35. hepatitis

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35. hepatitis

  1. 1. Hepatitis A-G Viruses Topic 40
  2. 2. A “ Infectious” “ Serum” Viral hepatitis Enterically transmitted Parenterally transmitted F, G, TTV ? other E NANB B D C Viral Hepatitis - Historical Perspectives
  3. 3. Source of virus feces blood/ blood-derived body fluids blood/ blood-derived body fluids blood/ blood-derived body fluids feces Route of transmission fecal-oral percutaneous permucosal percutaneous permucosal percutaneous permucosal fecal-oral Chronic infection no yes yes yes no Prevention pre/post- exposure immunization pre/post- exposure immunization blood donor screening; risk behavior modification pre/post- exposure immunization; risk behavior modification ensure safe drinking water Type of Hepatitis A B C D E
  4. 5. Hepatitis A Virus
  5. 6. Hepatitis A Virus <ul><li>Naked RNA virus </li></ul><ul><li>Formerly known as enterovirus 72, now it is in its own family: heptovirus </li></ul><ul><li>One stable serotype only </li></ul><ul><li>Difficult to grow in cell culture: primary marmoset cell culture and also in vivo in chimpanzees and marmosets </li></ul>
  6. 7. Hepatitis A Virus…. <ul><li>Survives well in the general environment </li></ul><ul><li>Somewhat resistant to heat and freezing </li></ul><ul><li>Remain active on the hands for several hours or in food kept at room temperature.  </li></ul>
  7. 8. <ul><li>Hepatitis A can be transmitted: </li></ul><ul><li>Through fecal-oral route </li></ul><ul><ul><li>by infected food handlers </li></ul></ul><ul><ul><li>in locations/sites with poor sanitation and hygiene (e.g., in developing countries) </li></ul></ul><ul><ul><li>by poor hygiene standards </li></ul></ul><ul><ul><li>after natural disasters, such as floods, when drinking water can become contaminated with sewage </li></ul></ul><ul><li>during sex, particularly oral/anal sex </li></ul>
  8. 9. <ul><li>Close personal contact (e.g., household contact, sex contact, child day care centers) </li></ul><ul><li>Contaminated food, water (e.g., infected food handlers, raw shellfish) </li></ul><ul><li>Blood exposure (rare) (e.g., injecting drug use, transfusion) </li></ul>Summary of Hepatitis A Virus Transmission
  9. 10. Endemicity Disease Rate Peak Age of Infection Transmission Patterns High Low to High Early childhood Person to person; outbreaks uncommon Moderate High Late childhood/ young adults Person to person; food and waterborne outbreaks Low Low Young adults Person to person; food and waterborne outbreaks Very low Very low Adults Travelers; outbreaks uncommon Global Patterns of Hepatitis A Virus Transmission
  10. 11. Infective dose …. <ul><li>Infective dose not known </li></ul><ul><li>But since hepatitis A is transmitted so easily through person to person contact, it is thought to be a small amount </li></ul>
  11. 12. <ul><li>Incubation period: Average 30 days </li></ul><ul><li>Range 15-50 days </li></ul><ul><li>Jaundice by <6 yrs, <10% age group: 6-14 yrs, 40%-50% >14 yrs, 70%-80% </li></ul><ul><li>Complications: Fulminant hepatitis Cholestatic hepatitis Relapsing hepatitis </li></ul><ul><li>Chronic sequelae: None </li></ul>Hepatitis A - Clinical Features
  12. 13. Fecal HAV Symptoms 0 1 2 3 4 5 6 12 24 Hepatitis A Infection Total anti-HAV Titre ALT IgM anti-HAV Months after exposure Typical Serological Course
  13. 14. Laboratory Diagnosis <ul><li>Acute infection : HAV-IgM in serum by EIA. </li></ul><ul><li>Past Infection i.e. immunity : HAV-IgG by EIA. </li></ul><ul><li>Cell culture – difficult and take up to 4 weeks, not routinely performed </li></ul><ul><li>Direct Detection – EM, RT-PCR of faeces. Can detect illness earlier than serology but rarely performed. </li></ul>
