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Contact Investigations. WHO ?. WHERE ?. WHEN ?. HOW LONG ?. WHY ?. HOW ?. WHO ? IS RESPONSIBLE FOR CONTACT INVESTIGATION?. YOU ARE!!!!!!. ROLE OF HEALTH DEPARTMENT.
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Contact Investigations WHO ? WHERE ? WHEN ? HOW LONG ? WHY ? HOW ?
WHO ?IS RESPONSIBLE FORCONTACT INVESTIGATION? YOU ARE!!!!!!
ROLE OF HEALTH DEPARTMENT TO ENSURE THAT ALL PERSONS WHO ARE SUSPECTED OF HAVING TUBERCULOSIS ARE IDENTIFIED AND EVALUATED PROMPTLY AND THAT AN APPROPERIATE COURSE OF TREATMENT IS PRESCRIBED AND COMPLETED SUCCESSFULLY MMWR TREATMENT OF TB pg.15
Health departments are responsible for ensuring contact investigations • Public health officials must decide which • Contact investigations should be assigned a higher priority • Contacts to evaluation first • Decision to investigate an index patient depends on presence of factors used to predict likelihood of transmission
WHY? • IDENTIFY TB EXPOSURE • IDENTIFY TRANSMISSION • PREVENT TB DISEASE
Purpose of Contact Investigation • Identify, evaluate and treat individuals who may have been infected with TB by a person with active, infectious TB • Detect additional cases of active TB • Identify and treat contacts with LTBI to prevent TB disease
VIRGINIA’S STANDARD OF CARE TBCASES/TBSUSPECTS - the initial interview will be conducted within 3 days At least 90% of newly reported AFB smear + cases will have contacts identified and at least 95% of the contacts will be evaluated for disease and/or infection
Contact investigation will be initiated within 3 days of the first notification and completed within three months 85% of contacts found to be infected with Mtb infection will complete a full coarse of recommended treatment
HOW? “Contact investigations are complicated undertakings that typically require hundreds of interdependent decisions, the majority of which are made on the basis of incomplete data, and dozens of time-consuming interventions…..”
CASE MANAGEMENT SKILLS • EFFECTIVE COMMUNICATION • CONFIDENTIALITY • THOROUGHNESS • PERSISTANCE
Evaluation of the Index Patient • Comprehensive information regarding the index patient is the foundation of a contact investigation • Requires review of medical records and patient interview(s) • Requires systematic collection and management of data
Guidelines for the Investigation of Contacts of Persons with Infectious Tuberculosis2005
Guidelines for Investigation of Contacts • Identification, evaluation and treatment of contacts is element of case management • Characteristics of case determine need for and extent of contact investigation • Contact investigation activities should be planned, prioritized to ensure identification and treatment of highest risk contacts
Probability of TB Transmission • Transmission dependent on three factors • Infectiousness of the person with TB • Environment in which the transmission occurs • Duration of the exposure to TB bacteria
Infectiousness of patient Pulmonary, laryngeal, or pleural AFB on sputum smear (1+ or 4+) Cavitation on x-ray, Adolescent or adult Period of infectiousness • Environment – activities leading to aerosolization Inspect home, work and social environment • Duration of exposure – proximity, small space, limited ventilation - increase chance that susceptible contact will breathe AFB into lungs
Additional considerations…. Pulmonary, laryngeal or pleural TB • Pleural is now grouped with pulmonary because sputum cultures can yield M. tuberculosis even when no lung abnormalities are apparent on x-ray • AFB smears should always be done when diagnosis is pleural TB (suspected or confirmed) because parenchyma abnormalities may be hidden by fluid
Additional considerations…. Consider contact investigation for TB case with extra pulmonary disease if there were procedures that generate aerosols (i.e. autopsy, embalming, wound irrigation or manipulation of a draining abscess)
Additional considerations…. • If original specimens were from bronchoscopy/bronchial washings: • Guidelines recommend equating results of AFB microscopy on bronch washings to sputum • VDH recommends that sputum be collected and assessment of infectiousness be based on sputum AFB results • If unable to collect sputum, use results of bronchial washings
