Infection and disease in reservoir and spillover hosts: determinants of pathogen emergence

P W Daniels1, K Halpin, A Hyatt

  • 1CSIRO Livestock Industries, Australian Animal Health Laboratory, Geelong, Australia. Peter.Daniels@csiro.au

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When a pathogen enters the body and reproduces, it can cause an infection, damage body cells, and cause illness symptoms that eventually lead to disease. Therefore, its prevention requires breaking the chain of infection.
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Infectious Diseases and Their Occurrence

Infectious diseases appear in populations through various transmission patterns, influenced by pathogen characteristics, population immunity, environmental conditions, and social behavior. Understanding these patterns is essential for effective public health surveillance and intervention. These categories—sporadic, outbreak, epidemic, pandemic, and endemic—help frame the nature and scope of disease events.Sporadic diseases occur irregularly and infrequently, without a predictable temporal or...
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Pathogens spread from their reservoirs to susceptible hosts through three main routes: contact transmission, vehicle transmission, and vector transmission. Each route involves distinct mechanisms of transfer.Contact TransmissionThis category includes direct contact, indirect contact, and droplet transmission:Direct contact involves immediate physical interaction between individuals—such as a handshake—which can spread pathogens like Streptococcus pyogenes, the bacterium responsible for...
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