ARO Training & Consulting
Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 69
Blood and Body Fluid Exposure Follow-up
Objectives:
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Describe the role of immunization with respect to prevention of HBV, HCV
and HIV infections.
Describe the role of prophylactic treatment with respect to prevention of
HBV, HCV and HIV infections, following exposure to blood or body fluids.
Describe post-exposure concerns and follow-up procedures that should be
initiated following exposure to blood and/or body fluids.
Describe safety measures associated with prevention of blood-borne
pathogen infection following exposure.
Introduction
As discussed previously, HBV infection is largely preventable through
immunization; however, currently there is no vaccine available for use in
preventing HCV and HIV infections.
Although occupational exposures to blood can be prevented in many cases by
the use of appropriate barriers, adherence to safe handling policies and the use
of devices with safety features, accidents still occur.
Development, implementation and communication of a post-exposure follow-up
protocol is essential to ensure that exposed workers receive treatment, testing,
follow-up management, and counselling that may help prevent infection,
unnecessary worry and anxiety.
Risk of infection following exposure to blood
HBV
The risk of BBP infection following percutaneous exposure to blood is directly
proportional to:
- the probability that the blood contains hepatitis B surface antigen (HBsAg)
- the immune status of the recipient
- the efficiency of transmission
Probability of blood containing HbsAg
The probability of the source blood being HBsAg positive ranges from 1 to 3 per
thousand (0.1 – 0.3%) in the general population, to 5-15% in high risk groups:
- immigrants from highly endemic regions (China and Southeast Asia, subSaharan Africa, most Pacific islands and the Amazon Basin)
- intravenous drug users (IDU)
- men who have sex with men
- household (sexual and non-sexual) contacts of HBV carriers
ARO Training & Consulting
Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 70
Recipient Immune Status
There is essentially no risk of contracting HBV infection following exposure to
blood, if the worker has been immunized with HBV vaccine and has developed
an adequate antibody response to the HBsAg.
If the worker is non-immune (HBsAb-negative), the risk of infection following
exposure to HBV infected blood varies, depending on the presence of ‘e’ antigen
(HBeAg) in the source patient’s blood.
As discussed previously, the relative risk of HBV transmission to a non-immune
individual following needle-stick exposure to HBeAg-negative blood ranges from
1-6%; whereas, in HBeAg-positive blood the risk of transmission ranges from 1940%. HBeAg-positive blood is associated with a higher transmission rate,
presumably because the number of infectious viral particles is greater than in
HBeAg-negative blood.
Efficiency of transmission
Blood contains the highest concentration of blood-borne viruses of all body fluids,
and is the most important mode of transmission in the health-care setting.
Percutaneous injuries</b> are the main source of occupational exposures to
blood-borne pathogens. The Canadian Needle Stick Surveillance Network
(CNSSN) indicated that during the first 6 months of data collection in 2000-2002,
HCWs in 12 participating centres were exposed to 497 known patient sources 48 of which tested positive for a blood-borne pathogen. HCV accounted for more
than half of the blood-borne pathogens, HBV accounted for 15 %, and HIV
accounted for 20%. In addition, 3 of the source patients were positive for HIV and
HCV.
Link: The Canadian Needle Stick Surveillance Network. http://www.hcsc.gc.ca/pphb-dgspsp/publicat/ccdr-rmtc/01vol27/27s3/27s3n_e.html
Percutaneous exposure
The risk of infection following exposure to HIV and/or HCV-positive blood is much
lower than that for HBV-positive blood, possibly due to higher concentrations of
virus in the blood of HBV-infected patients.
HCV
The relative risk for infection after a needle-stick or sharps injury involving HCVinfected blood is approximately 2.7%.
ARO Training & Consulting
Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 71
HIV
Currently, the relative risk of infection following one needle-stick exposure to
blood from a patient known to be infected with HIV is approximately 0.3-0.5%.
