TB Contact Investigation

TB Contact Investigation
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Module 15 – March 2010 TB Contact Investigation Instructor’s Notes Module 15: TB Contact Investigation ISTC Standards covered: Standards 18 and 19 Module Time: Approximately 2.75 hours This module has been divided into the following sections: Overview and Introduction (slides 3-14) – 20 min. Steps 1 and 2 (slides 15-35) – 50 min. (includes Case study activities part 1 [10min] and part 2 [15min]) Steps 3 – 5 (slides 36-44) –25 min. (includes Case study activity part 3 [15min]) Steps 6 – 7 and summary (slide 45-57) – 40 min. (includes Case study activities part 4 [20min] and part 5 [12min]) Resource document: Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV (CTBG) Appendix C Interactive options: Ideas for interactive discussions are offered on many of the slides in this module. The case study activity is interspersed throughout the presentation. You will need Worksheet 15.0 and Handouts 15.1, 15.2, and 15.3 for this session. Additional Material: Slides containing related material may be found in the following modules: 1, 5, 10, 14.

Funded by the Health Resources and Services Administration (HRSA)
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Project Partners Module Version Funded by the Health Resources and Services Administration (HRSA)

International Standards 18 and 19
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Overview Module Version Overview: Value (yield) of contact evaluation Clinical factors influencing transmission Evaluating contacts and determining priorities Vulnerable contacts Treatment of infected contacts Overview and Introduction (slides 3-14) – 20 min. Overview: [Review content of slide] Lecture/module includes International Standards for Tuberculosis Care 18 and 19 [Image credit: National Library of Medicine, National Institute of Health] International Standards 18 and 19

Learning Objectives At the end of this presentation participants
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Learning Objectives Module Version At the end of this presentation participants will be able to: Describe the criteria used and method for determining an infectious period Evaluate the risk of transmission based on the clinical extent of disease and diagnostic tests Determine who among contacts is at greatest risk should infection occur Identify and evaluate contacts who are at increased risk for TB infection The overall objective of this module is to provide the student with the knowledge and competencies necessary to investigate a contact situation and take the necessary actions in evaluation and management of contacts [Review objectives]

Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV
Definitions Module Version Case – a particular instance of disease (e.g., TB). A case is detected, documented and reported Index case – the first person who presents for evaluation as a confirmed or suspected case of tuberculosis Source case – the case or person that was the original source of infection for secondary cases or contacts There are a few definitions we need to review before we go into the steps involved in a contact investigation [Review slide content]

Definitions (2) Module Version Contact –someone who is at risk for acquiring M. tuberculosis infection by sharing airspace with an index case Converter – a person whose test result for M. tuberculosis has changed from negative (uninfected) to positive (infected) Window period – refers to the interval between infection and detectable reactivity to the tuberculin skin test (TST) [Review slide content] Converter – A conversion is presumptive evidence of new M. tuberculosis infection and poses an increased risk for progression from infection to disease. For the tuberculin skin test (TST), a change in the induration of >10mm within <2 years is defined as a TST conversion. As induration of >5mm is considered positive in contacts, this definition of TST conversion may be irrelevant for assessing risk for progression to TB disease among individual contacts. Conversions can also be documented from blood assay tests for M. tuberculosis (e.g. QuantiFERON-Gold or T-Spot are types of blood assay tests) Window period – was previously thought to be between 2-12 weeks following infection; now outer limit is estimated to be closer to 8-10 weeks post infection

Why do we do TB contact investigations (CI)?
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Why do we do TB contact investigations (CI)? [Pose question to participants. Take a few minutes to write participant’s ideas on flip chart, then show next slide]

Remember!! Every TB Case Began as a TB Contact
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Remember!! Every TB Case Began as a TB Contact Module Version Contact investigation helps to: Identify additional TB cases Identify persons with latent TB infection Prevent the further spread of TB Save someone’s life TB Index Case TB Case TB Contacts TB Cases The purpose of a TB contact investigation is to: Identify, examine and evaluate all persons who are at risk of infection with Mycobacterium tuberculosis due to recent exposure to a diagnosed or suspected tuberculosis case patient Identify new cases of TB disease Allows for early treatment of disease, and early detection and treatment of new TB infection. In some cases, it may prevent infection Interrupt and halt further TB transmission 1-5% of contacts have TB disease Finding & treating these additional cases may interrupt further transmission 20 – 30% of all contacts have latent TB infection (LTBI) (some studies up to 50%!) Greatest risk of progression to active disease within the first 2 year following exposure Finding & treating those with LTBI will prevent future cases [Click: Slide Animation] [Credit: Slide adapted from CDC slideset]

