Zoonoses Summary

Zoonoses

Lecture Objectives

  • Identify important zoonoses based on:
    • Commonality.
    • High impact on human health and economy.
    • Public perception.
  • Understand their existence in animals and transmission to humans.
  • Learn to recognize them and associated risks.
  • Know how to control and prevent them.

What are Zoonoses?

  • Definition: Any disease/infection naturally transmissible from vertebrate animals to humans (WHO).
  • Approximately 64% of current human infectious diseases are zoonotic.
  • Emerging Infectious Diseases (EIDs):
    • >75% are zoonotic.
    • May be new pathogens or new to a host/area.
    • Example: Hendra, COVID-19.

Transmission Types

  • Direct Transmission ("True" Zoonosis/Zooanthroponosis):
    • Animal reservoir.
    • Example: Rabies.
    • Typically no ongoing human-to-human transmission (dead-end host).
  • Reverse Zoonosis (Anthropozoonosis):
    • Human reservoir.
    • Example: Cysticercosis.
    • Typically no ongoing animal-to-animal transmission (dead-end host).
  • Indirect Transmission:
    • Infection transmitted via intermediate vector/material.
    • Animal remains the reservoir.
    • Involves environment, vehicles (air, water, soil, food, fomites), and vectors (e.g., insects).

Australian Zoonoses

  • National Notifiable Disease Surveillance Scheme (NNDSS):
    • Managed by the Department of Health & Aging with an online database.
    • Reports 633 notified zoonoses, 47% in QLD.
    • Importance of knowing common and possible diseases in your area.