Published studies on HIV sero-prevalence rates in exposed HCWs are needed to
effectively determine the extent of occupational risk of HIV infection.
There are more than 50 documented episodes of occupationally acquired HIV
infection in the U.S., of which almost 40% occurred during phlebotomy.
In Canada, there has been only one documented case of HIV transmission to a
HCW – infection occurred following a needle-stick injury.
Mucous membrane exposure
HBV
The risk of transmission following mucous membrane exposure is unknown.
HCV
The risk of HCV transmission following blood exposures to the eye, nose or
mouth is currently unknown, but thought to be small.
HIV
The risk of seroconversion
approximately 0.09%.
following
mucous
membrane
exposure
is
Non-intact skin exposure
The risk of HBV and HCV transmissions following exposure to non-intact skin is
unknown.
HIV transmissions following exposure of non-intact skin to blood have been
documented, but the relative risk is currently unknown, although it is expected to
be less than the risk following mucous membrane exposure, and far less than
that from percutaneous injection.
Relative Risk
HBV
The risk of contracting HBV infection following exposure to various body fluids is
unknown. Although HBsAg is found in several body fluids, the concentration of
infectious HBV particles is 100-1000 times lower than the concentrations of
HBsAg, and is not an efficient source of transmission.
HCV
The risk of contracting HCV infection following exposure to various body fluids
other than blood is unknown.
ARO Training & Consulting
Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 72
HIV
The risk of HIV transmission following exposure to fluids or tissues, other than
HIV-infected blood, has not been quantified, but is thought to be lower than the
probability associated with exposure to blood.
Recommendations concerning the management of health care workers following
an occupational exposure to bloodborne pathogens have recently been
published as a supplement to the Canada Communicable Disease Report
entitled "An Integrated Protocol to Manage Health Care Workers Exposed to
Bloodborne Pathogens".
Exposure follow-up (Act/Report/Test/Treat/Surveillance/ /Document)
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Act
Report
Initial testing
Treat
Surveillance testing
Document
Act Immediately!
Needle-sticks and cuts
- express (squeeze) fluid from wound, if appropriate (needle-stick)
- wash site well with disinfectant soap and water
- bandage wound
Splash to mucous membranes
Nose, mouth or skin
- flush with water
Eyes
- irrigate with clean water, saline or sterile irrigants
Report the Exposure
Report the exposure to your immediate supervisor, the occupational health clinic,
and risk management.
Your supervisor must complete the appropriate forms for Worker’s Compensation
in the event that time is missed from work.
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Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 73
Confidential 24-hour service should be available to HCWs in the event of a blood
and/or body fluid exposure. Occupational health will counsel the HCW, order
blood tests, refer the HCW for treatment as appropriate, investigate and follow-up
exposures, and document the incident.
Initial Testing
Follow-up testing should be available to all personnel who are concerned about
possible infection through occupational exposure. Post-exposure testing
protocols may vary slightly from one institution to another.
Initial (Baseline) Testing - All Exposures
Once an exposure has occurred, a blood sample should be drawn and tested for
HBsAb, if testing has not been performed within the previous 12 months.
Exposed workers should also be tested for antibodies to HCV and HIV.
Testing for HBsAg and antibodies to HCV and HIV should also be performed on
the exposure source - consent from the source individual is required before blood
samples can be collected and tested.
If the source refuses testing, s/he should be considered infectious.
Treatment and Counselling - HBV
Follow-up testing should be available to all personnel who are concerned about
possible infection through occupational exposure.
Source Negative for HBV
If the source individual is negative for HBsAg and the worker has not been
vaccinated, HBV vaccination should be initiated to provide protection against
future exposures.
If the worker has been vaccinated, and demonstrates adequate levels of HBsAb
no further action is necessary. If the worker has inadequate levels of HBsAb, a
second series of vaccine should be initiated.
