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Blood Borne Viruses

Blood Borne Viruses. Rob Hale Consultant in Special Care Dentistry King’s College London Dental Institute. Blood Borne Viruses. Viruses HBV HCV HIV Statistics General Prison Occupation exposures Oral health care Issues. Hepatitis B. Virus First isolated in 1969

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Blood Borne Viruses

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  1. Blood Borne Viruses Rob Hale Consultant in Special Care Dentistry King’s College London Dental Institute

  2. Blood Borne Viruses • Viruses • HBV • HCV • HIV • Statistics • General • Prison • Occupation exposures • Oral health care Issues

  3. Hepatitis B Virus First isolated in 1969 Virions known as “Dane particles” Hepadna virus with circular DNA genome Clinical features incubation period of 2-5 months insidious onset asymptomatic infections can occur symptoms may include short, mild flu-like illness nausea, vomiting, diarrhoea loss of appetite, weight loss jaundice, itchy skin, muscle pain, arthralgia, rash

  4. Hepatitis B Pathogenesis infection transmitted parenterally virus replicates in liver viral particles, surface protein shed into blood About 30% have no signs or symptoms Most patients with clinical hepatitis will recover completely with no untoward long term effects

  5. Hepatitis B - complications • Carrier status HBV persists for > 6 months develops in 5-10% carriage may persist up to 20 years and be asymptomatic carrier status more likely in: those who have received blood products those co-infected with HDV those with immune defects • Persistent infection Approx 5% fail to eliminate the virus completely These at risk include – babies, young children, immunocompromised, males>females ongoing liver damage occurs because of host response against infected liver cells Chronic infection Chronic persistent hepatitis Chronic active hepatitis – cirrhosis, liver failure Hepatocellularcarcinoma Treatment for chronic HBV – Interferon Lamivudine

  6. Hepatitis B - serology Antigens Surface antigen ( HBsAg) virus replication is occurring in the liver “e” antigen ( HBeAg) high level of virus replication high infectivity Core antigen ( HBcAg) not found in blood

  7. Serology Antibody response Surface antibody (anti- HBs) Detectable late in convalescence, indicates immunity following infection, detectable for life, not found in chronic carriers “e” antibody (anti-Hbe) Detectable as viral replication falls, indicates low infectivity in a carrier Core IgM Rises early infection and indicates recent infection Core IgG Rises soon after IgM, present for life in chronic carriers and those who clear the virus , indicates exposure to HBV

  8. Hepatitis B - prevention • Active immunisation • Serum derived • Recombinant Three doses induces protective level of antibodies Vaccines should be administered to • healthcare workers • sexual partners of chronic carriers • infants of HBV carrier mothers • Passive antibody Hep B immune globulin administered to non immune individuals following single exposure to Hep b infected blood i.e. Needle stick injuries

  9. Hepatitis C Virus • Togavirus with single stranded RNA • six genotypes identified • responsible for most cases of “non-A, non B hepatitis” • ranks second only to alcoholism as cause of liver damage Clinical features • incubation period of 6-8 weeks • causes a milder form of acute hepatitis than HBV • No signs or symptoms for many on infection • Mild, flu-like illness, nausea, vomiting, loss of appetite, weight loss, jaundice • Many individuals develop chronic infection following exposure

  10. Hepatitis C Infection transmitted parenterally About 20% of individuals will clear the virus within 6 months but this does not mean they are immune from future infection 80% will develop chronic hepatitis C infection – remain lifelong carriers/infectious

  11. Hepatitis C Complications Chronic hepatitis Liver cirrhosis Liver failure Liver cancer (<3%) Treatment Interferon Ribavirin

  12. HIV/AIDS HIV Human immunodeficiency virus AIDS Acquired immunodeficiency syndrome What’s the difference?

  13. HIV RNA virus Reverse transcriptase Transmitted parenterally

  14. HIV antibody test • ELISA • Western blot A positive test indicates: • Exposure to the virus • Persistent infection • Infectiousness It does not indicate AIDS

  15. HIV Progression • Becoming HIV antibody positive • Seroconversion illness • Asymptomatic HIV infection • Symptomatic HIV infection • AIDS diagnosis

