Standard Precautions and Post Exposure Prophylaxis

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Standard Precautions and Post Exposure Prophylaxis

• Unit 17
• HIV Care and ART A Course for Healthcare
  Professionals

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Learning Objectives

• Describe the basic principles and procedures of
  standard precautions
• Identify the risks of HIV, HCV, and HBV
  seroconversion following accidental occupational
  exposures
• List the management steps of occupational
  exposure
• Describe the principles of HIV post-exposure
  prophylaxis

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Case study

• Abebech is a 32 year-old nurse. She came to the
  ART clinic after she sustained a needle stick
  while providing an injection to a hospitalized
  patient. She thinks that the patient is HIV
  positive and she is requesting HIV post-exposure
  prophylaxis
• What measures are important for preventing this
  problem in the future?
• What further information is needed to manage this
  patient?

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Occupational Exposure Risk
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Estimated Pathogen-Specific Seroconversion Rate
Per Exposure for Occupational Needlestick Injury
.
AETC http//depts.washington.edu/hivaids
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Type of Exposure Involved in Transmission of HIV
to Health Care Workers
AETC http//depts.washington.edu/hivaids
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Source of HIV Involved in HIV Transmission to
Health Care Worker
AETC http//depts.washington.edu/hivaids
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Risk Factors for HIV Transmission with
Occupational Exposure to HIV-Infected Blood
Risk Factor Odds Ratio Confidence Interval
Deep Injury 15 6.0-41
Visibly Bloody Device 6.2 2.2-21
Device Used in Artery or Vein 4.3 1.7-12
Terminally Ill Source Patient 5.6 2.0-16
Use of Zidovudine for PEP 0.19 0.06-0.52
Plt0.01 for all associations

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Other Possible Risk Factors

• Hollow bore vs solid bore
• No documented cases to date of seroconversion
  from suture needles
• Glove use
• 50 decrease in volume of blood transmitted
• Mucous membrane exposure

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HIV in the Environment

• How long does HIV live outside the body?
• HIV does not survive well in the environment
• When HIV-infected blood or body fluids dry, the
  theoretical risk of environmental transmission is
  essentially zero
• No reports of environmental transmission

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Standard Precautions
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Standard Precautions

• Definition
• Standards developed to prevent exposure and
  transmission of disease in occupational setting
• Provide guidance for the safe handling of
  infectious material
• Formerly referred to as Universal Precautions.
  Universal means everyone, everywhere, always

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Components of Standard Precautions

• Hand washing Key step in limiting nosocomial
  spread of disease
• Use protective barriers when indicated
• Gloves mucus membranes, body fluids, broken skin
• Goggles procedures
• Gowns/masks procedures

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Components of Standard Precautions (2)

• Sharps and waste - handle with gloves and dispose
  in designated containers
• Needles
• Scalpels
• Suture material
• Bandages
• Dressings
• Anything contaminated with any body fluid

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Rules to Follow While Disposing Sharps

• Do not recap needles!
• Put containers within arms reach
• Use adequate light source when treating patients
• Wear heavy-duty gloves when transporting sharps
• Incinerate used needles to a sufficient
  temperature to melt
• Keep sharps out of reach of children

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Components of Standard Precautions (3)

• Re-usable instruments - must be thoroughly
  disinfected
• Speculums
• Surgical tools
• Thermometers
• Immunizations
• Hepatitis A and B

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Recommended Antiseptic Solutions

• Ethyl alcohol, 70
• Chlorhexidine, 2-4 (e.g. Hibtane, Hibiscrub)
• Chlorhexidine gluconate and cetrimide, at least
  2 (e.g. Savlon)
• Iodine tincture, 3
• Iodophores, 7.5-10 (e.g. Betadine)
• Chlorozylenol in alcohol, 0.5-3.75, (e.g.
  Dettol)
• Use undiluted

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Recommended Disinfectants

• Chlorine, 0.5 (Barkina)
• Sedex and Ghion brands contain 5 Chlorine,
  dilute for use
• Glutaraldehyde, 2-4 (e.g. Cidex)
• Formaldehyde, 8
• Hydrogen peroxide, 6
• Soak the instrument for 20 minutes after
  decontamination and cleaning

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Management of Occupational Exposure
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Wound Care

• Gently wash wounds with soap and water (dont
  scrub vigorously)
• Allow wounds to bleed freely
• Irrigate exposed mucosal surfaces with sterile
  saline