Additional considerations…. • Available resources should be focused on identifying, evaluating and treating exposed persons who are more likely to be infected or to become ill with TB disease if they are infected • Persons with longest, closest contact • Infants, young children , immunocompromised, persons with serious underlying medical conditions
Concentric Circle Work/School Household Social/ Community
Additional considerations • Do we suspect the base case to be MDR? • Contacts of MDR need to be continually re-assessted • Potential for prolonged periods of infectiousness
INDEX CASE • THE FIRST PERSON WITH TB DISEASE WHO IS IDENTIFIED IN A PARTICULAR SETTING
SOURCE CASE • THE PERSON OR CASE THAT WAS THE ORIGINAL SOURCE OF THE INFECTION • TWO CIRCUMSTANCES FOR SOURCE INVESTIGATION • WHEN CONGREGATE LIVING SETTING DETECTS AN UNEXPLAINED CLUSTER OF TST CONVERSIONS • WHEN LTBI OR TB DISEASE IS DIAGNOSED IN A YOUNG CHILD
Evaluation of the Index Patient and Possible Sites of Transmission • Elements of the patient investigation • Pre-interview phase • Background information (case report, records, laboratory results, x-rays) • Patient characteristics (language, severity of illness, ability to cooperate) • Determination of infectious period (preliminary)
Determining the Infectious Period Above is a starting point for estimating the period of likely infectiousness. Interview the patient and/or review medical records to determine duration of symptoms. If estimates vary, use the longer time.
Interviewing the Patient • Recommendation that interview occur < 1 business day for persons considered to be infectious and < 3 business days for others • Interview conducted in person (face-to-face, not phone!), by prepared interviewer with requisite skills • Second interview 1-2 weeks later • Interview process continues throughout course of treatment
Interviewing the Patient • Language of patient’s choice; interpreter if required • Assurance of confidentiality and privacy • Review and verify information gathered from other sources • Infectious period • Potential transmission settings – patient’s ADL • Day, night, work, school, social, health care, travel • Refer to calendar, use holidays as reminders • List of contacts • Names, including street names,types, frequencies and duration of exposure, • Use a standard form to record information • If no names, ask about “groups”, social network
WHERE ? • WHERE ARE WE GOING TO LOOK FOR PEOPLE WHO HAVE SHARED AIRSPACE WITH OUR TB CASE? • REMEMBER, YOUR CONTACT LIST WILL CHANGE, CI IS AN ONGOING PROCESS • USE YOU ORW AS A SOURCE OF INFORMATION FOR CONTACTS
Field Investigation • Site visits • First visit to site should be to gather information; second and subsequent visits should be done after specific investigation plan is in place • Each site will have it’s own culture • Should be made within 3 days of initial interview • Media concerns
Field Investigation/Site Visits • Complimentary/supplementary to interviews • All possible sites of transmission should be evaluated • May identify additional contacts • May identify high-risk contacts (children) • Size, ventilation characteristics may help estimate level of exposure • May raise additional questions for re-interview of patient • Likely to attract attention, raise questions • Requires planning, anticipation of questions
“Specific Investigation Plan” • The final step in the evaluation of the index patient and possible sites of transmission • Summarize information from interviews, site visits • Make a decision on need for/extent of contact investigation • If a contact investigation is indicated • List contacts and assign priorities • Establish time line • Develop list of resource requirements and staffing plan • If a contact investigation is not required • Summary of available information and reason for decision • Include investigation plan in permanent record
“Priorities” • Is the contact investigation high priority? • Is the contact high risk and therefore high priority?