Source HBV Status Unknown, Source Refuses Testing, or is HBV Positive
If the source is unknown or refuses testing, s/he should be considered infectious
for HBV.
If the patient tests positive for HBV (HBsAg-positive and/or HBeAg-positive), s/he
is considered infectious for HBV.
In these cases, the exposed worker should be tested for HBsAb, and treated as
described below.
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Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 74
HBV Immunized Worker
If the HCW has received 3 HBV vaccine doses and demonstrates antibodies to
HBV (within past year), no further action is necessary.
If the HCW has received 2 HBV vaccine doses and demonstrates antibodies to
HBV, resume vaccination schedule.
If HBV antibody levels are inadequate, the exposed worker should receive
{glossary}prophylactic{/glossary} treatment - one dose of vaccine and one dose
of {glossary}hepatitis B immune globulin{/glossary} (HBIG) within 48 hours of
exposure.
Non-Immunized Worker
Non-immunized workers should receive prophylactic treatment - HBV vaccine
and a single dose of hepatitis B immune globulin (HBIG) within 48 hours of
exposure.
If the worker has not been immunized, or has only been partially immunized, and
is non-immune (i.e. HBsAb negative), a single dose of hepatitis B immune
globulin (HBIG) is recommended within 48 hours of exposure, and if the worker
has not previously received HBV vaccine or completed the vaccine schedule,
immunization should be resumed or continued.
Treatment and Counselling - HCV
Follow-up testing should be available to all personnel who are concerned about
possible infection through occupational exposure.
If the source individual's HCV status is unknown, or s/he refuses testing or tests
positive for HCV, surveillance testing should be performed in the exposed
worker. Surveillance testing for anti-HCV should be performed at a minimum of 6
and 12 months, and possibly even at 3 months following exposure.
All illnesses occurring during this period (especially those involving fever) should
be reported to the healthcare provider.
Treatment and Counselling - HIV
Follow-up testing should be available to all personnel who are concerned about
possible infection through occupational exposure.
When the HIV status of the source individuals is unknown, or if the source
refuses testing or tests positive for HIV, surveillance testing should be performed
on the exposed worker.
Testing for anti-HIV should be performed at 3, 6 and 12 months following
exposure.
ARO Training & Consulting
Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 75
All illnesses occurring during this period (especially those involving fever) should
be reported to the healthcare provider.
HBV Prophylactic Treatment
HBV vaccines are 70%-88% effective when given within 1 week after HBV
exposure (optimally within 24 hours of exposure).
Hepatitis B immune globulin (HBIG), a preparation of immunoglobulin with high
levels of antibody to HBV (anti-HBs), provides temporary passive protection
following exposure to HBV.
HBIG alone or in combination with vaccine is effective in preventing HBV
infection in approximately 90% of cases.
HBV infection during pregnancy can cause severe illness in the mother and
chronic infection in the newborn. HBV vaccine and HBIG therapy is safe for use
during pregnancy and while breast-feeding, and should be administered following
exposure to HBV infected blood.
HCV Prophylactic Treatment
Currently, there is no available HCV vaccine (vaccine development has been
problematic due to the rapid mutation rate and multiple genotypes).
Immune globulin and antiviral agents (interferon with or without ribavirin) are not
recommended for post-exposure prophylaxis (PEP) of hepatitis C. Clinical trials
have not been conducted to adequately assess post-exposure use of antiviral
agents (interferon +/- ribavirin) for prevention of HCV infection, and FDA-approval
does not extend to prophylactic treatment.
Following exposure to an HCV-positive source, the HCV status of the exposed
worker should be determined initially, and follow-up testing should be performed
to determine if infection develops.
HIV Prophylactic Treatment
Although drugs for the treatment of existing HIV infection have been approved by
the FDA, they have not been approved as prophylactic treatment to prevent
infection; however, physicians may prescribe any approved drug if it is their
professional judgment that use of the drug is warranted.
