Bloodborne Pathogens

1. Bloodborne Pathogens ENVH 451/541 November 12, 2008

2. Bloodborne Pathogens (BBPs) Present in Blood Other Potentially Infectious Materials or

3. Bloodborne Pathogens OPIM • any unfixed tissue or organ (other than intact skin) from a human (living or dead) • HIV- or HBV-containing cultures (cell, tissue, or organ), culture medium, or other solutions • blood, organs, & tissues from animals infected with HIV, HBV, or BBPs • semen • vaginal secretions • body fluids such as pleural, cerebrospinal, pericardial, peritoneal, synovial, and amniotic • saliva in dental procedures (if blood is present) • any body fluids visibly contaminated with blood • body fluid where it is difficult to differentiate

4. 2 Methods of Entry: • Mucocutaneous • Enters through mucus membranes • Percutaneous • Enters through some opening of the skin

5. Modes of Transmission • Mucocutaneous (through a mucous membrane) • Having infected blood or other body • fluids splashed into eyes, nose or • mouth

6. Modes of Transmission • Percutaneous (through the skin) • Being stuck with needles or other sharps • Having infected blood or other body • fluids splashed onto skin that is cut, • scratched, has sores or rashes or other • skin conditions

7. Bloodborne Pathogen Diseases Some examples of bloodborne pathogens: • Malaria • Syphilis • Brucellosis • Leptospirosis • Arboviral infections • Relapsing fever • Creutzfeld-Jakob Disease • Viral Hemorrhagic Fever • Ebola, Marburg Primary Pathogens of Concern: • Hepatitis B Virus (HBV) • Hepatitis C Virus (HCV) • Human Immunodeficiency Virus (HIV)

8. HIV

9. A global view of HIV infection33 million people [30–36 million] living with HIV, 2007

10. HIV/AIDS in King County • HIV - 2,773 • AIDS - 3,532 • HIV/AIDS - 6,305

11. HIV and AIDS The CDC defines AIDS as a positive HIV test and one of the following: The development of an opportunistic infection an infection that occurs when your immune system is impaired A CD4 lymphocyte count of 200 or less a normal count ranges from 800 to 1,200 directly attack and kill invading cells

12. Natural History of Infection

13. Symptoms • Immediately following infection • Nonspecific “viral illness” • Low grade fever, rash, muscle aches, headache, fatigue • Resolve in 5-10 days • Asymptomatic • Immune system is cycling with CD4 cells • AIDS • Extreme fatigue, rapid weight loss, swollen lymph nodes, dry cough and shortness of breath, night sweats

14. Management • No “cure” • HAART • “cocktail” of 3 -4 AR drugs • Difficult: complex regimes, severe side effects, compliance very important • Diarrhea, vomiting, nausea, headache, blurred vision, dizziness, congestion, dry mouth, fatique, body ache, fever, rash, sores, feeling loss, difficulty sleeping, changing body shape, hair loss, dry skin, etc.

15. HIV IN BLOOD • SURVIVAL OUTSIDE THE BODY • In dry blood the virus can survive for up to 6 days in laboratory conditions • QUANTITY OF VIRUS IN BLOOD • 1 mL of blood contains 200-10,000 particles of virus. • RISK OF INFECTION FOLLOWING NEEDLE STICK INJURY • Low - 0.3% - 3 people in 1,000. • RISK OF INFECTION FOLLOWING EYE SPLASH • Low - 0.09% * Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis. MMWR Recommendations and Reports, June 29, 2001 / 50(RRll);1-42. Centers for Disease Control and Prevention

16. Hepatitis C

17. Global Burden of HCV

18. Hepatitis C Symptoms • flu-like symptoms • jaundice • fatigue • dark urine • abdominal pain • loss of appetite • nausea

19. US HCV Infection • Incubation period Average 6-7 weeks • Range 2-26 weeks • Acute illness (jaundice) Mild (<20%) • Case fatality rate Low • 8-10 K • Chronic infection 60%-85% • 2.7M people • Chronic hepatitis 10%-70% • Cirrhosis <5%-20% • Mortality from CLD 1%-5%

20. Sources of Infection forPersons With Hepatitis C Injecting drug use 60% Sexual 15% Transfusion 10% (before screening) Occupational 4% Other 1%* Unknown 10% * Nosocomial; iatrogenic; perinatal Source: Sentinel Counties, CDC

21. Occupational Transmission • Inefficient by occupational exposures • Incidence 1.8% following needle stick from HCV-positive source • Associated with hollow-bore needles • Prevalence 1-2% among health care workers • Lower than adults in the general population • Most appear related to HCW substance abuse • No restrictions routinely recommended for HCV-infected HCWs

22. Perinatal Transmission of HCV • Transmission only from women HCV-RNA positive at delivery • Average rate of infection 6% • Higher (17%) if woman co-infected with HIV • Role of viral titer unclear • No association with • Delivery method • Breastfeeding • Infected infants do well • Severe hepatitis is rare

