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Occupational Exposures to Bloodborne Pathogens

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Occupational Exposures to Bloodborne Pathogens Arjun Srinivasan Johns Hopkins Hospital Outline What s an exposure? 1st step in all exposures - Clean the site!! – PowerPoint PPT presentation

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Title: Occupational Exposures to Bloodborne Pathogens


1
Occupational Exposures to Bloodborne Pathogens
  • Arjun Srinivasan
  • Johns Hopkins Hospital

2
Outline
  • Whats an exposure?
  • 1st step in all exposures - Clean the site!!
  • Specific pathogens
  • Hepatitis C
  • Hepatitis B
  • HIV

3
Scope of the Problem
  • Difficult to asses up to 70 of exposures go
    unreported
  • (Marcus, R. et. al. Ann Emerg Med 199525776)
  • 1990 estimate 500,000 exposures/year
  • (Henry, K. Minnesota Medicine 19957841-44)
  • Costs are also tough to asses but JHH spent
    282,000 on post-exposure evaluation and
    treatment in 1998

4
Scope of the Problem
  • Impossible to measure the psychological stress
    that an exposure places on a health care worker

5
At Risk Exposures
  • 1. Percutaneous injury
  • Hollow needle gt Solid sharp
  • Visible blood
  • Deep injury
  • Device in patients artery or vein
  • 2. Splash on non-intact skin
  • 3. Splash on mucous membrane

6
Risks From Body Fluids
  • Known to be infectious
  • Blood
  • Any fluid visibly contaminated with blood
  • Semen
  • Vaginal secretions
  • Concentrated virus (used in labs)

7
Risks From Body Fluids
  • Potentially infectious
  • CSF
  • Pleural fluid
  • Pericardial fluid
  • Peritoneal fluid
  • Amniotic fluid
  • Synovial fluid
  • Tissue samples

8
Risks From Body Fluids
  • Not Infectious (if not visibly bloody)
  • Tears
  • Saliva
  • Urine
  • Feces
  • Sweat
  • Emesis

9
The Solution to Pollution . . .
  • Exposure site should be cleaned IMMEDIATELY!
    This may be the most important part of PEP
  • Skin wounds should be washed with soap and water
  • No evidence that antiseptics are useful and
    caustic agents (bleach) may do more harm than good

10
The Solution to Pollution (cont)
  • Mucous membranes should be flushed thoroughly
    with water
  • Eyes should be irrigated with a liter of saline

11
A word from our lawyers . . .
  • ALL exposures should be reported to the proper
    people (Occupational health, Employee health
    etc.)
  • Disability claims can be denied if follow up
    reporting was not done right

12
Hepatitis C
13
Hepatitis C Risk of Exposure
  • Risk of seroconversion following needlesticks
    involving Hep C positive patients is 0-7 (avg
    1.8)
  • (Kiyosawa, K. et.al. Ann Int Med 1991115367)
  • (Lanphear, B.P. et.al. Inf Ctrl Hosp Epi
    199415745)
  • Transmission via mucous membrane exposure
    described in one case
  • (Sartori, M. Jnl Inf Dis 199325270)

14
Hepatitis C Risk of Disease
15
Post Exposure Recommendations
  • Clean the site immediately
  • Hepatitis B immune globulin has NOT been
    effective
  • Interferon is NOT recommended at this time
  • (Infect Control Hosp Epi 199415742-4)
  • (MMWR 200150(RR-11)1-67)

16
Hepatitis C Follow Up
  • Enzyme linked immunoassay (EIA) is screening test
    of choice
  • ALL exposed HCWs should have LFTs monitored
  • Average interval between exposure and
    seroconversion with EIA is 8-10 weeks
  • Follow up guidelines vary - CDC recommends follow
    up at 4-6 months

17
Hepatitis C Follow up issues
  • EIA is falsely positive in up to 50 of HCW and
    falsely negative in 5 - results must be
    confirmed by RIBA or VL
  • PCR may catch infection earlier but detection is
    highly variable
  • Immediate referral for treatment if HCW
    seroconverts

