What is genital herpes? Is genital herpes a sexually transmitted disease?

In daily outpatient clinics and personal website Q&A, I encounter many inquiries about the diagnosis, treatment, and prevention of genital herpes. Many patients have many misunderstandings in these areas, so I will answer some questions for you below.

1. What is herpes simplex virus?

Humans are the only natural host of the herpes simplex virus (HSV), with 80-90% of the population infected and 10% being asymptomatic. HSV has a diameter of about 120-150 microns and is composed of three concentric structures: envelope, body coat, and capsid. The body coat is made of cellulose and the cell membrane contains lipid components, so the herpes simplex virus is particularly sensitive to ether and lipid solvents. It can survive for several months at low temperatures, but can be eliminated in 30 minutes under humid heat of 50°C and dry conditions of 90°C.

2. How many types of herpes simplex are there?

Herpes simplex virus can be divided into two types, type I and type II, referred to as HSV-1 and HSV-2. HSV-1 is mainly transmitted through close contact with the respiratory tract, skin and mucous membranes, infecting the skin, mucous membranes and organs above the waist. For example, inflammation and herpes of the oral mucosa, nasal vestibule, conjunctiva, and throat, and herpes in and around the mouth are 99% caused by HSV-1 infection.

HSV-2 mainly exists in the female cervix, vagina, vulva skin and male penis, urethra, etc., and is the culprit for genital inflammation and herpes. According to relevant statistics, 90% of the pathogens of genital herpes are herpes virus type 2, and only 10% are HSV-1. It is estimated that 20% of the world's population is HSV-2 positive, and the number of cases is increasing by about 25% each year. HSV-1 is one of the most widespread viral infections in the world, with a positive rate in adult serum exceeding 85%, and even reaching 100% in some countries and regions.

3. Is genital herpes a sexually transmitted disease?

Genital herpes is mainly caused by the herpes simplex virus HSV-2. Both at home and abroad, the disease is clearly defined as a sexually transmitted disease. Abroad, the incidence of genital herpes is second only to gonorrhea and syphilis among sexually transmitted diseases, ranking third in the incidence of sexually transmitted diseases, and ranks first among sexually transmitted diseases caused by viruses. In our country, genital herpes has shown an increasing trend in recent years.

4. Why is genital herpes prone to recurrence?

Neutralizing antibodies and complement-fixing antibodies are produced in the human body 1-3 weeks after herpes simplex infects the human body. The remaining virus may be transferred along the peripheral nerves to the trigeminal ganglion (herpes simplex virus type 1) or sacral ganglion (herpes simplex virus type 2), and remain latent for a long time, entering a dormant state.

When certain inducing factors such as anxiety, mental trauma, cold, sun exposure, wind, trauma, infection, drug allergy, high fever, menstruation, pregnancy, etc. disrupt the body's physiological balance, specific transcriptases required for viral proliferation appear in nerve cells, activating the virus and causing recurrence. Humoral antibodies cannot prevent the recurrence of herpes virus, and weakened cellular immunity has a significant impact on recurrence. The recurrence rate of genital herpes caused by HSV-1 infection is much lower than that caused by HSV-2 infection.