Tuberculosis Update Rachel L. Stricof, Epidemiologist New York State Department of Health...
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Transcript of Tuberculosis Update Rachel L. Stricof, Epidemiologist New York State Department of Health...
Tuberculosis Update
Rachel L. Stricof, EpidemiologistNew York State Department of Health
TB & MDR-TB - 2005• 1,294 cases in NYS, a 4.9% decrease
from 2004• > 72 percent decrease since 1992• > 51 of cases outside NYC are from
Nassau, Suffolk and Westchester counties
• 27 MDR cases: 24 from NYC, 3 in rest of state
• Approximately, 70 percent of cases born outside U.S.
Key to Control• Know the epidemiology of TB in the
community you serve• Changes can occur rapidly
– HIV epidemic– MDR transmission– Introduction of TB in homeless shelters,
prisons, high risk populations, etc.• e.g., Hmong Refugees
• Changes can have significant impact
What you don’t want to happen…
• Time 0 through day 5– 45-year-old female admitted through ED– 3 month history of productive cough,
pleuritic chest pain, low grade temp and night sweats
– CXR examination revealed RLL infiltrate– Past medical history – diabetes, smoking
and asthma– Discharged on oral Levaquin after clinical
improvement on IV Levaquin
And the story continues….• Day 23 - ED Visit
– Fever, chills, productive cough– CXR examination reveals RLL pneumonia– Given prescription for 10 day course of
Levaquin
• Day 37 - ED Visit– Fever, chills, productive cough, chest pain– Dx: resolving pneumonia and pleuritis– Plan: Motrin and follow-up with PMD in 3
days
And the sad story continues….• Day 41 - 45
– Patient admitted from ED– Worsening shortness of breath, chest pain,
cough, low grade fever– Blood glucose = 592– CXR exam: RLL pneumonia– Placed on Augmentin and develops pruritis
and hives– Switched to Ceclor and develops pruritis– Discharged on Clindamycin and Zithromax
Is there no end………
• Day 157 (5+ months) – – Patient readmitted from the ED– Blood glucose up to 609– CXR exam: RLL infiltrate, pleural effusion,
LUL nodule– CT exam: Cavitary lesions in LUL and RLL– ID consultation obtained on 5th hospital day
• Noted weight loss (size 18 to 8)• Orders TST, sputum for AFB, isolation • Sputum: 4+ AFB, M. tuberculosis
Early Identification
• Most critical component• As incidence goes down, so does
index of suspicion• As incidence goes down, public
health infrastructure in jeopardy• As incidence goes down, more
difficult to maintain competency (lab, radiology, clinical acumen, etc.)
What’s New?
• Expanded scope – additional settings• Criteria for moving into/out of isolation • Revised risk assessment recommendations• TB screening frequency modifications• Respiratory fit testing and training
wording• Voluntary use of respirators by visitors• QuantiFERON testing• Frequently asked questions section added
Other Settings• ERs• Medical offices• Bronchoscopy
suites• Autopsy suites• Embalming rooms• Operating suites• Laboratories• TB clinics
• Ambulatory care units
• Dialysis units• Correctional
facilities• EMS• Home healthcare• Hospices• LTCF
Frequency of Sputum Collection for TB Suspects
• Three consecutive negative sputum smears
• Taken 8 - 24 hours apart• Previous guideline recommended 24 hour
intervals between specimens
• At least one specimen obtained AM
• In most cases, collection will occur over 2 days
NYS NAA Testing *on AFB+ respiratory specimens – Not CDC
• Mycobacteriology Standard 8 ( to go into effect later this spring ):– All respiratory specimens which test acid-fast smear
positive and are from patients who have not previously been diagnosed with tuberculosis shall have nucleic acid amplification testing performed
• Guidance:– Specimens from patients with a past history of NTM
infection and without clinical suspicion of tuberculosis (e.g., cystic fibrosis patients) do not need nucleic acid amplification testing performed.
– If the laboratory does not have the capability to perform nucleic acid amplification testing, an additional respiratory specimen shall be immediately requested and sent to a New York State permitted laboratory that performs nucleic acid amplification.