ISTC Standard 18 Module Version All providers of care for patients with TB should ensure that persons who are in close contact with patients who have infectious TB are evaluated and managed in line with international recommendations. The determination of priorities for CI is based on the likelihood that a contact: Has undiagnosed TB Is at high risk of developing TB if infected Is at risk of having severe TB if the disease develops Is at high risk of having been infected by the index case [Invite a participant to read International Standard for TB Care 18] The risk of acquiring infection with M. tuberculosis correlates with the intensity and duration of exposure to a person with infectious TB Close contacts of patients with TB, therefore, are at high risk for acquiring the infection Contact evaluation is considered an important activity, both to find persons with previously undetected tuberculosis and persons who are candidates for treatment of latent tuberculosis infection (LTBI)

ISTC Standard 18 (2) The highest priority contacts for evaluation are:
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV ISTC Standard 18 (2) Module Version The highest priority contacts for evaluation are: Persons with TB symptoms Children aged <5 years Contacts with known or suspected compromised immune systems, particularly HIV infection Contacts of patients with MDR/XDR tuberculosis Other close contacts are a lower priority group Among close contacts, there are certain subgroups that are particularly at high risk for acquiring the infection with M. tb and progressing rapidly to active disease: children (particularly those under the age of 5 years) and persons with HIV infection Children are also more likely to develop disseminated and serious forms of TB such as meningitis International recommendations state that children under the age of 5 years living in the same household as a sputum smear-positive TB patient should be targeted for preventive therapy (after exclusion of TB to prevent de facto monotherapy of TB). [Can refer to page 113 of Caribbean TB Guidelines] Similarly, contacts who have HIV infection are at substantially greater risk for progressing to active TB [Image credit: Lung Health Image Library/ Gary Hampton]

Standards for Public Health
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Standards for Public Health Module Version TB Contact Investigation is one of the Standards for Public Health; however, lack of adequate staff and resources in many areas makes contact evaluation difficult Inability to conduct targeted contact evaluations results in missed opportunities to prevent additional cases of TB, especially among children More energetic efforts are necessary to overcome these barriers to optimize TB control practices [Image credit: Lung Health Image Library/Jan Van Den Homberg]

Systematic Review of Contact Investigations
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Systematic Review of Contact Investigations Module Version Yield for all active TB among household contacts was 4.5% Pooled yield for confirmed TB among household contacts was 2.3% Nearly one-half of the household contacts evaluated had LTBI indicated by a positive tuberculin skin test, but a negative evaluation for active TB In a systematic review of contact evaluations in low and middle income countries, the yield for all active TB among household contacts was 4.5% For bacteriologically confirmed TB among household contacts, the yield was 2.3% These are remarkably high yields for a TB control intervention. However, less than half of the cases of active TB have bacteriological evidence to confirm the diagnosis In the same systematic review the pooled estimate for the percentage of household contacts who were found to be tuberculin skin test positive was 50%. Obviously this includes infections that occurred in the past as well as possible recent infections as a consequence of exposure to the index case [Reference: Morrison J, Pai M, Hopewell PC. Tuberculosis and latent tuberculosis infection in close contacts of people with pulmonary tuberculosis in low-income and middle-income countries: a systematic review and meta-analysis. Lancet Infect Dis 2008;8(6): ] Morrison J, et al. Lancet ID 2007

Yield: Active TB and LTBI by Age
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Yield: Active TB and LTBI by Age Module Version TB1 LTBI2 Children < 5 years 12 30.4 5 –14 17 47.9 Adults 15 64.6 The pooled yields of both active TB and LTBI vary with age In a systematic review, the yield of all active TB among child contacts under 5 years old was higher than that of children 5-14 and adult contacts, resulting in a number needed to evaluate (NNE) to find one case of 12 for children under 5, 17 for children 5-14 and 15 for adults 15 and older. (Note: This analysis was performed on a slightly different data set than the analysis shown in the preceding graphs) This is consistent with evidence that young age is a risk factor for TB. However, because of the difficulty in diagnosing TB in children, there may be a tendency toward over-diagnosis in children in contact with an infectious case In contrast, the NNE for LTBI among child contacts and child contacts under 5 was lower than among children 5-14 and non-child contacts. This can likely be explained by the limited years of exposure children have had as compared with adults, resulting in lower rates of LTBI among the youngest children and the highest among adults [Reference: Morrison J, Pai M, Hopewell PC. Tuberculosis and latent tuberculosis infection in close contacts of people with pulmonary tuberculosis in low-income and middle-income countries: a systematic review and meta-analysis. Lancet Infect Dis 2008;8(6): ] 1 Number needed to evaluate to find 1 case of TB 2 % of examined contacts with latent TB infection Morrison J, et al. Lancet ID 2008;8(6)

TB Contact Investigation Steps
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV TB Contact Investigation Steps Module Version Decide whether to initiate a contact investigation Interview the index case Examine sites of transmission Prioritize contacts Locate and evaluate contacts Treat and follow-up contacts Evaluate contact investigation activities We’ve discussed some of the theory and research to highlight the importance of this TB prevention and control activity, now let’s look at what is involved in carrying out TB contact investigation (CI) There are 7 basic steps involved in a TB CI and we’ll be going through each one of these in more detail [Review slide content] These steps outline the CI framework [Image Credit:Edi Berton] 14

