Transcript Useful Facts about TB Infection

Testing Positive to
Contagious Disease
Jean Marie McMahon MD
Tuberculosis
Useful Facts about TB
Infection
• TB is carried in airborne
particles called droplet nuclei.
• These droplet nuclei are
generated when persons who
have pulmonary or laryngeal
TB disease cough, sneeze,
shout or sing.
• Normal air currents can keep
them airborne for prolonged
periods.
• Droplet nuclei are
approximately 1-5 um in
diameter.
Fraction of particles deposited in the three respiratory tract compartments as a function of
particle diameter.
Stanek L W et al. Toxicol. Sci. 2011;120:S8-S27
Published by Oxford University Press 2010.
More Useful Facts about TB
Infection
• Usually within 2 - 12 weeks after initial
infection with M. tuberculosis, the
immune response limits additional
multiplication of the tubercle bacilli and
immunologic test results for M.
tuberculosis infection become positive.
The Tuberculin Skin Test
(TST)
• Although currently
available preparations of
PPD used in the TST are
< 100% sensitive and
specific for detection of
tuberculosis infection, the
TST is currently the most
widely used diagnostic
test for tuberculosis
infection.
Sensitivity of the TST
• Sensitivity of a test refers to the
percentage of people who have the
disease who test positive with the test.
• A person with active TB might actually
have a negative TST result.
• A person with severe problems with their
immune system might have a negative TST
result.
Specificity of the TST
• The specificity of a test refers to the
percentage of people who do not have
the disease who will have a negative
test for the disease.
• BCG vaccination
• Infection with other types of Mycobacteria
Blood Assay for M. tuberculosis
(BAMT)
• This test measures the immune response of your
blood cells (in a test tube) to two M. tuberculosis
proteins that are not present in BCG and that are
absent from the majority of non-tuberculosis causing
mycobacteria.
• More specific than the TST – if you test positive,
you are probably infected with M. tuberculosis.
BAMT - Sensitivity
• Conditions requiring caution in
interpreting negative BAMT’s:
• HIV, treatment with immunosuppressive
drugs (organ transplantation), TNF-alpha
• Diabetes, silicosis, chronic renal failure
• Leukemia, lymphoma, cancers of the head,
neck or lung
Boosting
• Occurs in:
• Remote TB
infections.
• MOTT infection
• Previous BCG
vaccination
Boosting
• In these people, the immune response to
mycobacteria may have waned and might not be
elicited on the first TST.
• A second TST, performed 1-3 weeks after the 1st will
be positive.
• Important: This person did not become infected
between tests. He had been infected all along. But if
he was not tested using a 2-step procedure, it will
look like he was infected during the interval between
the tests.
Baseline Testing for M.
tuberculosis infection
• The CDC recommends that baseline
testing be performed for all newly hired
HCW’s, regardless of the risk
classification of the setting.
• Can be done with TST or BAMT.
• If TST chosen, 2-step testing is
recommended for HCW’s whose initial
TST results are negative.
Exceptions to the 2-step Rule
• Previous documented negative TST < 12
months before new employment
• > 2 previous documented negative TST’s.
• Previous documented positive TST
Everyone Else Gets a 2-step
upon Hire
• Including:
• People who say they have tested positive
in the past but cannot document that.
• One previous negative TST (documented
or not) > 12 months before employment.
Pregnancy
• Tens of thousands of pregnant women have received
TST without any documented episodes of TST-related
fetal harm.
• There is no evidence that the TST has adverse effects on
the pregnant mother or fetus.
• Pregnant HCW’s should be included in serial skin
testing as part of an infection control program or a
contact investigation.
• Guidelines issued by The ACOG emphasize that
postponement of the diagnosis of infection with M.
tuberculosis during pregnancy is unacceptable.
BCG
•
•
•
•
BCG is the most commonly used vaccine in the world.
Some people who receive BCG never have a positive result.
For others, the positive reaction wanes after 5 years.
US guidelines state that a positive TST result in a person who
received BCG should be interpreted as indicative of infection.
• HCW’s who have previously received a BCG vaccination should
receive baseline and serial skin testing in the same manner as
those who have not received a BCG vaccination.
• This would be a good situation in which to use the BAMT.
