Adenovirus

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Adenovirus

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Adenovirus

  1. 1. ADENOVIRUSES Dr.T.V.Rao MD10/11/2012 Dr.T.V.Rao MD 1
  2. 2. Human Adenoviruses Adenoviruses were first isolated in 1935 from human adenoid tissues. Since then, at least 49 distinct antigenic types have been isolated from humans and many other types from animals. All human serotypes are included in a single genus within the family Adenoviridae.10/11/2012 Dr.T.V.Rao MD 2
  3. 3. What are Adenoviruses Adenoviruses are a group of medium sized, nonenvelopedd, double stranded DNA viruses that share a common complement fixing antigen They infect humans and animals10/11/2012 Dr.T.V.Rao MD 3
  4. 4. Adenoviruses Adenoviruses are medium-sized (90–100 nm), nonenvelopedd (naked) icosahedral viruses composed of a nucleocapsid and a double-stranded linear DNA genome. There are over 52 different serotypes in humans, which are responsible for 5–10% of upper respiratory infections in children, and many infections in adults as well.10/11/2012 Dr.T.V.Rao MD 4
  5. 5. Classification Adenoviruses are divided into six groups (A to F) based on:  physical,  chemical  biological properties Antigenic structure divides adenoviruses into: - 49 serotypes: - About 1/3 of the 49 known human serotypes are responsible for most cases of Adenovirus disease.10/11/2012 Dr.T.V.Rao MD 5
  6. 6. Morphology of Adenovirus Adenovirus are 70-75 nm in size The capsid contains 252 capsomers arranged as icosahedrons with 20 triangular facets and 12 vertices 240 are called as hexons 12 are called as 10/11/2012 Dr.T.V.Rao MD 6 pentons.
  7. 7. Appear as space vehicle10/11/2012 Dr.T.V.Rao MD 7
  8. 8. Adenoviruses are prevalent all over the world Over 50 serotypes are isolated Most of the recent isolates are from AIDS patients Infections are common in children and world wide prevalence. doctorrao”s slide share 10/11/2012 Dr.T.V.Rao MD 8
  9. 9. Morphological configuration Each penton unit consists of penton base anchored in the capsid and projection or fibre consists of a rode like portion with a knob attached at the distal end The virus appears like a space vehicle.10/11/2012 Dr.T.V.Rao MD 9
  10. 10. Classification Contain two genera Mast adenovirus. Infects the mammals Aviaadenovirus Infects birds They infect only the homologues species with the exception of oncogenic human adenovirus Type 12, 18,and 31 cause sarcoma when injected into new born hamsters. Doctorraosslideshare10/11/2012 Dr.T.V.Rao MD 10
  11. 11. Pathogenesis Adenovirus cause infections in Respiratory tract Eye, Urinary bladder, and Intestines More than one type of virus may cause clinically different diseases10/11/2012 Dr.T.V.Rao MD 11
  12. 12. Clinical Features Clinical features: Adenoviruses most commonly cause respiratory illness; however, depending on the infecting serotype, they may also cause various other illnesses, such as gastroenteritis, conjunctivitis, cystitis, and rash illness. Symptoms of respiratory illness caused by adenovirus infection range from the common cold syndrome to pneumonia, croup, and bronchitis.10/11/2012 Dr.T.V.Rao MD 12
  13. 13. 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.10/11/2012 Dr.T.V.Rao MD 13
  14. 14. 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 childrens summer camps (swimming pool conjunctivitis).10/11/2012 Dr.T.V.Rao MD 14
  15. 15. 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 fatigue and overcrowding  Pneumonia: a complication of acute respiratory disease in both children and adults.10/11/2012 Dr.T.V.Rao MD 15
  16. 16. Adenovirus infections are important in Military MedicineAdenoviruses are responsible for 3-5%of acute respiratory infections inchildren and 2% of respiratory illnessesin civilian adults. They are more apt tocause infection among military recruitsand other young people who live ininstitutional environments. Outbreaksamong children are frequently reportedat boarding schools and summer10/11/2012 Dr.T.V.Rao MD 16
  17. 17. Adenovirus - Pharyngitis Major cause of infections associated with nonbacterial pharyngitis and tonsillitis Causes febrile common cold Types 1 – 7 are common types10/11/2012 Dr.T.V.Rao MD 17
  18. 18. Adenovirus Common cause of Respiratory infections10/11/2012 Dr.T.V.Rao MD 18
  19. 19. Pneumonia - Adenovirus  Adenovirus types 3 and 7 are associated with pneumonia resembles like atypical pneumonia in adults.  Type 7 causes serious and even fatal pneumonia in infants and young children10/11/2012 Dr.T.V.Rao MD 19
  20. 20. ARD – Acute respiratory disease with Adenovirus Occurs usually in military recruits Serotypes 4,7,and 21 are agents commonly associated.10/11/2012 Dr.T.V.Rao MD 20