Step 1: Decide if a CI should be initiated
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version To make this decision, you will be assessing for: Evidence that the index case may be infectious Presence of vulnerable contacts Those with an immature or weakened immune system Steps 1 and 2 (slides 15-35) – 50 min. (includes Case study activities part 1 [10min] and part 2 [15min]) [Review slide content] [Interactive option: Ask participants to list populations with immature or weakened immune systems] [Image Credit: Microsoft Word clip art 2007]

Review Medical Record Site of TB disease
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Review Medical Record Module Version Site of TB disease TB symptoms and approximate date of onset Test results Sputum AFB smear and culture results Including dates of specimen collection Chest X-ray results and date TB treatment (medications, dosage, and date treatment was started) Method of treatment administration DOT or self-administered Whenever possible, the patient’s medical record should be reviewed In settings where drug susceptibility results may be available, checking DST information may be helpful in assessing adequacy of drug regimen, a factor which may impact a patient’s period of infectiousness and for later on when decisions on treatment of contacts with LTBI will be made [Interactive option:] Ask “Who can tell me what you might look for in your record review?” What information from your Health Record Review would indicate to you that the patient’s likelihood of infectiousness was high? [Review slide content] [Click: Slide Animation]

Assessing Infectiousness
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Assessing Infectiousness Module Version High degree of infectiousness Sputum smear-positive pulmonary TB (PTB) Symptomatic with cough Cavitation on chest radiograph (correlates with positive smear) Laryngeal tuberculosis Lesser degree of infectiousness Sputum smear-negative, culture-positive PTB Minimal if any cough Lesser radiographic extent of disease Extrapulmonary TB In assessing the degree of infectiousness, a high degree of infectiousness is indicated by a positive sputum smear, cavitary lesions seen on the chest radiograph, and the presence of cough The absence of these features indicates a lesser degree of infectiousness

Indices of Infectiousness
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Indices of Infectiousness Module Version Source-Case Variables Tuberculin Reactors (%) among household contacts Radiographic extent of disease Minimal 16.1 Moderately advanced 28.3 Far advanced 61.5 Bacteriologic status Smear –, culture – 14.3 Smear –, culture + 21.4 Smear +, culture + 44.3 Mean 8-hour overnight cough count < 12 27.5 12-48 31.8 48 43.9 These data from a study conducted in the United States show the relative effects of these factors as indicated by the percentage of household contacts with positive tuberculin skin tests Cough counts were determined before treatment was begun Loudon RG. ARRD 1969;99:109

Prevalence of Infection in Contacts
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Source case status Age (yrs) Smear + Culture ? Smear – Culture + Culture – General Population 0-4 29.1% 6.0% 6.5% 0.7% 5-9 35.9 12.4 6.2 0.9 10-14 39.5 14.1 19.1 2.2 15-19 47.0 18.1 4.2 20-29 51.5 32.9 43.4 10.5 30-39 59.2 52.2 46.2 21.3 40+ 61.1 50.3 47.9 38.5 These data from Canada show the effects of bacteriological status on the percentage of household contacts with a positive tuberculin skin test by age group. For purposes of comparison, the prevalence of positive tuberculin tests in the general population is also shown For all age groups the highest prevalence of infection is associated with exposure to a sputum smear-positive case The prevalence of positive tuberculin skin test reactors is also increased, compared to the general population, among persons exposed to smear-negative, culture-positive cases and even smear and culture negative cases Grzybowski S. BIUAT 1975;60:90

How do we decide to initiate the contact tracing process?
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version How do we decide to initiate the contact tracing process? [Pose question to participants. Take a few minutes to write participant’s ideas on flip chart, then show next slide]

Decision to Initiate TB Contact Tracing
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Site of disease Pulmonary/ laryngeal/ pleural/ miliary AFB * sputum smear positive Contact tracing should always be initiated Pulmonary suspect (tests pending, e.g., sputum, cultures) AFB sputum smear-negative Non-pulmonary and/or extra pulmonary (pulmonary and laryngeal involvement ruled out) Contact tracing NOT indicated Contact tracing should always be initiated Abnormal CXR** indicates cavitary disease or TB culture positive Abnormal CXR ** non-cavitary consistent with TB Contact tracing should be initiated if sufficient resources Abnormal CXR NOT consistent with TB Contact tracing should be initiated only in extreme circumstances [Refer participants to handout 14.1: Decision to Initiate a TB Contact Investigation] This algorithm can be used to help you determine which situations should be prioritized for initiating a TB contact investigation The clinical factors that you will be looking for include: Site of disease Sputum smear and/or culture status Chest X-ray findings We start by looking at the site of disease. If the TB case patient has pulmonary, laryngeal , pleural or miliary TB AND sputum smear is positive, THEN a TB contact investigation should always be initiated [Click: Slide Animation - Continue to present the next leg of the algorithm by click of the mouse or pressing the down arrow] [Credit: Graph adapted from: Guidelines for the Investigation of Contacts of Persons with Infectious Tuberculosis. Recommendations from the National Tuberculosis Controllers Association and CDC ] * Acid-fast bacilli; * * Chest radiograph

