Infectious Diseases Case Conference

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Infectious Diseases Case Conference

• Jason H. Kettler
• November 17, 2003
• Wake Forest University

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Contact Isolation
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The Safety of Contact Isolation

• Stelfox HT, DW Bates and DA Redelmeier. Safety
  of Patients Isolated for Infection Control.
  JAMA, October 8, 2003.
• Collaborative effort involving two teaching
  hospitals examining the quality of medical care
  received by patients isolated for infection
  control

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Background

• Human factors research in nonmedical settings
  suggests that people tend to take the path of
  least effort
• Demands of greater vigilance ? improved safety
• Patient isolation may be a system that
  predisposes patients to errors and adverse events

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General Principles of Isolation

• Recommendations depend on the infectious agent,
  but typically involve
• private room
• protective apparel (gloves, gowns, masks)
• restricting movement of the patient outside of
  the room
• Inf. control authorities view isolation as an
  important tool for management of established
  (MRSA) emerging (SARS) infectious diseases

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What is the downside of isolation?

• Critics of isolation policies have raised
  questions about quality of care and whether
  patients receive less attention
• At least two prior studies have shown ?ed
  contact from clinicians and a trend toward
  avoidance of PEs during rounds

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Context of the Stelfox study

• To examine the safety of isolating patients for
  infection control in two teaching hospitals
• Sunnybrook and Womens College Health Sciences
  Centre, Toronto
• Brigham and Womens Hospital and Harvard Medical
  School, Boston

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Two Cohorts

• Toronto ? consecutive adults admitted 1/1/99
  1/1/00, who were isolated for at least 2 days for
  MRSA colonization or infxn
• Controls were the two patients in the same bed
  immediately before or after the isolated patient
• Similar treating physicians, located w/in similar
  proximity to the nursing station, same time of
  year

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Two Cohorts

• Boston ? 1/1/99 7/1/2 patients all had the
  admitting dx of CHF and had a previously recorded
  isolate of MRSA
• Controls were the two patients admitted w/ the dx
  of CHF immediately before and after the isolated
  patient

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Isolation Precautions

• Based upon the most recent CDC recommendations
  (ICHE 1996)
• Private rooms
• Visitors and HCPs are required to wear gloves and
  gowns
• Patient movement from the room is limited to
  essential purposes
• Dedicated equipment (stethoscope and BP cuff) is
  used for each patient

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Patient Care

• Documentation of vital signs and doctors
  narrative notes were noted as general
  process-of-care measures and markers of
  thoroughness of care
• Process-of-care measures specific to CHF pts.
  were recorded (e.g. eval. of LV fxn, of ischemia,
  efforts toward CHF education, etc.)

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Outcomes of Care

• A medical analyst abstracted each pts
  hospitalization into a one-page summary
• No mention of MRSA or isolation
• Two independent blinded physicians reviewed each
  summary for adverse events (i.e. injuries that
  prolonged the hospital stay or produced
  disability)

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Patient Satisfaction

• Each medical record was reviewed to find evidence
  of dissatisfaction
• Patients leaving AMA
• Recorded complaints about medical care
• Attempted suicide
• Altercations
• Files from public relations were reviewed for
  unsolicited complaints

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Two Cohorts
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RESULTS

• Isolated patients were more likely to
• have their VSs incompletely recorded
• have days w/ NO VS recordings at all!
• Isolated patients were also more likely to have
  days w/ NO nursing narrative notes or physician
  progress notes recorded!! (p

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RESULTS CHF Cohort

• Similar care in the ED
• Once on the ward, isolated pts. were far less
  likely to have a stress test or angiogram if they
  had angina (pLV fxn while in the hospital (p0.049)
• Also statistically significant less likely to
  have documented CHF education, timely F/U, or CHF
  medicine adjustments