18
Hepatitis C Counseling
  • Risk of transmission to infants and partners is
    thought to be low
  • Exposed HCW do not need to modify sexual
    practices, stop breast feeding or refrain from
    becoming pregnant
  • Should not donate blood
  • MMWR 200150(RR-11)23

19
Hepatitis B
20
Hepatitis B Risk of Exposure
  • Most infectious bloodborne pathogen
  • Risk of clinical hepatitis up to 30 in
    percutaneous exposures to patients who are e
    antigen positive
  • (Werner, B.J. et.al. Ann Int Med 198297367)
  • Risk from mucous membrane exposure less well
    defined but also felt to be high

21
Hepatits B Outcome of Infection
  • In patients who are infected with Hep B
  • 25 get jaundice
  • 5 require hospitilization
  • 6-10 become chronically infected
  • .125 die of fulminant hepatitis

22
Hepatitis B Good News
  • Most HCWs have been vaccinated and vaccine offers
    virtually complete protection to responders

23
Hepatitis B Bad News
  • Some employees are NOT vaccinated
  • 6-10 of vaccinees do NOT develop antibody
  • Really bad news
  • CDC estimates that 50-75 HCW die from Hep B each
    year

24
Hepatitis B Post Exposure
  • Clean the site immediately
  • Determine the vaccine status of the HCW
  • Determine the surface antigen status of the
    source patient

25
Hep B HCW Never Vaccinated
  • HCW should receive vaccine ASAP
  • 1. Source patient is sAg positive
  • HCW should also receive one dose of Hep B immune
    globulin (HBIG) .06ml/kg (1 vial5 ml) ASAP and
    absolutely within 7 days of exposure
  • 2. Source patient sAg neg or unknown
  • Vaccine alone

26
Hep B HCW Vaccinated(one or more doses)
  • Source patient should be tested for sAg AND HCW
    should be tested for sAb
  • If HCW has adequate Ab gt10 IU/mL (now or at any
    time) then no additional treatment

27
Hep B HCW Vaccinated
  • IF HCW has inadequate Ab
  • 1. If pt is sAg negative
  • HCW should get booster dose of vaccine (or
    complete series)
  • 2. If pt is sAg positive
  • HCW should receive HBIG AND a booster dose of
    vaccine at different sites (complete series if
    necessary)

28
Hep B HCW Vaccinated (cont.)
  • If HCW has inadequate Ab
  • 3. Unknown source
  • Give vaccine booster or complete series

29
Vaccine non-responders
  • If HCW has inadequate Ab after 3 dose series they
    should get another series 30-50 chance of
    responding to 2nd series
  • If no response to 2nd series HCW should be
    considered susceptible
  • PEP for known non-responders exposed to Hep B
    positive or high risk unknown sources 2 doses of
    HBIG- 1 at exposure then 4 weeks later

30
Hep B Follow Up Testing
  • Hepatitis B sAg is the test of choice as it rises
    in about 6 weeks
  • LFTs should be monitored at regular intervals

31
Post Exposure Counseling
  • Risk of transmission to infants and partners is
    thought to be low
  • Exposed HCW do not need to modify sexual
    practices, stop breast feeding or refrain from
    becoming pregnant
  • Should not donate blood
  • MMWR 200150(RR-11)23

32
HIV
33
HIV Risk of Exposure
  • Risk of transmission from percutaneous expsosures
    involving HIV positive pts estimated at 0.3
  • Risk from mucous membrane exposure estimated at
    0.1
  • As of 2000 there were 56 confirmed and 138
    possible cases of occupational transmission in
    the US

34
Rationale for PEP
  • HIV infects dendritic cells and then regional
    lymph nodes before becoming systemic
  • AZT blocks infectivity of HIV infected dendritic
    cells
  • Goal of PEP is to halt viral replication before
    systemic infection is established

35
Does It Work?
  • Several animal studies showing efficacy
  • Peri-natal prophylaxis has been effective
  • Retrospective study showed that risk of
    seroconversion after exposure was 81 lower in
    HCWs who took AZT PEP.
  • (NEJM 19973371485)