  14. 15. <ul><li>NO medical treatment available to treat the virus. </li></ul><ul><li>Symptoms of hepatitis A : can be relieved to some extent with rest and a healthy diet, there is </li></ul><ul><li>People who have close contact with someone who has hepatitis A: </li></ul><ul><ul><li>should receive normal human immunoglobulin within 2 weeks of exposure </li></ul></ul><ul><ul><li>Hepatitis A vaccine can be given at the same time as the immunoglobulin. </li></ul></ul>
  15. 16. <ul><li>Pre-exposure </li></ul><ul><ul><li>Travelers to intermediate and high HAV-endemic regions </li></ul></ul><ul><li>Post-exposure (within 14 days) </li></ul><ul><ul><li>Routine </li></ul></ul><ul><ul><li>household and other intimate contacts </li></ul></ul><ul><ul><li>Selected situations </li></ul></ul><ul><ul><li>institutions (e.g., day care centers) </li></ul></ul><ul><ul><li>common source exposure (e.g., food prepared by infected food handler) </li></ul></ul>Hepatitis A Prevention - Immune Globulin
  16. 17. <ul><li>There are currently four hepatitis A vaccines and two combined hepatitis A / hepatitis B vaccines registered for use in Australia. </li></ul><ul><li>  </li></ul>
  17. 18. Vaccine … <ul><li>People at risk of getting both hepatitis A & B, (i.e. healthcare workers, IV drug user, gay males (MSM)n and travellers to developing countries ), should consider receiving the combined hepatitis A / hepatitis B vaccines.  </li></ul><ul><li>Recommendation : persons with hepatitis C be vaccinated for hepatitis A, as well as for hepatitis B. </li></ul>
  18. 19. <ul><li>Hepatitis A vaccines do not affect liver enzyme levels. </li></ul><ul><li>  </li></ul><ul><li>Pregnant women should delay being immunized against hepatitis A, unless there is a substantial risk of them coming into contact with the virus. </li></ul><ul><li>Local pain at the injection site may be experienced, but this will only be for a short period of time </li></ul>
  19. 20. <ul><li>Vaccination for hepatitis A should give immunity against the disease for at least 20 years.  </li></ul>
  20. 21. <ul><li>Many cases occur in community-wide outbreaks </li></ul><ul><ul><li>no risk factor identified for most cases </li></ul></ul><ul><ul><li>highest attack rates in 5-14 year olds </li></ul></ul><ul><ul><li>children serve as reservoir of infection </li></ul></ul><ul><li>Persons at increased risk of infection </li></ul><ul><ul><li>travelers </li></ul></ul><ul><ul><li>homosexual men </li></ul></ul><ul><ul><li>injecting drug users </li></ul></ul>Hepatitis A Vaccination Strategies Epidemiologic Considerations
  21. 22. Epidemiology <ul><li>Hepatitis A virus is closely linked to social and environmental situations, patterns of the virus are recognized in: </li></ul><ul><li>areas where there is poor sanitation and hygiene </li></ul><ul><li>regions where there have been recent improvements in the environment or economy </li></ul><ul><li>areas with high standards of hygiene and sanitation but which are susceptible to new infections because people may not have been previously exposed to such viruses </li></ul>
  22. 24. Hepatitis A Prevention <ul><li>To avoid transmission of hepatitis A, always wash hands thoroughly: </li></ul><ul><li>after going to the toilet </li></ul><ul><li>before preparing food </li></ul><ul><li>after handling nappies and condoms </li></ul>
  23. 25. Hepatitis A Prevention <ul><li>Avoid sharing food, cutlery, crockery, cigarettes and drinks with other people.  </li></ul><ul><li>In a natural disaster, listen to warnings about contaminated drinking water and follow any instructions issued by the relevant authorities. </li></ul>
  24. 27. Hepatitis B Virus
  25. 28. Hepatitis B Virus - Virology <ul><li>ds DNA </li></ul><ul><li>Complete Dane particle 42 nm ( the virus) </li></ul><ul><li>28 nm electron dense core ( include the HBcAg and HBeAg </li></ul><ul><li>coat and the 22 nm free particles contain HBsAg </li></ul><ul><li>At least 4 phenotypes of HBsAg are recognized; adw, adr, ayw and ayr. </li></ul><ul><li>The HBcAg is of a single serotype </li></ul>