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Outcomes and Satisfaction

• Isolated pts. had longer hospitalizations and
  higher rates of adverse events compared with
  control pts.
• Isolated pts. twice as likely to experience
  adverse events during their hospzn (p
• Eight times more likely to have supportive care
  failures such as falls, pressure ulcers, or
  electrolyte disorders

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Outcomes and Satisfaction

• No differences in total hospital mortality were
  observed (26 isolated pts. 17 v. 30 control
  pts. 10) p0.16
• Isolated pts. expressed greater dissatisfaction
  with their care reflected by both informal and
  formal complaints

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Stelfox et al CONCLUSIONS

• Compared with controls, pts. isolated for IC
  precautions experience more preventable adverse
  events, express greater dissatisfaction with
  their treatment, and have less documented care
• Though many studies support the effectiveness of
  isolation in preventing nosocomial infxns,
  persistent concerns remain about the safety of
  isolation practices b/c IC is only one component
  of pt. safety

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Future Directions

• Multicomponent interventions (e.g. barriers,
  unrestricted access, reduced mobility) should
  have their individual parts examined to determine
  whether all parts are essential
• Need for individualization
• The pts. who experience the most negative effects
  from isolation strategies may not be those who
  present the highest risk of disease transmission

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Future Directions

• While educational or regulatory policies that
  update clinicians w/ new information on an
  interventions risks benefits (such as
  unintentional discrepancies in the care of
  isolated patients) have intuitive appeal, they
  are unlikely to have a significant effect on
  safety. Rather, creative solutions that
  recognize the limitations of clinicians are badly
  needed.
• Effective eradication techniques to allow pts. w/
  drug-resistant pathogens to avoid isolation
  altogether

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Decolonization

• There is a relative paucity of literature about
  removing patients from isolation
• No practice guidelines/procedures guiding how one
  might go about trying to remove a colonized
  patient from isolation

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• Rohr U, C Mueller, M Wilhelm, G Muhr, S
  Gatermann. Methicillin-resistant Staphylococcus
  aureus whole-body decolonization among
  hospitalized patients with variable site
  colonization by using mupirocin in combination
  with octenidine dihydrochloride. J Hosp Infect.,
  August 2003.

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Rohr et al

• 32 hospitalized carriers
• Intranasal mupirocin octenidine dihydrochloride
  body wash x five days
• Multiple samples taken before tx, 24-48h post-tx,
  and 7-9 days post-tx
• Overall decolonization rate for all sites was
  56.3 at 24-48h and 64 at 7-9d

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Finally

• The findings of the Stelfox study provide greater
  incentives for the eradication of chronic carrier
  and disease states
• The complexities of health care are likely to
  increase in the future, making the detection of
  unintended adverse consequences even more
  challenging

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INFECTION CONTROL ISSUESPart II

• Occupational HIV, HBV, HCV Exposure Management

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Case Presentation

• While obtaining a peripheral venous blood sample
  from a patient with AIDS, a 35-year-old
  phlebotomist is injured by a bloody 18-gauge
  needle attached to a syringe. The patient has
  been taking didanosine and stavudine for more
  than six months, but her quantitative plasma HIV
  RNA titer and CD4 T-lymphocyte count have not
  been measured for many weeks. What is the
  appropriate postexposure treatment for the
  phlebotomist?

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• Gerberding JL. Occupational Exposure to HIV in
  Health Care Settings. NEJM. February 27, 2003.
• As of December of 2001, CDC had received reports
  of 57 documented cases of HIV seroconversion
  temporally associated w/ occupational exposure to
  HIV, among U.S. health care personnel
• An additional 138 cases were considered possible

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True or False?

• Percutaneous injury, usually inflicted by a
  hollow-bore needle, is the most common mechanism
  of occupational HIV transmission

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TRUE!!!

