What are sexually transmitted diseases ? Name four such diseases. Which one of them damages the immune system of human body?

Sexually transmitted diseases (STD):

1. The infectious or contagious diseases, which spread from an infected person to a healthy person by sexual contact, are called sexually transmitted diseases.
2. It is also known as reproductive tract infection (RTI).

Common sexually transmitted diseases:

1. Gonorrhea: It is a sexually transmitted infection that affects both meth and women. It is a severe disease; if left untreated, it can lead to serious health complications. The bacteria that causes gonorrhea is Neisseria gonorrhoeae. The bacteria germinate quickly in the body's mucous membranes and are found in an infected person's sperm and vaginal fluids.
2. Syphilis: It is a sexually transmitted infection caused by Treponema pallidum. It typically enters the body through the rectum, vaginal canal, or nose tissue lining. It has four stages: primary, secondary, latent, and tertiary.
3. Acquired immunodeficiency syndrome (AIDS): It is a sexually transmitted disease caused by the human immunodeficiency virus (HIV). It weakens the person's immune system by reducing the T- cells in the body.
4. Genital herpes: It is a sexually transmitted disease caused by the Epstein-Barr virus. It affects the lower body portion, specifically the reproductive organs. The main symptom is that it causes lesions on the reproductive organs. It can also lead to the adverse malformation of the fetus.

AIDS:

1. AIDS weakens the immune system of the host organism.
2. The HIV virus attacks the CD₄ cells of the host and reduces the T-cell count of the body.
3. The host becomes immune-compromised and can easily be infected with pathogenic agents.