Adenoviruses are non-enveloped DNA viruses that commonly cause respiratory illness. There are multiple serotypes that can cause pharyngitis, conjunctivitis, or pneumonia. Adenoviruses are transmitted through direct contact or respiratory droplets. Laboratory diagnosis involves virus isolation in cell culture or PCR detection of viral DNA. There is no vaccine or antiviral treatment available.

1. SPACE VEHICLE
APPEARENCE
ADENOVIRUSES

2. DNA VIRUSES
All are DS except Parvoviridae
All replicate in the nucleus except Poxviridae
Icosahedral Complex
1- Poxviridae
Naked Enveloped
non-enveloped
1- Parvoviridae 1- Herpesviridae
2- Papillomaviridae 2- Hepadnaviridae
3- Adenoviridae

3. DNA viruses first isolated from adenoidal tissue in 1953
Family Adenoviridae
Genus Mastadenovirus

4. Morphology
• Non-enveloped, 70-90nm in size.
• Capsid is icosahedral, comprised of 252
capsomeres -240 are hexons and 12 pentons at
the vertices.
• Each penton has a projecting fiber with a
terminal knob. Together, this complex is toxic
to cells, causing rounding and death of cells
through inhibition of protein synthesis.
• The fiber proteins determine target cell
specificity.
• Genome is made of linear double-
stranded (ds) DNA

5. CLASSIFICATION
• Family Adenoviridae : 2 genera
– Aviadenovirus : adenoviruses of birds;
– Mastadenovirus : infect mammals;
• 47 serotypes of human origin;

6. DISEASE ASSOCIATIONS
Serotype Disease At risk
1-7 Acute febrile pharyngitis Children
3,7,14 Pharyngoconjunctival fever Young
children
8,9,37 Epidemic
keratoconjunctivitis
(shipyard eye)
Adults
3,4,11 Acute follicular conjunctivitis Any age
40,41 Diarrhoea Infants,
young
children
11,21 Hemorrhagic cystitis Children

7. Pathogenesis:
• Adenoviruses spread by:
– direct contact,
– respiratory droplets
– feco-oral route.

8. Pathogenesis:
• Adenoviruses infect and replicate in the epithelial cells of the:
– pharynx,
– conjunctiva,
– urinary bladder
– small intestine.
They usually do not spread beyond the regional lymph nodes
EXCEPT IN THE IMMUNE COMPROMISED HOST.

9. Pathogenesis:
• The virus has a tendency to become latent in
lymphoid tissue,
• The virus can be reactivated by
immunosuppression.

10. Clinical Syndromes:
• Adenoviruses cause primary infection in:
– children
– less commonly adults.
• Several distinct clinical syndromes are associated
with Adenovirus infection.

11. CLINICAL SYNDROMES
A. Respiratory diseases:
B. Eye infections:
C. Gastrointestinal disease
D. Other diseases:
E. Adenoviral infections of the immune compromised host

12. A. Respiratory diseases:
• The most important etiological association of adenoviruses is
with the respiratory diseases.
• They are responsible for 5% of acute respiratory diseases in:
– young children
– and much less in adults.

13. A. Respiratory diseases:
Four different syndromes of respiratory infection have been linked
to Adenoviruses.
• Acute febrile pharyngitis:
– most commonly seen in infants and young children,
– symptoms include cough, stuffy nose, fever and sore throat.
• Pharyngo conjunctival fever:
– symptoms are similar to those of acute febrile pharyngitis but
conjunctivitis is also present.
– It tends to occur in outbreaks such as at children's summer camps
(swimming pool conjunctivitis).

14. A. Respiratory diseases:
• Acute respiratory disease:
– is characterized by pharyngitis, fever, cough and
malaise.
– It occurs in an epidemic form among young recruits
under conditions of overcrowding
• Pneumonia: a complication of acute respiratory
disease in both children and adults.

15. NOTE
Outbreaks & epidemic adenovirus infections
• Pharyngo conjunctival fever:
– outbreaks
– in children's summer camps (swimming pool conjunctivitis).
• Acute respiratory disease:
– occurs in an epidemic form
– among young recruits
• Epidemic keratoconjunctivitis:

16. B. Eye infections:
• Mild conjunctivitis:
– can occur as a part of respiratory pharyngeal syndromes.
– Complete recovery with no lasting sequelae is the common
outcome.
– Can occur sporadically or in outbreaks.
• Epidemic keratoconjunctivitis:
• a highly contagious and a more serious disease occurring mainly in adults.
• Corneal involvement may be followed by various
degrees of visual disability.

17. C. Gastrointestinal disease:
1. No disease association
1. Many Adenoviruses replicate in intestinal cells and are present
in the stools without being associated with GIT disease.
2. Infantile gastroenteritis
1. Two serotypes (40, 41) have been etiologically associated with
infantile gastroenteritis.