• *Nucleic Acid Amplification: – Gen-Probe AMPLIFIED Mycobacterium tuberculosis Direct
(MTD) or Roche AMPLICOR Mycobacterium tuberculosis (MTB) test
Free MTD testing on AFB smear negative specimens: Wadsworth*
• All of the following criteria should be met: – High clinical suspicion of TB, previously
untreated or <7 days of treatment– Respiratory specimen, or – Non-respiratory specimens (request from
the lab on a case by case basis if clinical suspicion is high)
– *For NYC specimens, Wadsworth or NYCPHL
*not CDC
Infectious TB disease is unlikely
AND
Another etiology is identified
OR
Three consecutive negative sputum smears taken 8 - 24 hours apart
OR
Smear +, NAA-negative for M. tb
Discontinuing Isolation for Suspect or Rule-out TB Patients
Discontinuing Isolation for Suspected/Confirmed TB Patients
• Remain in airborne isolation until: – Three consecutive negative AFB sputum
smear results collected 8 - 24 hours apart, with at least one being an early morning specimen
– On appropriate anti-TB treatment• Usually a 4 drug regimen to start • Usually for at least 2 weeks prior to
discontinuing isolation
– Demonstrated clinical improvement
Airborne Infection Isolation Rooms (AIIRs)
• 6 ACH (existing); 12 ACH (new)• Minimum of 2 outdoor air exchanges per hour
• Recommended minimum pressure differential has been increased from 0.001 to 0.01 w.g. (AIA Guidelines 2001)
• Monitoring is essential
• Direct exhaust to outside • If must recirculate air to other areas, HEPA
• Proper installation and maintenance
HEPA Filter
High Efficiency Particulate Air
• 99.97% @ 0.3 micron• high air resistance
– may lose airflow – leakage at seals
• special maintenance
Proper
Installation and
Maintenance
Are Essential
Continuous Monitors vs. Smoke
• 189 New York State hospitals• 172 (91%) had at least one AII room• 117 rooms had a continuous-pressure
monitoring device – 25% had a discrepancy between smoke testing and
continuous monitor– Not associated with any particular type of device or
manufacturer– Discrepancies increased with increased verification
w/smoke
• Recommend daily smoke test when room in use
Pavelchak N, Cummings K, Stricof R et al. Infect Control Hosp Epidemiol 2001; 22(8):518–19
Smoketesting
Disruption of Ventilation
• Opening/closing windows or doors• Movement of elevators• Blocked air diffusers or exhaust grills• Outdoor wind direction and speed• Dirty filters• Variable air volume (VAV) systems
Changes in one area affect other areas
Ultraviolet Germicidal Irradiation (UVGI)
• Can be used as a supplement to ventilation
• Not a substitute for negative pressure
• Can substitute for HEPA filtration when recirculated into same AIIR
• Guidelines provide new emphasis on safety and maintenance
• Provide guidance on occupational exposure limits
CDC Guidelines -Respiratory Protection for Workers
• Determining need for a respiratory protection program for TB– Suspect or confirmed TB patients
• Selection of respirators• Fit testing
– Initial– Periodic
• Annual training
Selection of Respirators• Certified by CDC/NIOSH as a non-
powered particulate filter respirator, including disposable respirators, or PAPRs with high efficiency filters
• Have the ability to adequately fit respirator wearers who are included in a respiratory-protection program
• Have the ability to fit the different facial sizes and characteristics of HCWs (This criterion can usually be met by making respirators available in different sizes and models.)
Page 39
Fit Testing (Cut and Pasted)A fit test is used to determine which respirator fits the user adequately and to ensure that the user knows when the respiratorfits properly. After a risk assessment is conducted to validatethe need for respiratory protection, perform fit testingduring the initial respiratory-protection program training andperiodically thereafter in accordance with federal, state, andlocal regulations (http://www.osha.gov/SLTC/respiratoryprotection/index.html).Fit testing provides a means to determine which respiratormodel and size fits the wearer best and to confirm that thewearer can don the respirator properly to achieve a good fit.Periodic fit testing for respirators used in TB environmentscan serve as an effective training tool in conjunction with thecontent included in employee training and retraining. Thefrequency of periodic fit testing should be supplemented bythe occurrence of 1) risk for transmission of M. tuberculosis,2) facial features of the wearer, 3) medical condition that wouldaffect respiratory function, 4) physical characteristics of respirator(despite the same model number), or 5) model or size ofthe assigned respirator (281). Page 39
Respiratory Protection for Visitors
• Visitors can use N-95’s – Why?
