More than 30 bacteria, viruses and parasites are known to spread through sexual contact. Eight of these pathogens have the highest risk of disease. Of the eight infections, four are currently curable, namely syphilis, gonorrhea, chlamydia and trichomoniasis. The other four are non-curable viral infections, namely hepatitis B, herpes simplex virus, HIV, and human papilloma virus. The symptoms or diseases caused by these incurable viral infections can be alleviated or improved by treatment.
Some sexually transmitted infections can spread through sexual contact with skin contact. Microorganisms that cause sexually transmitted infections can also be transmitted by means other than sexual contact, such as shared blood products and tissue transplants. Many sexually transmitted infections, including chlamydia, gonorrhea, hepatitis B, HIV and syphilis, can also be passed from mother to baby during pregnancy and childbirth.