tuberculosis update rachel l. stricof, epidemiologist new york state department of health...

Tuberculosis Update

Rachel L. Stricof, EpidemiologistNew York State Department of Health

rls01@health.state.ny.us

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