Download presentation

Herpes Viruses
Cytomegalovirus
1
30/11/98
Presentation Outline
Structure
Classification
Multiplication
Clinical manifestations
Epidemiology
Diagnosis
Control
2
30/11/98
Latent Infections
 ALL herpes viruses can establish latent
infections. The viral genome may become
incorporated into the host DNA or remain
extrachromosomal
Latent viruses can be reactivated by stress,
menstruation or uv light
Reactivation may be asymptomatic or lead
to mild or severe disease.
3
30/11/98
Herpes Diagnosis
Isolation of virus by tissue culture
 herpevirinae cause cytopathic effects
intranuclear fluorescence of scrapings using
fluorescent antibodies
PCR being developed
CMV retiniitis is diagnosed clinically
4
30/11/98
Cytomegalovirus
5
30/11/98
Cytomegalovirus
6
Cytopathic effect on the host cell. The cell
swells and a large inclusion body forms in
the nucleus.
Transmission:
not highly infectious, virus found in saliva,
urine and blood.
infants and children acquire CMV from
other children.
congenital. In utero, at birth during perinatal
30/11/98
Disseminated cytomegalovirus
Symptoms:
fever, severe diarrhea, hepatitis, arthritis,
pneumonia, high mortality.
activation of inapparent infection.
also due to:



immunosuppressive therapy.
cancer.
AIDS.
Virus in blood or organ:
7
30/11/98
Epidemiology of CMV
8
whereever human populations tested - high
percentage (40-100%) were positive for the
antibodies.
newborns 7.5% positive in the USA & UK.
woman of child bearing age were 20-100%
positive in many countries that were studied
(pregnant - virus in the urine).
IV drug users were 100% positive for the
antibodies.
30/11/98
Cytomegalovirus - con’t
Laboratory diagnosis:
virus can be grown from all organs.
many serological tests.
Treatment:
gancyclovir, foscarnet, hyperimmune CMV
immunoglobulin, have some effect.
interferon does not prevent infection or
promote recovery.
9
30/11/98
EBV and burkitt’s lymphoma
were shown to be the same virus
when a lab technician acquired
mononucleosis while working
with the Burkitt’s lymphoma
virus.
10
30/11/98
Cytomegalovirus
Urine isolate
11
30/11/98
Intranuclear inclusions
The cell swells
and a large
inclusion body
forms in the
nucleus.
12
30/11/98
Cytomegalovirus
Nuclear & cytoplasmic inclusions
13
30/11/98
Transmission: CMV
not highly infectious, virus found in saliva,
urine and blood.
infants and children acquire CMV from
other children.
congenital. In utero, at birth during perinatal
period.
14
30/11/98
Congenital: CMV
15
the following possibilities relate to the
congenital type.
severe deformities and death.
survive with serious defects - physical and
mental.
survive with out deformities.
newborns: - Enlarged liver and spleen,
jaundice, capillary bleeding, microcephaly,
ocular inflammation.
30/11/98
Disseminated
cytomegalovirus
fever, severe diarrhea, hepatitis, arthritis,
pneumonia, high mortality.
activation of inapparent infection.
also due to:
immunosuppressive
therapy.
cancer.
AIDS.
16
30/11/98
Virus in blood or organ:
post transfusion.
post organ transplant.
17
30/11/98
Cytomegalovirus mononucleosis:
teenage, young adult similar to other mono.
18
30/11/98
Epidemiology of CMV
 high percentage (40-100%) were positive for the
antibodies.
newborns 7.5% positive in the USA & UK.
woman of child bearing age were 20-100% positive
in many countries that were studied (pregnant virus in the urine).
IV drug users were 100% positive for the
antibodies.
homosexual males were 30% positive for the
antibodies - high percentage shed virus.
19
30/11/98
Transmission:
saliva, respiratory mucus, milk, urine,
semen, cervical secretions, feces and
lymphocytes.
20
30/11/98
Differential Diagnosis:
the differential diagnosis in neonates must
include toxoplasmosis, rubella, herpes
simplex, bacterial sepsis.
in adults it must be differentiated from
Epstein-Barra and hepatitis A & B.
21
30/11/98
Laboratory diagnosis: CMV
virus can be grown from all organs.
many serological tests.
22
30/11/98
Treatment: CMV
gancyclovir, foscarnet, hyperimmune CMV
immunoglobulin, have some effect.
interferon does not prevent infection or
promote recovery.
23
30/11/98
Prevention:CMV
no animal can be found that can be infected
with CMV.
Two deterents:
vaccine stimulated antibodies may not be
protective. Patients already seropositve can
be reinfected.
a vaccine could be oncogenic.
24
30/11/98