18. NOTE
1. The enteric Adenoviruses are very difficult to cultivate.
2. Lab diagnosis depend on direct detection

19. D. Other diseases:
• Acute haemorrhagic cystitis:
– types 11, 21 may cause acute haemorrhagic cystitis in
children especially boys.

20. E. Adenoviral infections of the immune
compromised host
• The most common clinical manifestations are:
• pneumonia,
• hepatitis
• gastroenteritis.

21. LABORATORY DIAGNOSIS
• Specimens : from throat, eye, urine, feces.
• Isolation of virus:
– Inoculation into cell cultures;
– human embryonic kidney/HeLa/HEp2
– CPE : cell rounding and aggregation into grape
like clusters;
– Other tests : HA, Neutralization, CF

22. • Serology : rise in titre of antibodies in
paired sera; (single specimen – not
useful)
• Electron Microscopy : for stool to see
virus
• Immunofluorescence : antigen detection
in Nasopharyngeal /occular specimens

23. Prevention and control
• Careful hand washing is the easiest way to prevent infection.
• Disinfection of Environmental surfaces with hypochlorites.
• The risk of water borne outbreaks of conjunctivitis can be minimized by
chlorination of swimming pools.
• Epidemic keratoconjunctivitis can be controlled by strict asepsis during
eye examination.

24. Parvoviruses

25. Introduction
• Smallest DNA virus
• Belong to Family Parvoviridae
• Icosahedral in shape
• Non enveloped
• Single stranded DNA
• Human parvovirus B19 is only pathogenic in man
• Shows tropism for erythroid progenitor cells

26. Classification
Consists of 3 genera
Dependovirus also called adeno associated virus no
disease in humans
Parvovirus cause leucopenia in canine animals
Erythrovirus consist of B19virus cause Flu,
erthyematous infection, infection in pregnant,
chronic viral infection leucopenia aplastic anemia,
Thrombocytopenia

27. Pathogenesis
• Virus shows tropism for RBC’s & endothelial cells of blood
vessels
• Virus enters nasopharynx----spreads in the blood cause
viremia-----then infect mitotically active erythroid precussor
cells in bone marrow------ infection established-------virus
infects nucleus of the cells ----replicates----kill erythroid cells--
--lead to flu like symptoms--- virus shed in oral and respiratory
secretions and can cross the placenta
• Antibodies IgM & IgG appear in due course of time and form
immune complexes---deposit of immune complexes lead to
artharlgia & rash

29. HumanparvovirusB19
• Discovered in the serum of
asymptomatic blood donors.
• Associated with:
• A very common exanthematous disease of
children (Fifth disease)
• Aplastic crisis (in patients with chronic
hemolytic anemia)
• Hydrops fetalis
5th
.

30. Erythema infectiosum or fifth disease Gloves and sock syndrome

31. Human Parvo virus infection

32. Clinical syndromes of B19 virus Contd….
Chronic B19 infection
• Infection occurs in immunocompromised
patients such as HIV, patients receiving
chemotherapy, Transplant patients
• Patient develops chronic anemia, leucopenia,
thrombocytopenia

33. Laboratory Diagnosis
• Demonstration of specific IgM & IgG Ab
• In pregnant woman serum positive for IgM &
IgG indicates infection within 1-4 weeks.
• Positive IgG and negative IgM indicates past
infection
• PCR to demonstrate B19 genome

34. Treatment & Prevention
• No specific therapy is available
• Supportive treatment only
• No vaccine available
• Phase I trial are on

35. Human
papilloma
virus
Human papillomavirus is the
most common sexually
transmitted infection. Most
sexually active men and
women being exposed to the
virus at some point during
their lifetime

36. Structure
• small, non-enveloped, icosahedral
Double stranded DNA viruses that have
a diameter of 52–55 nm.
• single double-stranded DNA molecule of
about 8000 base-pairs.
• a protein capsid composed of 72
pentameric capsomers.
Structure

37. Structure
Classification
• the International Committee on the Taxonomy of
Viruses (ICTV) as two separate families —
Papillomaviridae and Polyomaviridae.
• HPV is divided into High risk HPV and Low risk HPV. Low-
risk types cause warts and high-risk types can cause
cancer.

38. Structure
Pathogenesis
• HPV infection is limited to the basal cells of stratified
epithelium cells and induce within those cells through
micro-abrasions leading to characteristic cytoplasmic
vacuole.
• The virus cannot bind to live tissue
Most warts are benign and do not progress to
malignancy. However, HPV infection is associated
with carcinoma of the uterine cervix and penis.
Immunosuppressed patients have more extensive
warts, and women infected with human
immunodeficiency virus (HIV) have a very high
rate of carcinoma of the cervix.

39. Symptoms
• HPV may not cause symptoms at once, but they can appear years later. Some types can
lead to warts, while others can cause cancer.
• Warts
• Common symptoms of some types of HPV are warts, especially genital warts.
• Genital warts may appear as a small bump, cluster of bumps. They commonly affect
the vulva in women, or possibly the cervix, and the penis or scrotum in men. They
may also appear around the anus and in the groin.
• They can range in size and appearance and be large, small, flat, or cauliflower shaped,
• and may be white or flesh tone.
• HPV6 and HPV11 are common causes of genital warts and laryngeal papillomatosis.