  26. 29. Hepatitis B Virus - Virology <ul><li>It has not yet been possible to propagate </li></ul><ul><li>the virus in cell culture. </li></ul>
  27. 30. <ul><li>Sexual - sex workers and homosexuals are particular at risk. </li></ul><ul><li>Parenteral - IVDA, Health Workers are at increased risk. </li></ul><ul><li>Perinatal - Mothers who are HBeAg positive are much more likely to transmit to their offspring than those who are not. Perinatal transmission is the main means of transmission in high prevalence populations. </li></ul>Hepatitis B Virus Modes of Transmission
  28. 31. Transmission… <ul><ul><li>sharing toothbrushes or razors </li></ul></ul><ul><ul><li>unsterilised tattooing and body piercing equipment </li></ul></ul><ul><ul><li>needle –stick injury   </li></ul></ul>
  29. 32. <ul><li>Hepatitis B is found in body fluids including blood, saliva, semen, mucus, vaginal fluid and breast milk. </li></ul>
  30. 33. High Moderate Low/Not Detectable blood semen urine serum vaginal fluid feces wound exudates saliva sweat tears breastmilk Concentration of Hepatitis B Virus in Various Body Fluids
  31. 34. <ul><li>Incubation period: Average 60-90 days </li></ul><ul><li>Range 45-180 days </li></ul><ul><li>Clinical illness (jaundice): <5 yrs, <10% 5 yrs, 30%-50% </li></ul><ul><li>Acute case-fatality rate: 0.5%-1% </li></ul><ul><li>Chronic infection: <5 yrs, 30%-90% 5 yrs, 2%-10% </li></ul><ul><li>Premature mortality from chronic liver disease: 15%-25% </li></ul>Hepatitis B - Clinical Features
  32. 35. Spectrum of Chronic Hepatitis B Diseases <ul><li>1. Chronic Persistent Hepatitis - asymptomatic </li></ul><ul><li>2. Chronic Active Hepatitis - symptomatic exacerbations of hepatitis </li></ul><ul><li>3. Cirrhosis of Liver </li></ul><ul><li>4. Hepatocellular Carcinoma </li></ul>
  33. 36. Symptoms HBeAg anti-HBe Total anti-HBc IgM anti-HBc anti-HBs HBsAg 0 4 8 12 16 20 24 28 32 36 52 100 Acute Hepatitis B Virus Infection with Recovery Typical Serologic Course Weeks after Exposure Titre
  34. 37. IgM anti-HBc Total anti-HBc HBsAg Acute (6 months) HBeAg Chronic (Years) anti-HBe 0 4 8 12 16 20 24 28 32 36 52 Years Weeks after Exposure Titre Progression to Chronic Hepatitis B Virus Infection Typical Serologic Course
  35. 38. Symptomatic Infection Chronic Infection Age at Infection Chronic Infection (%) Symptomatic Infection (%) Birth 1-6 months 7-12 months 1-4 years Older Children and Adults 0 20 40 60 80 100 100 80 60 40 20 0 Outcome of Hepatitis B Virus Infection by Age at Infection Chronic Infection (%)
  36. 40. Diagnosis : Battery of serological Tests <ul><li>MARKERS USED </li></ul><ul><li>HBsAg - used as a general marker of infection. </li></ul><ul><li>HBsAb - used to document recovery and/or immunity to HBV infection. </li></ul><ul><li>anti-HBc IgM - marker of acute infection. </li></ul><ul><li>anti-HBcIgG - past or chronic infection. </li></ul>
  37. 41. Diagnosis….. <ul><li>HBeAg - indicates active replication of virus and therefore infectiveness. </li></ul><ul><li>Anti-Hbe - virus no longer replicating. However, the patient can still be positive for HBsAg which is made by integrated HBV. </li></ul><ul><li>HBV-DNA - indicates active replication of virus, more accurate than HBeAg especially in cases of escape mutants. Used mainly for monitoring response to therapy. </li></ul>
  38. 42. Treatment <ul><li>Interferon - for HBeAg +ve carriers with chronic active hepatitis. Response rate is 30 to 40%. </li></ul><ul><ul><li>alpha-interferon 2b (original) </li></ul></ul><ul><ul><li>alpha-interferon 2a (newer, claims to be more efficacious and efficient) </li></ul></ul><ul><li>Lamivudine - a nucleoside analogue reverse transcriptase inhibitor. Well tolerated, most patients will respond favorably. However, tendency to relapse on cessation of treatment. Another problem is the rapid emergence of drug resistance. </li></ul>
