Tuberculosis Screening Valerie Dzubur EdD APRN FNP-BC Samuel Merritt University This presentation will discuss TB screening

TB Caused by Mycobacterium tuberculosis, Mycobacterium bovis, and other mycobacteria Humans are the only reservoirs Occurs by means of inhalation Although world wide rates of new TB infection have declined in recent years, it is estimated that 1/3 of the population of the world is infected The biggest worry is the development of (MDR)TB and( XDR)TB The largest number of new cases occur in Southeast Asia The highest number of deaths from TB occur in Africa Caused by Mycobacterium tuberculosis, Mycobacterium bovis, and other mycobacteria Humans are the only reservoirs Occurs by means of inhalation Although world wide rates of new TB infection have declined in recent years, it is estimated that 1/3 of the population of the world is infected The biggest worry is the development of (MDR)TB and( XDR)TB The largest number of new cases occur in Southeast Asia The highest number of deaths from TB occur in Africa

TB – Natural History Inhalation of the TB bacterium = primary infection Immunocompetent – macrophages contain the infection The greatest risk for active TB is within 2 years following infection Incubation from exposure to conversion of the ppd is 2 – 10 weeks Infection usually requires prolonged exposure (weeks) to an individual with active pulmonary tuberculosis Good ventilation and light reduce the chances of transmission Mask on patient, avoid coughing Inhalation of the TB bacterium = primary infection Immunocompetent – macrophages contain the infection The greatest risk for active TB is within 2 years following infection Incubation from exposure to conversion of the ppd is 2 – 10 weeks Infection usually requires prolonged exposure (weeks) to an individual with active pulmonary tuberculosis Good ventilation and light reduce the chances of transmission Mask on patient, avoid coughing

Tuberculosis – Active Disease is not a screening situation Any person for whom you suspect active TB needs A complete history A complete ROS A complete physical examination Diagnostics testing Chest x-ray CBC Sputum for AFB Consider pulmonary CT & MRI PPD or IGRA testing Any person for whom you suspect active TB needs A complete history A complete ROS A complete physical examination Diagnostics testing Chest x-ray CBC Sputum for AFB Consider pulmonary CT & MRI PPD or IGRA testing

Tuberculosis Screening USPSTF – recommends targeted screening bases on CDC recommendations – not updated since 1996 Skin Testing or IGRA screening for high risk groups only No screening is recommended for immunocompetent persons not in a high risk group USPSTF – recommends targeted screening bases on CDC recommendations – not updated since 1996 Skin Testing or IGRA screening for high risk groups only No screening is recommended for immunocompetent persons not in a high risk group

Tuberculosis Screening HIGH RISK GROUPS Close contacts of persons who have active TB Infants and children exposed to high risk adults Foreign-born in endemic area Migrant workers, homeless, indigent Healthcare providers IVDU, HIV + Nursing Home Residents, other group living situations Institutionalized, incarcerated Travel to endemic area On immunosuppressive therapies or chronic diseases e.g. diabetes HIGH RISK GROUPS Close contacts of persons who have active TB Infants and children exposed to high risk adults Foreign-born in endemic area Migrant workers, homeless, indigent Healthcare providers IVDU, HIV + Nursing Home Residents, other group living situations Institutionalized, incarcerated Travel to endemic area On immunosuppressive therapies or chronic diseases e.g. diabetes

Tuberculosis Screening False Negative TB Screening – factors related to person being screened Infections Live Virus Vaccinations e.g. MMR and Varicella Vaccinations Metabolic derangements e.g. chronic renal failure Low protein states Lymphomas, leukemia, Sarcoidosis Drugs e.g. steroids Age of person Stress e.g. surgery, burns, mental illness Graft vs host reactions False Negative TB Screening – factors related to person being screened Infections Live Virus Vaccinations e.g. MMR and Varicella Vaccinations Metabolic derangements e.g. chronic renal failure Low protein states Lymphomas, leukemia, Sarcoidosis Drugs e.g. steroids Age of person Stress e.g. surgery, burns, mental illness Graft vs host reactions

Tuberculosis Screening False Negative TB Screening – factors related to PPD product Improper storage Improper dilutions]Chemical denaturation Contamination Adsorption (partially controlled by adding Tween 80) False Negative TB Screening – factors related to PPD product Improper storage Improper dilutions]Chemical denaturation Contamination Adsorption (partially controlled by adding Tween 80)

Tuberculosis Screening False Negative TB Screening –Factors related to administration Injection of too little antigen Subcutaneous injections Delayed administration after drawing into syringe Injection too close to other skin test False Negative TB Screening –Factors related to administration Injection of too little antigen Subcutaneous injections Delayed administration after drawing into syringe Injection too close to other skin test

Tuberculosis Screening False Negative TB Screening – factors related to reading & recording Inexperienced reader Conscious or unconscious bias Error in recording False Negative TB Screening – factors related to reading & recording Inexperienced reader Conscious or unconscious bias Error in recording

Tuberculosis Screening PPD – produces a delayed hypersensitivity reaction Procedure Use a 1 cc syringe with a 27 g ¼ - ½ inch needle Draw up .1 cc Place as a intradermal wheel on the forearm Must be read in 48 – 72 hours Do not rub, dab, pad, if patient request you can cover lightly with a band aide Documentation of administration Date, Lot #, expiration date, name, place e.g. right forearm or left forearm Ideally the patient should return to the same place the ppd was placed to have it read PPD – produces a delayed hypersensitivity reaction Procedure Use a 1 cc syringe with a 27 g ¼ - ½ inch needle Draw up .1 cc Place as a intradermal wheel on the forearm Must be read in 48 – 72 hours Do not rub, dab, pad, if patient request you can cover lightly with a band aide Documentation of administration Date, Lot #, expiration date, name, place e.g. right forearm or left forearm Ideally the patient should return to the same place the ppd was placed to have it read

