A virus is a small infectious agent which is not a living organism. Viruses are unable to engage in self replication, and only replicate themselves by manipulating the reproductive process in an infected cell. The first virus was detected in 1892. Viruses are able to infect animals, plants, bacteria, and archaea.
A stomach virus is one of the most common types of viral infections. A stomac virus may be caused by a rotavirus, norovirus, adenovirus, or astrovirus. A stomach virus can result in colitis or gastroenteritis. Typically, a stomach virus will not actually affect the stomach, and will in fact affect the small intestine.
Virology is the study of viruses. A scientist who engages in the study of virology is a virologist. 5450 viruses, of two thousand virus species, 287 virus genera, 73 virus families, and 3 orders of viruses have been discovered through the study of virology. Viruses studied in virology may be DNA viruses, RNA viruses, or retroviruses.
Journal of Virology and Journal of General Virology
The Journal of Virology is published semi-monthly by the American Society for Microbiology. The Journal of General Virology is published monthly by the Society of General Microbiology. These journals cover the field of virology, and use a approached founded upon biochemistry, biophysics, cell and molecular biology, genetics, immunology, morphology, physiology and pathogenesis.
Adenoviruses are medium sized viruses. An adenovirus can cause conjunctivitis, gastroenteriris, respiratory diseases, tonsilitis, ear infections, and croup. There are fifty five adenoviruses that affect human beings. An adenovirus can be spread through respiratory droplets or fecal matter. There is no vaccine that can prevent adenovirus infection.
Human Papillomavirus is also known as HPV. HPV is associated with the development of anal, penile, vaginal, and cervical cancers. There are more than two hundred strains of human papillomavirus. Two different HPV vaccines have been developed, Gardasil and Cervarix. The human papillomavirus is one of the most widespread infections. It is likely that every sexually active adult will have been infected by HPV at some point in their lives.
The most common strain of human Parvovirus, B19, is believed to be one of the leading contributing factors to the development of new cases of arthritis. Parvovirus B19 was first identified in 1975. A parvovirus is an erythrovirus due to its interaction with red blood cells in the bone marrow. A parvovirus is one of the smallest kinds of viruses. This type of virus is restricted to humans, since there is a limited risk of cross-species infection.
Herpes Simplex Virus
The herpes simplex virus affects as much as ninety percent of the world's population. It is typically associated with sexual infection, although it may be transmitted in several different ways. There are two common versions of herpes simplex, herpes simplex type 1 and herpes simplex type 2. One of the common complications of herpes simplex 1 and herpes simplex 2 is the development of herpes simplex encephalitis. Herpes simplex is characterized by sores at the site of the infection.
The Varicella Zoster virus is more commonly known as chicken pox when it affects children, and shingles when it affects adults. Although the development of chicken pox and Varicella Zoster usually prevents a person from developing Varicella Zoster later in life, in some circumstances an adult may be reinfected.
Cytomeglovirus infection affects between fifty and eighty percent of the population. Cytomeglovirus is related to herpes simplex type 1, herpes simplex type 2, Epstein Barr virus, and Varicella Zoster. Cytomeglovirus is usually innocuous, but presents a fatal risk to individuals with compromised immune systems. Cytomegalovirus infection is usually asymptomatic.
The Epstein-Barr Virus is one of the most common human viruses, and is associated with the development of dermatomyositis, systemic lupus erythematosus, rheumatoid arthritis, infectious mononucleosis, Sjogren's syndrome, multiple schlerosis, Hodgkin's disease, Burkitt's lymphoma, and nasopharyngeal carcinoma. More than ninety five percent of adults have been infected with Epstein Barr virus.
The smallpox virus was a human exclusive virus infections. A smallpox vaccine was developed, which caused the smallpox virus to be practically eradicated by 1979. It is believed that the smallpox virus first appeared near 10,000 B.C.E., and lead to many new infections each year. At its height in 1967, it is estimated that there were 15 million new infections each year, leading to two million smallpox related deaths annually.
Hepatitis A Virus
The hepatitis A virus has an average incubation period of twenty eight days. It leads to an acute inflammation of the liver. The hepatitis A virus does not cause a chronic condition, can be vaccinated against, and can be developed throughout a person's life. The hepatitis A virus is primarily found in underdeveloped countries or areas with poor hygiene levels. A vaccine is availible which can prevent hepatitis A virus infection.
Hepatitis B Virus
The hepatitis B virus can lead to the development of both chronic or acute hepatitis B inflammation of the liver. There is an effective hepatitis B virus vaccine. Complications from the hepatitis B virus include liver cirrhosis and liver cancer.
Hepatitis C Virus
The hepatitis C virus is a primarily human condition. Although a chimpanzee can be infected by a live hepatitis C virus, the chimpanzee will not develop any complications. Hepatitis C virus cannot be vaccinated against, causes chronic complications, and has an incubation period between fifty and one hundred and fifty days.
Progressive Multifocal Leukoencephalopathy
Progressive Multifocal Leukoencephalopathy is associated with the progressive damage and inflammation of the white matter found at multiple locations in the brain, and usually only affects individuals with a compromised immune system. Progressive Multifocal Leukoencephalopathyis caused by the JC virus. Most people are infected by Progressive Multifocal Leukoencephalopathyin childhood or adolescence.
An RNA virus is a virus which uses RNA as its genetic material. RNA viruses are more prone to mutation than the more common DNA viruses. Common examples of an RNA virus are SARS, influenza, and hepatitis C. An RNA virus may include a single strand or double strand of RNA.
Viroids are single strand RNA viruses. A viroid does not have a typical virus coat. The first viroid was discovered in 1971, and thirty three viroids have been discovered since then. A viroid is much smaller than other kinds of viruses. Viroids are plant based viruses.
Prions are caused by proteinaceous infectious particles. The word prion was created as a portmanteu of protein and infection. The most famous prion disease is Mad Cow Disease. Every prion disease is difficult to treat and impossible to vaccinate against or cure because after a prion causes an infection, the prions form very stable tissue structures which lead to cell death and are difficult to dispose of through physical and chemical agents.