©2013 MFMER | slide-1 Screening for Tuberculosis Infection Shea Rabley, RN, MN TB Center Webinar...

2013 MFMER | slide-1 Screening for Tuberculosis Infection Shea Rabley, RN, MN TB Center Webinar May 1, 2014

2013 MFMER | slide-2 Disclosures None

2013 MFMER | slide-3 Objectives List the 2 methods that can be used when screening TB Infection. Describe the difference between a TB reactor and a TB converter.

2013 MFMER | slide-4 Why Screen for TB Infection? Tuberculosis is one of the worlds deadliest diseases. At least one-third of the worlds population are infected with TB. At least one person becomes infected every second. Each year, approximately 8.6 million people around the world become sick with TB disease. TB kills 3 people every minute annually worldwide.

2013 MFMER | slide-5 Why? There were an estimated 450,000 cases of multi-drug resistant (MDR) TB in 2012. TB is the leading killer of people who are HIV- infected. Children account for 500,000 new cases annually and 75,000 will die of TB disease. Approximately one in every 10 people with TB infection will progress to active TB at some point in their life; 5% in the first 2 years and the other 5% at some time over their lifespan.

2013 MFMER | slide-6 Why? Foreign born persons comprised 64.6% of the cases of TB in the US in 2013. The key to controlling TB is accurately and efficiently identifying those who have the potential to become infected or to progress to TB disease once infected. Global organizations are beginning to acknowledge that to fight TB effectively, identifying and treating latent TB infectionas well as active TB diseaseare vital.

2013 MFMER | slide-7 Who Should be Tested? Persons at risk of exposure to person known to have TB disease OR Persons who once infected have conditions assoicated with an increased risk of progression from TB infection to TB disease.

2013 MFMER | slide-8 Specifically Contacts to known cases Persons with HIV or other diseases that weaken the immune system Persons with signs/symptoms of TB disease Persons from countries where TB is common (Latin America, Caribbean, Asia, Africa, Eastern Europe & Russia) People who live or work in facilities where TB is common: hospitals that care for persons with TB disease, homeless shelters, correctional facilities and other congregate settings (nursing homes, CRCFs, other locally defined facilities)

2013 MFMER | slide-9 Specifically Persons with: Radiological evidence of old healed TB Low body weight or malnourished Conversions in their tuberculin test status Medical conditions such as: Diabetes Mellitus Silicosis Organ transplantation Chronic Renal Failure Cancers of head and neck Gastrectomy or jejunoileal bypass Conditions that require prolonged use of corticosteroids or other immunosuppressive agents (TNF- antagonists, cancer chemotherapy)

2013 MFMER | slide-10 How to Determine TB Infection I. Tuberculin Skin Test TST II. Interferon Gamma Release Assay - IGRA A. QuantiFERON-TB Gold In-tube QFT-GIT B. T-Spot.TB T-Spot

2013 MFMER | slide-11 I. Tuberculin Skin Testing In 1890, Robert Koch announced a cure for tuberculosis - 8 years after discovering the cause of TB Cure consisted of subcutaneous doses of tuberculin Subsequently found to be ineffective Ultimately became a widely-used diagnostic test for TB infection

2013 MFMER | slide-12 Immune Response to Tuberculin A positive test is result of a delayed-type hypersensitivity (DTH) response Reaction characterized by edema and formation of induration a hard, raised area, not redness measured in mm Reaction generally complete in 48-72 hours DTH response detectable 2-10 weeks after initial infection

2013 MFMER | slide-13 Mantoux Skin Testing Method Developed by Charles Mantoux in 1908 The standard tuberculin skin test Two Purified Protein Derivative (PPD) antigen products licensed by FDA: - Tubersol - Aplisol Do not indiscriminately switch between brands of tuberculin antigen

2013 MFMER | slide-14 Administering the Tuberculin Skin Test Inject intradermally 0.1 ml of 5 TU PPD tuberculin Produce wheal 6 mm to 10 mm in diameter Standardize your test procedure Follow standard precautions for infection control; gloves are not necessary

2013 MFMER | slide-15

2013 MFMER | slide-16 Needle Too Deep

2013 MFMER | slide-17 Needle Too Shallow

2013 MFMER | slide-19 Factors that May Affect the Skin Test Reaction Type of Reaction Possible Cause False-positive Nontuberculous mycobacteria BCG vaccination Anergy False-negative Recent TB infection Very young age (

2013 MFMER | slide-27 Key Definitions Reactor - an individual with a + skin test reaction (size interpreted as positive based on risk factors) with no clear documentation or history of being skin tested in the last two years. Convertor any individual with a negative skin test documented as baseline but who developed positive reaction with increase in reaction size of >10 mm within the past two years or a change from negative to positive on an IGRA.

