What are the causes of herpes virus infection?

Herpes simplex virus infection is the most common DNA virus infection, with a high incidence rate among people with low resistance. If a normal person is infected with the herpes virus, severe cases will cause systemic lesions, and pregnant women infected with this virus have a high probability of causing miscarriage, premature birth or fetal malformations.

1. The main causes of herpes simplex virus infection

The disease is caused by the herpes simplex virus, a DNA virus. Human herpes simplex virus is divided into two types, herpes simplex virus type 1 (HSV-I) and herpes simplex virus type 2 (HSV-II). Type I causes infections primarily of the skin, mucous membranes (oral mucosa), and organs (brain) other than the genitals. Type II mainly causes skin and mucous membrane infections in the genital area. The virus enters the body through the respiratory tract, oral cavity, genital mucosa and broken skin, and resides in the normal mucosa, blood, saliva and sensory ganglion cells of the human body. When the body's resistance is reduced, such as during fever, gastrointestinal dysfunction, menstruation, pregnancy, focal infection and mood changes, latent HSV in the body is activated and the disease occurs.

2. Clinical manifestations

1. Normal people infected

HSV can quickly produce immunity, and the lesions are limited to the surface of the skin and mucous membranes. However, when HSV infection occurs in newborns whose immune function has not yet matured and people with immune defects (such as organ transplant patients, patients receiving immunosuppressants and anti-tumor treatment), the lesions often spread throughout the body, such as the brain, liver, lungs, eyes, adrenal glands, and skin and mucous membranes. The condition is serious and the mortality rate is high. When there is extensive skin damage such as eczema and burns, HSV infection often manifests as generalized herpes on the skin and mucous membranes, and can cause systemic disseminated lesions and serious conditions. In pregnant women with genital herpes, HSV can be transmitted to the fetus through ascending infection of the cervix, causing congenital infection and leading to stillbirth, miscarriage, premature birth and congenital malformations. During delivery, the virus can also pass through the birth canal and cause neonatal infection. The incubation period of HSV infection is 2 to 12 days, with an average of 6 days. Different clinical types may have different clinical manifestations.

2. Primary infection

It is more common in children aged 1 to 4 years old. Most of them do not show symptoms after infection and the infection is latent, and only a few show symptoms. HSV-1 infection often occurs in the mouth, lips, eyes, brain and skin above the waist. HSV-2 infection is common in the cervix, external genitalia, and skin below the waist.