– Visitors may have much more intense and prolonged contact
– Minimizes confusion for employees and visitors
– No medical assessment or fit-testing is required for visitors
• Only necessary when mandated for workers• OSHA standard
– Selecting a respirator with inherently good fit characteristics will benefit all
Worker Screening
Depends on Facility TypeAnd
Specific Regulations
TB Screening Prior to Employment
• Clinical signs and symptoms• History of previous exposure,
disease or treatment• History of BCG, especially if born
outside of the US• Perform TB screening• Evaluate based on results
Tuberculin Skin Test (TST)
• Intradermal (Mantoux) method• 5 TU of PPD tuberculin• Read by designated, trained
personnel at 48-72 hours• Read transverse diameter of
induration• Record mm of induration, not
redness
Boosting
• Some people with TB infection may have a negative skin test when tested many years after infection
• The initial skin test may boost (stimulate) their ability to react to tuberculin
• Positive reactions on subsequent tests may be misinterpreted as new infection
Two-step Testing
• All newly employed HCWs with negative initial TST should be retested within 1-3 weeks
• Second reading should be recorded in mm induration
• This reading should serve as baseline
Tuberculin Screening: CDC vs. NYS
• CDC no longer recommends routine, periodic tuberculin skin testing ( or QFT) in low risk settings. [12/30/2005]
• NYSDOH still requires annual tuberculin screening in licensed healthcare facilities.– May use Mantoux method tuberculin
skin test or QuantiFERON TB Gold
QuantiFERON-TB Gold (QFT-G)
• December, 2004 – FDA approval announced
• Whole blood assay • Detects M. tuberculosis infection• Detects immune responses to
specific M. tb proteins
Advantages of QFT-G• Higher specificity
– Not affected by prior exposure to BCG or most nontuberculous mycobacteria (exceptions: M. kansasii, M. marinum and M. szulgai )
• Eliminates issues surrounding appropriate placement, tuberculin product, reading and interpretation
• Requires one visit, not multiple visits– Results within 24 hours– No need for 2-step baseline, does not induce
boosting
• Can target follow-up resources on positives
Disadvantages of QFT-G• Specimen must reach lab within 12 hours• Reagents are more costly
– But, other costs need to be considered• Results not directly comparable with TST
– HCWs move between different facilities• Some may use QFT-G, others TST• Implementation strategies may need to be developed
• Most labs are not offering QFT-G• Not every laboratory will be able to reliably
perform this test in a cost-effective manner
Disadvantages of TST
Placement issuesReading issuesInterpretation issuesElicits boostingReagent issuesReproducibility issuesSpecificity poor
For more information on QuantiFERON-TB Gold….
• Review CDC Guidelines on QuantiFERON-TB Gold– http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5415a4
.htm
– Review literature as it evolves– Definitely more specific, may be more
sensitive
• Although NYS regulations specify Mantoux method, QFT is acceptable alternative.
TB Prevention and Control in LTC
• Letter has been sent to long term care facilities – http://www.health.state.ny.us/professionals/nursing_
home_administrator/docs/dal_06-03_guidelines_for_tuberculosis_control.pdf
– Employee screening•Baseline and annual
– Resident screening•Baseline only• No longer recommend routine, annual
testing
Chest x-ray Examination
• After baseline chest radiograph, no need to repeat CXR unless signs or symptoms of TB disease develop or a clinician recommends a repeat chest radiograph.
CDC TB Guideline Reference
• CDC Guidelines for Preventing the Transmission of M. tb in Health-Care Settings, 2005– http://www.cdc.gov/mmwr/preview/m
mwrhtml/rr5417a1.htm