1 / 50

ADENOVIRUS

ADENOVIRUS. ADENOVIRUS. DNA viruses first isolated from adenoidal tissue in 1953. ADENOVIRUS. Family Adenoviridae Genus Mastadenovirus. Transmission electron micrograph of adenovirus Source- PUBLIC Health Image Library, CDC. ADENOVIRUS - Classification.

nevada-cervantes
Download Presentation

ADENOVIRUS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ADENOVIRUS

  2. ADENOVIRUS DNA viruses first isolated from adenoidal tissue in 1953

  3. ADENOVIRUS FamilyAdenoviridae GenusMastadenovirus

  4. Transmission electron micrograph of adenovirusSource- PUBLIC Health Image Library, CDC

  5. ADENOVIRUS - Classification Subgroups- 6 subgroups (A-F), based on hemagglutination Serotypes- 1-49 (human) Common serotypes:- 1-8, 11, 21, 35, 37, 40 Enteric Adenoviruses belong to subgroup F

  6. ADENOVIRUS – Classification Adapted from Fields Virology

  7. ADENOVIRUS - Structure Non-enveloped DNA virus 70-90 nm in size Linear ds DNA genome with core proteins

  8. ADENOVIRUS EM APPEARANCE

  9. ADENOVIRUS - Ultra structure Icosahedralcapsid with 252 capsomeres (12 pentons at vertices and 240 hexons) Each penton has a fibers with terminal knob projecting from it

  10. Adenovirus- 3 D structure

  11. ADENOVIRUS STRUCTURE

  12. Adenovirus - EM appearance

  13. ADENOVIRUS-Ultrastructure

  14. Structure

  15. Pathogenesis and Replication Infects mucoepithelial cells of respiratory, GI and GU tracts Enter via epithelium, replicate and spread to lymphoid tissue Viremia occurs Secondary involvement of viscera

  16. Pathogenesis and Replication (contd.) Fiber protein determines target cell specificity and attachment Viral DNA enters host cell nucleus Virus replicates in cytoplasm

  17. Adenovirus- replication

  18. Replication (contd.) Early and late phases of replication Error-prone process Inclusion bodies in nucleus

  19. ADENOVIRAL INCLUSION BODIES

  20. Types of infection Lytic Latent/occult Oncogenic Transformation

  21. Types of infection • Lytic • Results in cell death; seen in mucoepithelical cells • Latent/occult • Virus remains in host cell; seen in lymphoid tissue, Groups B and C • Oncogenic Transformation • Uncontrolled cell growth and replication occur; seen with Group A viruses in hamsters

  22. Adenovirus Used as VECTORS to transfer desired genetic material into cells Viral genome is relatively easily manipulated in vitro Efficient expression of inserted DNA in recipient cell

  23. Adenovirus- Properties • Stable in the environment • Relatively resistant to disinfection • (Alcohol, chlorhexidine, detergents) • Stable in GI tract- can withstand low pH, bile acids and proteolytic enzymes

  24. Time-course of infection Incubation period- 2-14 days Infective period continues for weeks Intermittent and prolonged rectal shedding Secondary attack rate within families up to 50%

  25. Timecourse - Respiratory infectionSource- Medical Microbiology, 5th Edition (Murray, Rosenthal, and Pfaller)

  26. EPIDEMIOLOGY Endemic, epidemic and sporadic infections Many infections are sub-clinical

  27. EPIDEMIOLOGY-contd.’Tip of the iceberg phenomenon’ Classical disease presentation Mild clinical disease Asymptomatic infection but +infectivity

  28. EPIDEMIOLOGY- Outbreaks Military recruits, swimming pool users, hospitals, residential institutions, day care settings

  29. EPIDEMIOLOGY-transmission Prolonged infective period (weeks) Intermittent and prolonged rectal shedding Stable in the environment

  30. TRANSMISSION Droplets Fecal-oral route Direct and through poorly chlorinated water Fomites

  31. CLINICAL SYNDROMES Respiratory Eye Genitourinary Gastrointestinal Others

  32. Acute Respiratory Disease(LRI) Fever Tracheobronchitis Pneumonia Children and adults Epidemics in military recruits Types 4 and 7 most frequently

  33. Acute Respiratory Disease

  34. Pharyngoconjunctival fever Headache, fever, malaise Conjunctivitis and Pharyngitis Cervical adenopathy, rash and diarrhea also Main adenovirus types: 3, 4, 7, 14 Epidemics in summer months Contaminated water in swimming pools, fomites

  35. Adenoviral Infections of the eye Epidemic Keratoconjunctivitis (EKC) Acute follicular conjunctivitis Pharyngoconjunctival fever

  36. Adenoviral conjunctivitis Early conjunctivitis (top) and Bilateral conjunctivitis (lower)

  37. Epidemic Keratoconjunctivitis Incidence in summer Types 8, 19, 37 Outbreaks- in situations of close contact (e.g., schools, hospitals, camps, nursing homes, workplaces) Spread via droplets and contaminated water (ophthalmologic solutions and equipment, swimming pools), fomites, hands

  38. EKC-Clinical features SYMPTOMS • Pink/red eye • Irritation, tearing, foreign-body sensation • Ocular pain • Photophobia • Fever, malaise • Respiratory symptoms SIGNS • Conjunctival injection, ecchymosis • Corneal injection (limbus) • Diffuse→focal epithelial keratitis • ↓Visual acuity (subepithelial corneal opacities) • Ipsilateral pre-auricular lymphadenopathy

  39. Gastrointestinal Infections Types 40, 41 Age <4 years Spread via fecal-oral route Year round

  40. Gastrointestinal Infections- (contd.) • Incubation period 3-10 days • Diarrhea lasts for 10-14 days • Fever • Also, intussusception, mesenteric adenitis, appendicitis

  41. INTUSSUSCEPTION

  42. ADENOVIRAL INFECTIONS- Genitourinary system Acute hemorrhagic cystitis • fever, dysuria, hematuria • Types 11, 7, 4, 21, 1 • More common in boys Others • Orchitis, nephritis, cervicitis with ulcerated vesicular lesions, urethritis • Types 2, 8, 19, 37

  43. Other Infections due to Adenovirus Myocarditis Pericarditis Meningitis Rash Arthritis

  44. Adenovirus infections in Immunocompromised hosts Disseminated, severe and often fatal infections Due to new infection or reactivation of latent virus Prolonged infections with prolonged viremia and viral shedding Necrotizing pneumonia, hepatitis, rash, disseminated intravascular coagulation (DIC), CNS involvement

  45. Adenovirus infection in the immunocompromised

  46. DIAGNOSIS OF ADENOVIRAL INFECTIONS • Variety of clinical specimens depending on clinical syndrome-NP, conjunctival, stool, urine, • tissue, etc. • Transport in viral transport media • Isolation from pharyngeal site correlates better with current clinical infection

  47. Methods for diagnosis Culture in HeLa, HEK cell lines Shell vial cell culture DFA PCR, nucleic acid probes EM and Immune EM

  48. Diagnosis-Enteric adenoviruses Isolation requires special media-Graham 293 ELISA for rapid detection is available

  49. Prevention Good handwashing Contact precautions Chlorination of water Disinfection or sterilization of ophthalmologic equipment Use of single dose vials Oral vaccine- restricted use

  50. ADENOVIRUS VACCINE • Oral live attenuated vaccine • Strains 4, 7 • Used in military recruits • Manufacture of vaccine was halted in 1996 • Lapse in immunization was associated with outbreaks in military recruits

More Related