How do viruses infect humans?

Answer 1

They can enter through any moist, unarmed passage such as open wounds (wounds that have not yet clotted and been armed with white blood cells) and the eyes. The famous HIV enters through the female orifice. Contrary to popular belief, most pathogens are destroyed going down the digestive tract because of the extremely acidic stomach and extremely alkaline small intestines.However, there is always a fair chance that some viruses survive and enter the bloodstream in the small intestines, or infect epithelial cells in the pharynx or esophagus.

Answer 2

Many common viruses (like flu, common cold, viral gastroenteritis known as "stomach flu", etc.) enter through the germs on your hands that you "caught" from someone else by touching them or something they touched. Or you can also get contact with these types of virus particles that come off an infected person if you are exposed to their respiratory droplets in the air. They are carried for short distances on droplets from coughs and sneezes and can be breathed into your respiratory system through your mouth or nose.

They can also be spread by sharing drinking or eating utensils (e.g. forks, straws, glasses, etc.) which allows the viruses to get into your gastrointestinal system through the mucous tissue of your mouth. If these droplets containing the virions come in contact with your mucus membranes (usually of the eyes and respiratory or gastrointestinal systems including the mouth and nose), then the virus can attach to the mucous tissue cells using special proteins on their coats and enter the cells to begin using you as the host and replication factory. See the related question below for more details of this viral process of the lytic cycle that many, but not all, viruses use to reproduce.

Some kinds of viruses use different methods to enter the body, however, such as through sexual contact in the example of viral STDs. This sexual transmission is through the reproductive system organs and mucous tissues (like Herpes and HIV/AIDS).

Some require blood to blood contact and can be passed from a mother to a fetus directly in the blood or to others in transfusions (for example, hepatitis B). Some can be transferred to a fetus through mother's milk and other body fluids. There are also some that can enter through a cut or opening in the skin (e.g. via infected needles etc.).

See the related questions below for more information, there are many details re:specific modes of transmission in the question below: "How can you protect yourself and others from viruses and flu?"

Answer 3

Viruses infect humans by attaching to host cells and injecting their genetic material into the cell. The virus then hijacks the cell's machinery to replicate itself and spread throughout the body, causing the host cell to produce more viruses. This process ultimately leads to the virus causing symptoms of infection in the human host.

Answer 4

They can enter through the mouth, breaks in the skin, or nose. Once they have entered they find a host cell to infect.

Answer 5

They go into and alter the DNA of cells to multiply.

Answer 6

There are various ways through which a virus can enter the body. In most cases, viruses will access the body through germs that you come into contact with.

Answer 7

Through your eyes, mouth, nose or through broken skin (e.g. a needle or rough sex)

Answer 8

When a virus happens to collide with a cell that it can infect, it inserts its genome in the host cell and then the infected cell is then directed to make more viruses.

Answer 9

You enter the body through anything !