Who is Responsible for Conducting TB Contact Investigations?
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version The National TB Program is responsible for ensuring contact tracing occurs and this includes ensuring: Identification and evaluation of contacts Treatment of contacts found to have TB disease Preventive treatment of contacts with TB infection Monitoring of treatment and adherence to prescribed regimens A system is in place to assess completion of treatment [Pose question to participants] [Review slide content] In larger countries with regional health authorities, the NTP must ensure that there is regular communication with the regional health authority to make certain that contact investigation is happening in a timely fashion and to identify which agency is taking responsibility for the process and any follow-up action. [Click: Slide Animation]

How Quickly Should a TB Contact Investigation be Carried Out?
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Begin as soon as TB is diagnosed or strongly suspected in a patient Initiate no more that 7 working days after the case is reported to the National TB Program Contacts should be examined within 14 working days after the index patient has been diagnosed [Review slide content] [Ask participants:] These are the recommended timeframes but are realistic where you work? What are some of the barriers to timely initiation of contact investigations?

Rationale for Prompt Contact Tracing
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Some contacts may develop TB disease very quickly after being exposed to and infected with M. tuberculosis Infants and children <5 years of age HIV-infected or other immunosuppressed Increases likelihood that all contacts will be found and evaluated [Review slide content]

Part 1 Contact Investigation Case Study
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Contact Investigation Case Study Part 1 Case Study Activity – Part 1: Decide whether a contact investigation should be initiated This activity will require approximately 10 minutes Refer participants to their Contact Investigation Case Study (Participant Worksheet 15.0) Explain that we will be utilizing this case study throughout this session as we go through each of the steps involved in a contact investigation Invite a participant to volunteer to read the initial case information from their worksheet Instruct participants to take 1-2 minutes to answer the two questions that follow under the heading Decide whether a contact investigation should be initiated. They can utilize Handout 15.1: Decision to Initiate a TB Contact Investigation algorithm as a guide. Ask for a volunteer to share their responses to questions 1 & 2 Pose question to the group “What if all three sputum smears were negative?” Proceed to next slide to discuss Step 2

Step 2: Interview the Index Case
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Step 2: Interview the Index Case Module Version Conduct a minimum of 2 interviews 1st interview ≤1 business day of reporting for infectious patients ≤3 business days for others 2nd interview 1–2 weeks later May need additional interviews Now that you have determined a contact investigation is needed, the next step is to interview the TB index case. (Note: The term index case is used rather than source case. The index case is the case around which a contact investigation is built. He/she is not necessarily the source of any infection or active TB found among contacts) Because of the urgency of finding other infectious persons associated with the index patient, the first interview should be conducted within 1 working day of reporting for infectious TB cases and within 3 working days for others A minimum of 2 interviews should be conducted with the 2nd occurring 1- 2 weeks after the initial interview Additional interviews may be necessary to clarify information as you move through the investigation It’s a rare event to get and give all the information you need to in one interview therefore, you should plan from the start that there will be multiple interview interactions with the patient The interview should be conducted with the assistance of someone who understands both languages [Image Credit: Microsoft Word clip art 2007.]

TB Interview Goals Provide appropriate TB education
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV TB Interview Goals Module Version Provide appropriate TB education Identify problems/concerns Determine period of infectiousness (IP) and where patient spent time during IP Identify contacts and locating information Establish contact investigation priorities Reinforce follow through with treatment plan The TB interview is the foundation to a thorough contact investigation Essentially, it is a dialogue that allows for giving and receiving information [Ask:] What are some goals of interviewing? [Post responses on flip chart or white board then review slide] Education – particularly on how TB is spread, basic infection control info. (covering mouth, wearing of mask) and importance of taking treatment as prescribed Patient concerns – allowing concerns to be expressed aides in building trust and rapport as well as allows intervention [Click: Slide Animation]

Circles of Contacts Household Contacts Out-of-Household Contacts
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Circles of Contacts Module Version Index case A systematic review of contact investigation found that in low and middle income countries there was an average of 4-5 household contacts per case Household contacts are at greatest risk of being infected by an index case (in this illustration 3/5 or 60%) In the systematic review, about 50% of all household contacts were infected. Because there is a larger number of out-of-household contacts, a greater number of out-of-household contacts may have been infected (in this illustration 5/15 or 33%) However, because the yield is lower and the individual risk for acquiring infection is less, out-of-household contacts should generally be given a low priority for investigation In certain situations, however, because of the closeness and duration of out-of-household contact or because the out-of-household contacts have a high degree of vulnerability (such as in a newborn nursery for example) out-of-household contacts may warrant investigation It is important to note that at least some of the infections may not be from the index case, and the prevalence of infection among out-of-household contacts may not be different from the community prevalence of infection Uninfected, 2 Uninfected, 10 Infected, 3 Infected, 5 Household Contacts Average 4 – 5/case Out-of-Household Contacts (Work, school, social) Unknown number Morrison J, et al. Lancet ID 2008;8(6)