Morbidity and Mortality
Weekly Report
Guidelines for Preventing the
Transmission of Mycobacterium
tuberculosis in Health-Care Settings,
December 30, 2005
Pertinent Excerpts from the
New Guidelines.
• The new guidelines broaden the scope
of settings to which they apply to
include “nontraditional facility-based
settings.”
• This includes EMS.
• The list of “HCW’s Who Should Be
Included in a TB Surveillance Program”
includes “Patient Transport Staff,
including EMS.”
Risk Classification for a Nontraditional
Facility-Based Health-care Setting
Low Risk
Medium Risk
Potential
Ongoing
Transmission
< 3 TB Patients > 3 TB Patients Evidence that
a Year
a Year
person-toperson
transmission of
TB disease has
occurred in the
setting in the
last year
Baseline TST or BAMT
• Indicated for new hires to all
“nontraditional facility-based settings”,
including EMS, regardless of risk
classification.
Why the Emphasis on
Baseline Testing?
• Because the type f medical care that you
receive after an exposure is going to be
based on a comparison between your
baseline testing and your post-exposure
testing.
• There are also medico-legal
ramifications.
What is an Exposure?
• A person with TB is transported who is only later
diagnosed with TB. This resulted in failure to apply
recommended TB infection controls during transport.
• A patient is considered infectious for the 3 month
period preceding their diagnosis or beginning with
their symptom onset date, whichever is earlier.
• Although the overall risk is low, documented
transmission of TB has occurred in EMS occupational
settings.
How Will I Find Out that I Have
Been Exposed?
• EMS personnel should be
included in the follow up
contact investigations of
patients with infectious TB
disease.
• The Ryan White
Comprehensive AIDS
Resource Emergency Act of
1990 mandates notification of
EMS personnel after they have
been exposed to a patient with
suspected or confirmed TB
disease.
You’ve Been Exposed
What Now?
• You will be assessed for symptoms of
TB disease. If you have symptoms of
TB, you will be promptly evaluated for
active TB disease. This will include a
CXR.
You’ve Been Exposed!
What Now?
• No symptoms, baseline TST was
positive:
• You do not need to have another TST.
Another TST will not provide any
additional useful information.
• You only need to have a CXR if you are or
immunocompromised or otherwise at risk
for TB.
You’ve Been Exposed!
What Now?
• No symptoms, baseline TST negative
(0-9 mm):
• You will be given another TST
immediately. If this TST is negative, you
will be given another TST 8-10 weeks after
exposure ended.
• If either of these post-exposure TST’s is
positive, you will have a CXR.
What is a “Positive” TST in
This Scenario?
• If your previous TST result was 0 mm, a
post-exposure TST result of > 5 mm will
be considered positive and evidence of a
new infection.
• If your previous TST results was > 0 but <
10 mm, your post-exposure TST will have
to increase by 10 mm in order to be
considered positive and evidence of a new
infection.
You’ve Been Exposed!
What Now?
• If:
• You have no symptoms,
• Either of your post-exposure TST’s is
positive, and
• Your CXR is negative,
• You will be diagnosed as having “latent
tuberculosis infection” (LTBI)
What Is LTBI?
• LTBI is a condition that develops after
exposure to a person with infectious TB
disease, and subsequent development of
infection with M. tuberculosis where the
bacteria are still alive but inactive in the body.
• Persons with LTBI do not have any
symptoms.
• They cannot spread TB to other persons.
However
• Typically, approximately 5-10% of
persons who become infected with M.
tuberculosis (i.e. who have LTBI) will
develop TB disease during their
lifetimes.
• The risk for progression of LTBI to
active TB disease is highest during the
first several years after infection.
So
• If you have been exposed and your TST
turns positive (and your CXR is
negative), you will be referred to a TB
clinic or county health department
where you will be evaluated for and
encouraged to take treatment for LTBI.
Baseline Testing
• You will probably have some baseline blood work
performed.
• Baseline testing is indicated for:
• Persons infected with HIV
• Pregnant women
• Women in the immediate postpartum period (usually
within 3 months of delivery)
• Persons with a history of liver disease
• Persons who use alcohol regularly
• Those who have or are at risk of chronic liver disease.
What Is Treatment for LTBI?
• Isoniazid (INH) daily for 9 months
(preferred), or
• INH twice weekly for 9 months or,
• INH daily or twice weekly for 6 months.