36
Time is Virus
  • Animal studies show that PEP should be given
    within 2-8 hours of exposure for maximal effect
  • (JID 1991163625 - Within 2 hrs optimal)
  • (JID 1993168825 - Within 8 hrs optimal)
  • PEP may have some benefit up to 36 hrs but seems
    to be ineffective if given later

37
What To Use?
  • Before AZT3TC /- IDV or NFV
  • Now Becoming more difficult to answer!
  • Regimens may need to be tailored based on the
    treatment history of the source patient
    -Surveillance study from 1998-1999 found that 39
    of virus from source patients had some NRTI
    resistance and 10 had some PI resistance.

38
Nucleoside Reverse Transcriptase Inhibitors (NRTI)
  • Still form the backbone of most regimens
  • AZT has been formally studied thus it should be
    included if possible
  • Addition of 3TC is recommended because
  • 1. It appears non-toxic
  • 2. It has some synergistic effect with AZT with
    respect to mutations

39
NRTI (cont)
  • If source patients virus is felt to be resistant
    to AZT or 3TC alternatives include
  • d4T 3TC
  • d4T ddI
  • Role of abacavir?
  • Role of tenofovir?

40
Protease Inhibitors (PI)
  • Are very potent anti-virals and work very well in
    patients
  • BUT they have significant side effects and can
    cause HCW to stop PEP altogether
  • PI should be recommended primarily when the
    exposure is high risk
  • Any PI can be used but indinavir and nelfinavir
    have been used the most

41
Non Nucleoside Reverse Transcriptase Inhibitors
(NNRTI)
  • Not much experience using these for PEP
  • Use should be reserved for situations when source
    patients virus is thought to be resistant to all
    PIs
  • Nevirapine should probably be avoided as PEP
    from 1997-2000 there were 22 reports of serious
    toxicity in HCW taking it for PEP

42
Toxicity of PEP
  • 50-90 of HCWs report some side effects from PEP
  • 24-36 of HCWs stop PEP because of side effects
  • PEP only works when taken - More may not be
    better!

43
Side Effects of PEP
  • All side effects have been described in some
    degree in HCWs on PEP
  • Serious side effects appear rare isolated
    reports of hepatitis and pancytopenia
  • Excluding problems with nevirapine, all side
    effects have reversed with stopping meds
  • (MMWR May 15, 1998/ 47(RR-7)1

44
PEP Counseling
  • Clean the site immediately
  • Determine the HIV status of the source
  • Determine the extent of the exposure

45
PEP management Source Patient Testing
  • Crucial 1st step as most exposures do NOT involve
    HIV positive patients
  • Rapid test kit (SUDS) is available and yields an
    answer in about 30 minutes
  • Rapid test is an EIA that is gt99.9 sensitive
  • Testing of blood on sharps is NOT recommended
  • Patient consent is required in Maryland

46
HIV RNA Testing of Source
  • No official recommendations and test is not
    approved for this indication
  • Should be reserved for cases where there is a
    suspicion of acute retroviral conversion

47
Source Patient
  • 1. Patient HIV negative - No PEP
  • 2. Patient HIV positive
  • Low viral load / high CD4 class 1
  • High viral load / low CD4 class 2
  • 3. Patient HIV positive, unknown CD4, VL
  • Use best judgement - err towards class 2
  • 4. Unknown source

48
Exposure Types
  • 1. Non-infectious fluids - No PEP
  • 2. Mucous membrane, non-intact skin
  • Small volume
  • Large volume
  • 3. Percutaneous injury
  • Less severe
  • More severe

49
HIV PEP Recommendations
  • Percutaneous injuries
  • Less severe
  • Source pt HIV negative - No PEP
  • Source pt class 1 - Recommend 2 drugs
  • Source pt class 2 - Recommend 3 drugs
  • Source of unknown status- Consider 2 drugs in
    setting where exposure to HIV positive pt likely
    or if pt has HIV risk factors