Initial Interview Preparation
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Initial Interview Preparation Module Version Review TB patient’s medical records Determine interview objective and strategy Arrange interview place and time Preparing for the interview will help you focus on the information you need to verify or determine: The estimated infectious period Locations/settings where the patient spent time during period of infectiousness, and Persons who may have been exposed A good place to start is the patient’s medical record You want to make a list of questions you have following the review of the medical record so you can follow-up on these questions when you interview the patient Lastly, you need to make arrangements for the interview [Image source: Francis J. Curry National Tuberculosis Center]

TB Interview Components
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV TB Interview Components Module Version Introduction Education Contact List Conclusion Follow-up [Refer participants to Handout 15.2: TB Patient Interview Outline. This outline can be used to organize the interview and the content that should be covered] [Review handout with participants and cite examples for each of the sections of the interview components] [Image source: CDC Self Study Module 6. Contact Investigations for Tuberculosis.1999.]

Identification of Contacts
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Identification of Contacts Module Version Focus on those in the same household but don’t neglect out-of-household contacts Tailor interview to patient’s circumstances (homeless, congregate living facility, etc.) Determine the circumstances of exposure, and attempt to quantify the closeness and duration Determine if there are other persons within the group of contacts who have symptoms associated with TB Parts of the interview may be structured but the interviewer will likely need to use judgment in probing more deeply and tailoring the interview to the patient’s circumstances

Determine Infectious Period
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Determine Infectious Period Module Version The timeframe during which an individual with TB disease is capable of transmitting infection This timeframe is determined by estimating the duration of the individual’s symptoms, especially coughing In the absence of symptoms, this timeframe is determined based on the date of diagnosis of TB disease Determining an “infectious period” focuses the investigation on those who are at greatest risk for having become infected [Review slide content] It’s important to make sure all team members involved in the care of the TB patient and in the associated contact investigation are aware of the determined infectious period [Image Credit: Microsoft Word clip art 2007.]

Estimating Onset of Infectious Period
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Estimating Onset of Infectious Period Module Version Characteristic TB symptoms? AFB sputum smear positive? Cavitary chest radiograph? Recommended minimum beginning of likely period of infectiousness Yes No 3 months before symptom onset or 1st positive findings consistent with TB disease, whichever is longer Yes or No 3 months before 1st positive finding consistent with TB disease Abnormal, not cavitary 4 weeks before date of diagnosis as a TB suspect or confirmed case [Refer participants to Handout 15.3: Estimating Onset of Infectious Period table] Because the onset of infectious period date cannot be determined with precision, most TB experts recommend an estimated timeframe of 3 months before TB diagnosis has been established This is a modification of a table from the 2005 CDC Guidelines for the Investigation of Contacts of Persons with Infectious Tuberculosis that guides the estimation of onset of infectiousness based on 3 key characteristics of the TB case which include: -The presence or absence of symptoms, -Sputum smear status and -Whether the patient has cavitary disease on chest X-ray It gives a suggested timeframe for calculating backwards the potential onset of infectious period based on these 3 clinical findings There are situations that will arise that might warrant modifying the onset of IP to an earlier date than what is recommended in this table such as if: There is evidence of TB transmission among contacts with exposure only in early part of the original infectious period and/or There is evidence of significant transmission in the original infectious period (e.g., high TST conversion rate), particularly if the patient’s symptom onset history is questionable and/or the patient’s clinical presentation suggests advanced TB disease (cavitation, disseminated TB, severe wasting, etc.) Onset of infectious period should be given a specific date (e.g. April 15, 2010 vs. April 2010). This date may change as new information is obtained during the course of the investigation SOURCE: Modified from the California Department of Health Services Tuberculosis Control Branch; California Tuberculosis Controllers Association. Contact Investigation Guidelines. Berkley, CA: California Department of Health Services; 1998, p.23.

Closing the Infectious Period
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Closing the Infectious Period Module Version Infectious period closed when all the following criteria are met: Effective treatment for ≥ 2 weeks, Diminished symptoms, and Bacteriologic response The TB patient can be considered no longer infectious when he/she: Has been on effective treatment for >2 weeks Is clinically improving as noted by resolution or substantial decrease in TB symptoms and Demonstrating bacteriologic response with sputum smears becoming negative And is continuing with uninterrupted treatment

Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Contact Investigation Case Study Part 2 Case Study Activity - Part 2: Determine the Infectious Period Allow approximately 15 minutes for this portion of the Case Study 2 minute to read case scenario update and orient to handout they will use for this portion (15.3) 3 minutes to answer in large group question #3 5 minutes to work in small group (or pairs) to estimate onset of infectious period 5 minutes to report back to large group onset date Refer participants to their Contact Investigation Case Scenario worksheet Ask for a volunteer to read the case scenario update Pose question #3 to the participants in the large group and solicit their responses. May consider writing responses on flip chart or white board Now instruct participants to work with the others at their table. They will have 5 minutes to discuss and answer question #4 When groups look like they have completed their task (or after 5 min.), ask for a group to volunteer to report the onset date Answer: Infectious period start = June 8, 2007. Admitted to hospital – October 8, 2007 Symptoms began 1 month prior - September 8 IP began = June 8 (3 mo’s prior to symptom onset - row #2 on Handout 15.3) If time allows, ask when will they close the infectious period (when will the patient be considered no longer infectious)

Step 3: Examine Sites of Transmission
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Visit the sites where the patient spent time during the infectious period Components of the field investigation include: Interview, test & provide TB information to contacts Identify additional contacts Assess physical conditions of the setting (room size, ventilation, airflow, etc.) Steps 3 – 5 (slides 36-44) –25 min. (includes Case study activity part 3 [15min]) Site visits are complementary to interviewing and is the most reliable method for assessing the risk for transmission to contacts at that setting Each site visit creates opportunities to perform interviews, test contacts, collect diagnostic sputum specimens, schedule clinic visits, and provide education Pertinent details of the physical conditions at each site should be assessed. This might include room size, ventilation systems, and airflow patterns. This is particularly important when you have a site where there may be a large number of persons potentially exposed (e.g. school, or work site) These factors should be considered in the context of how often and how long the index patient was in each setting [Image Credit: Microsoft Word clip art 2007.]

Levels of Exposure Closeness and duration of exposure:
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Levels of Exposure Module Version Closeness and duration of exposure: Grading exposure settings Size of a car Size of a bedroom Size of a house Larger than a house Estimating critical exposure duration Thresholds are highly variable Exposure duration threshold should be determined by index case characteristics, settings, contact risk factors Estimating the closeness and duration of exposure is quite imprecise. The size of the setting in which the exposure occurred can be roughly quantified as described. Commonly exposures have taken place in different settings. In this case the smallest space should be utilized. The amount of ventilation is also important but difficult to quantify The critical exposure time is even more difficult to determine and there is little guidance in the literature

Step 4: Prioritize Contacts
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Step 4: Prioritize Contacts Module Version Concentric Circle Approach + Infectiousness Exposure intensity Susceptibility of the contact The concentric circle approach has guided TB contact investigations for many years; however, there are other factors equally important to proximity that must be considered when prioritizing contacts for evaluation We must consider both the factors known to be associated with transmission (such as frequency and duration) and also the reality that there may be contacts at increased risk for progressing to active TB disease once infected (the vulnerable or susceptible contacts) that regardless of amount of exposure, you want to identify and prioritize their evaluation [Image Credit: Microsoft Word clip art 2007.]

Prioritizing Contacts
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Prioritizing Contacts Module Version High priority contacts are determined by: Most likely to be infected Most likely to progress to disease if infected Contact Roster All contacts should be given a priority classification of either high or low priority. This will help you to keep your focus on those contacts deemed high priority [Image Credit: Microsoft Word clip art 2007.]

Factors for Assigning Priority
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Factors for Assigning Priority Module Version Infectiousness Environment Freq/duration Consider: Infectiousness of the TB case Environment where transmission likely occurred Frequency, duration and proximity of exposure Susceptibility factors: Age, immune system status At this point you’ll be pulling from information gathered during the index case interview and field investigation to decide where you need to focus your investigation efforts Factors to consider when assigning contact priority include: Infectiousness of the TB patient- whether the index case was symptomatic, sputum smear results, site of TB, presence of cavitary disease on chest X-ray Environment where transmission likely occurred- size of room, amount of ventilation, presence of air cleaning systems Characteristics of the contact’s exposure such as the frequency of contact and duration of the exposure; and Contact susceptibility - any information you may have on the characteristics of the contact such as age and possibly, the presence of other medical conditions that put the individual at risk such as conditions that might compromise the contact’s immune system [Image Credit: Microsoft Word clip art 2007.]

