infectious diseases- pathogens Flashcards
organism that is capable of causing disease
pathogen
causes disease in a healthy population
high virulence
causes diseases only in susceptible populations
low virulence
opportunistic infection
-non-pathogenic organism
-low virulence
-immunocompromised host
-interaction between two organisms
-both organisms benefit
mutualism
-interaction between two organisms
-one organism benefits and other is neither harmed nor helped
(c. albicans)
commensalism
how do pathogens injure cells and cause tissue damage?
-bindt 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
pathogens:
- viruses
- bacteria
- fungi
also
-prions
-chlamydia
-mycoplasma
-protozoa
-helminths
-ectoparasites
-rickettsia
3 general principles of viral infections:
- intracellular parasites
- cell type specific
- viral latency
-virus is a nucleic acid looking for a home
viral infection and replication steps:
- attach
- penetrate
- reproduce
- assemble
- release
4 types of viral infections with virus
- transient infections
-hepatitis a virus - chronic latent infetions
-herpes simplex virus - chronic productive infections
-hepatitis b virus - transforming infections
-epstein barr virus, human papilloma virus
-humans are natural reservoir
-latency
-reactivation
human herpes virus (HIV)
human herpes virus
HHV-1
HHV-2
HHV-3
HHV-4
HHV-5
HHV-8
HHV-1- herpes simplex virus type 1
HHV-2- herpes simplex type 2
HHV-3- varicella zoster virus
HHV-4- epstein barr virus
HHV-5- cytomegalovirus
HHV-8- kaposi sarcoma associated virus
transmission of HSV
-contact with affected individual shedding virus
-symptomatic active lesions
-asymptomatic viral shredding
herpes simplex virus type 1 is mostly
oral infections
herpes simplex virus type 2 is mostly
genital infections
-initial exposure to virus in an individual without immunity
primary infections with herpes simplex virus
generally occurs at young age after physical contact with infected individual
primary infection with herpes simplex virus
mostly subclinical disease
80% of US population has antibodies to HSV
primary infection with herpes simplex virus
flu-like illness with fever, malaise, arthralgia, headache
-eryhtema orally and small clusters of ulcerations/large
IF YOU HAVE COLD SORES=you have herpes
-cervical lymphadenopathy
primary herpetic gingivostomatitis
reactivation of herpes
recurrent herpes
(like recurrent herpes labialis -on lip, or recurrent intra-oral herpes)
herpes simplex virus infection can cause infection after what nerve
trigeminal ganglion