• If you have acute hepatitis or end stage liver
disease, you will not be offered INH. In this
case, rifampin daily for 4 months will be
offered.
Treatment for LTBI
• These regimens might be modified if:
• You are pregnant
• You have HIV infection
• The index case has drug resistant TB
Directly Observed Therapy
DOT
• Adherence-enhancing strategy in which
a HCW or other trained person watches
a patient swallow each dose of
medication.
• DOT is the standard of care for all
patients with TB disease and is a
preferred option for patients treated for
LTBI.
Follow Up
• You will be seen monthly.
• You will be asked about symptoms of liver disease: nausea,
vomiting, abdominal pain, jaundice and yellow or brown urine.
• You will be advised about the adverse effects of the drugs you
are taking and the need for prompt cessation of treatment and
clinical evaluation if adverse effects occur.
• If you have adverse effects of medications, you will have repeat
blood tests performed.
• If your baseline lab tests are abnormal or if you are otherwise at
risk for liver disease, you will have repeat blood tests
performed.
If You Develop Active TB:
• You will probably receive 2 months of
four drugs (INH, rifampin,
pyrazinamide and ethambutol).
• Then, you will receive at least 4 months
of INH and rifampin.
• DOT is the standard of care and should
be used for all doses.
Prevention of Unprotected
Exposure
• The threat to HCW’s is mainly from
patients or others with unsuspected and
undiagnosed infectious TB.
Symptoms of Active Infectious TB
Disease
• Look for symptoms of pulmonary, laryngeal and
to a lesser extent, pleural disease.
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–
–
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Coughing for more than 3 weeks
Loss of appetite
Weight loss
Night sweats
Hemoptysis
Hoarseness
Fever
Fatigue
Chest pain
Environmental Controls for the
Fire Service
•
The ambulance ventilation system should be
operated in the nonrecirculating mode.
•
The maximum amount of outdoor air
should be provided to facilitate dilution.
•
If the vehicle has a rear exhaust fan, this
should be used during transport.
•
If the vehicle is equipped with a
supplemental HEPA filter, use this.
•
Air should flow from the cab over the
patient and out the rear exhaust fan.
•
If an ambulance is not used, the ventilation
system for the vehicle should bring in as
much outdoor air as possible and the system
should be set to nonrecirculating
•
If possible, physically isolate the cab from
the rest of the vehicle and put the patient in
the rear seat
Respirators:
Nonpowered air-purifying respirator
filter classes certified in 42 CFR 84
Resistance to
Filter
Degradation
95 (95%
efficient)
99 (99%
efficient)
100 (99.97%
efficient)
N (Not resistant
to oil)
N95
N99
N100
R (Resistant to
oil)
R95
R99
R100
P (Oil proof)
P95
P99
P100
Respirators
• So an N95 is fine.
• It must be fit tested.
• You can’t use it with facial hair.
How Long/How Many Times
Can I Wear My N95?
• In health care settings in which
respirators are used for protection
against bioaerosols, the concentration of
particles in the air is probably low.
Thus, the filter in the respirator is
unlikely to become obstructed with
airborne material.
How Long/How Many Times
Can I Wear My N95?
• Furthermore, no evidence exists to indicate that
infectious particles trapped in the filter material of
the respirator are reaerosolized easily.
• Therefore, the filter material used in respirators in
health care settings might remain functional for
weeks.
• Because electrostatic filter media can degrade, ask the
manufacturer about the product’s service life.
• But as a general rule, one can use the same N95
several times a day and discard it after one day’s use.
What’s the Difference Between an
N95 and a Surgical Mask?
• An N95 protects the wearer (the health care
worker) from droplet nuclei present in the air
space shared with the patient.
• A surgical mask does not protect the wearer.
It protects others in the shared air space from
the wearer’s droplet nuclei.
• One cannot be substituted for the other.
Respiratory Controls for the Fire
Service
• Drivers or other HCWs
who are transporting
patients with suspected
or confirmed infectious
TB disease in an enclosed
vehicle should wear at
least an N95 disposable
respirator.
• If the patient has signs of
symptoms of infectious
TB disease, consider
having the patient wear a
surgical or procedure
mask during transport.
