Infectious Disease Flashcards
what is a pathogen
organism capable of causing disease
what does high virulence cause
disease in a healthy population
what does low virulence cause
disease only in susceptible populations
describe an opportunistic infection
- non pathogenic organism
- low virulence
- immunocompromised host
describe mutualism
- interaction between two organisms
- both organisms benefit
describe commnsalism and give an example
- interaction between two organisms
- one organism benefits
- other is neither harmed nor helped
- ex: C. albicans
how do pathogens injure cells and cause tissue damage
- bind to or enter host cells
- release endotoxins or exotoxins
- release enzymes that degrade tissue components
- damage blood vessels and cause ischemic injury
- induce host inflammatory and immune responses
what are the general principles of viral infections
- intracellular parasites
- cell type specific
- viral latency
what is a virus made off
nucleic acid
what are the steps in viral infection and replication
- attach
- penetrate
- reproduce
- assemble
- release
what are the types of viral infections
- transient infections
- chronic latent infections
- chronic productive infections
- transforming infections
what is an example of a transient infection
hepatitis A virus
what is an example of a chronic latent infection
herpes simplex virus
what is an example of a chronic productive infection
hepatitis B virus
what is an example of a transforming infections
Epstein Barr Virus, Human Papilloma Virus
what are the resevoir of human herpes virus
humans
what are the periods of HHV
latency
- reactivation
what is HHV-1
herpes simplex virus Type 1
what is HHV-2
herpes simplex virus type 2
what is HHV-3
varicella zoster virus
what is HHV-4
epstein barr virus
what is HHV-5
cytomegalovirus
what is HHV-8
Kaposi Sarcoma associated virus
what is the transmission of HSV
- contact with affected individual shedding virus
- symptomatic active lesions
- asymptomatic viral shedding
what is another name for HHV -1
-herpes labialis
- fever blister
- cold sore
describe the lesions in HHV-1 and common location
start as vesicles then rupture and turn into ulcers
- mostly oral infections
where are HSV-2 infections located
mostly genital infections
what is a primary infection with herpes simplex virus and what age does it occur with
- initial exposure to virus in an individual without immunity
- occurs at young age after physical contact with infected individual
what percentage of population of US has antibodies to HSV
80%
describe the presentation of primary herpetic gingivostomatitis
- flu like illness with fever, malaise, arthralgia, headache
- cervical lymphadenopathy
what tissues in the oral cavity are affected in primary herpetic gingivostomatitis and primary infection with herpes simplex virus
all tissues in the oral cavity
where do recurrent herpes labialis occur and what is the presentation
- anywhere
- patient will be sick and have systemic signs
where do recurrent intra oral herpes occur and give examples of the tissues it would be on
- on bound down mucosa
- on keratinized mucosa
- on nonmovable tissues
- ex: hard palate and attached gingiva
where does the herpes simplex virus stay dormant in its latent phase
trigeminal ganglion