Tuberculosis Screening Reading the PPD result 48 – 72 hours Measure diameter of induration in transverse direction Do Not measure redness If no induration document 0 mm of induration Document date and your name Required reportable disease to Public Health, TB Clinic + ppd = chest x-ray Reading the PPD result 48 – 72 hours Measure diameter of induration in transverse direction Do Not measure redness If no induration document 0 mm of induration Document date and your name Required reportable disease to Public Health, TB Clinic + ppd = chest x-ray

Tuberculosis Screening 5 mm induration Close contact, immunosuppressed, Abnormal chest x-ray, clinical evidence of disease 10 mm induration High-risk categories, HIV +, travel to endemic area, children< 5-yrs old 15 Mm induration Children aged 5-yrs or older without any risk factors for TB

Tuberculosis Screening Interferon gamma release assays = IGRA IGRAs – whole blood tests that measure a person’s immune reactivity to M tuberculosis QuantiFERON – TB Gold: aka QFT-G QuantiFERON – TB Gold in-Tube: aka QFT-GIT T-SPOT TB: aka T-SPOT.TB CDC recommends that IGRAs can be used instead of but not in addition to PPD in all situations as an aid in diagnosing tuberculosis infection PPD is preferred for testing children under 5-years old Interferon gamma release assays = IGRA IGRAs – whole blood tests that measure a person’s immune reactivity to M tuberculosis QuantiFERON – TB Gold: aka QFT-G QuantiFERON – TB Gold in-Tube: aka QFT-GIT T-SPOT TB: aka T-SPOT.TB CDC recommends that IGRAs can be used instead of but not in addition to PPD in all situations as an aid in diagnosing tuberculosis infection PPD is preferred for testing children under 5-years old

Tuberculosis Screening IGRAs are preferred If patient is unlikely to return to have ppd read If the patient has received a BCG Vaccination There is an established protocol for performance & interpretation of the test Blood drawing and handling arrangements are in place to ensure proper tube is used and specimen is handled so that testing is done in required time frame Setting should consider cost, availability, potential benefits based on characteristics of the test population in the setting to select screening method IGRAs are preferred If patient is unlikely to return to have ppd read If the patient has received a BCG Vaccination There is an established protocol for performance & interpretation of the test Blood drawing and handling arrangements are in place to ensure proper tube is used and specimen is handled so that testing is done in required time frame Setting should consider cost, availability, potential benefits based on characteristics of the test population in the setting to select screening method

Tuberculosis Screening IGRA – OTHER BENEFITS Results available in 24 hours Not affected by BCG vaccination Not subject to reader bias Single patient visit to draw blood sample IGRA – OTHER BENEFITS Results available in 24 hours Not affected by BCG vaccination Not subject to reader bias Single patient visit to draw blood sample

Tuberculosis Screening Positive PPD or IGRA – 5 – 10 % will develop active TB, treatment with INH reduces the risk of developing active TB… Recent converters – at greatest risk of developing active disease Screen for symptoms of TB Negative chest x-ray Consider Rx INH 6 – 9 months If DOT available can consider INH-RPT Rx once a week for 12 weeks Monitor for adverse reactions Check LFTs Discontinue if LFTs 5 x normal asymptomatic Discontinue if LFTs 3x normal symptomatic Positive PPD or IGRA – 5 – 10 % will develop active TB, treatment with INH reduces the risk of developing active TB… Recent converters – at greatest risk of developing active disease Screen for symptoms of TB Negative chest x-ray Consider Rx INH 6 – 9 months If DOT available can consider INH-RPT Rx once a week for 12 weeks Monitor for adverse reactions Check LFTs Discontinue if LFTs 5 x normal asymptomatic Discontinue if LFTs 3x normal symptomatic

Tuberculosis Screening PPD or LGRA + w/o INH Rx Annual TB symptom screen Chest x-ray only if symptomatic Medical risk increases consider need for chest x-ray and more frequent symptom screen See next slide PPD or LGRA + w/o INH Rx Annual TB symptom screen Chest x-ray only if symptomatic Medical risk increases consider need for chest x-ray and more frequent symptom screen See next slide

Tuberculosis Screening PPD / IGRA + Asymptomatic w/o INH Rx with risk factors Immunocompromised Symptom screen q 3 months, x-ray q 6 months + ppd < 2-yrs since conversion Symptom screen q 6 months, x-ray q 6 months for 2 year period Autoimmune disease, CRF, Carcinoma of head/neck Symptom screen q 3 – 6 months x-ray annually Evidence of old inactive TB on chest x-ray Symptom screen annually,, test sputum AFB culture and x-ray if symptomatic PPD / IGRA + Asymptomatic w/o INH Rx with risk factors Immunocompromised Symptom screen q 3 months, x-ray q 6 months + ppd < 2-yrs since conversion Symptom screen q 6 months, x-ray q 6 months for 2 year period Autoimmune disease, CRF, Carcinoma of head/neck Symptom screen q 3 – 6 months x-ray annually Evidence of old inactive TB on chest x-ray Symptom screen annually,, test sputum AFB culture and x-ray if symptomatic

Tuberculosis Screening BCG – Vaccination Not routinely used in the US due to TB prevalence We use targeted screening of high risk groups and hot spots PPD is not contraindicated Screen as you would per targeted screening Does not affect results obtained from IGRAs BCG – Vaccination Not routinely used in the US due to TB prevalence We use targeted screening of high risk groups and hot spots PPD is not contraindicated Screen as you would per targeted screening Does not affect results obtained from IGRAs