useful information about adenovirus

1. By: Miriam Ramez

2. Causes a variety of upper and lower
respiratory tract diseases such as:
 Pharyngitis
 Conjunctivitis (pink eye)
 Common cold
 Pneumonia
 Keratoconjuctivitis
 Haemorrhagic cystitis
 Gastroenteritis
 Cancers in rodents but not in humans

5. Important properties:
Medium-sized (90-100nm)
Non-enveloped (largest)
Double stranded linear DNA
Icosahedral nucleocapsid
Only virus with a fiber protruding from each of
the 12 vertices of the capsid.
Fiber is organ of attachment and is a
hemagglutinin (main type specific antigen)
All have a common group antigen located on
hexon protein
41 antigenic types

7. Summary of replicative
cycle:
 Virus attaches to cell surface via its fiber.
 The virus enters the cell and uncoats.
 Viral DNA moves to the nucleus.
 Host cell DNA-dependent RNA polymerase transcribes
early genes, splicing of introns producing a functional
mRNA.
 Early mRNAs is translated into non-structural proteins
in the cytoplasm.
 After DNA replication in nucleus, late mRNA is
transcribed and translated into structural virion
proteins.
 Viral assembly occurs in nucleus, and virion released
by lysis of cell

8. Transmission:
1)Aerosol droplets.
2)Fecal-oral route.
3)Direct inoculation of conjunctivas by
tonometer or fingers.

9. Epidemiology:
o In military due to close contact.
o Adenovirus infection typically affects
children from infancy to school age.
o Serotypes 3,4,7,21 causes respiratory
disease.
o 8,19 causes keratoconjuctivitis.
o 11,21 causes haemorrhagic cystitis .
o 40, 41 causes infantile gastroenteritis.

10. Pathogenesis and immunity:
Infect mucosal epithelium of several
organs of the upper and lower
respiratory tract, gastrointestinal tract,
and conjunctivas.
Immunity is based on neutralizing
antibody is type-specific and life long.
Latent infection occurs particularly in
adenoidal and tonsillar tissues of
throat.

11. Clinical findings:
 Upper respiratory tract: pharyngitis,
pharyngoconjunctival fever, and acute
respiratory disease characterized by fever,
sore throat, coryza(runny nose), and
conjunctivitis.
 Lower respiratory tract: bronchitis and
atypical pneumonia.
 Haemolytic cystitis: haematuria and dysuria
 Gastroenteritis with non-bloody diarrhea
mainly in children younger than 2 years of age
 Most infections resolve spontaneously and half
of them are asymptomatic.

12. Diagnosis:
Isolation of virus in cell culture.
Detection of four fold increase in
antibody titer.
Complement fixation and
hemagglutinin inhibition are most
important for serologic tests.

13. Treatment and prevention:
 No antiviral treatment, only
symptomatic.
 3 live non-attenuated live
viruses against serotypes 4,
7, and 21.
 Administered separately
because they interfere with
each other when given
together.
 Vaccines delivered in an
enteric coated capsule which
protects live virus from
inactivation by stomach acid.

14. References:
Clin Microbiol Rev. 2014 Jul;
27(3): 441–462.PubMed.
http://kidshealth.org/parent/infe
ctions/lung/adenovirus.html#
http://www.cdc.gov/adenovirus/
about/transmission.html