Bloodborne Pathogens
Hepatitis B
Hepatitis C
HIV
Hepatitis B
• Can causes fulminant hepatitis.
• Chronic carrier state in up to 10% of those infected.
• Chronic carriers suffer higher rates of:
• Cirrhosis
• Liver failure
• Liver cancer.
• In the decade before the introduction of the hepatitis
B vaccine in 1991, the prevalence of HBV infection
among HCW’s was 10x that in the general
population.
Hepatitis C
• 70-90% of those infected become
chronic carriers.
• Chronic carriers have:
• a 20% chance of developing cirrhosis
• increased risk for developing hepatocellulalar
carcinoma.
Antigens and Antibodies
• Hepatitis B surface antigen: HbsAg
• Hepatitis B e antigen: HBeAg
• Hepatitis B surface antibody: HBsAb or
anti-HBs
• Hepatitis C antibody: anti-HCV
Occupational Transmission
of HBV
• Percutaneous:
• Risk of infection depends on:
• Degree of contact with blood
• Hepatitis e antigen status of the source person.
• When the source of the HBV-contaminated
needle stick is HBeAg +, the risk of clinical
hepatitis to the unvaccinated HCW is 22%31%. The risk of developing serologic
evidence of HBV infection is 37%-62%
Occupational Transmission
of HBV
• Although percutaneous injuries are the most efficient modes of
HBV infection, they account for only a minority of HBV
infections among HCW’s.
• Most infected HCW’s have not been able to recall an overt
percutaneous injury although up to 1/3 can recall caring for a
patient who was HBsAg +.
• HBV survives in dried blood at room temperature on
environmental surfaces for at least 1 week.
• HBV infections might have resulted from mucosal exposures
or exposures that inoculated HBV into breaks in the skin.
• The potential for HBV transmission through contact with
environmental surfaces has been demonstrated.
HBV Vaccine
• HBsAb is protective (forever).
• We can stimulate the body’s production of HBsAb by
injecting HBsAg.
• Injections at 0, 1 and 6 months.
• If interrupted, just resume ASAP (no need to start
over)
• The last dose confers long term immunity. It must
be given at least 2 months after the 2nd dose in
order to do this.
Documentation of Serologic Status
• Every HCW who expects ongoing
exposure to blood or blood products
should know his/her serologic status.
• Why? Because documenting surface
antibody protection at any time
following the vaccination series
significantly streamlines post-exposure
management for hepatitis B.
Documentation of Serologic
Status
• 90% of 40 year olds develop protective
levels of surface antibody after
vaccination.
• 75% of 60 year olds do.
Documentation of Serologic
Status
• Testing for HBsAb should be performed 1-2
months after completion of the 3-dose
vaccination series.
• Persons who do not respond to the 1st 3-dose
series should receive a 2nd 3-dose series. 3050% of persons who do not respond to the 1st
series respond to the 2nd.
• Revaccinated persons should be retested at
the completion of the 2nd vaccine series.
Documentation of Serologic
Status
• What about those of us who were vaccinated but
never had a titer done?
• In 50% of responders, the antibody titer declines over
time and > 6 months after vaccination, can be
undetectable or lower than what is usually
considered protective. These people remain
protected.
• However, it is not possible to distinguish the
responder whose level of antibody declined (but is
still protected) from the non-responder (who is not
protected).
Nonresponders
• Should be checked for HBsAg.
• If negative for HBsAg, they remain
susceptible to HBV infection and need
to be treated as such upon exposure.
Boosters
• Not necessary
• Periodic serologic testing to monitor
antibody concentrations after a person
has been shown to have a protective
level of HBsAb is not recommended.
Occupational Transmission
of HCV
• HCV is not transmitted efficiently through blood.
• The average incidence of infection after percutaneous
exposure from a positive source is 1.8%.
• Transmission from mucous membrane exposure to
blood is rare.
• No transmission in HCW’s has been documented
after skin exposure.
• Environmental contamination is usually not a
significant risk factor.
Occupational Transmission
of HIV
• Average risk after percutaneous exposure to infected
blood is 0.3%.
• Risk after mucous membrane exposure to infected
blood is ~ 0.09%.
• Although HIV transmission after non-intact skin
exposure has been documented, the risk is estimated
to be less than the risk for mucous membrane
exposures.
