CASE MANAGEMENT AND CONTACT INVESTIGATION INTENSIVE May 26-28, 2015

Curry International Tuberculosis Center, UCSF

300 Frank H. Ogawa Plaza, Suite 520 Oakland, CA; Office (510) 238-5100

BASIC CONCEPTS IN TB

OBJECTIVES

Upon completion of this session, participants will be able to:

1. List three priority strategies that the Centers for Disease Control and Prevention recommends for public health agencies to implement in order to control and prevent tuberculosis

2. Identify several characteristics that distinguish active TB disease from latent TB infection (LTBI)

3. Appropriately apply the American Thoracic Society TB classifications

INDEX OF MATERIALS PAGES

1. Basic concepts in TB-slide outline Presented by: April King-Todd, RN, BSN, MPH

1-9

SUPPLEMENTAL READING MATERIALS

1. CDC. Table 2.8: TB Classification System. In: Chapter 2: transmission and pathogenesis of tuberculosis. Core Curriculum on Tuberculosis: What the Clinician Should Know. Atlanta, GA: 2011:40

2. Resources on Tuberculosis

3. Acronyms and Abbreviations

TB Case Management and Contact Investigation Intensive May 26-28, 2015 Curry International Tuberculosis Center

Basic Concepts in TB1

Basic Concepts in TB

Tuberculosis Case Management and Contact 

Investigation Intensive  May 26‐28, 2015

April King‐Todd, BSN, MPH

Nurse Manager 

Los Angeles County TB Control Program

Basic Concepts in TB

TB Control Priorities in US

Pathogenesis 

Transmission

Risk factors associated with transmission

TB vs LTBI

Drug resistant & MDR ‐TB

TB Classification system

1

Objectives

Upon completion of this session, participants will be able to:

1. List three priority strategies that the Centers for Disease Control and Prevention recommends for public health agencies to implement in order to control and prevent Tuberculosis

2. Identify several characteristics that distinguish active TB disease from latent TB infection (LTBI)

3. Appropriately apply the American Thoracic Society TB classifications

TB Case Management and Contact Investigation Intensive May 26-28, 2015 Curry International Tuberculosis Center

Basic Concepts in TB2

• Tuberculosis (TB) remains one of the world’s deadliest communicable diseases.

• In 2013, an estimated 9.0 million people developed TB and 1.5 million died from the disease,360 000 of whom were HIV-positive. TB

National Priorities for TB Control 2015‐2019

Priority 1:

• Identify & treat active cases

• Identify, evaluate & treat contacts

Priority 2:

• Evaluate & treat new immigrants & refugees with “Class B” TB notifications upon arrival to U.S.

Priority 3:

• Targeted testing and treatment of high‐risk populations

Source: Tuberculosis Elimination and Laboratory Cooperative Agreement, CDC‐RFA‐PS15‐1501 National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention

Introduction

Airborne disease caused by the bacterium Mycobacterium tuberculosis (M. tb)

M. tb complex (M. tb, M. bovis, M. africanum, M. microti,M. canetti,  M. caprae, M. pinnipedii, and M. mungi) can cause TB disease

Majority of TB cases caused byM. tb

M. tb organisms also called tubercle bacilli

TB Case Management and Contact Investigation Intensive May 26-28, 2015 Curry International Tuberculosis Center

Basic Concepts in TB3

Transmission of M. tuberculosisM. tb spread via airborneparticles called dropletnuclei

Expelled when person withinfectious TB coughs, sneezes, shouts, or sings

Transmission occurs when droplet nuclei inhaled and reach the alveoli of the lungs, via nasal passages, respiratory tract, and bronchi

Probability TB will be Transmitted

Susceptibility of the exposed person

Infectiousness of person with TB (i.e., number of bacilli TB patient expels into the air)

Environmental factors that affect the concentration of M. tborganisms

Proximity, frequency, and duration of exposure (e.g., close contacts)

Can be transmitted from children, though less likely

PathogenesisDroplet nuclei containing tubercle bacilli are inhaled, enter the lungs, and travel to the alveoli.

Tubercle bacilli multiply in the alveoli.