  39. 43. Treatment….. <ul><li>Adefovir – less likely to develop resistance than Lamivudine and may be used to treat Lamivudine resistance HBV. However more expensive and toxic </li></ul><ul><li>Entecavir – most powerful antiviral known, similar to Adefovir </li></ul><ul><li>Successful response to treatment will result in the disappearance of HBsAg, HBV-DNA, and seroconversion to HBeAg. </li></ul>
  40. 44. Prevention of Hepatitis B.. Ways to reduce transmission <ul><li>wash hands after touching blood or body fluids </li></ul><ul><li>wear disposable gloves if giving someone first aid or cleaning up blood or body fluids </li></ul><ul><li>avoid sharing toothbrushes, razors, needles, syringes, personal hygiene items and grooming aids or any object that may come into contact with blood or body fluids </li></ul><ul><li>use new and sterile injecting equipment for each injection </li></ul>
  41. 45. Prevention of Hepatitis B.. Ways to reduce transmission… <ul><li>cover all cuts and open sores with a bandage </li></ul><ul><li>wipe up any blood spills and then clean the area with household bleach </li></ul><ul><li>throw away personal items such as tissues, menstrual pads, tampons and bandages in a sealed plastic bag </li></ul><ul><li>practice safe sex </li></ul>
  42. 46. Prevention <ul><li>Vaccination - highly effective recombinant vaccines are now available. Vaccine can be given to those who are at increased risk of HBV infection such as health care workers. It is also given routinely to neonates as universal vaccination in many countries. </li></ul>
  43. 47. Prevention…. <ul><li>Hepatitis B Immunoglobulin – </li></ul><ul><ul><li>HBIG may be used to protect persons who are exposed to hepatitis B </li></ul></ul><ul><ul><li>It is particular efficacious within 48 hours of the incident. </li></ul></ul><ul><ul><li>It may also be given to neonates who are at increased risk of contracting hepatitis B i.e. whose mothers are HBsAg and HBeAg positive. </li></ul></ul><ul><li>Other measures - screening of blood donors, blood and body fluid precautions. </li></ul>
  44. 49. Hepatitis C Virus <ul><ul><ul><li>Resembles flavivirus </li></ul></ul></ul><ul><ul><ul><li>+ stranded RNA genome of around 10,000 bases </li></ul></ul></ul><ul><ul><ul><li>enveloped virus; morphological structure remains unknown </li></ul></ul></ul><ul><ul><ul><li>HCV has been classified into a total of six genotypes (type 1 to 6 on the basis of phylogenetic analysis </li></ul></ul></ul><ul><ul><ul><li>Genotype 1 and 4 has a poorer prognosis and response to interferon therapy, </li></ul></ul></ul><ul><ul><ul><li>In Hong Kong, genotype 1 accounts for around 67% of cases and genotype 6 around 25%. </li></ul></ul></ul>
  45. 50. Incubation period: Average 6-7 wks Range 2-26 wks Clinical illness (jaundice): 30-40% (20-30%) Chronic hepatitis: 70% Persistent infection: 85-100% Immunity: No protective antibody response identified Hepatitis C - Clinical Features
  46. 51. Chronic Hepatitis C Infection <ul><li>The spectrum of chronic hepatitis C infection is essentially the same as chronic hepatitis B infection. </li></ul><ul><li>All the manifestations of chronic hepatitis B infection may be seen, but with a lower frequency i.e. chronic persistent hepatitis, chronic active hepatitis, cirrhosis, and hepatocellular carcinoma . </li></ul>
  47. 52. Symptoms anti-HCV ALT Normal 0 1 2 3 4 5 6 1 2 3 4 Hepatitis C Virus Infection Typical Serologic Course Titre Months Years Time after Exposure