• The risk for transmission after exposure to fluids or
tissues other than blood is probably considerably
lower than for blood exposures.
Transmission Summarized
Source +
for:
Percutaneous XP
to blood
HBV
(HBeAg +)
62% (31%
clinical
infection)
MM XP to
blood
Non-intact XP to
skin XP to other
blood
fluids and
tissues
Environmental
Yes
Yes
Low Risk
Yes
HCV
1.8%
Rare
No cases
Low
Low
HIV
.3%
.09%
Occurs but
< .09%
<< 0.3%
------
What Happens After
Exposure?
• Treatment of Exposure Site:
• Wounds and skin sites that have been in contact with blood or
body fluids should be washed with soap and water.
• Mucous membranes should be flushed with water.
• No evidence exists that using antiseptics for wound care reduces
the risk of transmission but their use is not contraindicated.
• Do not:
• Squeeze the wound
• Apply caustic agents like bleach to the wound
• Inject anything into the wound
• Get medical care immediately after treating the site!
• Notify your supervisor or infection control officer per protocol.
Why the Rush?
• Because PEP (for HIV) has to be started ASAP!
• Animal studies suggest that PEP probably is
substantially less effective when started more than
24-36 hours postexposure.
• In humans, the interval after which no benefit is
gained from PEP is undefined. Therefore, PEP
should be started even when the interval since
exposure exceeds 36 hours. If the risk of
transmission is very high, PEP can be started 1 week
after exposure.
Evaluation of the Exposure
• Type of exposure:
• Percutaneous: For HCV and HIV, exposure to a
blood-filled hollow needle or visibly bloody
device suggests a higher risk exposure than
exposure to a needle that was most likely used for
giving an injection.
• Mucous membrane exposure
• Non-intact skin exposure
• Bite
If the Source Person Is
Known to Be HIV +
• Available information about his stage of
infection.
• CD4+ T-cell count
• Viral load
• Current and previous antiretroviral
therapy
• Results of resistance testing.
HIV Testing of the Source is
Negative
• If the source person is HIV negative and has
no clinical evidence of AIDS or symptoms of
HIV infection, no further testing of the person
is indicated.
• The likelihood of the source person being in
the “window period” of HIV infection in the
absence of symptoms of acute retroviral
syndrome is extremely small.
What Blood Tests Are You
Going to Have?
• HBV: You are only going to have a blood test for
HBsAb if your antibody response to the vaccine is
unknown.
• If you have already had hepatitis B or if you are a
known responder to the vaccine or a known nonresponder to the vaccine, you do not have to be
tested. If you have never been vaccinated, you
aren’t going to be tested . You are going to get
HBIG and start the hepatitis B vaccine series.
What Blood Tests Are You
Going to Have?
• Hepatitis C: Baseline testing for anti-HCV
and ALT.
• HIV: If the source person is negative, you
don’t have to be tested. However, serologic
testing should be made available to all
HCW’s who are concerned that they might
have been exposed.
What Blood Tests Are You
Going to Have?
• If PEP for HIV is being considered, you
will have a CBC, tests of kidney and
liver function and possibly a glucose.
(Protease inhibitors can cause diabetes,
hyperglycemia and diabetic
ketoacidosis.)
• You might also have a baseline urinalysis
(indinavir can cause kidney stones.)
PEP: HBIG
• HBIG is prepared from human plasma known to
contain a high titer of anti-HBs. The plasma from
which HBIG is prepared is screened for HBsAg and
antibodies to HIV and HCV.
• Since 1999, all products available in the US have
been manufactured using methods that inactivate
HCV and other viruses.
• No evidence exists that HBV, HCV or HIV have ever
been transmitted by HBIG commercially available in
the US.
HBIG
• When HBIG is indicated, it should be
administered ASAP after the exposure
(preferably within 24 hours).
• The effectiveness of HBIG when
administered > 7 days after exposure is
unknown.
• The dose is 0.06 ml/kg IM (4.2 ml for a
70 kg man)
HBIG
Side Effects
• Local pain and tenderness at the
injection site
• Allergic reactions:
• Hives
• Angioedema
• Anaphylaxis
PEP: Hepatitis B Vaccine
• When hepatitis B vaccine is indicated, it
should also be administered ASAP (and
preferably within 24 hours).
