Viruses

• Viruses are NON LIVING because

  1. Can form crystals and survive in this form for many years (except HIV)
  2. They do not respire
  3. Cannot reproduce outside the body of a host (host = parasitic)
• Viruses are LIVING because:

  Can reproduce when within cells of a living organism.
• Basic Structure of a Virus:

  1. Very small
  2. Core of DNA or RNA, surrounded by a protein coat (capsid)
  3. Non cellular or acellular - no nucleus, ribosomes or mitochondria
  4. +/- 4 different shapes
• Viral Diseases

  1. Measles
  2. Polio
  3. Chicken Pox
  4. A cold
• • Rabies affects both domestic and wild animals
  • The Rabies virus is passed from one animal to another in saliva.
  • Humans usually get infected when they are bitten by a rabid animal
  • Incubation period = up to 60 days = no symptoms
• Rabies symptoms after 60 days

  1. Headaches and fever
  2. Sore throat
  3. Nausea
  4. Fatigue or tiredness
  5. Following an agitated phase
• Agitated phase symptoms:

  1. Convulsive seizures
  2. Salivates
  3. Fear of water
  4. Difficulty in swallowing and breathing
  5. Death
• Treatment and management of Rabies

  1. without treatment = fatal
  2. Treatment should start before symptoms start showing
  3. Antiviral drug and blood transfusion
• Prevention of Rabies

  1. Vaccination of dogs and livestock in areas where the disease is found.
  2. Immunization of people with high risk occupations such as vets
  3. Immunization of travelers going to areas where the disease is found
  4. Training of health workers and vets
  5. Destroying of animals infected with the disease