Infections causes by viruses are probably the most common of any type of infection. Colds and flus are caused by viruses. Depending on the type of virus, immunization may be successful in preventing the infection. In other cases, no prevention is realistically possible since the virus continually mutates. A virus is defined as a sub-microscopic agent that causes infection. It is unable to reproduce or grow when outside the host cell space. Scientists continue to argue whether the virus lives or not. Viruses are attacked by the immune system of the host unit. Antibiotics don't affect viruses, but viruses can be prevented by inoculations of vaccines.

Arboviruses

Arboviruses are a shortened version of the name arthropod borne viruses. These are carried by mosquitoes and are typically transmitted to the bloodstream by biting. Many of the viruses are not infectious to humans but others are epidemic in nature and can be deadly. Examples of arboviruses today include Dengue fever, West Nile virus, Ross River virus, tick-borne encephalitis and equine encephalitis. The best treatment for arboviruses is prevention. Vector control to eliminate mosquito breeding sites and insect repellents will help eliminate the likelihood of getting bitten by the virus-carrying mosquito.

Herpes virus

Herpes virus comes in two main types, Herpes simplex virus 1 and Herpes simplex virus 2. Both are marked by watery blisters on the mucous membranes of the mouth or genitals, or on the skin. Herpes simplex virus 1 is usually found on the face, specifically the lips and is commonly known as a cold sore. Herpes simplex virus 2 is usually called genital herpes. The two viruses are similar under a microscope. The usual treatment for an outbreak of herpes simplex is acylovir as an antiviral drug. Two recent medication developments are Famciclovir and Valacyclovir. These drugs are taken orally to control the visible lesions.

Hepatitis

A hepatitis infection comes from hepatitis virus in the liver tissue. There are seven types of hepatitis, labeled from Hepatitis A to Hepatitis G. Hepatitis A is usual caused from ingestion of contaminated food and has only the acute stage. Hepatitis B is found as a result of contaminated blood, tattoos, sexual contact and breast feeding. It has both a chronic stage and an acute stage. Hepatitis C is a virus spread by blood to blood contact with an infected person's blood and results in scarring of the liver as well as liver cancer. Hepatitis D propagates only in the presence of Hepatitis B and results in a more severe symptom set. Incidence of liver failure is at a higher rate with Hepatitis D. Hepatitis E is similar to Hepatitis A and is found mostly on the Indian subcontinent. Hepatitis F is not yet verified as a separate virus. Hepatitis G is confirmed although its exact role in viral incidence is not positively delineated.

Vaccine-preventable virus

Viruses which can be prevented by inoculations with small amounts of the virus are known as vaccine preventable viruses. The body builds up antibodies which fight off potential invasions by viruses in the future. These ten significant childhood diseases can all be prevented by inoculations: Chickenpox, tetanus, whooping cough, polio, rubeola, mumps, rubella, diphtheria, hepatitis B, and Haemophilus influenzae type B infections.

Sexually transmitted virus

The most common sexually transmitted viruses in the United States are human papilloma viruses (HPV). Up to twenty million Americans are currently infected with the virus and it is estimated that 75% of adults have had genital HPV during their reproductive years. Genital warts are just one of the types of viruses transmitted by direct skin to skin sexual contact. These warts may have a positive correlation with the incidence of cervical cancer.

Diseases caused by viral infections

Viruses enter bloodstream and are carried from there to the brain. Diseases caused by viral infections are typically grouped into two categories: Chronic infections and acute infections. Viral diseases of the acute category usually begin quickly, while chronic viral diseases develop more slowly and are often found to progress to the point of death. Common acute viral infections cause diseases such as encephalitis, aseptic meningitis, encephalomyelitis, and flaccid paralysis. Chronic viral infections lead to diseases such as subacute-sclerosing panencephalitis, retrovirus disease and spongiform encephalopathies.