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Blood borne occupational health risks

Blood borne occupational health risks

Terhi Heinäsmäki, MD

March 10, 2004

Tartu, Estonia

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A review:

Occupational accidents in Helsinki, 1998

A review:

Occupational accidents in Helsinki, 1998

Removing bloody device

5 %

Taking blood test (phlebotomy)

13 %Other15 %

Blood or bloody specimen

2 %

Operation/ precedure 16 %

Setting infusion5 %

Sharp object injury29 %

Resetting the needle cap

15 %

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Occupational exposure to blood (USA)Occupational exposure to blood (USA)

All contacts– surgeons 81-135/ year– obstetricians 77/ year– ward doctors 31/ year– emergency personnel

24/ year– ambulance personnel

12/ year

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

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Management of Occupational Blood ExposuresManagement of Occupational Blood Exposures

Make sure that the exposure is not repeated Provide immediate care to the exposure site Determine risk associated with exposure Give post-exposure prophylaxis (PEP) for

exposures posing risk of infection transmission

Perform follow-up testing and provide counseling

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The risk of HIV-infection in exposure to HIV-infected bloodThe risk of HIV-infection in exposure to HIV-infected blood

Penetrating injury– 0.3 % (20/6202)– exposure to mucous membranes 0.09 %– exposure to intact skin <0.09 %

Work-related HIV-infections in health care personnel in USA up to June 1996*

– documented 51– possible 108– in Finland 0

* S ource: MMWR1995:44;929-933: case-control study

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Risk factors for HIV infection in health-care workers after percutaneous exposure to HIV-infected blood

Risk factors for HIV infection in health-care workers after percutaneous exposure to HIV-infected blood

Deep injury RR 16.1 Visible blood on device RR 5.2 Procedure involving needle placed

directly in a vein or artery RR 5.1 Terminal AIDS in source patient RR 6.4 Postexposure use of zidovudine RR 0.2

Source: MMWR1995:44;929-933: case-control study

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HIV-infective body fluidsHIV-infective body fluids

blood and serum semen all bloody fluids synovial fluid pleural effusion pericardial effusion ascites amniotic fluid cerebrospinal fluid (CSF)

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Possible occupational risks for HIV-infectionPossible occupational risks for HIV-infection

Needle injuries– intravenous catheters, cannules– contaminated i.v drug needles and vials

Human bites Blood on broken skin or on eczema Blood on mucous membranes

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HIV post exposure prophylaxisHIV post exposure prophylaxis

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

Severe exposure, large amount of blood : 3 antiretrovirals– e.g. zidovudine+lamivudine +nelfinavir/ indinavir

– 4-week regimen Follow-up up to 6-12 months

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Hepatitis BHepatitis B

Infection through transfusion, sex, needles, transplacental

Hepatis B carrier state (HBs-Ag> 6kk)– infected as newborn 70-90%

– adults 1-5%

20-30% of carriers develop liver cirrhosis and 1-4% proceed to hepatoma

Recovered are immune for life Effective vaccines available Treatment available: interferon, lamivudine

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Hepatis B in laboratory termsHepatis B in laboratory terms

HBs-Ag– acute or chronic hepatitis B, infective

Hbe-Ag– acute or chronic hepatitis B, highly infective

Hbs-Ab– has recovered from hepatitis B (non-carrier) or vaccinated

HBc-Ab– has recovered from hepatitis B or recovering from it,

infectivity depends on HBs-Ag

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Hepatis B -immunisationHepatis B -immunisation

Vaccine– manufactured in yeast using HBs-Ag as an

antigen– three doses in 0,1 and 6 months– newborns 4 doses

Hyperimmunoglobuline (HBIG)– post exposure prophylaxis

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Hepatitis B post exposure prophylaxis IHepatitis B post exposure prophylaxis I

Unvaccinated or no immunity– hepatitis B hyperimmunoglobuline– initiate hepatitis B vaccination

Known source, hepatitis B status not known – examine HBs-ag as soon as possible

Source unknown or not available for testing– initiate hepatitis B vaccination

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Hepatitis B post exposure prophylaxis IIHepatitis B post exposure prophylaxis II

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

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Hepatitis CHepatitis C

Infection through needles, transfusion, transplacental

85% remain carriers Cirrhosis develops in 20 % in 20 years No vaccination Treatment available: interferon, ribavirin Post exposure prophylaxis not used

– Follow up of serology and liver enzymes

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Follow-up testing Follow-up testing

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

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Needle stick injury from a virus carrier: probability of virus transmissionNeedle stick injury from a virus carrier: probability of virus transmission

Hepatis B– Hbe-Ag-positive source 20-25 %– HBs-Ag- positive source 5 %

Hepatis C 1-5 % HIV 0.3 %

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Occupational blood exposureOccupational blood exposure

Real occupational risk is minimal– almost all exposures outside work

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

Protection – vaccination against hepatitis B– gloves (double), masks, gowns