TB Contact Investigation Basics

Transcription

1 TB Nurse Case Management Lisle, Illinois April 27-28, TB Contact Investigation Basics Carrie Storrs, RN April 28, 2010 Contact Investigation Carrie Storrs TB Program Illinois Department of Public Health 1

2 Objectives Identify the components of a TB contact investigation Initiation of a contact investigation Interviewing the index patient Prioritizing contacts Evaluation of contacts Specialsettings and source case investigation Data management and community communications Confidentiality TB Contact Investigation Anintegralprogram component, a fundamental strategy for the control of TB Every case of TB was once a contact 2

3 Contact Investigation Objectives To identify: persons who have been exposed contacts infected with TB and with active TB the source of TB disease transmission To refer: for evaluation, treatment, and follow up To prevent: TB disease in contacts already infected TB infection in contacts not already infected 3

4 With our present methods of examination, and particularly with the tuberculin skin test, the trail which the contagious tuberculous person leaves can be picked up almost as the hound senses the trail of the fox or as the game animal is trailed in the snow Quote by : J. Arthur Myers, M.D. Director of Tuberculosis Activities, Lymanhurst Health Center, Minneapolis, MN Decision To Initiate A Contact Investigation Investigate suspected and confirmed cases of pulmonary and/or laryngeal TB Highest Priority AFB sputum smear positive Pulmonary cavities Next Priority Oh Other pulmonary cases and suspects Investigation not required for adult cases of extrapulmonary TB when concurrent pulmonary or laryngeal TB has been ruled out 4

5 Factors that Predict Likelihood of Transmission Anatomical site of disease Sputum bacteriology Radiographic findings Behaviors that increase aerosolization of secretions Age Immune status Administration of effective treatment CDC Guidelines Page 5 FIGURE 1. Decision to initiate a tuberculosis (TB) contact investigation Site of disease Pulmonary/laryngeal/ pleural Pulmonary suspect (tests pending, e.g., cultures Nonpulmonary (pulmonary and laryngeal involvement ruled out) AFB* sputum smear positive AFB sputum smear negative or not performed Contact investigation not indicated NAA Positive or not performed NAA negative Cavitary disease Abnormal CXR non-cavitary consistent with TB Abnormal CXR not consistent with TB Contact Investigation should always be initiated Contact Investigation not indicated Contact investigation should always be initiated if sufficient resources Contact investigation should be initiated if sufficient resources Contact investigation should be initiated only in exceptional circumstances *Acid-fast bacilli. Nucleic acid assay. According to CDC guidelines. Chest radiograph. 5

6 The TB Interview Written policies provide efficiency and uniformity Trained staff should be assigned Systematic gathering of detailed information Pre interview preparation Interviews should be in primary language of the interviewee Interview in person within one day of report for infectious persons Proxy interviews in special circumstances The TB Interview Multiple interviews Establish rapport Information exchange Transmission settings Residence of index case should be visited within three days All potential transmission sites should be visited within five days Identify contacts Prioritized contact lists should be written into investigation plan Closure 6

7 Confidentiality Multiple laws and regulations protect the privacy and confidentiality of patient s health care information. Section ofhipaa lists exemptions to the need to obtain authorization and requires an authorization disclosure, which include communicable diseases reported by public health authority as authorized by law Consult with Health Department legal counsel regarding Federal and State codes when preparing policies governing contact investigations Confidentiality Explain measures that will be taken to protect confidentiality Prepare for protecting confidentiality at each visit Confidentiality y applies to all private and medical information in addition to TB 7

8 Places Where Patients Spend Time Work/School Household/Residential Leisure/Recreation Once you identify your index case where do you start your CI? TB Symptoms AFB Sputum Smear Positive Infectious Period Begins: Cavitary CXR Likely Onset of Infectiousness Yes No No 3 months before symptom onset or first positive finding (e.g. abn CXR), whichever is longer Yes Yes Yes 3 months before symptom onset or first positive finding, whichever in longer No No No 4 weeks before date of suspected diagnosis No Yes Yes 3 months before first positive finding consistent with TB Table 2, page 7 8