What Behavioral Changes Are
You Going to Have to Make?
• Exposure to HBV or HCV infected
blood:
• Refrain from donating blood, plasma,
organs, tissue or semen.
• The exposed person does not need to
modify sexual practices or refrain from
becoming pregnant.
• If an exposed woman is breast feeding, she
does not need to discontinue.
What Behavioral Changes
Are You Going to Have to
Make?
• HIV Exposure: Especially during the 1st 6-12 weeks post –
exposure when most HIV-infected persons are expected to
seroconvert:
• Sexual abstinence or use condoms to prevent sexual
transmission and avoid pregnancy.
• Don’t donate blood plasma, organs, tissue or semen.
• HIV can be transmitted through breast milk – consider
discontinuation of breast feeding, especially for high risk
exposures.
• Some PEP drugs pass into breast milk.
How Is My Job Going to Be
Affected by My Exposure?
• HBV or HCV exposure: No modifications
necessary.
• HIV exposure: No modifications necessary.
• If you become infected with HIV or HBV,
your patient care responsibilities might be
affected.
• There are no recommendations regarding
restricting the professional activities of HCP’s
with HCV infection.
What Next?
• You should be seen again 72 hours after exposure.
• More information about the exposure source should be
available by then.
• You will undoubtedly have questions that will need to be
answered.
• Counseling continues: You will be asked to seek medical
evaluation for any acute illness that occurs during the
ensuing follow up period. Such an illness, particularly if
characterized by fever, rash, myalgia, fatigue, malaise or
lymphadenopathy, might be indicative of acute HIV
infection or a drug reaction.
And Then?
• If PEP for HIV was started, you will be
seen 2 weeks afterward.
• Baseline lab tests (CBC, kidney
function, liver function, glucose and
urinalysis) will be repeated.
How Long Do I Need to Take PEP?
• The optimal duration of PEP is
unknown. Because 4 weeks of ZDV
appeared protective in occupational
and animal studies, PEP probably
should be administered for 4 weeks, if
tolerated.
Why Is PEP Discontinued?
Side Effects, Side Effects, Side Effects
• 50% of HCW’s experience nausea,
malaise, headache or anorexia
while taking PEP.
• 17-47% of HCW’s stop taking PEP
because of side effects.
• More side effects with the 3-drug
regimen than the 2-drug regimen.
Nausea and Vomiting
• The most common side effect (26.5% of
HCW’s taking PEP.
• Can often be managed with antimotility and anti-emetic agents without
changing the regimen.
• Administering a lower dose of drug
more frequently throughout the day
might facilitate adherence.
Serious Side Effects
Drug
Side Effect
Drug
Side Effect
Didanosine
(ddi)
Fatal and nonfatal pancreatitis
Nevirapine
(NVP)
Protease
inhibitors
Diabetes,
hyperglycemia,
DKA, worsening
of existing DM,
dyslipidemia
Fatal liver
necrosis;
rhabdomyolysis;
allergies,
including
anaphylaxis;
pancytopenia; SJ
syndrome
Lamivudine
Neuropathy;
pancreatitis;
lactic acidosis
Efavirens
SJ syndrome;
severe
psychiatric
symptoms
Indinavir
(IDV)
NNRTI’s
Kidney stones
Life-threatening
TEN and SJ
syndrome
Serious Drug Interactions
• All of these drugs have the potential for serious drug
interactions. Examples:
• They decrease the clearance of statins, predisposing
to the development of rhabdomyolysis.
• PI’s can accelerate the clearance of OC’s.
• St. John’s Wort increases clearance of PI’s.
• Garlic lowers the level of saquinavir.
• These drugs can interfere with each other.
Resistance
• When the source person’s virus is known or suspected to be
resistant to one or more of the drugs considered for the PEP
regimen, the selection of drugs to which the source person’s
virus is unlikely to be resistant is recommended.
• Resistance testing of the source person’s virus at the time of
exposure is not recommended. Results will come back too late
to be of use (1-2 weeks).
• Rather, information about the source person’s medication
history, clinical response to medications, CD4+ counts, viral
load measurements and current disease stage should be used.
• If this information is not readily available, start PEP and revise
later: one good reason for the 72 hour follow up.
