Sexually transmitted disease causes

Overview
Sexually transmitted diseases (STDs) are infections that you can get from having sex with someone who has the infection. The causes of STDs are bacteria, parasites and viruses. There are more than 20 types of STDs, including Chlamydia, Gonorrhea, Herpes Simplex, HIV/AIDS, HPV, Syphilis, Trichomoniasis

Types and their pathogenic causes
Most of the diseases on this list are most commonly transmitted sexually. Some are commonly transmitted in other ways as well; for example, HIV/AIDS is also commonly transmitted through the sharing of infected needles by drug users, while SARS, which can be spread through casual contact such as coughing and sneezing, is very often not associated with sexual activity.

Bacterial

 * Chancroid (Haemophilus ducreyi)
 * Donovanosis (Granuloma inguinale or Calymmatobacterium granulomatis)
 * Gonorrhea (Neisseria gonorrhoeae)
 * Lymphogranuloma venereum (LGV) (Chlamydia trachomatis serotypes L1, L2, L3. See Chlamydia)
 * Non-gonococcal urethritis (NGU) (Ureaplasma urealyticum or Mycoplasma hominis)
 * Staphylococcus aureus, MRSA.
 * Syphilis (Treponema pallidum)

Fungal

 * Jock Itch
 * Yeast Infection

Viral

 * Cytomegalovirus (CMV) through skin to skin contact, saliva, not only sexually.

(Note: Hepatitis A and Hepatitis E are transmitted via the fæcal-oral route, not sexually; Hepatitis C is rarely sexually transmittable, and the route of transmission of Hepatitis D is uncertain, but may include sexual transmission.  )
 * Hepatitis B.


 * Herpes simplex
 * Herpes simplex virus implicated in Alzheimer's disease.
 * Human Immunodeficiency Virus (HIV/AIDS)
 * Human papillomavirus (HPV)
 * Certain strains of HPV cause genital warts
 * Certain strains of HPV cause cervical dysplasias which can lead to cervical cancer, penis cancer, anal cancer, oral cancer, head and neck cancer.
 * Marburg virus and Ebola, as any contact can spread it, sexual transmission has been documented.
 * Molluscum (MC)
 * Mononucleosis is spread through saliva, can occur during sex.
 * Kaposi's sarcoma-associated herpesvirus (KSHV/HHV8)
 * The cause of Kaposi's sarcoma

Parasites

 * Pubic lice, colloquially known as "crabs" (Phthirius pubis)
 * Scabies (Sarcoptes scabiei)

Protozoal

 * Trichomoniasis (Trichomonas vaginalis)

Sexually transmitted enteric Infections
Various bacterial (Shigella, Campylobacter, or Salmonella), viral (Hepatitis A), or parasitic (Giardia or amoeba) pathogens are transmitted by sexual practices that promote anal-oral contamination. Sharing sex toys without washing or multiple partnered barebacking can promote anal-anal contamination. Although the bacterial pathogens may coexist with or cause proctitis, they usually produce symptoms (diarrhoea, fever, bloating, nausea, and abdominal pain) suggesting disease more proximal in the GI tract.

Sexually transmitted oral infections
Common colds, influenza, Staphylococcus aureus, E.Coli and the yeast Candida albicans can all be transmitted through the oral route.