9 Assigning Priorities to Contacts Directs resources to contacts who: Have secondary case of TB disease Have recent M. tb infection (most likely to benefit from treatment) Are most likely to develop TB disease if infected OR could suffer severe morbidity of they develop TB disease Assigning Priorities to Contacts Prioritization based on: Index case characteristics Duration of exposure Circumstances of exposure Vulnerability/susceptibility of contact Duration of exposure guidelines need to be defined locally based on resources and experience of the local larea Prioritize as high, medium or low 9

10 Characteristics of Index Case AFB sputum smear and culture CXR findings Symptoms Age Treatment status Assigning Priority to Contacts Characteristics of contacts Age Immune status Medical conditions Exposure Medical procedure Congregate setting Characteristics of the environment Air volume Ventilation Environmental controls 10

11 Evaluation of Contacts Public Health Responsibility Laws areavailableavailable in some jurisdictions but least restrictive methods should be used first Each high and medium contact should be evaluated within three days Each high and medium contact should be evaluated for TB or LTBI 11

12 High-Priority Contacts for Evaluation Contacts Most Likely To be Infected Contacts exposed to a high degree of infectiousness: (index patient) - Pulmonary/laryngeal TB - AFB smear + sputum - CXR (cavitary) - Cough - M. Tb culture + - Exposure in crowded conditions, poor ventilation Contacts at High Risk of TB Disease Once Infected Contacts with these health conditions: - HIV infection - Immunosuppressed tx - Injection of illicit drugs - Diabetes Mellitus - Silicosis - Corticosteroid tx (>15mg of prednisone or its equivalent for >4 weeks) Children <5 years of age Evaluation of Contacts Immunosuppressed contacts are high priority Educate ALL contacts that HIV is the greatest known risk for disease progression and ASK if they have been HIV tested OfferHIV counseling and testing to contacts who do not know their current HIV status 12

13 Evaluation of Contacts Evaluation of HIV+ or other immunosuppressed contacts CXR recommended in addition to medical history, exam and TST/BAMT Sputum collection for any symptomatic contact or if CXR has abnormality that could be TB related Evaluation of Contacts Evaluation of children younger than 5 Contacts younger than 5 are automatically high priority All contacts younger than 5 should have a medical exam and CXR regardless of previous or current TST/BAMT or history of previous TB disease 13

14 Evaluation of Contacts All high and medium priority contacts All contacts with a + TST (> 5 mm) or + BAMT should have a medical exam and CXR All symptomatic contacts should have a medical exam and CXR regardless of TST/BAMT result or past history High and medium contacts with TST/BAMT results less than 8 weeks after last exposure should have second TST/BAMT 8 10 weeks after last exposure Low priority contacts may have initial TST/BAMT delayed until 8 10 weeks after last contact What about BCG? 14

15 Treatment of Contacts Treatment to completion is public health responsibility LTBI contacts from high incidence countries should be treated regardless of BCG Treatment offered to all with LTBI Window period treatment given to all younger than 5 years Full LTBI treatment recommended for all HIV/immune suppressed regardless of TST Treatment of Contacts Treatment contacts with previous + TST/BAMT on an individual basis HIV+ with previous TST+ should be treated again regardless of past treatment history Rifampin treatment for contacts to INH resistant cases Expert consultation for treatment of all LTBI contacts to presumed or confirmed MDR cases Directly Observed Treatment of LTBI/Window Period Treatment when possible Monthly or more frequent monitoring of the self administered LTBI contact Enablers, incentives and positive rapport 15

16 Expanding Contact Investigation Inclusion of low priority contacts not indicated until high and medium priority contacts are evaluated Consider expanding if: Unexpected large rate of LTBI in high Evidence of second generation transmission TB disease found in any low priority contacts Infection in contacts younger than 5 Contacts with change in TST status Review of data should guide expansion plan Call for help if resources are exhausted and data indicates need to expand Expanding Contact Investigation The Concentric Circle Model is still a good epidemiologic tool. Disadvantages 1) surrogates for estimating exposure (e.g., living in the same household) often do not predict the chance of infection. 2) the susceptibility and vulnerability of contacts are not accommodated by the model 3) the estimated prevalence for tuberculin sensitivity in a specified community may be unknown. 4) if the prevalence is known but is substantial (e.g. >10%), the end point for the investigation is obscured. 16