Priorities in Contact Evaluation
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Priorities in Contact Evaluation Module Version 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 other immunocompromising conditions or therapies Priorities in evaluation can be set based on the circumstances of the exposure and the risk to the contact if he/she is infected [Review content of slide] [Ask:] What are some of the other conditions that can increase the risk of TB infection progressing to TB disease? Answers should include the following (covered in Module 2): Young age (children under 5 years of age) and the very old have weak immune systems Silicosis Diabetes mellitus Chronic renal failure or on hemodialysis Solid organ transplantation Certain types of cancer (e.g., leukemia) Gastrectomy or jejunoileal bypass Underweight or malnourished persons Persons taking prolonged corticosteroid therapy, chemotherapy for treatment of cancer, antirejection treatment post-transplant Persons taking tumor necrosis factor alpha antagonist drugs Substance abuse (e.g., drugs and alcohol) and tobacco smoking

Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Contact Investigation Case Study Part 3 Case Study Activity – Part 3: Examine Sites of Transmission and Prioritize Contacts Allow 15 minutes for this portion of the Case Study 2 minutes to read case scenario update and give instructions 10 minutes for participants to discuss and answer questions #5 & 6 in their small group 3 minutes for report back Refer participants to their Contact Investigation Case Scenario worksheet Ask for a volunteer to read the case scenario update Instruct participants to work with the others at their table. They will have 10 minutes to discuss and answer questions #5 & 6 After 10 minutes, have groups report back their answers. Rotate between groups for report back Answers: High = Contacts from Houses 1 & 4; 2-year-old from House #3; named friends Low = Cousin Areva and Cosmetology College contacts No contact = House #3 because preceded IP

Step 5: Locate and Evaluate Contacts
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Step 5: Locate and Evaluate Contacts [Image Credit: Lung Health Image Library]

Initial Assessments of Contacts
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Initial Assessments of Contacts Module Version Approach to evaluation of contacts may vary depending on local circumstances, resources, and policies Evaluation: Question contacts about symptoms and evaluate if symptoms are present TST followed by chest X-ray (CXR) for all positive Mantoux (≥5 mm induration) CXR all children < age 5 and any symptomatic or immunocompromised contacts regardless of TST Sputum examinations for all symptomatic contacts and any with CXR abnormalities suggestive of TB The actual evaluation of contacts may vary depending on local circumstances and resources At a minimum, all contacts should be asked about symptoms consistent with TB In low prevalence countries, the first step usually is application of a tuberculin skin test (Mantoux). If induration measures >5mm, this would be considered a “positive” result and requires further evaluation with a chest X-ray and possibly sputum if indicated In many programs, all exposed children under age 5 years have chest radiography performed (PA & Lateral views). Additionally, any high priority contact with TB symptoms should be further evaluated with a CXR regardless of TST result as should any contact identified with significant immune suppression Sputum specimens should be collected for all persons with symptoms and/or radiographic findings suggestive of TB

Step 6: Treat & Follow-up Contacts
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Rationale: Risk of active tuberculosis is greatest soon after infection occurs Contacts of infectious cases are likely to have been infected recently Treatment of those found to have a positive tuberculin skin test will reduce the likelihood of active tuberculosis Steps 6 – 7 and summary (slide 45-57) – 40 min. (includes Case study activity part 4 [20min]) The risk of developing active TB within the first 1-2 years after infection is estimated to be 5% and it is assumed that all infected contacts were infected by the index case Consequently, tuberculin positive contacts, especially children and HIV-infected persons, are a high priority to receive isoniazid for treating LTBI In TB endemic or high burden settings, isoniazid preventive therapy (IPT) may be indicated for contacts with known HIV-infection and children < 5 years-old that are asymptomatic for TB despite TST result [Image Credit: Microsoft Word clip art 2007.]

Treatment for LTBI: Evaluation
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Treatment for LTBI: Evaluation Module Version Evaluate all potential LTBI treatment candidates for active TB Identify those who have been treated previously Identify those with contraindications to treatment for LTBI (prior allergic reactions, severe unstable liver disease) Identify co-morbid conditions and other medications being used If it is decided that treatment for LTBI is indicated, it is essential that active TB be excluded. This usually requires a physical exam, chest X-ray and sputum for AFB smear and culture when indicated (abnormal CXR or when symptom positive) It is also important to seek information that would influence the decision to treat [Review content of slide]

ISTC Standard 19 Module Version Children <5 years of age and persons of any age with HIV infection who are close contacts of an infectious index patient and who, after careful evaluation, do not have active tuberculosis, should be treated for presumed latent TB infection with isoniazid ISTC standard 19 addresses the need for treatment of LTBI in child contacts and persons with HIV infection

Treatment for LTBI: Priorities
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Treatment for LTBI: Priorities Module Version 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) The highest priorities for treating LTBI are children <5 years of age and persons with HIV infection or other immunocompromising conditions [Review content of slide] [Image credit: US AID, Manila]

Other Treatment Considerations
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Other Treatment Considerations Module Version “Window-period” prophylaxis – treatment (usually INH) given to high risk contacts with an initial negative TST during the period following last contact until the follow-up TST Priorities for initiating window-period prophylaxis include: Children <5 years of age Persons with HIV infection Exposure to drug resistant TB – consult an expert in the management of drug resistant TB [Review slide content] Treatment for contacts at “high risk” for rapid progression to active TB disease is recommended during the window period. This would included children <5 years of age and persons with HIV or otherwise immune suppressed Window prophylaxis in children may be terminated if they are found to be TST-negative and asymptomatic at 8-10 weeks after break in contact. HIV-infected contacts should continue a full 6-9 month course of INH regardless of the follow-up TST results If the index case patient is found to have drug resistant tuberculosis, it is advisable to consult an expert in the management of drug resistant TB as the treatment options and management becomes more complicated. This is particularly true when the index patient is found to have multi-drug resistant TB (MDR-TB)

