W06_02 Herpesviridae virology Flashcards
what is tegument?
between envelope and capsid of a virus; like the cytoplasm of cells
which of the 8 herpesviridae are airborne?
only VZV
why don’t herpesviridae transfer via fomites readily?
survival in environment is unlikely due to envelope destruction
note 4 out of 5 people with genital herpes hasn’t been diagnosed
3/5 have symptoms that are unrecognized as herpes!
what percentage of primary herpes infections are symptomatic?
10-15%
hsv-1 mostly affects where?
lips
hsv-2 mostly affects where?
genitals
corneal keratitis is caused by which herpes?
hsv-1
note: hsv-2 is more persistent and more highly recurrent than hsv-1
okay
is there an IgM test for herpes?
no
how can you distinguish herpes primary infection from recurrence?
you can’t
what drugs can you take for herpes?
acyclovir, famciclovir, valacyclovir;
note these have to be taken within 3 hours of initial herpes attack
when’s the infectious period of VZV?
2 days BEFORE symptoms to full crusting
what is the longterm consequence of VZV?
it lies latent in the nerve root ganglia (DRG); can come out as shingles with 30% chance
how does shingles/zoster present?
it’s latent in the DRG, so will have dermatomal distribution
effects of congenital vzv infection?
CNS retardation, muscular atrophy, limb hypoplasia
where does shingles present the most?
on the chest
how to diagnose vzv?
can use IgM for acute, IgG for immune status;
EM or immunofluorescence;
isolation - vesicular fluid
how to prevent vzv post-exposure?
give varicella zoster immunoglobulin (VZIG) within 96 hours of exposure
what kind of vaccine is the varicella vaccine?
live, attenuated vaccine that causes an antibody response in 95% of people
what kind of vaccine is the zoster vaccine?
live, attenuated vaccine that prevents shingles in 50% of people. give to elderly >50
what does HHV-6 do?
causes roseola infantum, with feverx3d, then rash. treated symptomatically. not really diagnosed in lab
what’s epstein barr virus?
causes “infectious mono”. 4-7 incubation. associated with burkitt’s lymphoma and naso-pharyngeal carcinoma
how to diagnose EBV?
can’t diagnose but can PCR for monitoring immunocompromised patients
how to treat for EBV?
no vaccine. protect spleen from trauma.
symptoms of cytomegalic inclusion disease?
jaundice, hepatosplenomegaly, petechial rash, microcephaly, cerebral calcifications, chorioretinitis
what can you use to diagnose CMV infection?
the whole range of tests - culture, EM, immuno, PCR, serology
what’s the treatment for CMV?
none for normal people.
ganciclovir or foscarnet for immunocompromised
what does HHV-8 cause in healthy people?
febrile exanthem and maybe mono. it causes kaposi’s sarcoma in immunocompromised hosts
how to diagnose HHV-8 infection?
biopsy of skin lesion - can test that.
can’t PCR blood because low viral titres. serology not always available