TB Case Management and Contact Investigation Intensive May 26-28, 2015 Curry International Tuberculosis Center

Basic Concepts in TB4

Pathogenesis

A small number of tubercle bacilli enter the bloodstream and spread throughout the body. The tubercle bacilli may reach any part of the body, including areas where TB disease is more likely to develop (such as the brain, larynx, lymph node, lung, spine, bone, or kidney).

PathogenesisWithin 2 to 8 weeks, special immune cells called macrophages ingest and surround the tubercle bacilli. The cells form a barrier shell, called a granuloma, that keeps the bacilli contained and under control (LTBI).

If the immune system cannot keep the tubercle bacilli under control, the bacilli begin to multiply rapidly (TB disease). This process can occur in different areas in the body, such as the lungs, kidneys, brain, or bone.

Latent TB Infection (LTBI) Granulomas may persist (LTBI), or may break down to produce TB disease

2 to 8 weeks after infection, LTBI can be detected via TST or interferon‐gamma release assay (IGRA)

The immune system is usually able to stop the multiplication of bacilli

Persons with LTBI are not infectious and do not spread organisms to others

TB Case Management and Contact Investigation Intensive May 26-28, 2015 Curry International Tuberculosis Center

Basic Concepts in TB5

TB Disease

In some, the granulomas break down, bacilli escape and multiply, resulting in TB disease

Can occur soon after infection, or years later

Persons with TB disease are usually infectious and can spread bacteria to others

Positive M. tb culture confirms TB diagnosis

Sites of Disease

Lungs (pulmonary): most common site; usually infectious

Miliary: occurs when bacilli spread to all parts of the body; rare, but fatal if untreated

Central nervous system: usually occurs as meningitis, but can occur in brain or spine

Sites of Disease (cont.)Outside the lungs (extrapulmonary): usually not infectious, unless person has

Concomitant pulmonary disease,

Extrapulmonary disease in the oral cavity or larynx, or

Extrapulmonary disease with open site, especially with aerosolized fluid.

TB Case Management and Contact Investigation Intensive May 26-28, 2015 Curry International Tuberculosis Center

Basic Concepts in TB6

Risk of Developing DiseaseNormal Immune System

Untreated, 5% of infected persons with normal immunity develop TB in first 1–2 years post infection, another 5% later in life

Thus, about 10% of infected persons with normal immunity will develop TB at some point in life if not treated

Risk of Developing Disease (cont.)Weak Immune System

Persons with weak immunity at increased risk of progressing to TB disease

Untreated HIV infection highest risk factor: risk of developing TB disease is 7%–10% each year; 

Children <5 years of age also at increased risk

TB Case Management and Contact Investigation Intensive May 26-28, 2015 Curry International Tuberculosis Center

Basic Concepts in TB7

LTBI vs. TB Disease

Person with LTBI (Infected) Person with TB Disease (Infectious)

Has a small amount of TB bacteria in his/her 

body that are alive, but inactive

Has a large amount of active TB bacteria in 

his/her body

Cannot spread TB bacteria to others May spread TB bacteria to others

Does not feel sick, but may become sick if the 

bacteria become active in his/her body

May feel sick and may have symptoms such as a 

cough, fever, and/or weight loss

Usually has a TB skin test or TB blood test 

reaction indicating TB infection

Usually has a TB skin test or TB blood test 

reaction indicating TB infection

Radiograph is typically normal Radiograph may be abnormal

Sputum smears and cultures are negative Sputum smears and cultures may be positive

Should consider treatment for LTBI to prevent 

TB disease

Needs treatment for TB disease

Does not require respiratory isolation May require respiratory isolation

Not a TB case A TB case

Drug‐Resistant TB

Caused by organisms resistant to one or more TB drugs

Transmitted same way as drug‐susceptible TB, and no more infectious

Delay in detecting drug resistance may prolong period of infectiousness because of delay in starting correct treatment

Multidrug‐Resistant (MDR) and Extensively Drug‐Resistant (XDR) TB

MDR TB caused by bacteria resistant to best TB drugs, isoniazid and rifampin

XDR TB caused by organisms resistant to isoniazid and rifampin, plus fluoroquinolones and ≥1 of the 3 injectable second‐line drugs

*Often resistant to additional drugs

**Resistant to any fluoroquinolone and at least one of three injectable second‐line drugs  (i.e., amikacin, kanamycin, or capreomycin

