What Is Horizontal Transmission?

Horizontal transmission means that the virus is spreading 1. Transmission through the mucosa Many viruses are caused by mucosal infections; 2. Transmission through the skin Some viruses can penetrate the body through insect bites or animal bites, injections or mechanically damaged skin Cause infection; 3. iatrogenic transmission Some viruses can also be transmitted by injection, blood transfusion, tooth extraction, surgery, organ transplantation.

Horizontal spread

Pathogens can be transmitted in two ways: horizontal transmission and vertical transmission. The former refers to the transmission of pathogens among individuals, and the latter refers to the transmission of pathogens from the mother to the fetus through the placenta or birth canal. Mother-to-child transmission is vertical transmission, and other transmission channels are collectively referred to as horizontal transmission.

When pathogens spread among individuals, they mainly invade the body through the following channels.

1. Mucosal transmission of many viruses is caused by mucosal infections. Some viral infections may be confined to the mucous membranes, and some viral infections can spread to adjacent tissues and lymphatic vessels and merge into the bloodstream, causing viremia. It then spreads to the target organ through the bloodstream, causing typical lesions and clinical manifestations. Some viruses can form secondary viremia during infection and eventually invade target organs to cause disease.

2. Transmission through the skin Some viruses can invade the body through insect bites or animal bites, injections or mechanically damaged skin and cause infections. For example, bites of mosquitoes can spread Japanese encephalitis virus, and bites of rabies can spread rabies virus.

3. Iatrogenic transmission Some viruses can also be transmitted by injection, blood transfusion, tooth extraction, surgery, organ transplantation, such as hepatitis B virus and hepatitis C virus.