  48. 53. <ul><li>Transfusion or transplant from infected donor </li></ul><ul><li>Injecting drug use </li></ul><ul><li>Hemodialysis (yrs on treatment) </li></ul><ul><li>Accidental injuries with needles/sharps </li></ul><ul><li>Sexual/household exposure to anti-HCV-positive contact </li></ul><ul><li>Multiple sex partners </li></ul><ul><li>Birth to HCV-infected mother </li></ul>Risk Factors Associated with Transmission of HCV
  49. 55. Laboratory Diagnosis <ul><li>HCV antibody - used to diagnose hepatitis C infection. Not useful in the acute phase as it takes at least 4 weeks after infection before antibody appears. </li></ul><ul><li>HCV-RNA - by PCR, may be used to diagnose HCV infection in the acute phase. Main use is in monitoring the response to antiviral therapy. </li></ul><ul><li>HCV-antigen - an EIA for HCV antigen is available. It is used in the same capacity as HCV-RNA tests but is much easier to carry out. </li></ul>
  50. 56. Treatment <ul><li>Interferon - may be considered for patients with chronic active hepatitis. The response rate is around 50% but 50% of responders will relapse upon withdrawal of treatment. </li></ul><ul><li>Ribavirin - there is less experience with ribavirin than interferon. However, recent studies suggest that a combination of interferon and ribavirin is more effective than interferon alone. </li></ul>
  51. 57. <ul><li>Screening of blood, organ, tissue donors </li></ul><ul><li>High-risk behavior modification </li></ul><ul><li>Blood and body fluid precautions </li></ul>Prevention of Hepatitis C
  52. 59. <ul><li>Hepatitis D, also called delta virus, is a virus that is only found in people who are already infected with hepatitis B. </li></ul>
  53. 60. HBsAg RNA  antigen Hepatitis D (Delta) Virus
  54. 61. Hepatitis D Virus <ul><li>The delta agent is a defective virus which shows similarities with the viroids in plants. </li></ul><ul><li>It is a particle 35 nm in diameter </li></ul><ul><ul><li>with delta antigen surrounded by an outer coat of HBsAg. </li></ul></ul><ul><li>The genome of the virus is very small and consists of a single-stranded RNA </li></ul>
  55. 62. <ul><li>Same way as hepatitis B </li></ul><ul><ul><li>through blood and infected blood products </li></ul></ul><ul><ul><li>through sexual intercourse </li></ul></ul><ul><ul><li>small risk of perinatal (maternal to infant) transmission, but this is rare. </li></ul></ul>
  56. 63. Those most at risk include people with hepatitis B who: <ul><li>inject drugs </li></ul><ul><li>practice unsafe sex </li></ul><ul><li>have unsafe tattooing or body piercing </li></ul>
  57. 64. <ul><li>Percutanous exposures </li></ul><ul><ul><li>injecting drug use </li></ul></ul><ul><li>Permucosal exposures </li></ul><ul><ul><li>sex contact </li></ul></ul>Hepatitis D Virus , Summary Modes of Transmission
  58. 65. <ul><li>The symptoms for hepatitis D are similar to hepatitis B, such as: </li></ul><ul><ul><li>fatigue </li></ul></ul><ul><ul><li>abdominal pain </li></ul></ul><ul><ul><li>loss of appetite </li></ul></ul><ul><ul><li>nausea and vomiting </li></ul></ul><ul><ul><li>fever </li></ul></ul><ul><ul><li>joint aches </li></ul></ul><ul><ul><li>Jaundice </li></ul></ul>
  59. 66. Hepatitis D - Clinical Features <ul><li>A person can be co-infected with hepatitis D and hepatitis B at the same time. </li></ul><ul><ul><li>severe acute disease. </li></ul></ul><ul><ul><li>low risk of chronic infection </li></ul></ul>
  60. 67. anti-HBs Symptoms ALT Elevated Total anti-HDV IgM anti-HDV HDV RNA HBsAg HBV - HDV Coinfection Typical Serologic Course Time after Exposure Titre
  61. 68. <ul><li>A person who is infected with hepatitis D after becoming infected with hepatitis B is said to have a super-infection . </li></ul><ul><li>usually develop chronic HDV infection. </li></ul><ul><li>high risk of severe chronic liver disease. </li></ul><ul><li>may present as an acute hepatitis. </li></ul>Hepatitis D - Clinical Features
