The number of sexually transmitted disease (STD) cases in the U.S. has increased considerably for the first time since 2006, particularly for gonorrhea, chlamydia and syphilis, according to the Sexually Transmitted Disease Surveillance 2014 report released Tuesday by the U.S. Centers for Disease Control and Prevention (CDC).

Statistics for the three key STDs in 2014 are as follows: 1,441,789 reported cases of chlamydia, a 2.8 percent increase since 2003 and equivalent to 456.1 cases for every 100,000 people; 350,062 reported cases of gonorrhea, a 5.1 percent increase since 2003 and equivalent to 110.7 cases for every 100,000 people; and 19,999 reported cases of syphilis, a 15.1 percent increase since 2003 and equivalent to 6.3 cases for every 100,000 people.

The number of congenital syphilis has increased by 27.5 percent since 2013, with 458 cases reported in 2014, or 11.6 cases for every 100,000 births.

Young people aged 15 to 24 years old comprised the highest number of chlamydia and gonorrhea infections in 2014. Some estimates show that young people constitute about 50 percent of the estimated 20 million new cases of STDs reported every year. The CDC says that many young people are not screened for STDs despite the recommendation that they undergo annual testing, leaving many of them unaware that they are infected.

"The consequences of STDs are especially severe for young people," Dr. Gail Bolan, lead researcher and director of the CDC's Division of STD Prevention, said in a press release. "Because chlamydia and gonorrhea often have no symptoms, many infections go undiagnosed and this can lead to lifelong repercussions for a woman's reproductive health, including pelvic inflammatory disease and infertility."

While these diseases severely affect women and the youth, the rise in STD cases is being driven by an increasing number of men who are affected by STDs. Gay and bisexual men account for the highest increase number of syphilis cases, comprising 83 percent of reported syphilis cases among men.

"We are concerned that most of the surging rates are among men," Bolan told HealthDay. "Men are driving these increases. There is an urgent need to tackle the increases we are seeing."

The CDC recommends an annual screening for chlamydia, gonorrhea and syphilis for all sexually active gay and bisexual men.

Cutting government funding could be one of the factors responsible for the rise in the number of STD infections, the CDC says. Several local health departments have closed their STD clinics, while others operated at lesser hours. Additionally, a number of these clinics raised their fees, which could have driven people away.

"Most recently, there have been significant erosions of state and local STD control programs," Bolan told NBC News. "Most people don't recognize that the direct clinical care of individuals with sexually transmitted diseases is supported by state and local funds and federal funds."