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1. Adenovirus Presented by:
Mohammad Luqman
Aditya Sarkar
BBT SEM VI
Adenoviridae

4. INTRODUCTION
 Adenoviruses (members of the family Adenoviridae) are medium-
sized (90–100 nm), nonenveloped (without an outer lipid
bilayer) viruses with an icosahedral nucleocapsid containing a
double stranded DNA genome.
 Their name derives from their initial isolation from
human adenoids in 1953.
 Adenoviruses are a group of viruses that can infect the
membranes (tissue linings) of the respiratory tract, eyes, intestines,
urinary tract, and nervous system.
 They are classified as Group 1(dsDNA) in the Baltimore
classification of virus.

5. HISTORY
Dr Trentin
 Adenoviruses were first discovered in 1953 by Wallace Rowe and his
colleagues. They were isolated from adenoid tissue cell culture, hence
the family name of Adenoviridae.
 In 1962, Dr John Trentin and his colleagues showed that human
adenovirus type 12 causes cancer in baby hamsters in a laboratory
setting. This was the first demonstration of oncogenic activity by a
human virus. Since then, adenoviruses have been suspected in inducing
human cancer but have yet to be strongly linked to it.

6. Contd…..
 Experiments involving adenoviruses, which are easy to culture and
work with, have made important contributions to eukaryotic
molecular biology.
 Adenoviruses have helped scientists understand messenger RNA
splicing, alternative polyadenylation, enhancers, and protein
inactivation of tumor suppressor genes.

7. CLASSIFICATION
 Adenovirus can be classified into fives genera that are Genus
Aviadenovirus, Genus Mastadenovirus, Genus Atadenovirus,
Genus Siadenovirus and Genus Ichtyadenovirus.

8. DIVERSITY
 Diversity of adenovirus is very complex. There are 54 types of
human adenovirus comprising of seven species (A to G).
• A: 12, 18, 31
• B: 3, 7, 11, 14, 16, 34, 35, 50
• C: 1, 2, 5, 6
• D: 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30,
32, 33, 36, 37, 38, 39, 42, 43, 44, 45, 46, 47, 48, 49, 51, 53, 54
• E: 4
• F: 40, 41
• G: 52

9. GENERAL
CHARACTERISTICS
Adenoviruses are the group of medium
sized, non enveloped ds larger DNA virus
that share common complement fixing
antigen.
Size: 70-90nm in diameter
Shape: IcosahedralLinear ds DNA molecule of 26-45 kbp
long and DNA have inverted terminal
repeats of approximately 100bp at both
ends.
 Capsid is Icosahedral in shape and is
composed of 292 capsomeres with 20
triangular facets and 12 vertices.
The capsid consists of 240 hexons and
12 pentons.

10. GENOME ORGANISATION
 The length of adenovirus linear genome is between 26 and 45 Kbp and
therefore allows the virus to theoretically carry 22 to 40 genes.
 Generally, this linear virus genome is about 36 Kbp in size and consists
of immediate early (E1A), early (E1-E4), intermediate and late genes
(L1-L5) .
 Transcription of these genes can be divided into early and late phase,
respectively, occurring before or after DNA replication.
 advantageous feature of this viral genome is that it has a terminal 55
kDa protein associated with each of the 5' ends of the linear dsDNA.

11. LIFE CYCLE OF ADENOVIRUS

12. Contd…
 Different steps involved in replication of adenovirus
1) Attachment (Adsorption)
2) Penetration
3) Uncoating
4) Targeting
5) Gene expression.
-synthesis of viral mRNA (transcription)
-synthesis of viral proteins (translation)
6) Genome replication
7) Virion assembly/maturation
8) Release of new infectious virus
-lysis : breakdown of cell membrane and release of virus
-budding: viruses "bud" through cell membrane and are released
without necessarily killing the cell.

13. PATHOGENESIS

14. EPIDEMIOLOGY
 The reservoir for adenovirus is in humans.
 Adenoviruses have a worldwide distribution, and they are ubiquitous in
the environment where contamination of human feces or sewage has
occurred.
 Most adenovirus infections are mild, fatality and a number of sequelae
are associated with immunocompromised patients.
 Adenovirus is a very common infection, estimated to be responsible
for between 2% and 5% of all respiratory infections. All ages are
susceptible to adenovirus infection, but infection usually occurs during
childhood.
 In the winter, adenovirus has caused many cases of illness in military
recruits, with about 25% requiring hospitalization for fever and lower
respiratory tract disease. Some cases result in death.

15. SIGNS & SYMPTOMS
Adenoviruses can cause a wide range of illnesses such as
•Common cold
•Sore throat
•Bronchitis (a condition that occurs when the airways in the
lungs become filled with mucus and may spasm, which causes
a person to cough and have shortness of breath)
•Pneumonia (infection of the lungs)
•Diarrhea
•Pink eye (conjunctivitis)
•Fever
•Bladder inflammation or infection
•Inflammation of stomach and intestines (gastroenteritis)
•Neurologic disease (conditions that affect the brain and spinal
cord)

16. DIAGNOSIS
 Polymerase chain reaction assay
These can be used to identify the viral nuclear material or the viral
DNA. Adenovirus has a double stranded linear DNA genome of
length 36-40 kilo basepairs (kbp).
 Serology tests
These tests utilize measures to assess the levels of the antibodies
that have been generated against an active infection with adenovirus.
 Antigen detection
The adenovirus, like other viruses, contains numerous proteins on its
surface. Within the body these act as antigens against which several
antibodies are formed. This helps the body to fight off an adenovirus
infection

17. TREATMENT
 There is no specific treatment for people with adenovirus infection.
 Some antiviral drugs such as Ganciclovir, Vidarabine, Ribavirin,
Cidofovir won't help adenovirus infections because these drugs
only kill bacteria. Children often get over the illness on their own
within a few days.
 Most adenovirus infections are mild and may require only care and
prevention measures to help relieve symptoms .

18. PREVENTION
 Adenovirus vaccine is for U.S. military recruits entering basic
training only.
 Adenovirus vaccine comes as two tablets, taken orally (by mouth) at
the same time. The tablets should be swallowed whole, not chewed or
crushed.
 It was used by the United States military from 1971 to 1999, but was
discontinued when the only manufacturer stopped production.
 On March 16, 2011, the U.S. Food and Drug
Administration approved an adenovirus vaccine manufactured
by Teva Pharmaceuticals under contract to the U.S. Army.
 In its first year of use, adenovirus vaccine prevented 15,000 cases
of Febrile Respiratory Illness, as evidenced by a reduction in the rate
of Febrile Respiratory Illness that began soon after October 2011.
 There is currently no adenovirus vaccine available to the general
public.

19. Contd...
 Simple steps to protect yourself from Adenovirus infection;
1. Wash your hands often with soap and water.
2. Cover your mouth and nose when coughing or sneezing.
3. Avoid touching your eyes, nose, or mouth with unwashed
hands.
4. Avoid close contact with people who are sick.
5. Stay home when you are sick .