Please enable JavaScript.
Coggle requires JavaScript to display documents.
Micro - Herpes Viruses (iii) (CMV (congenital CMV (10-15% of those…
Micro - Herpes Viruses (iii)
CMV
enlarged cells with 'owls-eye' inclusion bodies
primary infection
typically mild/asymptomatic, esp in young children
can uncommonly cause infectious mononucleosis-like syndrome
acquired from most bodily fluids (saliva, breastmilk, urine, blood) + tissues (beware in transplants)
latent in lymphocytes + reactivates in immunosuppressed
source of complicated infections
retinitis in HIV patients with low T cell count
colitis (most common) + pneumonitis in transplant patients
Tx: reduce immunosuppression in transplants, increase ART in HIV
congenital CMV
big concern
due to primary infection in pregnancy
only 10-15% symptomatic @ birth
1% of newborns infected @ birth
small size, microcephaly, intracerebral calcifications, chorioretinitis, encephalitis, jaundice, hepatosplenomegaly, rash, thrombocytopenia, unilateral/bilat deafness
10-15% of those asymptomatic @ birth fo on to develop sensorineural deafness / developmental delays
the later in pregnancy mam was infected, the later the deafness occurs
Lab Dx
PCR = gold-standard
blood for immunocompromised
urine/saliva for congenital infection
can also quantitatively measure response to TX
Serology
IgG + IgM
avidity testing (strength of IgG binding)
low: primary
high: recurrent
beware of false -ves in immunocompromised
histology for colitis
Prevention
no vaccine or maternal screening
suspected neonates screened @ birth
must test organ + blood donors
if not possible to find a CMV -ve donor for a CMV -ve recipient transplant CMV +ve organ + give prophylactic ganciclovir or IgG
don't share soothers' cups with babies (CMV in saliva)
EBV
95% of people are IgG +ve
often asymptomatic primary infection occurs in childhood
primary infectious in adolescents/young adults = infectious mononucleosis (aka glandular fever/kissing disease)
fever, fatigues, exudative pharyngitis, sore throat, lymphadenopathy, hepatosplenomegaly, hepatitis
disseminated rash can occur after ampicillin Tx if misdxed as GAS
transmission via saliva (close oral contact)
dDx: CMV, HIV, toxoplasmosis parasite
lab Dx
serology
heterophile Ig/monospot/Paul Bunnell test
cheap
cross reacting Igs cause horse/sheep RBCs to agglutinate
detectable @ end on 1st wk
10% of -ves are false
IgM detectable 1st, then anti-VCA (viral capsid antigen) IgG, then EBNA (ebstein barr nuclear antigen) after 4-6 wks
blood film (atypical lymphocytes)
PCR not routine
Latent in B cells
stims them to prolif indefinitely (useless as T cells are needed against viruses)
impaired T cell immunity results in EBV-associated malignancies...
Burkitt's lymphoma
poorly differentiated
swelling in face/jaw
endemic in parts of Africa (thought to be due to interaction between EBV + malaria)
Hodgkin's lymphoma
NP carcinoma
post-transplant lymphoproliferative disease (PTLD)
treatable
when EBV acquired post-transplant
T cell lymphomas
oral hairy leukoplakia
opportunistic infection of oral epithelium
lesions in mouth during EBV/HIV infection