Assigning Priorities to Contacts • Occurs after contact investigation decisions • Characteristics of the index patient • Availability of resources • Priority/order for investigation of contacts • Characteristics of contacts • Age, immune status, underlying medical conditions • Estimated level of exposure • Proximity, duration, volume of space (small room vs. large), ventilation
Priority for evaluation evaluation of contacts: AFB smear positive laryngeal/pulmonary/pleural TB • High • Under age 5 • Medical risk factors • HIV • Immunosuppressive agents (steroids, cancer chemotherapy, anti-rejection drugs for organ transplants, tumor necrosis factor alpha agents) • Other medical risk factors (silicosis, renal disease, diabetes, gastrectomy) • Exposure during medical procedure (bronchoscopy, autopsy, sputum induction) • Exposure in congregate setting
Priority for evaluation evaluation of contacts: AFB smear positive laryngeal/pulmonary/pleural TB • Medium • Aged 5-15 • Exposure exceeds time/space/ventilation limits recommended by state or local TB program • Estimate of exposure by setting • Time at location • Size/volume of shared airspace • Ventilation – windows, fans • May be up or downgraded depending on results of testing of higher priority contacts
Priority for evaluation evaluation of contacts: AFB smear negative laryngeal/pulmonary/pleural TB • High • Contacts < age 5 • Medical risk factor • Exposure during medical procedure • Medium • Household • Exposure in congregate setting • Exceeds duration/environmental limits
Priority for evaluation of contacts: Suspected pulmonary TB, AFB negative with abnormal chest x-ray not consistent with TB • High • None • Medium • Household • Age < 5 years • Medical risk factor • Exposure during medical procedure
Timeline for Contacting/Evaluation of Contacts • Establish after assignment to high, medium or low priority category • High or medium priority should be contacted within 3 days and evaluated within < 7 days for high priority and < 14 days for medium priority contacts • Symptomatic contacts should be evaluated immediately
Diagnostic and Public Health Evaluation of Contacts • Remember priority assignment • Highest risk = highest priority = major effort to contact and complete evaluation • Initial assessment for all high and medium priority contacts • Screen for symptoms of active disease; proceed immediately to x-ray and sputum collection if symptomatic; do not wait for results of TST • Children <5 and immunocompromised adults should be evaluated and have chest x-ray, whether symptomatic or not
Diagnostic and Public Health Evaluation of Contacts • Others (high and medium priority contacts) should receive TST ASAP if not already TST positive • Two step TST procedure should not typically be used for testing contacts • BCG exposure should be recorded, but is not a contra-indication to testing • > 5mm induration is considered to be a positive TST in a contact investigation • Individuals with positive TST require further evaluation • Chest x-ray • Sputum smears and culture if indicated (abnormal x-ray, symptoms) • Individuals who are previously TST positive should be screened for symptoms, further evaluated only if indicated by screening
Tuberculin Skin Testing of Contacts • Repeat testing • Estimated interval between infection and detectible skin test reactivity is 2-12 weeks • Reinterpretation of data previously collected indicates that 8 week is outer limits of window period. • CDC & NTCA recommendation that window period be decreased to 8-10 weeks • VIRGINIA – WINDOW PERIOD DEFINED AS 10 WEEKS FOR VIRGINIA CONTACT INVESTIGATIONS
HOW LONG? • EXPANDING THE CONTACT INVESTIGATION • FINDING NEW CONTACTS NOT IDENTIFIED IN THE BEGINNING
Should be considered only after results of investigation of high and medium priority contacts is complete and results have been evaluated • Infection rates are higher than expected • Evidence of secondary transmission • TB disease is found ( source vs. secondary) • Requires careful consideration – may require new contact investigation rather than expansion of initial investigation • TST conversions occur between first and second TST
INCIDENT COMMAND • VDH DDP-TB ENCOURAGES THIS MODEL IN ALL LARGE CONTACT INVESTIGATIONS • WE ARE AVAILABLE TO ANSWER YOUR QUESTIONS AND TO PROVIDE ASSISTANCE
DOES ANYONE HAVE AN UNUSUALCONTACT INVESTIGATION TO SHARE???
Required Documents • Guidelines for the Investigation of Contacts of Persons with Infectious Tuberculosis, December 16, 2005; Volume 54, # RR-15. • Treatment of Tuberculosis, June 20, 2003; Volume 52, # RR-11. • Controlling Tuberculosis in the United States, March 2005. • Targeted Tuberculin Testing and Treatment of Latent Tuberculosis Infection, 2005. • Virginia’s CI Nursing Directive/Guideline http://vdhweb/nursing/documents.asp