Tuberculosis in the Hospital

J Rush Pierce Jr, MD, MPHAssociate Professor, Texas Tech University HSC Health Authority, Amarillo Bi-City-County health District

Texas Society of Infection Control PractitionersIntermediate Course, Amarillo, TexasOctober 20, 2006

Disclosures Salaried by TTUHSC City of Amarillo Department of Public Health

provides approximately 30% salary support Consultant for Texas Dept. of Health and AIG

Annuity Insurance Company Some of Slides form CDC Teaching Library Received no financial compensation for

today’s talk

Objectives of today's’ talk

List the major symptoms of active tuberculosis. Define latent tuberculosis and explain how it is

different than active tuberculosis. List conditions which facilitate the transmission

of tuberculosis. List activities which minimize transmission of

tuberculosis in hospitals. Explain the role of the Health Department in the

management of tuberculosis.

An ICP Nightmare

A 54 year-old homeless man comes to the ED with cough and fever. He is dirty, unshaven, appears undernourished, and smells of alcohol. After an 8 hour stay in the ED, he is discharged with amoxicillin for bronchitis. Social service arranges stay in a homeless shelter.

He returns one week later. He says he has been sick for several weeks with night sweats and cough that has at times produced bloody sputum. He has lost 20 pounds in two months.

The ED physician orders a CXR and the patient is admitted to the floor to the on-call physician.

The patient is admitted to a semi-private room. The on-call physician orders a regular diet, oxygen, ceftriaxone and azithromycin.

The next day (hospital day 2), the radiologist reads the CXR and identifies a right upper lobe cavity. He dictates a report that goes to transcription.

The transcribed report arrives on the floor the following day (hospital day 3) and is filed by the clerk in the chart after the physician makes rounds.

The report is noted by the physician on hospital day 4. The physician orders sputum for AFB and a TB skin test, but fails to communicate concerns about the possibility of TB to the nursing staff.

On hospital day 6, positive AFB smears are reported by the lab. The patient is placed in respiratory isolation and the ICP is contacted.

Pertinent questions

What is tuberculosis? How is tuberculosis transmitted? What conditions facilitate the transmission of

tuberculosis? How is tuberculosis diagnosed? How is transmission of tuberculosis

prevented in hospitals?

25 - 49

50 - 99

100 - 300

0 - 9

10 - 24

300 or more

No estimate

Rate per 100 000

Estimated TB incidence rates, 2000

The boundaries and names shown and the designations used on this map do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement.

Global Tuberculosis Control. WHO Report 2002. WHO/CDS/TB/2002.295

Unusual qualities of Mycobacterium Slow growing (division time ~ once/day)

Symptoms subacute Laboratory isolation slow Long treatment necessary

Resistant to ordinary antibiotics Resistant to cellular enzymatic defense

mechanisms Unusual staining characteristics

Sequencing the genome of M. tuberculosis

Transmission of tuberculosis Spread by droplet nuclei

Expelled when person with infectious TB coughs, sneezes, speaks, or sings

Close contacts at highest risk of becoming infected

Transmission occurs from person with infectious TB disease (not latent TB infection)

Transmission and Pathogenesis

Conditions that facilitate the transmission of tuberculosis

Small closed spaces Lack of air movement Lack of light

Consequences of infection with Consequences of infection with M. tuberculosisM. tuberculosis

95% 5%

Infection Immunity Reactivation disease

5%

Primary disease

Types of Active Tuberculosis Lung Infections

PRIMARY

Recent infection Favors lower lobes Non-cavitary Less contagious Children > Adults

REACTIVATION

Remote infection Upper lobes Tends to cavitation More contagious Almost exclusively adults,

occasionally adolescents

Active tuberculosis ling infection - History and physical examination

Weight loss Night sweats Hemoptysis

Signs of weight loss +/- fever Lung exam is usually

normal

HISTORY EXAM

TB Skin Testing

AFB smear

AFB (shown in red) are tubercle bacilli

Chest Radiographin Active TB Lung Infection

Abnormalities often seen in upper lobe or superior segments of lower lobe

May have unusual appearance in HIV-positive persons

Cannot confirm diagnosis of TB

Baseline Diagnostic Examinations for TB Tuberculin skin test Chest x-ray Sputum specimens (= 3 obtained 8-24 hours

apart) for AFB microscopy and mycobacterial cultures

Routine drug-susceptibility testing for INH, RIF, and EMB on initial positive culture

Counseling and testing for HIV infection

Contact Investigation in the hospital Enlist the help of the Health Department Identify those at highest risk of transmission Test for acquisition of TB infection Consider preventive therapy (treatment of

latent infection) for those who have recently acquired TB infection

CQI review

Factors to consider when deciding who is at highest risk Duration of exposure Place of exposure (closed room worse than

open area) Type of exposure (aerosol-inducing

procedures like HHN and bronchoscopy highest risk)

Immune system of exposed persons

Who was exposed?

