Tuberculosis 101

Daniela Ingram, BSN RN

NC TB Nurse supervisor

NC DHHS- Epidemiology –

CD Branch – TB Control and Prevention Program

Statement

• No Disclosures

• No Conflict of Interest

Objectives

• History and definitions of MTB

• Testing methodologies (e.g., CXR, TST, IGRA, etc.) for the diagnosis of MTB

• Infection Control’s role in the management of possible/confirmed MTB

Tuberculosis – you say…

Tell me more

TB: Still a Big Problem in the United States

• Tuberculosis (TB) cases continue to be reported in every state

• Estimated 10-15 million persons in U.S. infected with the germ that causes TB

• Without treatment, about 10% of persons with TB infection will develop TB disease at some point in life

• Cost of TB in the U.S. is close to $1 billion every year

TB: Still a Big Problem in the United States

• NC had 196 reported cases of MTB in 2018• An epidemiolocal report for 2018 has not been posted yet

• US had 9,096 reported cases of MTB in 2018

• More numbers can be found on the NC TB website:https://epi.publichealth.nc.gov/cd/tb/figures.html

Tuberculosis Timeline

• Affliction of Mankind from the dawn of civilization-described as “lung fever” with emaciation, cough and expectoration of blood

• Human petrified bones dating back to 8000 B.C. showed evidence of TB

• Egyptian mummies (3000 – 2400 B.C)• Chinese literature (2700 B.C.)• Religious texts of India (1500 B.C.)• Greek literature (460 B.C.) phthisis

Tuberculosis Timeline

• Peak of epidemic in Europe late 1800’s, America early 1900’s

• 1882: Robert Koch identified tuberculosis bacillus

• 1895: Wilhelm Roentgen discovered X-ray

• Allowed physicians to diagnose and track progression of disease—effective medical treatment would not come for another 50 years

Tuberculosis Timeline

• Sanatorium Movement –By 1877, sanatoriums began to spread beyond Germany and through out Europe

• In the late 1800’s, it was believed that the best treatment for TB was clean air, low humidity, cool nights and abundant sunshine

• Western North Carolina (Asheville) became one of the premier destinations for people suffering from Tuberculosis

Tuberculosis Timeline

TB drug therapy developed-Streptomycin: 1946

Isoniazid: 1951Pyrazinamide: 1952Ethambutol: 1961

Rifampin: 1963

What is Tuberculosis (TB)?

• TB is a disease caused by bacteria called Mycobacterium tuberculosis

• The bacteria can attack any part of the body, but usually attacks the lungs

• With TB disease, the patient is symptomatic and feels ill

• With Latent TB infection, bacteria can be present in the body without causing TB- not sick

How is TB transmitted?

• TB is spread through droplet nuclei in the air from person to person when a person with active disease sings, coughs, sneezes or speaks

• Not everyone exposed becomes infected

• Droplet nuclei contain tubercle bacilli that settle into the lungs

• Bacilli multiply and some can enter bloodstream

• Immune system typically reacts and prevents spread

How is TB transmitted?

• Most infected people undergo complete healing of the initial infection and the tubercles calcify and lose their viability

• This tubercle may be noted as a calcified granuloma or Ranke Complex on chest x-ray report

Immune System

In most cases, the immune system will control the TB bacteria after infection to prevent the body from developing active TB disease (latent TB infection)

In other cases, the immune system is not able to control the bacteria and the patient develops Primary TB disease.

Later in life, if the immune system is weakened for those persons with latent TB infection, the TB can break through the wall of the granuloma and cause active disease-Reactivation Tuberculosis

Infectious TB is transmitted when a person is in VERYCLOSE CONTACTwith someone who is sick with TB disease over a prolonged period of time-dependent upon:

• amount of time • size of room • ventilation

Testing MethodologyEvaluation

TB Disease Evaluation

• Usually a positive skin test or blood test--(may be negative if immune-suppressed or has overwhelming TB disease)

• Abnormal chest x-ray (if pulmonary TB)

• Has symptoms of TB

• May be able to transmit TB to others (if pulmonary, pleural or laryngeal)

• Medical and Social History

• Curable

TST

Inject intradermally 0.1 ml of 5-TU PPD bevel up with a ¼ to ½ inch tuberculin syringe

1

produce wheal 6-10 mm in diameter

2

Read in 48 to 72 hours

3

Measure induration (not redness) transversely & record in mm

4

If there is no induration record as 0mm

5

Classifying the Tuberculin Reaction≥ 0 mm

• Immunocompromised individuals who are recent close contacts to a TB case or suspect, even if previously had TLTBI

• HIV + with CXR consistent with prior TB who received inadequate treatment

Classifying the Tuberculin Reaction≥ 5 mm is classified as positive for:

• HIV-positive persons• Persons suspected of having disease based upon

clinical presentation and/or chest x-ray evidence• Recent close contacts of known or suspected

infectious TB case • Persons with fibrotic changes on chest x-ray

consistent with old healed TB • Immunocompromised individuals

Classifying the Tuberculin Reaction≥10 mm is classified as positive

for:• Children < 4 years of age• Foreign born persons from a high prevalence area

• Injection drugs or crack cocaine user

• Persons with high risk medical conditions

• Residents and employees in high risk congregate settings

• Converters

• Mycobacteriology lab personnel

• Children and adolescents exposed to high risk adults

• Persons staying > 1 month in a high incidence area

Interferon Gamma Release Assays (IGRAS)

Blood test• Quantiferon Gold in-tube®• T-Spot. TB®

• Both measure an immune response• For indeterminate results-repeat the

same test with another blood sample• Factor out BCG and most other

nontuberculous mycobacteria

IMPORTANT

Negative TSTs and IGRAs do

not rule out TB!