MDR TB*with drug resistance to at least the first-line drugs isoniazid

and rifampin

TB with any

drug resistance

XDR TB**with drug resistanceto the first-line drugs

isoniazid and rifampin and to specific second-line

drugs

AllTB

TB Case Management and Contact Investigation Intensive May 26-28, 2015 Curry International Tuberculosis Center

Basic Concepts in TB8

Types of Drug ResistanceDrug resistance develops in two ways:

Primary resistance develops in persons initially infected with resistant organisms

Secondary (acquired) resistance develops during TB therapy

Circumstances Increasing the Risk of Drug‐Resistant TBRisk of drug‐resistant TB is increased with exposure to a person who

Has confirmed drug‐resistant TB

Had prior unsuccessful treatment for TB, and drug susceptibility results not known

Originated in a drug‐resistant TB prevalent country

Has positive smear and culture 2 months after treatment start

Classification System for TB

Based on TB pathogenesis (stage of disease)

Helps clinician track the development of TB in patients

Persons with class 3 or 5 TB should be reported to health department

Patients should not have class 5 classification for more than 3 months

TB Case Management and Contact Investigation Intensive May 26-28, 2015 Curry International Tuberculosis Center

Basic Concepts in TB9

TB Classification SystemClass Stage of Disease

0 No exposure, no infection

1 Exposure,  no evidence of infection

2 TB infection, no disease

3 TB, clinically active

4 TB,  not clinically active

5 TB suspect

References

• CDC Core Curriculum slide set

• TB Nursing: A Comprehensive Guide to Patient Care v 6/13/11

• CDC. Table 2.8: TB Classification System. In: Chapter 2: transmission and pathogenesis of tuberculosis. Core Curriculum on Tuberculosis: What the Clinician Should Know. Atlanta, GA: 2011:40

• Resources on Tuberculosis

• Acronyms and Abbreviations

Classification System for Tuberculosis

TB Class

Type

Description

0 No TB exposure

Not infected • No history of TB exposure and no evidence of M. tuberculosis infection or disease

• Negative reaction to TST or IGRA

1 TB exposure

No evidence of infection • History of exposure to M. tuberculosis

• Negative reaction to TST or IGRA (given at least 8 to 10 weeks after exposure)

2 TB infection No TB disease

• Positive reaction to TST or IGRA

• Negative bacteriological studies (smear and cultures)

• No bacteriological or radiographic evidence of active TB disease

3 TB clinically active

• Positive culture for M. tuberculosis OR

• Positive reaction to TST or IGRA, plus clinical, bacteriological, or radiographic evidence of current active TB

4 Previous TB disease (not clinically active)

• May have past medical history of TB disease

• Abnormal but stable radiographic findings

• Positive reaction to the TST or IGRA

• Negative bacteriologic studies (smear and cultures)

• No clinical or radiographic evidence of current active TB disease

5 TB suspected • Signs and symptoms of active TB disease, but medical evaluation not complete

From Centers for Disease Control and Prevention. Table 2.8: TB Classification System. In: Chapter 2: transmission and pathogenesis of tuberculosis. Core Curriculum on Tuberculosis: What the Clinician Should Know. Atlanta, GA: 2011:40.

Websites Checked 5/7/2015

Resources on Tuberculosis (TB)

Centers for Disease Control and Prevention (CDC) Division of Tuberculosis Elimination (DTBE)

Guidelines: http://www.cdc.gov/tb/publications/guidelines/default.htm

Online Courses:

Self-Study Modules on Tuberculosis:

http://www.cdc.gov/tb/education/ssmodules/default.htm

Core Curriculum on Tuberculosis: What the Clinician Should Know:

http://www.cdc.gov/tb/education/corecurr/index.htm

Curry International Tuberculosis Center (CITC)

Medical Consultation Warmline: http://www.currytbcenter.ucsf.edu/consultation

877-390-6682 (toll-free)

Warmline inquiries can also be sent to the CITC email address, currytbcenter@ucsf.edu

8:00 AM to 4:30 PM (Pacific Time), Monday through Friday (excluding holidays). Voicemail is available to record incoming messages 24 hours a day, 7 days a week.