  16. Medical monitoring • FBC • CD4 • 600- 1600 cells/mm3 • Viral load

  17. Medical Monitoring CD4 • Monitors immune system • Help decide when to start therapy • Monitor effectiveness of drugs Viral Load • Identifies number of HIV particles • Help decide when to start therapy • Monitors effectiveness of drugs

  18. Medication • Highly active antiretroviral therapy (HAART • Reverse transcriptase inhibitors • Nucleoside analogues ( AZT,ddI, ddC, d4T) • Non-nucleoside analogues ( nevirapine) • Protease inhibitors • Saquinavir, Retonavir etc • Combination therapy

  19. Tiredness Back pain Fever Nausea Headache Vomiting Diarrhoea Abdominal pain Skin rash Changes in taste Burning sensation of skin Muscle pain Peripheral neuropathy Mouth ulcers Constipation Insomnia Lipodystrophy Side effects of medication

  20. Transmission of Blood Borne Viruses • Body fluids • Route

  21. Transmission • Blood/blood products • Organ donation • Sexual intercourse • Artificial insemination with infected semen • Horizontal transmission • Vertical transmission • Unknown – Hep C

  22. Statistics

  23. Hepatitis C Approx 191,000 individuals between 15-59 years with antibodies to Hep C in England & Wales in 2003 Equates to approx 142,000 individuals with chronic Hep C infection Approx 0.4% of general population In Scotland, approx 50,000 infected of which 38,000 have chronic infection Northern Ireland approx 4000 individuals likely to be infected

  24. Hepatitis C Difficult to estimate new infection rates due to long time between infection and development of severe disease/death Increase in incidence until late 1980s peaking at about 14,900 in 1988 Larger degree of uncertainty of estimates for later years

  25. Hepatitis C Wide variation of HCV incidence in injecting drug users England 3.01- 41.8% Scotland 11.9 – 28.4 % Establishing contribution of this incidence to future prevalence of infection requires knowledge of IDU population 2004 study estimated between 100,000 – 150,000 current injectors in England in 2000

  26. HIV • Estimated 77,400 persons living with HIV in UK by end of 2007 • During 2007 7,743 new diagnoses • 55% heterosexual contact – majority acquired HIV abroad • 41% MSM • 70% of persons seen for HIV care were receiving antiretroviral therapy • Almost one in five with severe immunosuppression were not on therapy • Almost a third of persons newly diagnosed were diagnosed late • At a point at which therapy should have begun (CD4<200 )

  27. HIV and hepatitis in prisons Globally rates of HIV and hepatitis in prisons are higher than general populations HIV England & Wales in 1997 – 0.3% adult males, 1.2% adult females Scotland in 1997 – 0.3% adult males, 0.6% adult females Hepatitis C England & Wales in 1997 – 9% adult males and 11% adult females Scotland – 8% adult males, 14.8% adult females

  28. HIV and hepatitis in prisons Since 1997 prison population has increased by approx 29% Has the number of prisoners infected with blood borne viruses also increased by this amount or more? Nature of prison population Risks of transmission specific to prison environment

  29. Nature of prison population High risk for infection even before imprisonment IV drug users • 29% female, 24% male, 4% young offenders >90% HCV infections are through IVDU

  30. Risks of transmission specific to prison environment IVDU • One in five prisoners report having used heroin at some time whilst in prison (SSD/NAC 2005) • Sharing of needles/equipment

  31. Risks of transmission specific to prison environment Sexual activity • 2% of a sample of 208 prisoner participants had had forced penetrative sexual intercourse (2004) • In a population of approx 75,000 – how many victims would that make! • How many new infections? • Overcrowding, mental health problems, inadequate staff levels, absence of conjugal rights, homophobia, general intolerance, restriction of condoms • Sexual behaviour in situation of intimidation and violence – more risk of tearing and bleeding

  32. Risks of transmission specific to prison environment Violence • Fights/assaults • One in 10 men reported being assaulted • Gross under reporting • When bleeding occurs – may be low risk for HIV but greater for HCV Tattooing • Sharing tattooing equipment • 11% of study sample had been tattooed in prison • Fifth of those who had been tattooed had been tattooed whilst in prison (Strang 1998)

