Pattern of viral presence during infection Flashcards
What are patterns of viral presence during infection?
Localized infections
Disseminated infections
What are patterns of a localized infection?
viral multiplication and cell damage localized near the site of entry
What is the pattern of infection for disseminated infections?
1)Local multiplication at the site of entry.
2) Spread through the lymphatics to the blood stream and circulation in the blood. (primary viremia)
3) Multiplication at secondary sites
4) Secondary viremia
5) Infection of the target organ
Often the infection is asymptomatic through the first four steps. We call this the incubation period.
what are sites of entry of a virus into a host?
Conjuntivita Resp. tract arthropod scratch alimentary tract UI tract anus
What are inapparent infections?
asymptomatic viral infections.
What may inapparent infections result in?
These are very common, and may result from infection by an attenuated virus or from effective host defense mechanisms.
Why are inapparent infections important?
They represent an often unrecognized source for dissemination of a virus and may confer immunity on the host.
What are acute infections?
Virus infects host, shortly after disease ensues.
What ahappens to a host after getting sick from an acute infection?
After a defined but relatively short period of time the host recuperates. In some cases the virus is completely eliminated from the body. In other cases the virus can hide within the body perhaps in the host genome etc
What is a latent infection?
virus particles are not demonstrable, but reappear during recurrences. Viral nucleic acid is demonstrable, even between recurrence
virus hides in body
What is a example of a latent infection?
Herpesvirus infections
What is a chronic infection?
Virus is always demonstrable and often shed.
Infected cells produces and release virus, but cellular metabolism is little affected and the infected cells can grow and divide.