Follow-up Module Version All Contacts found to have latent TB infection (LTBI) and started on treatment should receive monthly visit by a nurse or physician MDR-TB exposure – seek expert consultation; follow-up for 2 years post exposure [Review slide content]

Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Contact Investigation Case Study Part 4 Case Study Activity - Part 4: Evaluate, Treat and Follow-up Contacts Allow 20 minutes for this portion of the Case Study 2 minutes to read case scenario update and give instructions 10 minutes for participants to discuss and answer questions 7-9 in their small group 8 minutes for report back Refer participants to their Contact Investigation Case Study worksheet Ask for a volunteer to read the case scenario update Instruct participants to work with the others at their table. They will have 10 minutes to discuss and answer questions #7-9 After 10 minutes, have groups report back their answers. Rotate between groups for report back Note: Practice may differ between countries on evaluation required and for determining criteria to initiate treatment (window prophylaxis and treatment for LTBI). Priorities for initiation of treatment for LTBI and window-period prophylaxis was covered on slides 48-49

Step 7: Evaluate C.I. Activities
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Management of care and follow up of TB case and contacts Epidemiologic analysis of the investigation in progress to allow prioritization of program activities and resources Program evaluation—measure how well objectives are being met This is an essential element that requires good record keeping and management of your contact investigation data (whether the files/records be written or electronic) in order to accomplish it. Evaluating your contact investigation activities is important for the following reasons: [Review the slide content] [Image Credit: Microsoft Word clip art 2007.]

Deciding Whether to Expand Testing
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Evidence of Recent Transmission: Infection in a child (<5 years of age) TST converters Secondary case TB disease in any contact assigned a low priority To determine whether a contact investigation should be expanded, you will be looking at your contact investigation data for evidence of recent transmission. The evidence you are looking for includes: [Review slide content]

Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Module Version Contact Investigation Case Study Part 5 Case Study - Part 5: Evaluate Contact Investigation Activities – Decide whether to expand the investigation Allow approximately 12 minutes for this portion of the Case Study 2 minute to read the contact investigation summary following initial round of testing 5-7 minutes to work in small group (or pairs) to answer 3 minutes to report back to large group Refer participants to their Contact Investigation Case Scenario worksheet Ask for a volunteer to read the contact investigation summary following initial round of testing Instruct participants to work with the others at their table. They will have 8 minutes to discuss and answer question 10 When groups look like they have completed their task (or after 8 min.), ask for a group to volunteer to report Answer: Groups should identify the following as criteria for expanding the investigation: Two secondary suspect cases (9-year-old and 2-year-old) TB infection in the 3-year-old Additional steps for expanding the CI might include: Test and evaluate Aunt and Uncle from Village Reinterview index case Interview friends and other family members to solicit additional contacts

Summary: ISTC Standards Covered*
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Summary: ISTC Standards Covered* Module Version Standard 18: All providers of care for patients with TB should ensure that persons who are in close contact with patients who have infectious TB are evaluated and managed in line with international recommendations. The highest priority contacts for evaluation are: Persons with symptoms suggestive of tuberculosis Children aged <5 years Contacts with known or suspected immunocompromise, particularly HIV infection Contacts of patients with MDR/XDR tuberculosis Other close contacts are a lower priority group And in summary, the International Standards reviewed with this material: (abbreviated) [Review the slide content] * Abbreviated versions

Summary: ISTC Standards Covered* (2)
Caribbean Guidelines for the Prevention, Treatment, Care, and Control of Tuberculosis and TB/HIV Summary: ISTC Standards Covered* (2) Module Version Standard 19: Children <5 years of age and persons of any age with HIV infection who are close contacts of an infectious index patient and who, after careful evaluation, do not have active tuberculosis, should be treated for presumed latent tuberculosis infection with isoniazid. [Review the slide content] * Abbreviated versions

Summary Module Version Between % of household contacts of new cases will be found to have active TB and up to 50% may have LTBI The likelihood of transmission relates directly to the bacillary burden of the index case Environmental factors also play an important role Priorities for evaluation include children <5 years of age, persons with HIV infection, and highly exposed contacts Treatment is indicated for high priority contacts with LTBI and during the “window period” Here are the important points to remember from this presentation [review summary bullets] Treatment of contacts with TB infection is particularly important for high priority contacts. High priority contacts include: Close contacts (e.g., household) Children < 5 years of age Contacts with HIV infection Contacts with other immunosuppressive conditions Treatment is also indicated for vulnerable contacts (children < 5 years old and HIV +) during the “window period” [Interactive option:] Ask participants “Who are the high priority contacts?” (summary listed above) and “Who can define the window period for TB?”

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