Virology

1. Virology An Introduction to the VirusesNon-Living Etiologies

2. Diagnostics of Pathogenic Viruses Cytopathic effect (CPE) (or Cytopathogenic effect) refers to degenerative changes in cells, associated with the multiplication of certain viruses. Thus identification of a viral infection can be made by examining the characteristic cytopathic effect produced on different cell sheets.

4. Influenza Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses), that affects birds and mammals. The name influenza is Italian and means "influence" (Latin: influentia). The most common symptoms of the disease are chills, fever, sore throat, muscle pains, severe headache, coughing, weakness and general Discomfort.

5. Influenza Swine Flu H1N1 The 2009 flu pandemic is a global outbreak of a new strain of influenza A virus subtype H1N1, first identified in April 2009, which is officially termed novel H1N1 and commonly called swine flu. The virus is a mixing of four known strains of influenza A virus: one endemic in humans, one endemic in birds, and two endemic in pigs (swine). Transmission of the new strain is typically human-to-human; eating cooked pork products will not transmit the virus.

6. Influenza Avian Flu H5N1 The reported mortality rate of highly pathogenic H5N1 avian influenza in a human is high; WHO data indicates that 60% of cases classified as H5N1 resulted in death. However, there is some evidence that the actual mortality rate of avian flu could be much lower, as there may be many people with milder symptoms who do not seek treatment and are not counted.

7. Arbovirus Arbovirus is a shortened name given to viruses that are transmitted by arthropods, or arthropod-borne viruses. Arthropods are able to transmit the virus upon biting allowing the virus to enter the bloodstream which can cause viraemia. The majority of the Arboviruses are RNA viruses. Symptoms consist of a mild infection such as a fever or a rash. Others however are epidemic and can cause serious infections such as meningitis and encephalitis that can be fatal WEE St. Louis EEE West Nile VEE Dengue Fever

8. Arbovirus Dengue Fever Dengue fever is an acute febrile diseases, found in the tropics, and caused by four closely related virus serotypes of the genus Flavivirus, family Flaviviridae.

9. Herpes Herpes simplex is a viral disease caused by both herpes simplex virus 1 (HSV-1) and herpes simplex virus 2 HSV-2). Herpes viral disease caused by varicella zoster virus. Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral Herpes, the visible symptoms of which are colloquially called cold sores, infects the face and mouth. Oral herpes is the most common form of infection. Genital herpes, commonly known simply as Herpes, is the second most common form of herpes

10. Herpes Common infection of the skin or mucosa may affect the face and mouth (orofacial herpes), genitalia (genital herpes), or hands (herpes whitlow). More serious disorders occur when the virus infects and damages the eye (herpes keratitis), or invades the central nervous system, damaging the brain (herpes encephalitis).

11. Rabies The central nervous system is made up of the brain and spinal cord. The brain functions to receive nerve impulses from the spinal cord and cranial nerves. The spinal cord contains the nerves that carry messages between the brain and the body. The rabies virus spreads through the nerves of the brain and spinal cord first causing flu-like symptoms such as fever and malaise. As the disease advances it causes anxiety, confusion, brain dysfunction, progressing to hallucinations, delirium, and insomnia. If left untreated, rabies is nearly always fatal.

12. Ebola The incubation period for Ebola Hemorrhagic Fever ranges from 2 to 21 days. The onset of illness is abrupt and is characterized by fever, headache, joint and muscle aches, sore throat, and weakness, followed by diarrhea, vomiting, and stomach pain. A rash, red eyes, hiccups and internal and external bleeding may be seen in some patients. Researchers do not understand why some people are able to recover from Ebola HF and others are not. However, it is known that patients who die usually have not developed a significant immune response to the virus at the time of death.

13. Small Pox Smallpox is an infectious disease unique to humans, caused by either of two virus variants, Variola major and Variola minor. Smallpox localizes in small blood vessels of the skin and in the mouth and throat. In the skin, this results in a characteristic maculopapular rash, and later, raised fluid-filled blisters. V. major produces a more serious disease and has an overall mortality rate of 30– 35%.

14. Acquired Immune Deficiency Syndrome Acquired immune deficiency Syndrome (AIDS) is a disease of the human immune system caused by the Human Immunodeficiency Virus (HIV). HIV causes AIDS by depleting CD4+ T helper lymphocytes. This weakens the immune system and allows opportunistic infections to manifest. T lymphocytes are essential to the immune response and without them, the body cannot fight infections or kill cancerous cells.

15. Dx Acquired Immune Deficiency Syndrome AIDS Diagnosis: HIV positive ARC (AIDS Relate Complex) CD4+ T cell count below 200 per µL In 1993, the CDC expanded their definition of AIDS to include all HIV positive people with a CD4+ T cell count below 200 per µL of blood or 14% of all lymphocytes. The AIDS diagnosis still stands even if, after treatment, the CD4+ T cell count rises to above 200 per µL of blood or other AIDS-defining illnesses are cured.

16. Sx Acquired Immune Deficiency Syndrome

17. Tx Acquired Immune Deficiency Syndrome Current treatment for HIV infection consists of highly active antiretroviral therapy, or HAART. This has been highly beneficial to many HIV-infected individuals since its introduction in 1996 when the protease inhibitor-based HAART initially became available. Current optimal HAART options consist of combinations (or "cocktails") consisting of at least three drugs belonging to at least two types, or "classes," of antiretroviral agents.

18. Tx Acquired Immune Deficiency Syndrome Standard goals of HAART include improvement in the patient’s quality of life, reduction in complications, and reduction of HIV viremia below the limit of detection, but it does not cure the patient of HIV nor does it prevent the return, once treatment is stopped, of high blood levels of HIV, often HAART resistant. Moreover, it would take more than the lifetime of an individual to be cleared of HIV infection using HAART. Despite this, many HIV-infected individuals have experienced remarkable improvements in their general health and quality of life, which has led to the plummeting of HIV-associated morbidity and mortality.

19. Prions A prion is an infectious agent that is composed primarily of protein. The protein itself does not self-replicate and the process is dependent on the presence of the polypeptide in the host organism. The prion protein has been implicated in a number of diseases in a variety of mammals, including bovine spongiform Encephalopathy (BSE, also known as "mad cow disease") in cattle and Creutzfeldt- Jakob disease (CJD) in humans. All known prion diseases affect the structure of the brain or other neural tissue, and all are currently untreatable and are always fatal.