Micro: Ryan/Whitt Flashcards
parvovirus B19
FIFTH DISEASE
non-enveloped, ssDNA
S PHASE replication: RBC PRECURSORS
transmission: respiratory, percutaneous through blood, mother to fetus: vertical transmission
human herpes virus 6 & 7
ROSEOLA
enveloped, large dsDNA
complications due to long-term latent infection if become immunosuppression (STEM CELL TRANSPLANT recipients): brain, lung, heart, kidneys, GI; COGNITIVE DYSFUNCTION, permanent disability and death
paramyxovirus
MEASLES, MUMPS
enveloped, large -ssRNA
togavirus
RUBELLA
enveloped, +ssRNA
Sx: mild, MORBILIFOM rash (maculopapular) on FACE that spreads to rest of body, low fever, conjunctivitis, sore throat, LAD
transmission: aerosol
isolate: stool, nasopharynx
viral shedding: continues after rash disappears
CONGENITAL BIRTH DEFECTS: 1st and 2nd trimester: retardation, motor disability, hearing loss, congenital heart disease, cataracts, BLUEBERRY MUFFIN rash
picronovirus (enteroviruses)
COXSACKIE A, ECHO, ENTEROVIRUSES
non-enveloped, +ssRNA
differentiate from rhinovirus: acid stability, less stringent growth requirement (human and primate cell lines, grows well at 37 C)
HUMANS only known reservoir
oral-fecal route, fomites
lymphoid replication: URT, tonsils, lymph nodes, Peyer’s patches, small intestine; followed by viremia and infects spinal cord, brain, meninges, myocardium, skin
isolated: throat culture
Coxsackie A
HAND, FOOT, MOUTH DISEASE
HERPANGINA
Sx: asymptomatic is common
MENINGITIS
ECHO
transient, non-descript rash
MENINGITIS
Enteroviruses
asymptomatic, self limiting (Polio is exception)
seasonal: summer and fall
measles
paromyxovirus: Morbilivirus genus
MV receptors: CD46, SLAM, NECTIN-4
H and F proteins (persistent CNS infection)
intracellular INCLUSION bodies
requires population greater than 100,000: under-vaccination, reservoir of susceptible individuals
respiratory route: extremely contagious
Sx: 10-14 days latent, HIGH FEVER, generalized RASH (T CELLS attack measles virus-infected vascular ENDOTHELIAL cells), COUGH, CORYZA, CONJUNCTIVITIS (PHOTOPHOBIA), MACULOPAPULAR RASH (cell mediated immune response and virus clearance); KOPLIK spots
mortality: bacterial pneumonia
MUST REPORT
LIFE-LONG immunity
Koplik spots
ONLY in measles
small abruption with blue-white centers in mouth
right before rash
MIBE
measles inclusion body encephalitis
result from persistent MV infection in brain
SSPE
subacute sclerosing panencephalitis
result from persistent infection in brain (years)
ADEM
acute disseminated encephalomyelitis
autoimmune demyelinating disease
against MYELIN BASIC PROTEIN
convulsions, deaf, retardation
PIE
postinfectious encephalomyelitis
autoimmune demyelinating disease
against MYELIN BASIC PROTEIN
convulsions, deaf, retardation
measles virus eradication
immunization: one serotype, clinical identifiable, no animal reservoir
requires HERD IMMUNITY
1963-67 vaccine not effective
MMR vaccine
mumps, measles, rubella
live, attenuated: life long immunity
SC
MMR at 12-15 months, 4-6 years 2nd dose; do not start before 6 months (mom Ab make vaccination incomplete)
vaccine effectiveness: ANTIGENICALLY STABLE MONOTYPIC VIRUSES
post exposure: MMR vaccine within 72 hrs of exposure or Ig within 6 days
only HUMANS have these viruses
CI: allergy to eggs, pregnancy, immunodeficient
MMRV (varicella): more AE
complication of measles
IMMUNE SUPPRESSION for a month after onset of rash (type IV hypersensitivity suppressed: TB), production of Ab and cell-mediated antigens suppressed (monocyte infection)
neuro: ADEM, PIE, MIBE, SSPE
Coxsackie B
pleurodynia, myocarditis, pericarditis