With Valentine's Day here, new reports from the Centers for Disease Control and Prevention spotlight an unhealthy and dangerous side of romance: Sexually transmitted diseases.
Two studies released by the CDC this week show surges in rates of STDs -- or STIs ("I" for infections) -- across the United States in addition to troubling reports of treatment-resistant gonorrhea appearing in the country.
"STIs take a big health and economic toll on men and women in the United States, especially our youth," CDC epidemiologist Dr. Catherine Lindsey Satterwhite, who led one of the studies, told NBC News.
Two studies published in the journal Sexually Transmitted Diseases on Feb. 13 examined the rates of STIs in the U.S. and costs associated with treating them, by looking at data collected in 2008. Satterwhite's study looked at overall rates of eight common STIS: chlamydia, gonorrhea, syphilis, herpes, human papillomavirus, hepatitis B, HIV, and trichomoniasis.
Researchers found there were about 110 million STIs in U.S. men and women that year, 20 percent of which -- or 22.1 million -- were in young men and women ages 15 to 24. Of those infections, 19.7 million were new that year, and half of them occurred in men and women under 24. Human papillomavirus (HPV), which can cause cancer, was the most common STI in terms of overall prevalence and newly reported infections.
The numbers may also underestimate the true number of infections, the researchers said.
The second study, which also looked at the same eight STIs, found that health care costs amounted to more than $15 billion for treating the 19.7 million new infections that occurred in 2008. HIV was the most costly, exceeding more than $12 billion in 2008,followed by HPV ($1.7 billion), herpes ($540.7 million), chlamydia ($516.7 million) and gonorrhea ($162.1 million).
"All STIs are preventable. They're all treatable, and many are curable. But if they're left untreated, they can lead to pretty serious lifelong problems and even death," Satterwhite told CNN.
The CDC says the most reliable way to avoid an STI is by not having sex. However, correct use of a latex condom in men is highly effective at reducing transmission, according to the agency, and a condom should be used every time before having anal, vaginal or oral sex. The HPV vaccine for young males and females under the age of 26 (recommended for boys and girls when they are 11-12) has been shown to protect against some of the most common types of HPV, according to CDC.
The CDC has more tips to prevent sexually transmitted diseases.