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Epstein-barr Virus, HHV-6, AND HHV- 7

Cytomegalovirus

Herpesviridae

200 mm in diameter

Double stranded DNA icosahedral capsid

Lipid-containing envelope (acquired from host cell nuclear membrane or cytoplasmic vacuoles)

Fusion: envelope glycoproteins and cell surface proteins

Cytomegalovirus Epidemiology

Present in all areas of world

No seasonal variation

No non-human vectors (human CMV)

Acquisition occurs at an earlier age in underdeveloped countries

Day-care and increased breast feeding has increased infection in younger children in developed countries

Most common cause of congenital infection in the United States

Cytomegalovirus Transmission

Direct or indirect person-to-person contact

Requires close or intimate contact with infected secretions:

Virus excretion persists for years

·Cytomegalovirus Perinatal Transmission

Cytomegalovirus Clinical SyndromesIcon

Asymptomatic

_ Congenital infection

_ Neonatal infection in premature infants

_ Mononucleosis syndrome

_ Immunosuppressed patients

Congenital infectionIcon

_ Intrauterine transmission

_ Maternal immunity (prior infection) affords protection (humoral ± cellular)

_ Effect of gestational age (primary infection)

- the earlier in gestation, the greater chance for severe sequela

_ Organs involved

- sensorineural deafness

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