Persons with active disease can

have negative TSTs and IGRAs

Positive PPD and IGRA’s support a

TB diagnosis

Persons with positive

TST/IGRAs need further evaluation-(CXR, symptom screen, epi form)

Diagnostic Tests: Chest X-ray

• Patchy or nodular infiltrate

• Upper lobes (or superior segment of lower lobes)

• Cavity

• Any lung abnormality with enlarged hilar nodes

• Large unilateral pleural effusion

• Miliary

Symptoms: Pulmonary TB Adults

• Coughing: 78-80%• usually worsening, > 2 weeks • often productive, becomes purulent

• Fever: 80%• Night sweats indicate low-grade fever (55%)• Weight loss (74%)

Barnes et al, Chest 1988;94:316-320

Symptoms: Pulmonary TB Adults

• Fatigue, Malaise (68%)

• Hemoptysis “classic” but infrequent

• Pleuritic chest pain (effusion)

• Dyspnea, late

Barnes et al, Chest 1988;94:316-320

Diagnostic Tests: Sputum

• Sputum acid fast bacteria (AFB)smear for acid fast bacteria (AFB), Polymerase Chain Reaction (PCR), AFB culture, and susceptibilities- sent to state lab (SPHL)-do not batch specimens

• Natural, induced• PCRs ran on Monday, Wednesday,

Friday (SPHL)• 2 sputua every 2 weeks until culture

negative

Medical & Social History

• Recent Exposure• Signs & symptoms of disease• Previous treatment for infection• Previous TB disease• Risk factors• HIV infection• Pregnancy

Infection Control

GUIDELINES FOR INFECTION CONTROL

• The CDC published the Guidelines for Preventing the Transmission of Mycobacterium Tuberculosis in Health Care Facilities, 2005 CDC, MMWR, December 30, 2005, Vol. 54, No. RR-17

GOALS OF A TB INFECTION CONROL PROGRAM

•Early detection of TB disease•Prompt isolation of suspected or

known cases or prompt referral•Appropriate treatment of TB

disease & LTBI

REQUIRED COMPONENTS

•Administrative controls

•Engineering controls

•Personal respiratory protection

TB RISK ASSESSMENT WORKSHEET

• Download a WORD version from http://www.cdc.gov/tb/publications/guidelines/infectioncontrol.htm

ENGINEERING CONTROLS

• Controlling the source of infection by using local exhaust ventilation and diluting and removing contaminated air by using general ventilation

• Controlling airflow to prevent contamination of air in areas adjacent to the source

• Required if cough-inducing procedures are performed within the facility

RESPIRATORY PROTECTION

• If personal respiratory protection is used in a health care setting, OSHA requires that an effective personal respiratory protection program be developed, implemented, administered, and periodically reevaluated. (OSHA standard 1910.134 at www.osha.gov)

RESPIRATORY PROTECTION

• NIOSH-certified personal respirators (N-95 is one type) are required when:

• entering the home of an infectious patient

• transporting an infectious patient in a closed

vehicle, or performing cough-inducing procedures.

• OSHA requires a medical eval by an MD or PE to

determine ability to wear a respirator prior to being

asked to use a respirator in the line of work or in

the event that a subsequent eval is indicated

RESPIRATORY PROTECTION

• Detailed policy & procedures for training, fit testing, & respirator use by workers, including the performance of a seal check by the user, proper cleaning and disinfection of the respirator & proper storage based on the manufacturer’s recommendation

• Training & fit-testing are required prior to the initial use of a respirator and periodically in accordance with Federal, state & local regulations & if there is a change in the respirator model, or a significant change in the employee wearing (weight loss/gain, beard or facial deformity

• The respirator must be fit-tested by the employee anytime it is used

RECORDS & DOCUMENTATION

The agency must maintain written & clear records documenting:

• That the mandated medical evaluation was

completed and the HCW was approved to

use a personal respirator

• The type of fit testing procedure used for the

HCW, the date it was done, the type of mask

(model, style & size) that was approved for

the HCW and who did the fit testing

RECORDS & DOCUMENTATION

The agency must maintain written & clear records documenting (continued):• That the HCW received training

about how to do a seal check each time the mask is worn

Call your Regional Nurse Consultant or your State Medical Consultant

• Dr. Jason Stout

• Julie Luffman, RN

• Myra Allen, RN

• Lynn Kearney, RN

• Daniela Ingram, RN

Call your Regional Nurse Consultant or your State Medical Consultant

• Daniela Ingram, RN• 919-755-3182

• daniela.ingram@dhhs.nc.gov

Questions?

SOURCES

• CDC, MMWR, December 30, 2005, Vol. 54, No. RR-17

• Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis

• https://www.cdc.gov/tb/publications/guidelines/pdf/clin-infect-dis.-2016-nahid-cid_ciw376.pdf

• North Carolina Tuberculosis Policy Manual

• http://epi.publichealth.nc.gov/cd/lhds/manuals/tb/toc.html

• TB 101 for Healthcare Workers

• https://www.cdc.gov/tb/webcourses/tb101/default.htm