23. HEPATITIS C IN BLOOD • SURVIVAL OUTSIDE THE BODY • Little is known but likely to be the same as hepatitis B, up to 10 days • QUANTITY OF VIRUS IN BLOOD • 1 mL of blood contains 1,000 - 10,000 particles of virus • RISK OF INFECTION FOLLOWING NEEDLE STICK INJURY • Medium - 3% - 3 people in 100 • RISK OF INFECTION FOLLOWING EYE SPLASH • Low * Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis. MMWR Recommendations and Reports, June 29, 2001 / 50(RRll);1-42. Centers for Disease Control and Prevention

24. Hepatitis B

25. Hepatitis B Incubation • 60-120 days following infection Duration • Several weeks to months Symptoms • flu-like symptoms • fatigue • abdominal pain • loss of appetite • nausea, vomiting • joint pain • jaundice

26. Global Distribution of HBV ³8% - High

27. Global Patterns of Chronic HBV Infection • High (>8%): 45% of global population • lifetime risk of infection >60% • early childhood infections common • Intermediate (2%-7%): 43% of global population • lifetime risk of infection 20%-60% • infections occur in all age groups • Low (<2%): 12% of global population • lifetime risk of infection <20% • most infections occur in adult risk groups

28. Hepatitis B Incidence

29. Risk Factors Associated with Reported Hepatitis B, 1990-2000, United States *Other: Surgery, dental surgery, acupuncture, tattoo, other percutaneous injury Source: NNDSS/VHSP

30. Transmission of HBV • Concentration of HBV in various body fluids • High: Blood, serum, wound exudates • Medium: saliva, semen, and vaginal secretions • Low/not detectable: urine, feces, sweat, tears, breastmilk • Household transmission – less risk than percutaneous but significant - can occur in settings such as shared toothbrushes, razors, combs, washcloths

31. Transmission of HBV • Likelihood of becoming a carrier varies inversely with the age at which infection occurs. • Pool of carriers in U.S. is 1-1.25 million persons. • ~5000 persons die/yr. from HBV-related cirrhosis.

32. Prevention & Treatment • “Advisory Committee on Immunization Practices (ACIP) recommends that all children receive their first dose of hepatitis B vaccine at birth and complete the vaccine series by age 6–18 months” (CDC) • Adults where deficient • Acute Infection • no medication is available; treatment is supportive • Chronic Infection • several antiviral drug • require regular monitoring to determine whether disease is progressing and to identify liver damage or hepatocellular carcinoma.

33. HEPATITIS B IN BLOOD • SURVIVAL OUTSIDE THE BODY • In dry blood the virus can survive for up to 10 days • QUANTITY OF VIRUS IN BLOOD • 1 mL of blood contains 100,000,000 particles of virus • RISK OF INFECTION FOLLOWING NEEDLE STICK INJURY • Very High - 30% - 3 people in 10 • RISK OF INFECTION FOLLOWING EYE SPLASH • High. * Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis. MMWR Recommendations and Reports, June 29, 2001 / 50(RRll);1-42. Centers for Disease Control and Prevention

34. Occupational Exposure

35. Transmission of BBPs Occupational Exposure • means reasonably anticipated skin, eye, mucous membrane, or parenteral (piercing of the skin) contact with blood or OPIM that may result from the performance of an employee's duties Exposure Incident • is a specific contact with blood or OPIM that is capable of transmitting a bloodborne disease

36. Most Common Occupational Exposure Needlestick Injuries Over 85% of documented occupational transmissions

37. Health Care Workers and Bloodborne Pathogens • HBV: 6%-30% • HCV: 1.8%(range 0%-7%) • HIV: 0.3% Occupational Transmission Risk of infection following needlestick/cut from a positive (infected) source:

38. Transmission of BBPs Risk of infection depends on several factors: • The pathogen involved • The type/route of exposure • The amount of virus in the infected blood at the time of exposure • The amount of infected blood involved in the exposure • Whether post-exposure treatment was taken • Specific immune response of the infected individual Courtesy of Owen Mumford, Inc.

39. Causes of percutaneous injuries with hollow-bore needles, by % total percutaneous injuries Handling/transferring specimens Improperly disposed sharp Manipulating needle in patients Other Disposal-related causes 4% 5% 10% 27% 12% 8% 8% 11% 10% 5% IV line-related causes Collision w/health care worker or sharp Clean-up Handling or passing device during or after use Recapping Source: CDC [1999] Health Care Workers and BBPs Occupational Transmission • Most common: needlesticks • Cuts from other contaminated sharps (scalpels, broken glass, etc.) • Contact of mucous membranes (eye, nose, mouth) or broken (cut or abraded) skin with contaminated blood

40. Exposure Controls • Universal precautions (or equivalent system*) • Equipment and Safer Medical Devices • Work practices • Personal protective equipment • Housekeeping • Laundry handling • Hazard communication- labeling • Regulated Waste

41. Occupational Exposure Protection

42. Exposure Controls Unprotectedposition Protectedposition

43. Universal Precautions • A system of infection control in which all human blood and OPIM are treated as if known to be infectious with a bloodborne disease.