TB Transmission What is TB? aTB is a disease caused by infection with a bacteria called Mycobacterium tuberculosis.

TB Infection and Disease aThe lungs are the most common place for TB. This is known as pulmonary TB. aTB of the voice box is the second most common and is usually called laryngeal TB.

TB Infection and Disease Can the TB bacteria affect other areas of my body other than the lungs? aTB can infect the brain, kidneys, bones, and other areas. aTB can also spread through the blood to other organs; this is called miliary TB.

TB Infection vs. TB Disease There is a difference between TB “infection” and TB “disease” TB infection: TB germs stay in your lungs, but they do not multiply or make you sick –You cannot pass TB germs to others TB disease: TB germs stay in your lungs or move to other parts of your body, multiply, and make you sick –You can pass the TB germs to other people

Natural History of TB Infection Exposure to TB No infection (70-90%) Infection (10-30%) Latent TB (90%) Active TB (10%) Untreated Die within 2 yearsSurvive Treated DieCured Never develop Active disease

TB Infection & Disease There are 2 Categories of TB: Latent & Active aTB infection of the lungs can fall into 2 categories of disease: Latent TB or Active TB. aLatent TB means a person is infected by TB bacteria, but cannot infect others, and is not coughing or appearing sick. aLatent TB means the body’s immune system has contained the infection.

TB - Infection & Disease Categories of TB - Latent aPersons with latent TB are identified by a positive skin test (PPD). aPersons who are not infected with Mycobacterium tuberculosis have a negative skin test (PPD).

How Are TB Germs Spread?

TB Transmission How can you catch TB? aTB is spread through tiny drops sprayed into the air when an infected person coughs, sneezes, or speaks, or another person breathes the air into their lungs containing the TB bacteria.

ISTC TB Training Modules 2009 Transmission of M.tb CASECONTACT  Site of TB  Cough  Bacillary load  Treatment  Closeness and duration of contact  Immune status  Previous infection  Ventilation  Filtration  U.V. light Environment Droplet nuclei

Tuberculosis Infection & Disease aHomeless persons are at increased risk for catching TB. aTB cases are rising in the prison population due to the increased number of HIV infected inmates, crowded environment, and IV drug abusers.

ISTC TB Training Modules 2009 Assessing Infectiousness  High degree of infectiousness Sputum smear-positive pulmonary TB Symptomatic with cough Cavitation on chest radiograph (correlates with positive smear)  Lesser degree of infectiousness Sputum smear-negative, culture positive pulmonary TB Minimal if any cough Lesser radiographic extent of disease Extrapulmonary TB

Common Symptoms of TB Disease Cough (2-3 weeks or more) Coughing up blood Chest pains Fever Night sweats Feeling weak and tired Losing weight without trying Decreased or no appetite If you have TB outside the lungs, you may have other symptoms

Diagnosis and Treatment for Latent & Active TB Tools for Diagnosing TB Infection aMantoux skin test (PPD) aChest x-ray aSputum cultures

Diagnosis and Treatment for Latent & Active TB Tools for Diagnosing TB Infection Mantoux Skin Test(PPD) aMantoux tuberculin skin test (PPD) is a skin test for identifying exposure to the TB bacteria, Mycobacterium tuberculosis (latent infection) aThe Mantoux test is recommended because it provides the most consistent and reliable result. aThe Mantoux test is read hours after administration. Induration or “knot-like” swelling at the test site is significant and the reaction is measured in millimeter units. Redness at the test site is not measured.

Diagnosis and Treatment for Latent & Active TB Tools for Diagnosing TB Infection Chest X-Ray aA chest x-ray is ordered when a person presents a recent skin test conversion and is suspected of having TB. aIf a chest x-ray is normal, further diagnostic testing may not be necessary.

Diagnosis and Treatment for Latent & Active TB Tools for Diagnosing TB Infection Chest X-Ray aIf the chest x-ray shows signs of disease, further diagnostic testing will be needed to confirm TB disease.

Diagnosis and Treatment for Latent & Active TB Tools for Diagnosing TB Infection Sputum aA sputum specimen is necessary to confirm that the TB bacteria is present in the lung. aThe sputum specimens should: -come from deep within the lungs; -be obtained from the first coughed up sputum of the day, for 3 consecutive days -may be obtained through special respiratory therapy procedures.

Latent TB vs. Active TB Latent TB (LTBI) (Goal = prevent future active disease) = TB Infection = No Disease = NOT SICK = NOT INFECTIOUS Active TB (Goal = treat to cure, prevent transmission) = TB Infection which has progressed to TB Disease = SICK (usually) = INFECTIOUS if PULMONARY (usually) = NOT INFECTIOUS if not PULMONARY (usually)

Treatment Most TB is curable, but… – Four or more drugs required for the simplest regimen – 6-9 or more months of treatment required – Person must be isolated until non-infectious – Directly observed therapy to assure adherence/completion recommended – Side effects and toxicity common May prolong treatment May prolong infectiousness – Other medical and psychosocial conditions complicate therapy TB may be more severe Drug-drug interactions common

ISTC TB Training Modules 2009 Effect of Therapy on M.tb Log cfu Effective multi-drug therapy reduces bacillary load Weeks

ISTC TB Training Modules 2009 Evaluating Contacts & Determining Priorities

ISTC TB Training Modules 2009 Priorities in Contact Evaluation At greatest risk of acquiring infection Close contacts of smear positive index cases Persons with HIV infection (?) Highly exposed persons At greatest risk of active TB Children < 5 years of age Persons with HIV infection Persons with other immunocompromising conditions or therapies

ISTC TB Training Modules 2009 Initial Assessments of Contacts Assessment depends on local circumstances, resources, and policies.  Minimal evaluation: Question contacts about symptoms and evaluate if symptoms are present  Tuberculin skin test followed by chest radiographs for all positives (either > 5 mm or > 10mm, depending on local policies)  Chest radiographs for all children < 5 years of age  Sputum examinations for all symptomatic contacts and all with radiographic abnormalities

ISTC TB Training Modules 2009  Children < 5 years of age  Persons with HIV infection  Persons with other immunocompromising conditions  Close contacts of highly infectious index case  Persons with other conditions that increase risk (example: silicosis) Isoniazid Preventive Therapy: Priorities

Fundamentals of TB Infection Control Practices aIdentify persons with active TB early. aInitiate effective and appropriate isolation of known or suspected TB cases. aInitiate effective anti-TB treatment promptly...

Fundamentals of TB Infection Control Practices aIdentify and evaluate persons and health care workers exposed to infectious TB. aScreen health care workers for skin test conversions. aConduct surveillance for TB cases among patients and healthcare workers.

Patient Education aPatient education is an essential component to prevent the spread of TB. aTB patients should be taught to use tissues to cover coughs and sneezes. aTissues should be disposed appropriately and not left on counter tops.

Patient Education aA surgical mask must be worn by a TB patient whenever they leave the isolation room. aVisitors of a TB patient must wear a respirator but are not required to be tested.

Even if a Skin Test is Negative….. Chiclls FFever THINK TB ! Chills Fatigue Difficulty in Breathing Anorexia Loss of Appetite Night sweats Coughing up Blood