• Percutaneous injury, usually inflicted by a
  hollow-bore needle, is the most common mechanism
  of occupational HIV transmission
• The CDC estimates that more than 380K
  needle-stick injuries occur in U.S. hospitals
  each year

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Strategies for Management

• Provide empirical treatment with two or more
  antiretroviral drugs (unless additional
  information suggests that treatment is not
  warranted)
• Conduct a thorough assessment of the exposure
• Risk of HIV infection posed by the exposure
• Risks and benefits of antiretroviral therapy

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More True or False

• T or F Pooled data from several prospective
  studies suggest that the average risk of HIV
  transmission from a needle-stick injury is 1 in
  100

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More True or False

• T or F Pooled data from several prospective
  studies suggest that the average risk of HIV
  transmission from a needle-stick injury is 1 in
  100
• T or F Transmission from source patients with
  undetectable HIV RNA has been documented

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More True or False

• T or F Pooled data from several prospective
  studies suggest that the average risk of HIV
  transmission from a needle-stick injury is 1 in
  100
• T or F Transmission from source patients with
  undetectable HIV RNA has been documented
• T or F Exposure of intact skin to contaminated
  blood has not been identified as a risk for HIV
  transmission

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More True or False

• T or F Pooled data from several prospective
  studies suggest that the average risk of HIV
  transmission from a needle-stick injury is 1 in
  100
• T or F Transmission from source patients with
  undetectable HIV RNA has been documented
• T or F Exposure of intact skin to contaminated
  blood has not been identified as a risk for HIV
  transmission

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Benefits of ART

• Indirect evidence suggests that tx w/
  anti-retroviral drugs soon after exposure to HIV
  ?es the risk of infection
• A window in which ART can prevent or abort
  irreversible systemic infxn and seroconversion
• Animal models and perinatal HIV transmission
  provide evidence
• In CDCs retrospective case-control study of
  HCWs, PEP w/ AZT was assoc. w/ an 81 reduction
  in the risk of HIV infxn
• No RCTs to assess the efficacy of PEP among HCWs

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Factors Assoc. w/ Transmission

• Viral inoculum
• The interval between inoculation and the
  initiation of therapy
• Duration of therapy
• Choice of antiretroviral drugs

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Risks of ART

• 50 of HCWs report AEs while taking ART
  prophylactically, and 1/3 stop taking the drugs
  as a result
• Regimens that include 3 drugs are worse
• Serious adverse events are rare
• From March 1997 through Sept. 2000, the FDA
  received reports of 22 persons w/ 1 or more
  serious AEs related to the use of __________

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Risks of ART

• 50 of HCWs report AEs while taking ART
  prophylactically, and 1/3 stop taking the drugs
  as a result
• Regimens that include 3 drugs are worse
• Serious adverse events are rare
• From March 1997 through Sept. 2000, the FDA
  received reports of 22 persons w/ 1 or more
  serious AEs related to the use of nevirapine

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Drug Resistance

• Drug-resistant strains have been implicated in
  occupational exposures
• Genotypes/phenotypes are not usually available at
  the time of the injury
• For this reason, 2 or more drugs are usually
  employed for prophylaxis after an occupational
  exposure

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Areas of Uncertainty

• It is unclear why 99.7 of occupational injuries
  do not transmit HIV
• Neither the window of opportunity during which
  PEP is beneficial nor the duration of tx has been
  established
• Three-drug HAART is the SOC for the tx of HIV
  infxn, but there is no clinical evidence that 3
  drugs are more efficacious than 1 in PEP

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Choices of Agents

• Current Public Health Service guidelines
  (available at cdc.gov), recommend 4
  weeks of 2 drugs
• AZT 3TC (CBV)
• 3TC d4T
• ddI d4T
• Many choices for expanded regimens
• Indinavir, Nelfinavir, Efavirenz, Abacavir

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Other Points

• The drugs should be started as soon after the
  exposure as possible
• The routine use of 3 drugs is not recommended

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Monitoring

• HIV testing of the exposed should be done as soon
  after the incident as possible (to establish that
  infxn is not already present) then periodically
  thereafter during the first 6 months
• Testing after 6 mos. is not usually indicated
• HIV viral load (RNA)? not recommended
• High rate of false positives
• CBC/CMP at baseline and then at 2 weeks

