Chapter 16+23 Flashcards
infectious mononucleosis is caused by:
Epstein-Barr virus
infectious mononucleosis
affects B cells in lymph nodes and spleen
can remain a carrier for several months, years
infectious mononucleosis complications
heart defects, facial paralysis, rupture of spleen, jaundice
monospot test
(heterophile antibody test)
diagnosis for infectious mononucleosis
agglutination = presence of antibodies against EBV
lymphocytosis
diagnosis for infectious mononucleosis
observation of elevated lymphocyte levels
cytomegalovirus (CMV)
a herpes virus
causes cytomegalic inclusion disease (CID) - generalized infection of infants; gastroenteritis and blindness
hepatitis B virus (HBV)
DNA virus - unusual genome; one complete strand, one incomplete
enveloped
causes fever, nausea, anorexia, then jaundice
HBV transmission
direct or indirect contact with bodily fluid
HBV antigens (3)
HBsAg - surface antigen
HBcAg - core antigen in capsid
HBeAg - soluble antigen; best indicator of transmissibility
HBV vaccine
HBsAg recombinant DNA-derived vaccine
produced in yeast cells
HBV incubation period
long - 1-6 months in the liver
HBV carrier rate
5%
HBV treatment
interferon for chronic infection
hepatitis C virus (HCV)
most common bloodborne infection in US
causes a mild, symptomless, chronic infection involving cirrhosis and other complications
HCV carrier rate
80-90%
HCV transmission
through blood
HCV treatment
combination of interferon and ribavirin
hepatitis D virus (HDV)
“piggyback” virus (incomplete) - can only cause infection with HBV; needs HBsAg
RNA virus
hepatitis A virus (HAV)
causes an acute inflammatory liver disease
HAV transmission
by GI tract
food or water contaminated by feces
raw shellfish
hepatitis E virus (HEV)
very similar to HAV, but not usually found in the US
West Nile fever
emerging disease in Western hemisphere
causes mild fever, aches, fatigue - sometimes leads to encephalitis or meningitis
West Nile virus transmission
through mosquitoes
West Nile virus reservoirs
birds, mosquitoes, humans, some other mammals
viral gastroenteritis
caused by several unrelated viruses
rotavirus infection
deadly form of gastroenteritis in children
diarrhea
rotavirus transmission
contaminated food or water
rotavirus treatment
oral rehydration therapy
norovirus infections
common cause of nonbacterial gastroenteritis
causes dehydration
highly contagious
norovirus transmission
fecal-oral route, person-to-person contact, fomites
can survive outside the body for a long time
Coxsackie virus
causes hand, foot and mouth disease - fever, poor appetite, sore throat, rash on palms and feet
rabies virus
bullet shaped
causes fever, headache, muscle tension, hydrophobia, aggression, paralysis, brain degeneration
rabies transmission
through skin wound contaminated with bodily fluid of an infected animal
rabies incubation period
varies from 6 days to a year - depends on location of entry and amount of virus entering
rabies treatment
post-exposure immunization - immediately after bite
need to get both passive and active
passive: gamma globulins (blood plasma)
active: attenuated virus
poliovirus
causes poliomyelitis - infection of gray matter of spinal cord and brain
poliovirus transmission
contaminated food and water
poliovirus multiplies in:
tonsils, lymph tissue, GI tract
postpolio syndrome
occurs in individuals who had the disease decades ago
polio vaccine
Jonas Salk vaccine - inactive
Sabin vaccine - live, attenuated
viral hemorrhagic fever (VHF) viruses
all RNA viruses, all enveloped
not naturally found in humans
damage endothelial cells, causing massive internal bleeding and hemorrhaging
50-90% mortality rate
chikungunya
newly emerging hemorrhagic fever
means “to walk bent over” - severe joint pain
fever, headache, fatigue, nausea, muscle pain, skin rash
spreads through blood to liver, muscles, brain, lymph tissue, joints
by mosquitos
human immunodeficiency virus (HIV)
positive RNA virus - two identical strands, not double stranded
enveloped
a retrovirus
HIV spikes
gp120 - attachment protein
gp41 - fusion protein
gp120
HIV spike
attachment protein - binds to CD4 receptor protein of (usually) T cells
gp41
HIV spike
fusion protein - helps virus fuse with host cell membrane
chemokine receptor
co-receptor with CD4 for gp120
HAART
highly active antiretroviral therapy - for those with HIV
combination of 3 anti-HIV agents: 2 nucleoside reverse transcriptase inhibitors and 1 protease inhibitor
prolongs and improves life, reduces viral load
does not cure HIV infection
nucleoside reverse transcriptase inhibitor
drug used in HAART
chain terminators, stops DNA replication
protease inhibitor
drug used in HAART
prevents protease, enzyme that cuts capsomeres into right lengths
infectious mononucleosis transmission
saliva - “kissing disease”
ribavirin
used with interferon against HCV
a nucleoside analog - inhibits synthesis of viral nucleic acid