Results from a small number of studies suggest that the use of some
antiretroviral drugs after certain occupational exposures may reduce the chance
of HIV transmission. Post-exposure prophylaxis (PEP) is recommended for
certain occupational exposure that pose a risk of HIV transmission.
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Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 76
PEP is not recommended when there is no risk of transmission, because the
drugs used to prevent infection may have serious side-effects.
Pregnancy should not rule out the use of post-exposure treatment, if it is
warranted.
The potential benefits and risks associated with the use of anti-HIV drugs should
be discussed with the healthcare provider in order that the individual can make
an informed decision about prophylactic treatment.
As described earlier, following exposure to an HIV-positive source, the HIV status
of the exposed worker should be determined initially, and follow-up testing
performed as early as 6 weeks post-exposure, and then again at 3 months, 6
months and 12 months to determine whether {glossary}seroconversion{/glossary}
and transmission has occurred.
HBV Prophylactic Treatment Side-effects
HBV vaccine and HBIG are considered very safe; however, any unusual reaction
should be reported. The most common side-effects include pain at the injection
site and fever (mild to moderate).
HBV Vaccine
Rarely, temporary or permanent hair loss has been reported following HBV
immunization.
Rarely, anaphylaxis has been reported in vaccine recipients (1/600,000), and
although none of the persons who developed anaphylaxis died, anaphylactic
reactions can be life-threatening, and further HBV vaccination is contraindicated
in persons with a history of anaphylaxis after a previous dose of vaccine.
HBIG
HBIG is prepared from human plasma containing a high titer of antibody to
HBsAg (HBsAb). The plasma is first screened for HBsAg and antibodies to HIV
(anti-HIV) and HCV (anti-HCV), and then processed to inactivate and eliminate
HIV, HCV and other viruses.
The most common side-effects following HBIG treatment involve local pain and
tenderness at the injection site, itching and swelling.
Anaphylactic reactions have been reported rarely - individuals with a history of
anaphylactic reaction to immunoglobulins should not receive HBIG.
ARO Training & Consulting
Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 77
HIV Prophylactic Treatment Side-effects
Side-effects have been associated with all HIV antiviral drugs – the most
common side-effects include upset stomach (nausea, vomiting, diarrhea),
fatigue, or headache.
Serious side-effects following combination antiviral therapy have been reported –
symptoms include stones, hepatitis, and suppressed blood cell production.
If prophylactic treatment is given, the exposed individual should be checked for
drug toxicity (complete blood count and kidney and liver function tests) before
starting treatment, and then again 2 weeks after starting treatment.
Surveillance Testing
HCV Positive or high-risk source
Workers who initially test negative for HCV antibodies (baseline testing) should
be retested again as early as 6 weeks post-exposure, then 3 months, 6 months,
and 12 months, to determine whether seroconversion and HCV transmission has
occurred.
Any sudden or severe flu-like illness occurring during the follow-up period should
be reported to a healthcare practitioner, especially if fever, rash, muscle-aches,
fatigue, malaise, or swollen glands are involved.
HIV Positive or high-risk source
Workers who initially test negative for HIV antibodies should be retested as early
as 6 weeks post-exposure, then again at 3 months, 6 months, and possibly 12
months, to determine whether seroconversion and HIV transmission has
occurred.
Exposed workers should refrain from donating blood, and be strongly
encouraged to use barrier protection during sexual intercourse during the followup period.
Any sudden or severe flu-like illness occurring during the follow-up period should
be reported to a healthcare practitioner, especially if fever, rash, muscle-aches,
fatigue, malaise, or swollen glands are involved.
Seronegative Source
If the source is known to be negative for HBsAg and antibodies to HCV and HIV,
and has no known high-risk behaviours, exposed workers should receive
baseline testing, and follow-up testing 3 months later, as recommended by the
healthcare practitioner.