50
HIV PEP
  • Percutaneous Injuries (cont.)
  • More severe injury
  • Source pt HIV negative - No PEP
  • Source pt HIV class 1 or 2 - Recommend expanded
    3-drug regimen
  • Source of unknown status - Consider 2 drugs in
    setting where exposure to HIV positive pt likely
    or if pt has HIV risk factors

51
HIV PEP
  • Mucous membrane exposures
  • Small Volume
  • Source pt HIV negative - No PEP
  • Source pt class 1 - Consider 2 drugs
  • Source pt class 2 - Recommend 2 drugs
  • Source of unknown status- Consider 2 drugs in
    setting where exposure to HIV positive pt likely
    or if pt has HIV risk factors

52
HIV PEP
  • Mucous membrane exposures
  • Large volume
  • Source pt HIV negative - No PEP
  • Source pt class 1 - Recommend 2 drugs
  • Source pt class 2 - Recommend 3 drugs
  • Source of unknown status- Consider 2 drugs in
    setting where exposure to HIV positive pt likely
    or if pt has HIV risk factors

53
Duration of Treatment
  • Current recommendation is 4 weeks but this is an
    arbitrary selection
  • Animal studies suggest 10 days is too short but
    28 days conferred protection

54
Resistance
  • Becoming a significant problem now that so many
    patients are getting treated
  • Treatment history can be helpful in the acute
    setting
  • Recent history may be more important than remote

55
Resistance Issues
  • Full medical history often not available when the
    exposure occurs - PEP should NOT be delayed
  • Data from maternal transmission studies shows
    viral resistance does not preclude benefit

56
Resistance Issues
  • Consultation with someone experienced in HIV
    treatment is recommended in cases where HIV
    resistance is possible
  • PEP may need to be modified once more history is
    available
  • Resistance testing is too slow to be of use right
    now

57
PEP and Pregnancy
  • Women of child bearing age should be offered a
    pregnancy test before starting PEP
  • BUT, recommendations on starting PEP should NOT
    change just because HCW is pregnant

58
HIV medications to avoid in Pregnant HCW
  • d4T, ddI have been associated with severe lactic
    acidosis in pregnant women
  • Efavirenz is teratogenic in primates
  • Indinavir causes hyperbilirubinemia in newborns
    if given near time of delivery

59
Post Exposure Testing
  • Testing should be done at regular intervals (eg
    6,12 weeks and 6 months)
  • Testing should continue for 12 months if the HCW
    contracts HCV from the exposure
  • Unclear if testing should be prolonged in
    exposures to pts with HIV and HCV or in HCW who
    have history of impaired Ab responses

60
Post Exposure Testing
  • EIA is test of choice
  • Viral loads and p24 assays should be reserved for
    suspected cases of acute seroconversion given
    high false pos rate

61
Counseling
  • For 3 months following exposure HCW should avoid
  • -unprotected sex
  • -donating blood
  • -sharing razors, toothbrushes
  • HCW should consider stopping breast feeding
    (risk of perinatal transmission and drugs may get
    into breast milk)

62
Time to Seroconversion
  • Most HCW seroconvert in 6-12 weeks with median
    time of 46 days
  • 95 seroconvert within 6 months
  • 100 seroconvert in one year
  • Co-infection with HCV may delay HIV
    seroconversion

63
Acute Retroviral Conversion
  • Symptomatic seroconversion develops in 50-90 of
    cases
  • Average time from exposure to symptoms is 2-6
    weeks
  • ANY HCW who develops a flu-like illness in the
    follow up period should be encouraged to get HIV
    RNA testing

64
Resources
  • US Public Health Service Guidelines
  • www.cdc.gov/ncidod/hip
  • National PEP Hotline (run by UCSF)
  • 1-888-448-4911 (24 hrs)
  • www.ucsf.edu/hivcntr

65
Conclusion
  • People react very differently to exposures - be
    prepared for anything!
  • The psychological impact of an exposure can be
    enormous
  • Your patience and understanding may be the best
    PEP of all
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