or eye infections if exposed.

For example, “reactive arthritis is an inflammatory arthritis that causes swelling and joint pain after chlamydial infection.”

How to Treat Chlamydia

Chlamydia infections can typically be treated with oral antibiotics, said Woollens.

But she highlights the importance of treating it fully before engaging in sexual activity because re-infection is very common.

“You often have to wait a full seven days after treatment before having sex to reduce the risk of transmission and re-infection,” she said.

She also recommends asking your doctor about “expedited partner therapy to help get your sexual partners treated quickly and effectively to prevent re-infection.”

Risks of Untreated Chlamydia

In women, leaving chlamydial infections of the cervix untreated can lead to pelvic inflammatory disease which can cause infertility, increased risk of ectopic pregnancy, or chronic pelvic pain, said Woollens.

In addition, chlamydia can also impact pregnancy.

“It can increase the risk of premature membrane rupture, premature delivery, and low birthweight infants,” she said. “Transmission from the mother to baby is also a concern, which can cause eye infections, blindness, pneumonia, or sepsis in newborns.”

Preventing Chlamydia

To prevent chlamydia and other STIs, “barrier methods, most commonly condom use, is highly recommended,” she said.

“Because chlamydia and other STIs can be asymptomatic, it’s important to get screened for STIs if you have new sexual partners, or to get screened regularly if you engage in high-risk sexual activity.”

She recommends people also get “multi-site STI testing, which includes chlamydia and gonorrhea testing of the urine, vagina, penis, rectum, and pharynx when applicable to their personal sexual practices.”

She said it’s important for people to be able to speak safely and openly with their medical providers about their sexual practices to ensure that they get the care they need.

“Sexual health is incredibly important, so be mindful and take care of yourself and others!”