  62. 69. Jaundice Symptoms ALT Total anti-HDV IgM anti-HDV HDV RNA HBsAg HBV - HDV Superinfection Typical Serologic Course Time after Exposure Titre
  63. 70. <ul><li>There is no specific treatment for hepatitis D. </li></ul><ul><li>There is some indication that antiviral medication, such as interferon or lamivudine, used to treat hepatitis B, will also treat hepatitis D. </li></ul>
  64. 71. <ul><li>Hepatitis D infection can be avoided by being vaccinated against hepatitis B. </li></ul><ul><li>A full course of hepatitis B vaccine for children, adolescents and adults consists of three doses with a specified interval in-between each dose. </li></ul>
  65. 72. Vaccination… <ul><li>Neonates should be given hepatitis B vaccination at birth.  </li></ul><ul><li>Babies born to hepatitis B carrier mothers should also receive hepatitis B immunoglobulin to provide immediate passive protection. </li></ul><ul><li>Combination hepatitis A/hepatitis B vaccination is recommended for those at risk of getting these infections, and would offer protection against hepatitis D. </li></ul>
  66. 73. <ul><li>HBV-HDV Coinfection </li></ul><ul><ul><li>Pre or postexposure prophylaxis to prevent HBV infection. </li></ul></ul><ul><li>HBV-HDV Superinfection </li></ul><ul><ul><li>Education to reduce risk behaviors among persons with chronic HBV infection. </li></ul></ul>Hepatitis D - Prevention
  67. 76. <ul><li>Hepatitis E is a contagious viral infection which causes acute hepatitis but does not lead to chronic hepatitis. </li></ul><ul><li>Hepatitis E is found mostly in developing countries, especially in India, Asia, Africa and Central America. </li></ul>
  68. 77. Hepatitis E Virus <ul><li>Calicivirus-like viruses </li></ul><ul><li>unenveloped RNA virus, 32-34nm in diameter </li></ul><ul><li>+ve stranded RNA genome, 7.6 kb in size. </li></ul><ul><li>very labile and sensitive </li></ul><ul><li>Can be grown in cellculture </li></ul>
  69. 78. Hepatitis E Virus
  70. 79. <ul><li>By ingestion of contaminated water </li></ul><ul><li>Easily transmitted by person to person contact where household and personal hygiene is poor </li></ul>
  71. 80. Transmission.. <ul><li>Hepatitis E is most often spread through fecal-oral route </li></ul><ul><li>NO evidence of transmission through needles, blood, body fluids or through sexual contact </li></ul>
  72. 81. <ul><li>Symptoms of hepatitis E are very similar to those of hepatitis A: </li></ul><ul><li>fever </li></ul><ul><li>weakness </li></ul><ul><li>fatigue </li></ul><ul><li>loss of appetite </li></ul><ul><li>nausea </li></ul><ul><li>vomiting </li></ul><ul><li>The majority of people with hepatitis E recover with no lasting immunity </li></ul>
  73. 82. <ul><li>1-2% chance of developing sudden and severe liver disease </li></ul><ul><li>  Hep E in pregnant women :with greater risk of acute illness and liver failure, and occasionally death.  </li></ul><ul><ul><li>occurs mainly in developing countries where hepatitis E is endemic, and where there is limited ante-natal care and maternal health is poor. </li></ul></ul>
  74. 83. <ul><li>Incubation period: Average 40 days </li></ul><ul><li>Range 15-60 days </li></ul><ul><li>Case-fatality rate: Overall, 1%-3% Pregnant women, 15%-25% </li></ul><ul><li>Illness severity: Increased with age </li></ul><ul><li>Chronic sequelae: None identified </li></ul>Hepatitis E - Clinical Features
  75. 84. Symptoms ALT IgG anti-HEV IgM anti-HEV Virus in stool 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Hepatitis E Virus Infection Typical Serologic Course Titer Weeks after Exposure
  76. 85. <ul><li>There is no medical treatment for hepatitis E. </li></ul><ul><li>The aim of treatment : to alleviate symptoms through: </li></ul><ul><ul><li>bed rest </li></ul></ul><ul><ul><li>fluid replacement </li></ul></ul>
  77. 86. <ul><li>There is no vaccination for hepatitis E. </li></ul>
