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• Zoonosis


  Any infectious disease which animals can transmit to human beings
• animal poisons

  Used zoonosis as a synonym for infections by contagious
• Pathogenic species responsible for zoonotic diseases can survive and multiply even without the presence of man
• Causes of zoonotic diseases

  • Viruses
  • Parasites
  • Bacteria
  • Fungi
• In zoonotic diseases caused by parasites, the types of signs and symptoms can be different depending on the parasite and the person
• Reverse Zoonosis


  Infectious disease of people occasionally transferred to animals and then transferred back to people
• Emerging Zoonosis


  Zoonosis that is newly recognized or newly evolved or that has occurred previously but shows an increase in incidence or expansion in geographical, host, or vector range
• Emerging Zoonotic Diseases


  • Bird Flu
  • AIDS
  • Mad Cow Disease
  • Nipah Virus
  • SARS-COV-2
• Factors influencing zoonoses


  • Environmental change
  • Human and animal demography (statistics)
  • Pathogen changes
  • Changes in farming practice
  • Social and cultural factors such as food habits
• Viruses


  • Especially RNA viruses are among the most prominent examples of emerging pathogens because of their ability to adapt quickly to changing environmental conditions
• Viruses


  • Dengue: Aedes aegypti
  • Malaria: female Anopheles
• 1918 Flu Pandemic


  1918-1920
• 1918 Flu Pandemic


  Unusually deadly influenza pandemic caused by H1N1 influenza virus believed to be of avian (birds) origin
• 1918 Flu Pandemic infected 500M people and had an estimated death toll of 17M–50M
• Asian Flu Pandemic


  1957
• Asian Flu Pandemic


  Caused by a virus known as Influenza A subtype H2N2 or Asian Flu virus, also of avian origin, with a death toll of 2M worldwide
• Hong Kong Flu Pandemic


  1968
• Hong Kong Flu Pandemic


  Caused by an Influenza A (H3N2) virus comprised of 2 genes from an avian influenza, with a death toll of 1M worldwide
• HIV/AIDS Pandemic


  1920-Present
• HIV/AIDS Pandemic


  Scientists identified a type of chimpanzee in Central Africa as the source of HIV infection in humans, with a death toll of 32M and 75.7M people infected up until 2019
• Prevention


  Inhibiting the introduction of a disease agent into an area, a specific population group, or an individual
• Control Efforts


  Steps taken to reduce a disease problem to a tolerable level and maintain it at the level
• Primary Prevention


  Aimed at maintaining a healthy population, like preventing the occurrence of a disease
• Secondary Prevention


  Attempts to minimize damage after a disease has already occurred
• Eradication


  The complete elimination of a disease-producing agent worldwide
• Methods to neutralize the reservoir of zoonotic infection


  • Removing infected individuals
  • Rendering infected individuals or individuals as "non shedder" or not shedding the virus or organism to the environment
  • Manipulating the environment
• Methods to reduce contact potential

  • Isolation and treatment of cases
  • Quarantine of possibly infected individuals
  • Population control
• Isolation


  Designed to keep the agent in
• Quarantine


  Designed to keep the agent out
• Increasing Host Resistance


  Reduction of stress, by providing improved shelter and nutrition to increase the survival ability of the affected population
• Chemoprophylaxis


  Passive means of increasing host resistance, to prevent infection or at least reduce the severity of the disease
• Purposes of Vaccination


  • To protect susceptible individuals from infection or disease
  • To prevent transmission of infectious agents by creating an immune population (Herd Immunity)
• Herd Immunity / Population Immunity


  The indirect protection from an infectious disease that happens when a large part of the population is immune to a certain disease, either through vaccination or immunity developed from past infection
• Surveillance


  Testing of accessible animals and biological materials to assess the presence of a disease and establish the pathogen involved
• Control measures in animals

  • Quarantine
  • Test and destruction of diseased or infected animals
  • Test and segregation of infected stock
  • Immunization of exposed animals
  • Vaccination campaigns
  • Treatment of sick and infected animals
  • Restriction of animal movements
  • Control of animal populations
• Prevention measures in humans

  • Occupational health education
  • Vaccination of at-risk categories
  • Post-exposure treatment
  • Proper food hygiene regarding food of animal origin
• Malaria


  A parasitic infection transmitted by female Anopheline mosquitoes
• Malaria causes an estimated 219 million cases globally, and results in more than 400,000 deaths every year
• Most of the deaths from malaria occur in children under the age of 5
• Dengue


  The most prevalent viral infection transmitted by Aedes mosquitoes