The infection can be picked up by the infection during sexual contact.
The most common viral infection of the nose, throat, and upper respiratory tract.
Doctors may base the diagnosis on symptoms, blood tests, culture, or examination of infected tissue.
Medicines may interfere
A virus is a small organism; The virus attaches to a cell (called the host cell), and enters it lubricates its DNA or tRNA inside the cell. DNA or tRNA is the genetic material that contains environmental information for the replication (re)ation of a virus. Material: The genetic material of a virus in a cell. The cell usually dies with the infection, because the virus prevents it from performing its normal functions. .
RNA, using deoxyribonucleic acid (DNA). RNA viruses root on retroviruses, such as the human immunodeficiency virus (HIV) (AIDS – see HIV infection). RNA viruses, RNA viruses, retroviruses, mutate.
Some viruses do not kill the cells they infect, but alter their cellular functions. The infected cell sometimes loses control of normal cell division and becomes cancerous. Some viruses, such as herpesviruses (see Overview of herpes virus infection) and human immunodeficiency virus (see HIV infection), leave their genetic material in the host cell, where the latent virus material remains dormant for a long time. infection), the virus can begin to multiply again and cause disease when the cell is disturbed.
Viruses usually infect a specific type of cell. For example, cold viruses target only the cells of the upper respiratory tract. In addition, most viruses infect only a few species of plants or animals. Some of them only affect people. It is common for many viruses to infect infants and children (see Viral Infections in Infants and Children).
(Transmitted) viruses spread in different ways; Some are ingested, inhaled, and others spread through the bites of insects, such as mosquitoes or some types of flies or ticks. Some are also spread through sex (see sexually transmitted diseases) or during transfusion of contaminated blood.
Many viruses, which were once restricted to a few parts of the world, are now circulating. These viruses include chikungunya virus, Crimean-Congo hemorrhagic fever virus, Japanese encephalitis virus, Rift Valley Fever virus, West Nile virus, Ross River virus, and Zika virus and louping ill virus. These viruses spread because, on the one hand, climate changes have increased the areas in which mosquitoes that transmit viruses can live; Travelers may also become infected on the other hand, and then return to their home country where they are bitten by mosquitoes that spread the virus to other people. The chikungunya virus, which is spread by mosquitoes, was first detected in Africa, but has recently spread in the Caribbean and in Central, South and North America. Chikungunya virus infection usually causes fever and severe joint pain, often in the hands and feet. Affected people may also have headaches, muscle pain, swollen joints, or a rash. However, most patients improve within a week.
In the body there are a number of means of protection against viruses; Physical barriers, such as the skin, prevent the virus from entering the body easily. Infected cells also make interferons, substances that can make uninfected cells more resistant to infection with many viruses.
When the virus enters the body, it stimulates the body’s immune defenses. These defenses begin with white blood cells, such as lymphocytes and monocytes, which learn to attack and destroy the virus or cells that have been infected (see ). If the body survives the virus attack, some white blood cells remember the invader and are able to react more quickly and effectively to a subsequent infection from the same virus. This reaction is called immunity. Immunization can also be obtained through the use of a vaccine (see Immunization).
Types of viral infections
Possibly the most common infections are:
Respiratory infections: Infections of the nose, throat, upper airways, and lungs
Upper respiratory tract infections are the most common respiratory infections, including strep throat, sinusitis, and the common cold.
Other viral respiratory infections include influenza and pneumonia.
In young children, viruses usually cause croup (an infection of the upper and lower airways called laryngotracheobronchitis) or of the lower airways (bronchiolitis).
Infants, older adults, and people with a lung or heart disorder are more likely to cause respiratory infections.