2013 MFMER | slide-28 II. Interferon Gamma Release Assay (IGRA) IGRAs measure the cell-mediated response to specific TB antigens in whole blood. WBCs in TB infected persons release INF-g when mixed with antigens derived from MTB. Initially, these tests were called a blood assay for mycobacterium tuberculosis or BAMT. Currently there are two (2) IGRAs in use: A. QuantiFERON-TB Gold In-tube (QFT-GIT) B. T-Spot.TB (T-Spot)

2013 MFMER | slide-29 Advantages Requires a single patient visit Results not subject to reader bias and error Greater sensitivity and specificity not affected by BCG or most nontuberculous mycobacteria Results are usually available within 24 hours. Does not boost responses measured by subsequent tests (as TSTs do).

2013 MFMER | slide-30 Disadvantages More costly than TST or assumed to be so Not recommended for use in children < five (5) years of age Blood must be processed in 8-30 hours Can have false positive, false negative or indeterminate test results

2013 MFMER | slide-31 Factors that May Affect the IGRA Result Type of Reaction Possible Cause False-positive Stage of infection Co-morbid conditions that affect immune functions Issues with collection tubes Improper collection, transport, running or interpretation of the result False-negative Delay in incubation Improper collection, transport, running or interpretation of the result

2013 MFMER | slide-32 QuantiFERON-TB Gold In-Tube QFT-GIT requires 3 tubes provided by the lab GRP - each designed to allow only 1ml of blood to enter. Gray Negative Control or Nil background noise Red Antigen Response of the test Purple Positive Control or Mitogen shows immune status and correct handling & incubation of the tubes Will receive a numeric as well as a positive, negative or indeterminate result. The result is based on IFN-g concentration Positive - > 0.35 Negative - < 0.35 Indeterminate - 0.35 if Nil > 8.0 & any result in Mitogen tube OR any result in antigen & mitogen with > 8.0 in Nil

2013 MFMER | slide-33 T-Spot.TB T-Spot uses 1 standard green top tube, but requires differing amounts of blood: 6 ml: Adults & children over 9 years old 4 ml: Children 2 to 9 years old 2 ml: Children up to 2 years old Interpretation of Results: Interferon-gamma is captured and presented as spots from T cells sensitized to Mycobacterium tuberculosis antigens. There are 4 panels used. Results are interpreted by subtracting the spot count in the negative (NIL) control from the spot count in Panels A and B. The 4 th panel is the anitgen panel or positive control. Results are reported as positive, negative, borderline and indeterminate.

2013 MFMER | slide-34 In Conclusion Choose a test for TB screening based on the individual factors associated with each person and the facts surrounding the need for testing.

2013 MFMER | slide-35 My Pets and Peeves TST vsPPD Reactor Convertor Miss PeachesSpeed

2013 MFMER | slide-36 References CDC. Targeted Testing and Treatment of Latent Tuberculosis Infection. June 9, 2000. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr4906a1.htm. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr4906a1.htm CDC. Testing for Tuberculosis. April 27, 2012. http://www.cdc.gov/tb/topic/testing/default.htm. http://www.cdc.gov/tb/topic/testing/default.htm CDC. Trends in Tuberculosis United States. MMWR.63 (11); 229-233. March 24, 2014. CDC. Updated Guidelines for Using Interferon Gamma Release Assays to Detect Mycobacterium tuberculosis Infection. United States. June 25, 2010. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5905a1.htm?s_cid=rr5905a1_e. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5905a1.htm?s_cid=rr5905a1_e Celestis (Qiagen). QuantiFERON-TB Gold Frequently Asked Questions Health Professionals. 2008. Oxfordimmunotec. T-Spot.TB The Easy TB Test. 2014. http://www.tspot.com/.http://www.tspot.com/ Qiagen. QuantiFERON Technology. 2014. http://www.qiagen.com/knowledge-and- support/spotlight/qft_technology-spotlightpages/.http://www.qiagen.com/knowledge-and- support/spotlight/qft_technology-spotlightpages/ WHO. Reach the 3 Million. Stop TB Partnership. 2014. http://www.stoptb.org/assets/documents/resources/publications/acsm/WORLD_TB_ DAY_BROCHURE_14March.pdf. http://www.stoptb.org/assets/documents/resources/publications/acsm/WORLD_TB_ DAY_BROCHURE_14March.pdf

2013 MFMER | slide-38 Questions & Discussion

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