  33. Occupational Exposure

  34. Occupational Exposure Since 1997 in UK: 3773 OE to blood or other high-risk body fluid 1595 of these from London 76% were percutaneous injuries

  35. Occupational exposure Risk of infection following a percutaneous injury: HBV 1 in 3 HCV 1 in 30 HIV 1in 300 Department of Health HIV Prophylaxis : Guidance from the UK Chief Medical officers Expert Advisory Group on AIDS September 2008From 2000-2007 68% attributed to hollow bore needles 19% solid needles 13% “other sharps” e.g scalpels, dental probes United Kingdom Surveillance of Significance Occupational Exposures to Blood Borne Viruses in Healthcare Workers 2008

  36. Occupational Exposure Deep penetrating injuries with hollow bore needles Device visibly contaminated with blood Needle from source patient's artery or vein Terminal HIV related illness in source patient

  37. Exposures to HCV,HIV HBV

  38. Exposures to HCV, HIV, HBV Of 15 seroconversions in UK: One dentist seroconverted to HCV reported in 2001

  39. Key recommendations Injuries with hollow bore needles remain most commonly reported occupational exposure in healthcare setting HCV exposures remain greatest proportion of percutaneous exposures HCWs exposed to HCV positive source patient still not receiving follow-up testing in line with national guidance No new HIV seroconversions since 1999 78% HCWs exposed to HIV positive source patient began PEP. 37% within an hour and 89% within 24 hours

  40. Post exposure prophylaxis • Truvada ( 300mg Tenofovir/200mg Emtricitabine) once a day (nucleoside reverse transcriptase inhibitor) • 2 Kaletra film-coated tablets ( 200mg Lopinavir/50mg Ritonavir) twice a day (protease inhibitor) • PEP as soon as possible after exposure, ideally within an hour following careful risk assessment • PEP now generally not recommended after 72 hours post exposure • Follow –up 12 weeks after exposure If PEP taken for at least 12 weeks from when PEP stopped Longer follow-up for complex/co-infected cases

  41. Truvada gastrointestinal disturbances (vomiting, abdominal pain, faltualence, diarrhoea) anorexia, pancreatitis, liver damage dyspnoea, cough, headache insomnia, dizziness, fatigue blood disorders (anaemia, neutropenia, thrombocytopenia) myalgia, arthralgia, rash, urticaria, fever Lypodystrophy, Kaletra gastrointestinal disturbances (vomiting, abdominal pain, faltualence, diarrhoea) anorexia., hepatic dysfunction, pancreatitis, blood disorders (anaemia, neutropenia, thrombocytopenia) sleep disturbances, headache, dizziness, fatigue, parathesia, Myalgia, myositis, rhabdomyolysis, taste disrturbances, rash, pruritis, Steven-Johnsons syndrome, lypodystrophy Side effects

  42. What if a healthcare worker becomes infected?

  43. Infected Health Care Workers • Seek confidential professional advice if believe to have been exposed • Majority procedures in health care setting pose no risk • Those infected must seek expert medical advice • Avoid exposure prone procedures

  44. The majority of procedures in dentistry are exposure prone except • Exam with mouth mirrors • Taking extra-oral radiographs • Visual/digital exam of head & neck • Visual/digital exam of edentulous mouth • Taking impressions of edentulous mouth • Construction & fitting of full dentures

  45. Oral Health Care (Decontamination and infection control – goes without saying)

  46. Oral health care Hepatitis Drug metabolism Bleeding tendencies Liaise with liver physician Prevention

  47. Dental treatment for HIV antibody positive individuals • Bleeding • Thrombocytopenia • Infections • Neutropenia • Antibiotic prophylaxis • Wound healing • Local anaesthesia • Indinavir reaction

  48. Oral Manifestations of HIV Infection • Group 1 - Lesions strongly associated with HIV infection • Group 2 – Lesions less commonly associated with HIV infection • Group 3 – Lesions seen in HIV infection

  49. Lesions strongly associated with HIV infection • Candidiasis - pseudomembranous erythematous • Oral hairy leukoplakia • Necrotising ulcerative gingivitis • Necrotising ulcerative periodontitis • Kaposi’s sarcoma • Non-Hodgkin’s lymphoma

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