Mcb 3 Flashcards
(20 cards)
What is HSV-1 commonly responsible for?
Cold sores
HSV-1 typically causes lesions at the lip or mouth.
What is HSV-2 commonly responsible for?
Genital herpes
HSV-2 is primarily associated with genital infections.
How may primary HSV infections manifest?
Asymptomatic or rarely as systemic disease
In immunocompromised hosts, systemic disease can develop.
Where do latent infections of HSV occur?
In nonreplicating state in ganglia
Oropharyngeal HSV-1 in trigeminal ganglia; genital HSV-2 in sacral ganglia.
What can reactivate HSV from its latent state?
Provocative stimuli such as fever and emotional stress
Over 80% of humans may manifest cold sores as a result.
What type of infections does HSV cause?
Cytolytic infections
Pathologic changes are due to necrosis of infected cells and inflammatory response.
What are the routes of HSV transmission?
Contact with excreting individuals or droplets via mucosal surfaces or broken skin
HSV-1 is usually limited to the oropharynx; HSV-2 is transmitted by genital routes.
What occurs during HSV replication?
Viral replication occurs at the site of infection and then invades local nerve endings
It is then transported to dorsal root ganglia for latency establishment.
What are the types of proteins involved in HSV replication?
α, β, and γ proteins
α and β are mainly enzymes or DNA-binding proteins; γ are structural proteins.
What is keratoconjunctivitis?
A condition caused by HSV-1 infections in the eye
It can lead to inflammation and damage to the eye.
What is neonatal herpes?
HSV infection of the newborn
It may be acquired in utero, during birth, or after birth and can be severe.
What severe condition can HSV-1 cause in adults?
Encephalitis
It has a high mortality rate and can lead to residual neurologic defects.
What laboratory methods are used for HSV diagnosis?
Cytopathology, virus isolation, PCR, and serology
Antibodies appear 4–7 days after infection and peak in 2–4 weeks.
What are common antiviral drugs for treating HSV?
Acyclovir, valacyclovir, and vidarabine
Acyclovir is the standard therapy for HSV.
What happens to host molecular synthesis during HSV infection?
It is shut off early in infection
Cellular DNA and protein synthesis virtually stop as viral replication begins.
What is the classification of herpes viruses?
α, β, and γ subfamilies
Each subfamily has distinct characteristics and types of viruses.
What is the genome structure of herpes viruses?
Double-stranded DNA
The size of the genomes varies among different herpes viruses.
What is a characteristic of the envelope of herpes viruses?
Acquired during budding from the nuclear membrane
The envelope contains glycoproteins essential for infection.
True or False: Herpes viruses establish latent infections.
True
This is a key characteristic of herpes viruses, allowing them to persist in hosts.
Fill in the blank: The name herpes comes from the Latin word _______.
herpes
It reflects the creeping or spreading nature of skin lesions.