  21. 21. Pharyngocongunctival fever Occurs in civilian population manifest with syndrome of febrile Pharyngitis and conjunctivitis Serotypes 3, 7, and 14 are associated.10/11/2012 Dr.T.V.Rao MD 21
  22. 22. Epidemic keratoconjunctivitis  Occurs with serious epidemic  Caused by serotypes 8, and less frequently with10/11/2012 19, and 37. Dr.T.V.Rao MD 22
  23. 23. A severe Adenoviral Infection10/11/2012 Dr.T.V.Rao MD 23
  24. 24. Other manifestations Acute follicular conjunctivitis, types 3,4 and 11 are responsible Adenoviral and chlamydial conjunctivitis are clinically similar Diarrhoea – not conclusively established Acute haemorrhagic cystitis in children and types 11 and 21 are responsible Mesenteric adenitis and intussusceptions in children.10/11/2012 Dr.T.V.Rao MD 24
  25. 25. Adenovirus in Immunocompromised Patients with compromised immune systems are especially susceptible to severe complications of adenovirus infection. Acute respiratory disease (ARD), first recognized among military recruits during World War II, can be caused by adenovirus infections during conditions of crowding and stress.10/11/2012 Dr.T.V.Rao MD 25
  26. 26. Immunity in Children Most children have been infected by at least one adenovirus by the time they reach school age. Most adults have acquired immunity to multiple adenovirus types due to infections they had as children.10/11/2012 Dr.T.V.Rao MD 26
  27. 27. Diagnosis Diagnosis: Antigen detection, polymerase chain reaction assay, virus isolation, and serology can be used to identify adenovirus infections. Adenovirus typing is usually accomplished by Hemagglutination-inhibition and/or neutralization with type-specific antiserum. Since adenovirus can be excreted for prolonged periods, the presence10/11/2012 Dr.T.V.Rao MD 27
  28. 28. Laboratory DiagnosisDirect detection: Virus particle by EM can be detected by direct examination of fecal extracts Detection of adenoviral antigens by ELISA. Enteric Adenoviruses Detection of adenoviral NA by Polymerase chain reaction: can be used for diagnosis of Adenovirus infections in tissue samples or body fluids.10/11/2012 Dr.T.V.Rao MD 28
  29. 29. Laboratory DiagnosisIsolation Isolation depending on the clinical disease, the virus may be recovered from throat, or Conjunctival swabs or and urine. Isolation is much more difficult from the stool or rectal swabs10/11/2012 Dr.T.V.Rao MD 29
  30. 30. Demographics Adenoviruses are responsible for 3 to 5 percent of acute respiratory infections in children. Most adenovirus infections occur between the ages of six months and five years. The incidence of adenovirus infection does not appear to differ among males and females or individuals of different race.10/11/2012 Dr.T.V.Rao MD 30
  31. 31. Treatment Treatment of adenovirus infections is usually supportive and aimed at relieving symptoms of the illness. Bed rest may be recommended along with medications to reduce fever and/or pain . (Aspirin should not be given to children because it is associated with Reyes syndrome.)10/11/2012 Dr.T.V.Rao MD 31
  32. 32. Treatment Eye infections may benefit from topical corticosteroids to relieve symptoms and shorten the course of the disease. Hospitalization is usually required for severe pneumonia in infants and for keratoconjunctivitis (to prevent blindness).10/11/2012 Dr.T.V.Rao MD 32
  33. 33. Prevention of Adenoviral Infections Prevention: Vaccines were developed for adenovirus serotypes 4 and 7, but were available only for preventing ARD among military recruits. Strict attention to good infection-control practices is effective for stopping nosocomial outbreaks of adenovirus-associated disease, such as epidemic keratoconjunctivitis. Maintaining adequate levels of chlorination is necessary for preventing swimming pool- associated outbreaks of adenovirus conjunctivitis.10/11/2012 Dr.T.V.Rao MD 33
  34. 34. 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.10/11/2012 Dr.T.V.Rao MD 34
  35. 35. Adenovirus a emerging tool in Genetic Engineering10/11/2012 Dr.T.V.Rao MD 35
  36. 36. Experiments with Adenovirus Adenovirus vectors are used by researchers to deliver genetic material into the cells. Not only is this but they also being used by molecular biologists for vaccination purposes. They are mostly used in in-vitro experiments at this time.10/11/2012 Dr.T.V.Rao MD 36
  37. 37. Simple Hand Washing Can Save Us From Serious Adenoviral Infections10/11/2012 Dr.T.V.Rao MD 37
  38. 38.  Programme Created by Dr.T.V.Rao MD for Medical and Paramedical Students in the Developing World  Email  doctortvrao@gmail.com10/11/2012 Dr.T.V.Rao MD 38

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