17 Special Circumstances Outbreak Outbreaks defined as: During a CI, two or more contacts are identified with active TB Any two or more cases occurring less than 1 year of each other are discovered to be linked and the link was not caught in CI Outbreaks may indicate lapse in regular TB control the lapse should be investigated along with the contact investigation Increased urgency and scope of investigation Consider conducting social network analysis Special Circumstances Congregate Settings Correctional facilities Workplaces Hospitals and other health care settings Schools Shelters and other settings providing services for homeless Transportation modes Drug and Alcohol usage sites 17

18 Special Circumstances Congregate Settings Congregate setting investigations need to include facility administration Large number of contacts Need customized algorithm for each site/situation Difficulty maintaining confidentiality Possible media attention Possible legal issues Interview and evaluation of contacts onsite usually best Special Circumstances MDR TB Contact investigations for MDR cases does not require change in procedures but should include exploring reasons for MDR Infectious period may be longer Treatment of contacts required expert consultation 18

19 Special Circumstances Inter jurisdictional contact investigations should ldbe coordinated d from the start tand include the next higher public health level Unusual exposures such as laboratory or animal transmission should be investigated on site and include subject matter experts Mycobacterium tuberculosis (M.tb): The primary causative agent of tuberculosis in humans; may also affect a variety of mammals, including non-human primates, pigs, cattle, dogs, parrots, elephants, and rhinos. 19

20 Source Case Investigations Reverse of a Contact Investigation Only recommended when all infectious case investigation objectives are being met including treatment completion of contacts Recommended for cases of children under 5 Yield typically less than 50% Searching for source of unexplained LTBI is generally not recommended and if done should be limited to LTBI in children younger than 2 Social Network Analysis Social Network linkage of persons and places where M. tuberculosis is spread via shared air space Social Network Analysis methodology of visualizing and quantitating the relative importance of members in a social network Social Network Analysis assumes there is some detectable patterning of the TB cases and their contacts in a community 20

21 Social Network Analysis Approach Provides desa systematic method to deal with data already gathered in routine contact investigations Analysis of the network can help identify important contacts (i.e., those most likely to be infected) Real time monitoring of network growth may facilitate early detection of outbreaks Social Network Analysis Approach May help programs focus control efforts May offer effective way to list contacts and assign priorities Has been tested retrospectively on TB outbreak and contact investigations 21

22 Personal Networks for Two TB Cases Juan Bill Ted Rose Ted Rita Ali Moe Combined: A Social Network Juan Bill Rose Ted Rita Ali Moe Allows review of multiple rather than individual personal networks 22

23 Combined: A Social Network with Place Bill Juan Ted Rita Rose Ali La Escondida Bar & Grill Moe Community Communications Anticipatory media communication (via press release) for large or highly visible contact investigations Coordination of media activity with all partners internal and external Use media message templates 23

24 Prepare yourself for the media and community communications Evaluation of Contact Investigation Policies assigning responsibility Training and policies for accuracy, completeness and security Periodic summary and review Program evaluation on CI activities at least annually Consider expanding beyond standard data elements when indicated locally 24

25 TB Cases 2007 TB Cases for 2009 TB Cases 2008 Data Management Data Management and Evaluation Collect specific data for evaluation Collect on standardized forms Use specified data definitions and formats When feasible standardize definitions and formats Electronic storage recommended 25

26 Data Management Example Determine the level of TB Infection for contacts: Level of infection = # of newly positive TST contacts X 100 Total # of contacts tested Example 40 contacts were identified, 30 were tested 5 contacts had previously positive TST s, and 15 were positive on current testing. Level of infection is 15 X 100 = 50% 30 Worksheet HOME WRK/SCH LEISURE TOTAL # contacts identified # prior positive PPD 5 5 # prior cases # contacts moved, no PPD # died prior to testing # lost or refused # appropriate for testing # PPD tested # infected, without disease # infected, with disease % infected of those tested 50 % # documented converters # appropriate for prev. tx # completed prev. tx # started prev. tx 26

27 Be Sure To Ask for Help Questions? 27