Herpeseviruses (CMV, EBV, VZV, HHV-6, HHV-8) Flashcards
unique contents of CMV tegument
carries mRNA and pp65(diagnostic protein)
interesting that it is a dsDNA virus, but carries mRNA
VZV tropism
permissive in mucoepithelial cells(skin)
latent in neurons
malignancies caused by EBV
Burkitt’s lymphoma
nasopharyngeal carcinoma
post-transplant lymphoproliferative disorder
some hodgkins lymphomas
treatment for HHV-6
ganciclovir, foscarnet
indicated for exanthem subitum(roseala)
clinical manifestation of VZV(reactivation)
complications?
shingles/zoster
VZV reactivates from latent DRG; vesiculopapular rash in dermatomal distribution
complications:
- ramsey-hunt syndrome(reactivation from geniculate ganglion) - vesicles in external auditory meatus
- guillan-barre syndrome: ascending bilateral paralysis;
shingles complications in immuncompromised
pneumonitis, hepatitis, meningoencephalitis
longer lasting rash and dissemination
describe the tropism of CMV during:
permissive
latent
and persistent infections
permissive = epithelial cells, fibroblasts, macrophages
latent = infects hematopoeitic cells
persistent = lymphocytes, endothelial cells, BM stroma
treatment/prophylaxis for CMV
specific treatment for CMV pneumonitis, retinitis
ganciclovir(BM toxicity)
foscarnet(renal toxicity)
hyperimmune globulin w/ganciclovir OR foscarnet for CMV pneumonitis in BMT pts
valganciclovir for retinitis
clinical manifestation of HHV-8
kaposi’s sarcoma
primary effusion lymphoma - b lymphocyte infection
multicentric calstleman’s disease - b cell lymphoma
lymphotrophic AND angiotrophic herpesevirus
HHV-8
kaposi’s
treatment for VZV
for chickenpox: acyclovir (use IV is immunocompromised)
for shingles, can bump it up to famciclovir, valacyclovir(still use IV for immunocompromised)
HHV-8 transmission, treatment
sexually transmitted
ganciclovir, valganciclovir, foscarnet
clinical manifestation of VZV(primary)
complications?
chickenpox - resp. tract infected; spread to blood/lyph; eventually reticuloendothelial cells; then skin
complications: acute cerebellar ataxia, meningoencephalitis, pneumonitis, hepatitis
- reyes syndrome: kids taking aspirin during chickenpox; fatty liver and encephalopathy
neurotropic herpesviruses
HSV-1, HSV-2, VZV
describe permissive, latent, persistent infections
permissive = lytic; producing infectious viral progeny
latent = silent genome persistence; nonlytic
persistent = low lvl of viral prgeny, nonlytic on cell level
CMV diagnosis
shell rapid CMV culture(uses IE and E antigens, pp65) - 12-24hrs
owl’s eye cell - cytomegalic inclusions
clinical manifestation of EBV?
manifestations of EBV in immunocompromised ?
- heterophile positive mononucleosis; virus in saliva, kissing disease
- autoimmune disease(ITP, hemolytic anemia)
- RASH w/AMPICILLIN; mono has exudative pharyngitis, making it look like GAStrep infection; Ampicillin is perscribed and if a rash forms, EBV is almost pathopneumonic
Immunocompromised
- post transplant lyphoproliferative disorder - solid organ and BMT recipients
- hairy oral leukoplakia - white patches on lateral surface of tongue in AIDS pts
- Burkitt’s lymphoma
prophylaxis for EBV
acyclovir, ganciclovir, valganciclovir
manifestation of CMV in immunocompetent, immunocompromised
immunocompetent: 80-90% asymptomatic - heterophile negative mononucleosis - idiopathic thrombocytopenic purpura
hemolytic anemia
immunocompromised: primary OR reactivated -
- retinitis(especially AIDS)
- pneumonia(especcialy BM recipients)
- hepatitis, gastroenteritis, glomerulopathy
- disseminated disease
tissue tropism for EBV
permissive and latent infections pursue lymphocytes(mostly B), and oral/nasopharyngeal epithelium
leading infectious cause of birth defects in US
cytomegalovirus
clinical manifestation of HHV-6
exanthem subitum: roseola rash(fever then maculopapular rash)
heterophile negative mononucleosis(like CMV)
BM suppression; delayed engraftment in BMT recipients
how does CMV evade immune system?
downregulation of MHCI,II antigens
inactivation of interferon genes
general structure of herpesviruses
enveloped dsDNA w/icosahedral, capsule, tegument, and IE, E and L proteins
lymphotrophic herpesviruses
EBV, CMV, HHV6
maculopapular rash, causes of ITP, mononucleosis w/atypical lymphocytosis