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Post Exposure Prophylaxis

• Definition
• Use of therapeutic agent to prevent establishment
  of infection following exposure to pathogen
• Roles in Occupational Exposure
• HIV prevention
• HBV prevention

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HIV PEP for Occupational Exposure

• Overview
• Limited data (animal)
• Better to err on side of treatment
• Exposed patient must be tested for HIV prior to
  PEP
• Start immediately after exposure
• Duration 28 days

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Decision-making Tools for PEP

• Source code (SC)
• Risk assessment of the source patient
• SC 1, SC 2, SC Unknown
• Exposure code (EC)
• Risk assessment of exposure type
• EC 1, EC 2, EC 3

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Step 1 Does This Patient Need HIV PEP?
Source patient
Unknown / Unwilling to get tested
HIV
HIV -
High back-ground risk
Low back-ground risk
PEP
No PEP
No PEP
CDC recom usually PEP unnecessary consider use
if source patient is high risk
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Step 2 Determine HIV Status Code of Source (HIV
SC)
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Step 3 Type of Exposure Determine the Exposure
Code
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Step 4 Determine PEP Regimen
HIV SC EC PEP Recommendation
1 1 PEP may not be warranted
2 1 Consider basic regimen
1 2 Recommend basic regimen
2 2 Expanded regimen recommended
1 or 2 3 Expanded regimen recommended
Unknown If EC is 2 or 3 and a risk exists, consider PEP basic regimen
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Step 4 Determine PEP Regimen (2)
Exposure Type Source Infection Status Source Infection Status
  HIV Class 1 HIV Class 2
Less Severe Basic (2 Drugs) Expanded (3 Drugs)
More Severe Expanded (3 Drugs) Expanded (3 Drugs)

• Less Severe Solid needle, superficial injury
• More Severe Large-bore hollow needle, deep
  punture, visible blood on device, or needle used
  in patient's artery or vein
• HIV Class 1 Asymptomatic or HIV RNA less than
  1500 copies/ml
• HIV Class 2 Symptomatic HIV infection, AIDS,
  acute seroconversion, or known high HIV RNA

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HIV Post Exposure Prophylaxis

• 2 drug regimen
• Zidovudine plus lamivudine (combivir)
• Stavudine plus Lamivudine
• Tenofovir plus lamivudine
• 3 drug regimen
• LPV/r or Indinivr or Nelfinavir plus NRTI
  backbone
• Efavirez plus NRTI backbone
• Consider resistance potential of source patient
• Dont use NVP (hepatotoxicity)

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HIV PEP - When to Start

• As soon as possible!
• U.S. Public Health Service Guidelines recommends
  prompt initiation of PEP (within hours of
  exposure), but does not rule out consideration of
  PEP even if more than 36 hours have elapsed since
  the exposure
• Animal data show no benefit when treatment is
  delayed 24-36 hours
• Most experts use 72 hour window limit

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The Early Stages of HIV Infection
Cell free HIV
CD40CD40
T-cell
Immature Dendritic cell
PEP
Skin or mucosa
Via lymphatics or circulation
Burst of HIV replication
24 hours
48 hours

1. HIV co-receptors, CD4 chemokine receptor CC5

1. Mature Dendritic cell in regional LN undergoes a
   single replication, which transfers HIV to T-cell

1. Selective of macrophage-tropic HIV

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HIV PEP - When to Stop

• Timing is unclear
• Animal studies suggest better efficacy with 28
  days of PEP when compared with shorter duration
  of therapy

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Current PEP Policy in Ethiopia

• Emphasis is on standard precautions
• Individual ART programs may access and distribute
  PEP free of charge

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Case Study 1

• 27 year-old female nurse presents to OPD for
  evaluation of needle stick injury 2 days ago from
  a diabetic lancet
• Source patient (SP) 35 year-old male, HIV
• Discussion
• What do we need to know about the source patient
  and exposure in order to manage this nurse?
• Would you offer her PEP? If so, which agents?

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Additional Information

• The SP has been taking AZT/3TC/NVP (1st regimen)
  for one year.
• He was WHO stage II prior to starting ART, and is
  currently in good health
• The SPs most recent CD4 count was 200 his
  initial CD4 before starting ART was 180
• Viral load 2 months ago was 60,000
• How does this information influence the choice of
  PEP regimen?

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Case Study 1 - Questions

• What is her risk for contracting HIV?
• What factors influence this risk?
• Is it too late to start PEP?
• Which regimen(s) should be considered?
• What follow-up should be arranged?