ARO Training & Consulting
Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 78
Source Unknown, Unidentified or Refuses to be Tested
If the source is unknown, decisions regarding follow-up testing should be based
on the individual risk, in consultation with the healthcare provider.
Serologic testing should be made available to workers concerned that they have
been infected with HIV.
Reference:http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/noib-inpb/no41002_e.html
Worker refuses follow-up
If worker refuses to follow OH polices, he/she must sign a waiver indicating that
he/she is aware of the consequences of exposure to HBV, HCV and HIV, and
does not wish to comply with follow-up protocols.
Documentation
Exposed individuals should complete an incident report, report to risk
management and complete Workmen’s Compensation Board (or local
equivalent) documents, as required..
The circumstances of exposure should be recorded, including the activity during
which the worker was exposed, work practices and protective equipment that
were used, and a description of the source of exposure.
Prevention of Transmission Following Exposure
HBV
If you are exposed to HBV and receive post-exposure treatment, it is unlikely that
you will become infected and pass the infection on to others. No precautions are
recommended.
HCV
Because the risk of becoming infected and passing the infection on to others
after an exposure to HCV is low, no precautions are recommended.
HIV
During the follow-up period (especially the first 6-12 weeks following exposure
when most persons are expected to show signs of infection), the exposed worker
should follow the recommendations for preventing transmission of HIV - not
donating blood, semen, or organs, and not having sexual intercourse. Condom
use should be very strongly encouraged if the worker has been exposed to an
HIV-positive, high risk or unknown source.
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Bloodborne Pathogens
Module 6: Blood and Body Fluid Exposure Follow-up
Page 79
Exposed women should consider not breast-feeding infants during the follow-up
period to prevent the possibility of exposing their infants to HIV that may be in
breast milk.
Management of human bites
When bites occur (police and correctional-facility officers are intentionally bitten
by suspects or prisoners), routine medical and surgical therapy (including an
assessment of tetanus vaccination status) should be implemented as soon as
possible. Such bites frequently result in infection with organisms other than HIV
and HBV.
Victims of bites should be evaluated as described above for exposure to blood or
other infectious body fluids. Saliva of some persons infected with HBV has been
shown to contain HBV-DNA at concentrations 1/1,000 to 1/10,000 of that found in
the infected person's serum. HBsAg-positive saliva has been shown to be
infectious when injected into experimental animals and in human bite exposures.
However, HBsAg-positive saliva has not been shown to be infectious following
oral mucous membrane exposure, or through contamination of musical
instruments or cardiopulmonary resuscitation dummies used by HBV carriers.
Studies of nonsexual household contacts of HIV-infected patients suggest that
the potential for salivary transmission of HIV is remote.
The Importance of Hand washing
Hands and other exposed skin surfaces should be washed immediately and
thoroughly if contaminated with blood or other body fluids to which universal
precautions apply, or potentially contaminated articles. Hands should always be
washed after gloves are removed, even if the gloves appear to be intact. Hand
washing should be completed using the appropriate facilities, such as utility or
restroom sinks. Waterless antiseptic hand cleanser should be provided on
responding units to use when hand-washing facilities are not available. When
hand-washing facilities are available, wash hands with warm water and soap.
When hand-washing facilities are not available, use a waterless antiseptic hand
cleanser. The manufacturer's recommendations for the product should be
followed.
Reference:http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/noib-inpb/no4-1002_e.html
Compliance with post-exposure plan
Among 77 HCWs exposed to patients with HCV, the follow-up rate was 84% at
baseline, 31% presented for follow-up 3 months later, and only 12% presented
for follow-up after 6 months. One HCW was anti-HCV positive at baseline (i.e.,
infected prior to exposure). Among 24 HCWs exposed to patients with HIV, the
follow-up rates for anti-HIV was 75% at baseline, 54% presented for follow-up 6
weeks later and 33% presented for follow-up at 3 months.
Reference:http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/noib-inpb/no4-1002_e.html