40. Symptoms

41. Symptoms
Other warts associated with HPV include common warts, plantar, and
flat warts.
• Common warts - rough, raised bumps most commonly found on
the hands, fingers, and elbows.
• Plantar warts - described as hard, grainy growths on the feet; they
most commonly appear on the heels or balls of the feet.
• Flat warts - generally affect children, adolescents, and young
adults; they appear as flat-topped, slightly raised lesions that are
darker than normal skin color and are most commonly found on
the face, neck, or areas that have been scratched.
Common warts on
the dorsal surface of
the hand
Planter wart

42. Plane wart

43. SUPERFICIAL (Flat) WARTS

44. Epidermodysplasia Verruciformis (Tree branches apperance)

45. PERIUNGUAL WARTS

46. GENITAL CONDYLOMAS

47. INTERNAL WARTS

48. CERVICAL WARTS

49. HPV-THE CARCINOGEN

50. Cervical – HPV infection




Cervical cancer is second most
frequent cancer in women
world wide
5,00,000 cases present with
cervical cancer
Major leading cause of deaths
related to malignancy in the
Devloping world
Several cases associated
with HPV infections.

51. Symptoms: Cervical Cancer
• As in many cancers, there may be no signs or
symptoms of cervical cancer until it has
progressed to a dangerous stage. However, if
symptoms do occur they may include:
• Abnormal vaginal bleeding
• Pain in very advanced stages
• Any bleeding from the vagina other than during menstruation.
• Abnormal vaginal discharge

52. Transmission
• HPV is transmitted through intimate skin-to-skin contact.
having vaginal, anal, or oral sex with someone who has the virus.
• It is most commonly spread during vaginal or anal sex.
• common that nearly all men and women get it at some point in their
lives.
• can be passed even when an infected person has no signs or symptoms.
• can develop symptoms years after being infected, making it hard to
know when you first became infected.
In most cases, HPV goes away on its own and does not cause any health problems. Butwhen
HPV does not go away, it can cause health problems like genital warts and cancer.

53. Diagnosis
The traditional methods of viral diagnosis such as electron
microscopy, cell culture, and certain immunological methods are
not suitable for HPV detection. HPV cannot be cultured in cell
cultures.
The important methods to diagnose HPV infection are:
• Biopsy
• DNA test (PCR, Southern Blot Hybridization, In Situ Hybridization)
• Pap smear

54. Diagnosis
PCR-based methods: HPV DNA can be amplified
selectively by a series of reactions that lead to an
exponential and reproducible increase in viral sequences
present in the biological specimen.
serological assays: ELISA or western blot analysis

55. Diagnosis
Biopsy: If the biopsy results show pre-cancer (dysplasia) or cancer,
then treatment is recommended. The dysplasia may be mild,
moderate, or severe.
PAP smear or PAP test: It is a screening test. Apart from
premalignant and malignant changes, viral infections like HPV
infection and Herpes can also be detected.

56. Treatment
There is currently no specific treatment for HPV infection.
However warts can be treated.
• Salicylic acid. Over-the-counter treatments that contain salicylic acid work by removing
layers of a wart a little at a time.
• Imiquimod (Aldara, Zyclara). This prescription cream might enhances immune
system's ability to fight HPV. Common side effects include redness and swelling at the
application site.
• Podofilox (Condylox). Another topical prescription, podofilox works by destroying
genital wart tissue. Podofilox may cause pain and itching where it's applied.
• Trichloroacetic acid. This chemical treatment burns off warts on the palms, soles and
genitals. It might cause local irritation.

57. Treatment
Surgical and other procedures
If medications don't work the following methods can be use
to remove warts
• Freezing with liquid nitrogen (cryotherapy)
• Burning with an electrical current (electrocautery)
• Surgical removal
• Laser surgery
"condom use may reduce the risk for genital human papillomavirus (HPV) infection"

58. Vaccination
Three vaccines are available to prevent infection by some HPV
types. All protect against initial infection with HPV types 16 and 18,
which cause most of the HPV-associated cancer cases.
Gardasil: protects against HPV types 6 and 11, which cause 90% of
genital warts. quadrivalent vaccine
Cervarix: bivalent, and is prepared from virus-like particles (VLP) of
The capsid.
Gardasil 9: nonavalent, it has the potential to prevent about 90% of
cervical, vulvar, vaginal, and anal cancers.

59. Prevention
• Vaccination
• Avoid skin-to-skin contact by not having sex with strangers.
• Use condoms and/or dental dams every time you have
vaginal, anal, or oral sex.
• Though condoms and dental dams are not as effective
against HPV as they are against other STDs like chlamydia
and HIV, safer sex can lower your chances of getting HPV.