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Back to the case Management

• A two-drug antiretroviral regimen would be
  prescribed
• Drugs chosen that were not part of the source
  patients current tx regimen, e.g. AZT 3TC
• No evidence that this strategy reduces the risk
  of infection
• If the puncture were deep, the needle visibly
  bloody, source had advanced HIV ? three drugs
  (after discussing this w/ the HCW)
• May adjust regimen on the basis of resistance
  test results

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A brief word about HBV
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Hepatitis B Occupational Risk

• Percutaneous injuries are among the most
  efficient modes of HBV transmission
• Blood contains the highest HBV titers of all body
  fluids and is the most important vehicle for
  transmission in the health care setting
• Most other body fluids are not efficient vehicles
  for transmission, because they contain low
  quantities of infections HBV, despite the
  presence of HBsAg

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Hepatitis B Occupational Risk

• The risk of infection is related to the HBsAg and
  HBeAg status of the source
• Potentially a VERY infectious virus
• HBV has been demonstrated to survive in dried
  blood on environmental surfaces for up to a week
• Transmission is possible through inoculation into
  cutaneous scratches or on mucosal surfaces

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PEP for HBV

• Involves the utilization of HBIG and/or the
  hepatitis B vaccine
• HBIG is prepared from human plasma known to
  contain a high titer of HBsAb
• Various PEP strategies depend principally on the
  vaccination history of the HCW
• ALL HCWs should be vaccinated for HBV

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Occupational Hepatitis C

• a work in progress

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HCV

• HCV transmission following a needlestick accident
  occurs approximately 10 times more often than HIV
  transmission
• The overall risk of infection following exposure
  ranges from essentially 0 to about 10
• Risk is determined by the infectivity of the body
  fluid and the tissue exposed

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HCV - Infectivity

• HCV RNA concentration is highest in blood
• Only the infectivity of blood and blood products
  has been firmly established
• Among exposures to blood containing HCV RNA, risk
  is probably greater when the RNA level exceeds
  500K (based on the analogy of other transmission
  models)
• Inoculum volume is also important

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Diagnosis

• A complex issue
• Two markers of infection which provide
  complimentary information
• HCV RNA
• direct indicator of viral replication
• detected in serum 10 days post-exposure
• quite variable in the initial stages of infection
• HCV Ab ? may not appear for 6 mos. after exposure

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Diagnosis

• Test source for HCV Ab if negative and no
  immunocompromising condition, generally no
  further testing indicated
• If source is HCV Ab positive obtain HCV Ab, ALT
  in the exposed immediately and at 6 months at a
  minimum
• Additional testing for HCV Ab, ALT, and HCV RNA
  at 4-6 weeks is recommended

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What if the RNA is positive?

• An HCV infection should never be diagnosed by a
  single test result
• If either the RNA or the Ab is positive, a repeat
  or confirmatory test is required

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Should acute HCV be treated?

• Data from controlled and uncontrolled studies
  suggest that IFN therapy may prevent chronic HCV
  when administered to pts. w/ acute HCV infxn
• It is not clear whether there is an advantage to
  administering tx during the first 6 months v.
  later in the course of the infxn

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Should acute HCV be treated?

• Since 15-20 of patients w/ acute HCV infxn will
  spontaneously clear viremia, a case can be made
  to restrict tx to persons who still have
  detectable HCV RNA after 6 months, sparing some
  HCWs the potentially adverse effects of IFN
• Furthermore, neither the appropriate antiviral
  regimen nor the duration of tx for acute HCV is
  known

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HCV PEP

• Easy! NONE
• No role for immunoglobulin
• Did not prevent infxn in chimpanzees even when
  given w/in 2 hours of infection
• Commercially available IG preparations do not
  contain HCV Abs
• IFN has failed to prevent HCV transmission after
  exposure
• IFN may only be effective after HCV infxn is
  established