Staff (nursing, physician, respiratory therapy, physicians, social service, dietary, admitting office, housekeeping, etc.)

Patients

Visitors

How do you know who was exposed?

Review of duty hours and work days of staff Post notices to staff Review patient room assignments With help of Health Department, interview

patient Letters to visitors, public notices

Contact investigation

Baseline testing Rationale How to do this

Repeat testing Assess positive reactors for active disease Offer positive reactors preventive therapy

(treatment of latent tuberculosis

Testing for TB Infection

The Tuberculin Skin Test

Inject intradermally 0.1 ml of 5TU PPD tuberculin

Produce wheal 6 mm to 10 mm in diameter

Follow universal precautions for infection control

No contraindication in pregnancy

Reading the Tuberculin Skin Test

•Read reaction 48-72 hours after injection

•Measure only induration

•Record reaction in millimeters

What is the booster phenomena and what is a two step tuberculin test?

Boosting

•Some people with LTBI may have negative skin test reaction when tested years after infection

•Initial skin test may stimulate (boost) ability to react to tuberculin

•Positive reactions to subsequent tests may be misinterpreted as a new infection

Two-Step Testing

Use two-step testing for initial skin testing of adults who will be retested periodically

• If first test positive, consider the person infected

• If first test negative, give second test 1-3 weeks later

• If second test positive, consider person previously infected

• If second test negative, consider person uninfected

How does BCG vaccine affect the tuberculin test?

BCG Vaccination and Tuberculin Skin Testing

• TST not contraindicated for BCG-vaccinated persons

• DX and RX for LTBI considered for any BCG-vaccinated person whose skin test reaction is >10 mm, if any of these circumstances are present:

-contact with another person with infectious TB- Was born or has resided in a high TB prevalence country- Is continually exposed to populations where TB prevalence is high

Consequences of infection with Consequences of infection with M. tuberculosisM. tuberculosis

95% 5%

Infection Immunity Reactivation disease

5%

Primary disease

Persons at Higher Risk of Developing TB Disease once Infected

•HIV infected

•Recently infected

•Persons with certain medical conditions

•Persons who inject illicit drugs

•History of inadequately treated TB

Conditions That Increase the Risk of Progression to TB Disease

•HIV infection

•Substance abuse

•Recent infection •Chest x-ray findings suggestive of

previous TB

•Diabetes mellitus

•Silicosis

•Prolonged corticosteriod therapy

•Other immunosuppressive therapy

Conditions That Increase the Risk of Progression to TB Disease (cont.)

•Cancer of the head and neck

•Hematologic and reticuloendothelial diseases

•End-stage renal disease

•Intestinal bypass or gastrectomy

•Chronic malabsorption syndromes

•Low body weight (10% or more below the ideal)

Candidates for Treatment of LTBI

Positive skin test result at least 5 mm

• HIV-positive persons • Recent contacts of a TB case

• Persons with fibrotic changes on chest radiograph consistent with old TB

• Patients with organ transplants and other immunosuppressed patients

Candidates for Rx of LTBI (cont.)

Positive skin test result at least 10 mm

• Recent arrivals from high-prevalence countries

• Injection drug users

• Residents/employees of congregate settings

• Mycobacteriology laboratory personnel

• Persons with certain clinical conditions

• Children < 4 years of age, or children and adolescents exposed to adults in high-risk categories

Candidates for Rx of LTBI (cont.)

Positive skin test result at least 15 mm

• Persons with no known risk factors for TB may be considered

• Targeted skin testing programs should only be conducted among high-risk groups

Decreasing transmission in hospitals High index of suspicion

ED staff Nursing staff Physicians

Early reporting of suspicions Early isolation Get to know your Health Dept Policies

Questions and/or comments