Chapter 3 Flashcards
Rules for Effective Infection
Need sufficient quantities of virus
Need a host that can support viral growth
Need host immunity to be weak enough to support growth or virus to have enough tricks to subvert the host immunity
Pathogenesis
Origination and development of a disease
Primary Viremia
Initial appearance of the virus in the blood
Secondary Viremia
Dissemination via blood to secondary sites, viral multiplication and high titers of virus in the blood
Local Infection
Infection at the site of entry
Systemic Infection
Generalized infection of many organs
Viral Ligands and Cellular Receptors
Some viruses remain localized e.g influenza and rhino [localized infections] while others spread all over the body [systemic infections] e.g measles. This is because measles has a receptor, CD46, which is present on many cell types.
Viral Release Mechanisms
Viruses that release particles on the apical surface will remain localized. Viruses that can release particles on both the apical and basolateral surfaces quickly reach the blood and disseminate
Viral Tropism
Viruses that can infect and be transported by lymphocytes are protected from antibodies and complement
Acute Infections
Very short incubation time
Peracute Infection
The host dies within a short time
Slow Infections
Starts as acute, disseminates to secondary sites and incubates for several years before the disease re-emerges
Chronic Infections
Have continuing and high levels of viremia. Disease may or may not be present
Papilloma Viruses
Remain in the vegetative state in the basal layers of the skin. When the basal layers become keratinocytes on the surface, the virus replicates and causes warts
Latent Infection
Hidden, dormant, or inactive infection
