1 / 10

Viruses

Viruses. Lytic Infections by viruses Lysogenic infections by viruses Treating viral infections Viral Epidemics Human Viral Diseases. What is a Virus?. Non-living particle made of proteins, nucleic acids, and sometimes lipids They can reproduce only by infecting living cells

nardo
Télécharger la présentation

Viruses

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Viruses Lytic Infections by viruses Lysogenic infections by viruses Treating viral infections Viral Epidemics Human Viral Diseases

  2. What is a Virus? • Non-living particle made of proteins, nucleic acids, and sometimes lipids • They can reproduce only by infecting living cells • Lytic Infections: virus enters a cell, multiplies, and causes cell to lyse, or burst, sending new viruses out to infect more cells (SARS, common cold, influenza, rabies) • Lysogenic Infections: viral DNA is inserted into host cell DNA and multiplies w/out harming host cell; causes each new cell to be infected with virus (HIV, Herpes, HPV, shingles)

  3. Prevention & Treatment • Viruses are difficult to eliminate b/c their replication pathway requires host cells; drugs are often toxic to the host cell • Also must be grown in live cells and tissues which takes time to do • Methods: vaccinations to provide immunity from infections and antiviral drugs that interfere with viral replication • ** viruses mutate rapidly so antiviral drugs must be used only when necessary • Viruses can become resistant quickly

  4. Viral Epidemics in history • Smallpox among Native Americans: 1492-1900, death toll is estimated at 80-90% of the population • Influenza: 1918-1929 worldwide, death toll approx. 75 million • HIV/AIDS: 1981-present worldwide, death toll approx. 25 million

  5. Human Viral Diseases • STD’S: HIV/AIDS, herpes • Childhood diseases: measles, mumps, chicken pox • Respiratory diseases: influenza, common cold • Skin diseases: shingles, warts • Digestive tract diseases: gastroenteritis • Nervous system diseases: polio, viral meningitis, rabies • Other diseases: smallpox, hepatitis

  6. Latest News • 7 APRIL 2013 - As of 7 April 2013 (16:30 CET), the Chinese health authorities notified WHO of an additional three laboratory-confirmed cases of human infection with influenza A(H7N9) virus. • To date, a total of 21 cases have been laboratory confirmed with influenza A(H7N9) virus in China, including six deaths, 12 severe cases and three mild cases. • The Chinese government is actively investigating this event and has heightened disease surveillance.

More Related