Transcript Blood borne diseases

Blood borne occupational
health risks
Terhi Heinäsmäki, MD
March 10, 2004
Tartu, Estonia
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A review:
Occupational accidents in Helsinki, 1998
Other
15 %
Taking blood test
(phlebotomy)
13 %
Blood or bloody
specimen
2%
Setting infusion
5%
Removing bloody
device
5%
Resetting the
needle cap
15 %
Sharp object
injury
29 %
Operation/
precedure 16 %
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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 Exposures
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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 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
– possible
– in Finland
51
108
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 HIVinfected blood
Deep injury
 Visible blood on device

RR 16.1
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 fluids

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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-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 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 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
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Effective vaccines available
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Treatment available: interferon, lamivudine 10
Hepatis B in laboratory terms
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HBs-Ag
– acute or chronic hepatitis B, infective
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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 -immunisation
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Vaccine
– manufactured in yeast using HBs-Ag as an
antigen
– three doses in 0,1 and 6 months
– newborns 4 doses
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Hyperimmunoglobuline (HBIG)
– post exposure prophylaxis
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Hepatitis B post exposure
prophylaxis I
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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 II
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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 C
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Infection through needles, transfusion,
transplacental
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85% remain carriers
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Cirrhosis develops in 20 % in 20 years
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No vaccination
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Treatment available: interferon, ribavirin
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Post exposure prophylaxis not used
– Follow up of serology and liver enzymes
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Follow-up testing
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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 transmission

Hepatis B
– Hbe-Ag-positive source
– HBs-Ag- positive source
Hepatis C
 HIV

20-25 %
5%
1-5 %
0.3 %
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Occupational blood exposure
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Real occupational risk is minimal
– almost all exposures outside work
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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
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