Sexually transmitted infections are infections that are usually spread through sexual contact, vaginal, anal and oral sex. Sexually transmitted infections initially do not cause pronounced symptoms. This leads to a greater risk of transmitting the disease to other people. Symptoms and signs of the disease may include: vaginal discharge, sores around or on the genitals, pelvic pain. Sexually transmitted diseases acquired before or during pregnancy can lead to deterioration of the condition of the fetus or baby after birth. Some sexually transmitted infections can make it difficult to get pregnant. More than 30 different types of bacteria, viruses and parasites can cause sexually transmitted infections. Bacteria that cause them most often are chlamydia, gonorrhea, syphilis and others. NEWS_MORE_BOX Viral causes of sexually transmitted infections include genital herpes, HIV, papillomaviruses, and more. Parasitic agents of sexually transmitted infections are mainly trichomoniasis and others. While they are usually spread sexually, some sexually transmitted infections can also be spread through non-sexual contact with infected blood and tissue, breastfeeding, or during childbirth. Diagnostic tests for STDs are available. The most effective way to prevent sexually transmitted diseases is to adhere to a healthy sexual culture. Infection can be avoided by practicing safe sex with the use of condoms. Fewer sexual partners also lowers the risk. STDs are of two types: curable and incurable. Among the most common infections are syphilis, gonorrhea, chlamydia, trichomoniasis, which are treatable. While herpes, hepatitis B, HIV and HPV are considered incurable, although some of them can be controlled. Resistance to some antibiotics in recent decades has led to the development of gonorrhea in some people. In the United States alone in 2010, there were 19 million new cases of disease due to sexually transmitted infections.