  78. 87. <ul><li>Most outbreaks associated with faecally contaminated drinking water. </li></ul><ul><li>Large epidemics occurred in :Indian subcontinent, USSR, China, Africa and Mexico. </li></ul><ul><li>USA and other nonendemic areas: a low prevalence of anti-HEV (<2%) has been found in healthy populations. The source of infection for these persons is unknown. </li></ul><ul><li>Minimal person-to-person transmission . </li></ul>Hepatitis E - Epidemiologic Features
  79. 89. <ul><li>Avoid drinking water (and beverages with ice) of unknown purity, uncooked shellfish, and uncooked fruit/vegetables not peeled or prepared by traveler. </li></ul><ul><li>IG prepared from donors in Western countries does not prevent infection. </li></ul><ul><li>Unknown efficacy of IG prepared from donors in endemic areas. </li></ul><ul><li>Vaccine? </li></ul>Prevention and Control Measures for Travelers to HEV-Endemic Regions
  80. 91. <ul><li>The hepatitis G virus is an RNA virus (ribonucleic acid) similar to, but distinct from, the hepatitis C virus. </li></ul>
  81. 92. <ul><li>Hepatitis G virus: newly identified virus.  </li></ul><ul><li>Found among people who had blood transfusion -- </li></ul><ul><li>developed post transfusion hepatitis which could not be </li></ul><ul><li>identified as any known virus. </li></ul><ul><li>Infection with the hepatitis G virus can lead to persistent </li></ul><ul><li>infection in 15 - 30% of adults. </li></ul><ul><li>Long term outcomes of the infection are not yet known. </li></ul><ul><li>  People with hepatitis A, B, or C can be co- or super- </li></ul><ul><li>infected with hepatitis G.  </li></ul><ul><li>There is no vaccination available for hepatitis G. </li></ul>
  82. 93. <ul><li>The transmission route known is through infected blood products.  This means that those at risk of infection may include people who: </li></ul><ul><ul><li>inject drugs </li></ul></ul><ul><ul><li>receive blood transfusions, haemodialysis, tissue and organ transplants </li></ul></ul><ul><ul><li>have being unsafely tattooed and/or body pierced. </li></ul></ul>
  83. 94. <ul><li>Can cause persistent viremia lasting for several years.   </li></ul><ul><li>Means ‘presence of virus in the blood’ and may not mean the person is sick. </li></ul><ul><li>  Like any viral infection, a person with hepatitis G may experience some flu-like symptoms. </li></ul>
  84. 95. <ul><li>To date: no links established between infection with hepatitis G virus and chronic liver disease. </li></ul><ul><li>  People with hepatitis G who also have hepatitis A, B or C do not appear to have worse health outcomes because of the co-infection. </li></ul>
  85. 96. <ul><li>There is no treatment currently available for hepatitis G. </li></ul>
  86. 97. <ul><li>There is no vaccination for hepatitis G </li></ul>
  87. 98. Hepatitis TT
  88. 99. History and characteristics <ul><li>In 1997, a novel DNA virus was isolated from the serum of a patient with post-transfusion hepatitis of unknown etiology in Japan </li></ul><ul><li>It was named TT virus (TTV) after the initials of the index patient. </li></ul><ul><li>TTV is a nonenveloped, single-stranded and circular DNA virus, and its entire sequence of ~3.9 kb has been determined. </li></ul>
  89. 100. Transmission <ul><li>Recent reports indicate that TTV can be transmitted via blood/blood products </li></ul><ul><li>In another study, a high rate of cervical carriage (66%) of TTV DNA was found by PCR, which suggests that perinatal and sexual transmission is possible. </li></ul>
  90. 101. Hepatitis F <ul><li>Hepatitis F is a hypothetical virus linked to hepatitis . </li></ul><ul><li>Several hepatitis F candidates emerged in the 1990s; none of these reports have been substantiated </li></ul>
  91. 102. End of lecture, thank you!

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