Online Products: http://www.currytbcenter.ucsf.edu/products

(selected highlights only—check the web page for the full list)

Drug-Resistant Tuberculosis: A Survival Guide for Clinicians, 2nd edition

Radiographic Manifestations of Tuberculosis: A Primer for Clinicians, Second Edition

Tuberculosis Infection Control: A Practical Manual for Preventing TB

Websites Checked 5/7/2015

Curry International Tuberculosis Center (continued) Online Courses & Presentations: http://www.currytbcenter.ucsf.edu/products

(selected highlights only—check the web page for the full list)

Asking the Right Questions

Medical Management of Tuberculosis

Pediatric Tuberculosis

Practical Solutions for TB Infection Control: Infectiousness and Isolation

TB Prevention in the HIV-infected Patient: Screening, Testing, and Treatment of LTBI

Tuberculosis Radiology Resource Page

Archived Webinars: http://www.currytbcenter.ucsf.edu/trainings/webinar-archive Classroom Trainings: http://www.currytbcenter.ucsf.edu/trainings

National Tuberculosis Controllers Association (NTCA)

Tuberculosis Nursing, 2nd Edition:

http://www.tbcontrollers.org/resources/tb-nursing- manual/#.VFuW7Wf4pws

Interjurisdictional Transfer Form and Contacts:

http://www.tbcontrollers.org/resources/interjurisdictional-transfers/#.VFuW3Wf4pws

California Tuberculosis Controllers Association (CTCA)

California Department of Public Health/CTCA Joint Guidelines:

http://www.ctca.org/index.cfm?fuseaction=page&page_id=5074

CTCA Directory: http://www.ctca.org/index.cfm?fuseaction=page&page_id=5071

Tuberculosis (TB) Acronyms and Abbreviations

AFB acid-fast bacilli

AIDS acquired immune deficiency syndrome

ALT alanine aminotransferase

ARPE Aggregate Reports for Tuberculosis Program Evaluation

ART antiretroviral therapy

AST aspartate aminotransferase

ATBD active tuberculosis diease

ATS American Thoracic Society

BCG bacilli Calmette-Guérin

CBC complete blood count

CC cultural competency

CDC Centers for Disease Control and Prevention

CI contact investigation

CNS central nervous system

CXR chest x-ray

DTBE Division of Tuberculosis Elimination

DOT directly observed therapy

DST drug sensitivity testing

EMB ethambutol

ESRD end-stage renal disease

FQN fluoroquinolone

IA injectable agent

IDSA Infectious Diseases Society of America

HIV human immunodeficiency virus

HPLC high performance liquid chromatography

IGRA interferon gamma release assay

INH isoniazid

IP infectious period

IUATLD International Union Against Tuberculosis and Lung Disease

LEP limited English proficiency

LFT liver function test

LJ Lowenstein-Jensen

LTBI latent TB infection

M. tb Mycobacterium tuberculosis

MDR-TB multidrug-resistant TB

MGIT mycobacteria growth indicator tube

MIRU mycobacterial interspersed repetitive units

MMCP MediCal Managed Care Plan

MMWR Morbidity and Mortality Weekly Report

MOTT mycobacteria other than tuberculosis

NAAT nucleic amplification test

NNRTI non-nucleoside reverse transcriptase inhibitor

NRTI nucleoside reverse transcriptase inhibitor

NTCA National Tuberculosis Controllers Association

NTIP National Tuberculosis Indicators Project

NTM nontuberculous mycobacteria

NTNC National Tuberculosis Nurse Coalition

OTIS Online Tuberculosis Information System

PCR polymerase chain reaction

PI protease inhibitor

PPD purified protein derivative

PZA pyrazinamide

QA quality assurance

QI quality improvement

QFT-GIT QuantiFERON®-TB Gold In-Tube test

RBT rifabutin

RPT rifapentine

RIF rifampin

RTMCC Regional Training and Medical Consultation Center

RVCT Report of Verified Case of Tuberculosis

TDR totally drug-resistant tuberculosis

TNF-α tumor necrosis factor-alpha

TST tuberculin skin test

T-Spot T-SPOT®.TB test

SAT self-administered therapy

SM streptomycin

WHO World Health Organization

XDR-TB extensively drug-resistant tuberculosis