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Case Study 1 PEP Options

• Source patients high-level viremia despite HAART
  suggests that he is either not taking his
  medications, or that he has developed resistance
  to his regimen
• Resistance assay is not performed in Ethiopia
  therefore must reason around patterns of
  anticipated resistance to SPs regimen
• If resistance has developed, would suspect
  resistance to lamivudine and zidovudine
• May have NNRTI cross resistance as well

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Case Study 1 PEP Options

• High viral load of source patient would warrant
  use of a three drug PEP regimen
• One reasonable PEP regimen didanosine
  tenofovir lopinavir/ritonavir

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Case Study 2

• 24 year-old dental technician splashed in the eye
  during dental procedure 3 hours ago
• Source patient 33 year-old male, co-infected
  with HIV and HCV
• What else do you need to know?

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Which Fluids are Potentially Infectious for HIV?

• Blood?
• Saliva?
• Sweat?
• Feces?

• Spinal fluid?
• Pleural fluid?
• Pus?
• Urine?

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Which Fluids are Potentially Infectious for HIV?
(2)

• Blood
• Saliva
• Sweat
• Feces

• Spinal fluid
• Pleural fluid
• Pus
• Urine

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Case Study 2 cont.

• Saliva was visibly bloody - in fact, it was
  mostly blood that splashed her
• She rinsed out her eye immediately
• Source patient has never taken antiretrovirals,
  has a CD4 count of about 500 and a viral load
  of 20,000 last time it was checked.
• The exposed patient is 8 weeks pregnant

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Case Study 2 Questions

• Discuss
• What are your PEP recommendations?
• How does her pregnancy affect your decision
  making?

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PEP in Pregnancy

• Most antiretrovirals class B or C in pregnancy
• Antiretroviral Pregnancy Registry has not
  detected increased teratogenic risk for ARVs in
  general, nor specifically for AZT and 3TC, in the
  first trimester1
• Avoid efavirenz (anencephaly in monkeys),
  amprenavir (ossification defects in rabbits),
  and, in late term, indinavir (hyperbilirubinemia)
• Avoid combination d4T and ddI
• Theoretically higher risk of vertical
  transmission with primary HIV infection

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Case Study 2 - cont.

• The patient starts AZT/3TC/Nelfinavir
• 3 days later she calls complaining of headache,
  congestion, an itchy rash, and URI symptoms
• What further information is needed for managing
  this patient?

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Case 2 cont.

• Exam
• VS T 99.0 R 14 P 78 BP 134/76
• Gen - alert, tired-appearing, no acute distress
• HEENT - hyperemic nasal mucosa with frontal sinus
  tenderness pharynx is also red
• Neck - 3 cm. left ant cervical lymph node
• Lungs, cardiac, abdomen normal
• Neuro normal
• Skin urticarial rash on trunk and legs no
  ulcerations

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Case 2 Questions

• What is the most likely diagnosis?
• How would you manage this patient?

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Primary HIV Infection

• Flu-like or mono-like illness often accompanied
  by a rash1
• Onset typically 2-6 weeks following exposure, but
  high variability
• Symptoms generally resolve spontaneously in 1-3
  wks (corresponding with VL reduction)
• Treatment of PHI with antiretroviral therapy may
  have significant long-term benefit3

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PHI Diagnostic Testing
Image courtesy of The Center for AIDS Information
Advocacy, www.centerforaids.org
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Could She Have Primary HIV Infection?

• Primary HIV Infection less likely
• Only three days since the exposure
• Presence of nasal congestion
• Rash is urticarial
• However, would not be unreasonable to check an
  HIV viral load to rule out PHI

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Follow-up HIV Testing

• CDC recommendations HIV Ab testing at 6 weeks, 3
  months, 6 months following exposure
• Extended HIV Ab testing at 12 months recommended
  if health care worker contracts HCV from a source
  patient co-infected with HIV and HCV
• VL testing not recommended unless Primary HIV
  Infection (PHI) suspected

MMWR June 29, 2001 / 50(RR11)1-42.
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Key Points

• Standard precautions should be implemented and
  practiced by all healthcare providers
• The most important infection control method is
  handwashing
• Proper handling of sharps is critical for
  reducing occupational exposure to blood borne
  pathogens
• Risk of HIV seroconversion after occupational
  exposure varies depending on source patient and
  exposure circumstance
• When indicated, PEP should be employed
  immediately (within hours)