Resistance
• Occupational transmission of drugresistant HIV strains despite PEP with
combination drug regimens has been
reported
• Luckily, not often. As of 09/30/05,
only six cases of occupational HIV
seroconversion despite combination
PEP have been reported.
Follow Up for Exposures to HCV
• For the person exposed to an HCVpositive source:
• There is no PEP.
• After baseline testing for anti-HCV and
ALT, repeat testing should be performed in
4-6 months.
• If an earlier diagnosis of HCV infection is
desired, testing for HCV RNA may be
performed at 4-6 weeks.
Follow Up for Exposure to
HIV
• HIV testing at baseline and then at 6 weeks,
12 weeks and 6 months post-exposure.
• If you become infected with HCV after
exposure to a source co-infected with HIV
and HCV, another test in 12 months is
recommended.
• We don’t know if you should receive a test in
12 months if you are exposed to a co-infected
source and you don’t develop HCV or if you
are immunosuppressed.
Use of Direct Virus Assays
• HIV p24, HIV RNA
• Not recommended
• These can detect HIV a few days earlier than
the routinely used assay but the infrequency
of occupational seroconversion and increased
costs of these tests do not warrant their
routine use in this setting.
• Relatively high false positive rate.
• HIV testing should be performed on any
exposed person who has an illness
compatible with an acute retroviral
syndrome, regardless of the interval since
exposure.
• Fever, rash, myalgia, fatigue, malaise or
lymphadenopathy.
Question #1
Which of the following exposures pose a risk for bloodborne
pathogen infection?
1. A nurse sustains a needle stick while drawing up insulin to
administer to a patient with diabetes.
2. A lab worker is splashed in the eye with urine from a patient
with HIV.
3. An operating room technician with chapped and abraded
hands notices blood under his/her gloves after assisting in a
surgery on a patient with hepatitis C infection.
4. While cleaning the bathroom, a housekeeper’s intact skin has
contact with feces.
Question 2
Which lab tests should be completed for the exposed
person to determine his/her susceptibility to a
bloodborne pathogen infection?
1.
2.
3.
4.
5.
HBsAg
HIV p24 antigen
HCV RNA
All of the above
None of the above
Question 3
Following a percutaneous exposure to HCV-infected
blood what action(s) is/are recommended?
1. Test the exposed person for antibody to HCV and
ALT at the time of exposure and 4-6 month later.
2. Administer one dose of immune globulin within 7
days of the exposure.
3. Immediately start PEP with interferon and ribavirin.
4. All of the above.
5. None of the above.
Question 4
After completing the initial 3-dose vaccine series against HBV,
HCP’s who will have contact with patients or blood and are at
ongoing risk for percutaneous injuries should have anti-HBs
testing completed:
1.
2.
3.
4.
5.
Every year.
After any blood exposure.
1-2 months after the completion of the vaccine series.
All of the above
None of the above.
Question 5
The type of occupational exposure to
HIV-infected blood that poses the
greatest risk for infection transmission is:
1. A percutaneous injury.
2. A mucous membrane injury
3. A bite
4. Skin contact with HIV-infected blood.
Question 6
For which of the following exposures would the use of HIV PEP be
recommended?
1.
A housekeeper sustains a percutaneous injury while emptying a
needle box on a pediatric ward with no known cases of HIV infection.
2.
A nurse has a urine splash to the eye while emptying an AIDS
patient’s urinal.
3.
A resident, after assisting with an emergency insertion of a central
venous line into an HIV-infected patient, notices a small tear in
his/her glove but does not observe any blood on his/her skin.
4.
A phlebotomist sustains a percutaneous injury while performing
phlebotomy on an HIV-infected patient.
5.
All of the above.
Question 7
Following an exposure to a bloodborne pathogen, what information
would be included as part of the post-exposure counseling? (Indicate all
that apply.)
1.
HCP exposed to HBV and HCV do not need to take any special
precautions to prevent secondary transmission during the follow up
period.
2.
Modifying an exposed person’s patient care responsibilities is not
necessary to prevent transmission to patients after an exposure to
HBV, HCV or HIV.
3.
HCP who have an HIV exposure for which PEP is not recommended
should be informed that the potential side effects and toxicity of
taking PEP outweigh the risk of transmission posed by the type of
exposure.
4.
HCP should seek medical evaluation for a any acute illness that
occurs during the follow-up period.