Cytomegalovirus

Question 1

What is the family?

Answer 1

Herpesvirus

Question 2

What are the clinical presentations?

Answer 2

1. Congenital CMV infection
2. Cytomegalic inclusion disease
3. Postnatal hepatitis
4. Infectious mononucleosis syndrome
5. Infection in immunocompromised host
6. Guillain-Barre syndrome

Question 3

What does cytomegalic inclusion disease cause?

Answer 3

• Severe generalised CMV infection of infants
• Intrauterine or perinatal infection
• Jaundice, hepatosplenomegaly, interstitial pneumonitis, thrombocytopenia, haemolytic anaemia
• Neurological sequelae (microcephaly, periventricular calcification, chorioretinitis, optic atrophy, mental retardation, spasticity, epilepsy)
• Affected organs show enlarged cells with large intramuscular owl eyes inclusion

Question 4

What does infectious mononucleosis syndrome cause?

Answer 4

Clinically similar to glandular fever but less pharyngitis and lymphadenopathy
Mild hepatitis

Question 5

Which groups of immunocompromised hosts get infected?

Answer 5

Cytotoxic, radiotherapy, cancer, organ transplantation, AIDS

Question 6

What does infection of immunocompromised hosts cause?

Answer 6

CMV pneumonitis, hepatitis, disseminated CMV (fever, leucopaenia, pneumonitis, hepatitis, colitis, retinitis)

Question 7

How to diagnose?

Answer 7

1. Virus isolation
   - from urine, throat swab into human cell culture (slow characteristic CPE of foci of swollen cells and intramuscular owl’s eye inclusions after 2-3 weeks)
2. Viral detection
   - Desquamated cells in urinary sediment
   - Owl’s eye inclusion
   - Viral antigen, DNA
3. Serology (IgM and IgG)
4. Immunology
   - Antibodies in most humans except young children without CMV
   - CMV secreted in urine even in presence of serum neutralising Ab

Question 8

How to treat?

Answer 8

Ganciclovir for life-threatening CMB infections (retinitis, colitis, pneumonitis in immunocompromised patients)

Question 9

What is the mode of transmission?

Answer 9

Close contact (urine-hand-mouth, sex)
Blood transfusion
Organ transplantation
Transplacental

Question 10

What is the pathogenesis?

Answer 10

Usually asymptomatic in healthy hosts (>50% of adults have CMV Ab)
Subclinical infection is followed by latent infection in various tissues (circulating leucoytes)

Question 11

How to control?

Answer 11

• Isolation of newborns with severe CMV infections
• Screening of organ and blood donors and recipients
• CMVIG prophylaxis in CMV-seronegative organ recipients receiving organs from seropositive donors