DD- VIRAL PATHOGENS Flashcards
Tropism
a given virus is likely to infect certain tissues and not others. Enterotropic viruses replicate in the gut and neurotropic viruses in nervous system tissue.
A virus acute infection is characterized by a _______and the production of a large number of progeny.
high viral replication rate
A _________ lasts for longer periods of time and may be the result of an acute primary infection that is not cleared, and the ability of the virus to be transmitted to other organisms or offspring of the host is maintained.
persistent infection
usually infections of epithelial cells at body surface, such as gut, respiratory tract, eyes.
Often have short incubation times and include viruses which include many serotypes (rapidly mutating)
and result in short-lived immunity, primarily via secretory IgA. Re-infections are common.
Acute local
Examples include colds and diarrheal disease.
Usually primary infection is also in epithelium, but viremia and systemic infection result in secondary replication at various sites, result in lifelong immunity and include both secretory IgA and serum IgG.
Acute systemic
Examples include measles and smallpox.
Ongoing virus infection and/or replication, usually with mild or inapparent disease in a healthy host. Manifestation of disease is often coincident with immune suppression or other complications.
Chronic viral infection
usually refers to virus infections that continue to produce new virus over a long period of time.
Chronic viral infection, Persistent
refers to virus infection in which the virus genome is relatively silent, there is little gene transcription in most infected cells, and there is little to no disease in a healthy host for a long time, in many cases for life
Latent Chronic viral infection
no symptoms on initial infection, long incubation period, may or may not induce an immune response, and eventual disease is followed by progressive deterioration and death.
Slow Chronic viral infection
Latent virus differs from dead-end infections (those caused by defective virus or which lack the ability to ever produce virus) in that they retain the ability to re-initiate transcription and replication to produce new virus. This process is referred to as:
reactivation or recrudescence.
VZV in nerves
Latent viral infection
Rubella in neonate
Chronic viral infection
Smallpox, measles
Acute Systemic viral infection
Colds, diarrhea
Acute Local viral infection
AIDS, cancer is a _____ virus
slow, progressive
