1 Blood borne occupational health risks Terhi Heinäsmäki, MD March 10, 2004 Tartu, Estonia

2 A review: Occupational accidents in Helsinki, 1998

3 Occupational exposure to blood (USA) n All contacts –surgeons / year –obstetricians 77/ year –ward doctors 31/ year –emergency personnel 24/ year –ambulance personnel 12/ year n Penetrating injuries –surgeons 8-13 / year –obstetricians 4 / year –ward doctors 1.8 / year –emergency personnel 0.4 / year –ambulance personnel 0.2 / year –dentists 4-12/ year

4 Management of Occupational Blood Exposures n Make sure that the exposure is not repeated n Provide immediate care to the exposure site n Determine risk associated with exposure n Give post-exposure prophylaxis (PEP) for exposures posing risk of infection transmission n Perform follow-up testing and provide counseling

5 The risk of HIV-infection in exposure to HIV-infected blood n Penetrating injury –0.3 % (20/6202) –exposure to mucous membranes 0.09 % –exposure to intact skin <0.09 % n Work-related HIV-infections in health care personnel in USA up to June 1996* –documented 51 –possible108 –in Finland0 * S ource: MMWR1995:44; : case-control study

6 Risk factors for HIV infection in health-care workers after percutaneous exposure to HIV- infected blood n Deep injury RR 16.1 n Visible blood on device RR 5.2 n Procedure involving needle placed directly in a vein or artery RR 5.1 n Terminal AIDS in source patient RR 6.4 n Postexposure use of zidovudine RR 0.2 Source: MMWR1995:44; : case-control study

7 HIV-infective body fluids n blood and serum n semen n all bloody fluids n synovial fluid n pleural effusion n pericardial effusion n ascites n amniotic fluid n cerebrospinal fluid (CSF)

8 Possible occupational risks for HIV-infection n Needle injuries –intravenous catheters, cannules –contaminated i.v drug needles and vials n Human bites n Blood on broken skin or on eczema n Blood on mucous membranes

9 HIV post exposure prophylaxis n Less severe exposure, small amount of blood: 2 antiretrovirals –e.g. zidovudine+lamivudine < onset as soon as possible, preferably < 2 hours from exposure, up to 72 hours < 4-week regimen n Severe exposure, large amount of blood : 3 antiretrovirals –e.g. zidovudine+lamivudine +nelfinavir/ indinavir –4-week regimen n Follow-up up to 6-12 months

10 Hepatitis B n Infection through transfusion, sex, needles, transplacental n Hepatis B carrier state (HBs-Ag> 6kk) –infected as newborn 70-90% –adults 1-5% n 20-30% of carriers develop liver cirrhosis and 1-4% proceed to hepatoma n Recovered are immune for life n Effective vaccines available n Treatment available: interferon, lamivudine

11 Hepatis B in laboratory terms n HBs-Ag –acute or chronic hepatitis B, infective n Hbe-Ag –acute or chronic hepatitis B, highly infective n Hbs-Ab –has recovered from hepatitis B (non-carrier) or vaccinated n HBc-Ab –has recovered from hepatitis B or recovering from it, infectivity depends on HBs-Ag

12 Hepatis B -immunisation n Vaccine –manufactured in yeast using HBs-Ag as an antigen –three doses in 0,1 and 6 months –newborns 4 doses n Hyperimmunoglobuline (HBIG) –post exposure prophylaxis

13 Hepatitis B post exposure prophylaxis I n Unvaccinated or no immunity –hepatitis B hyperimmunoglobuline –initiate hepatitis B vaccination n Known source, hepatitis B status not known –examine HBs-ag as soon as possible n Source unknown or not available for testing –initiate hepatitis B vaccination

14 Hepatitis B post exposure prophylaxis II n Valid immunisation against HBV –all three doses given –HBs-Ab + confirms the immunity –no need for hyperimmunoglobuline –an extra dose of hepatitis B vaccine if the last dose was given more than five years ago –if HBs-Ab <10 IU/ml and confirmed HBs-Ag positive source, hyperimmunoglobuline

15 Hepatitis C n Infection through needles, transfusion, transplacental n 85% remain carriers n Cirrhosis develops in 20 % in 20 years n No vaccination n Treatment available: interferon, ribavirin n Post exposure prophylaxis not used –Follow up of serology and liver enzymes

16 Follow-up testing n From the source and exposed –HBs-Ag, (HBc-Ab), HCV-Ab, HIV-Ab –immediately, follow-up at 1, 3, and 6 months –HBs-Ab from the exposed, if given hepatitis B vaccine < HBsAb response to vaccine cannot be ascertained if HB immunoglobuline was received in the previous 3--4 months

17 Needle stick injury from a virus carrier: probability of virus transmission n Hepatis B –Hbe-Ag-positive source20-25 % –HBs-Ag- positive source 5 % n Hepatis C 1-5 % n HIV0.3 %

18 Occupational blood exposure n Real occupational risk is minimal –almost all exposures outside work n Safe working habits –do not recap the needle –separate container for sharp objects –safe techniques: sutures only with instruments, no blind handling of sharp objects etc n Protection –vaccination against hepatitis B –gloves (double), masks, gowns