Contact Investigation for Tuberculosis Control

1. Contact Investigation for Tuberculosis Control Tim Epps & Bill White Division of Disease Prevention-TB Virginia Department of Health

2. Learning Objectives At the end of this lecture, the participants will be able to: • Describe the situations in which a contact investigation should be done; • Describe how to prioritize a contact investigation; • Describe the steps in a contact investigation; • Determine the infectious period, and; • Identify the contacts who should be considered high-priority

3. Decision to Initiate a Contact Investigation * * * * *

4. Investigating the index patient and sites of transmission • Pre-interview phase* • Determination of infectious period * • Interviewing the patient * • Field investigation * • Specific investigation plan *

5. 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. Above

6. 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

7. 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 • Should be made < 3 days of initial interview • May suggest additional questions for re-interview of patient • Likely to attract attention, raise questions • Requires planning, anticipation of questions • First visit to site should be to gather information; second and subsequent visits should be done after specific investigation plan is in place

8. Assigning Priorities (“First things first”) • Priority of contact investigation (smear positive pulmonary > smear negative pulmonary > extra-pulmonary) • Priority of investigation of contacts (close, small children, immunocompromised > > less close, older, healthy)

9. Specific Investigation Plan • Final step in “investigating the index patient and sites of transmission” section • Summary of information from interviews, site visits • List of contacts and their assigned priorities • Time line • Resource requirements/staffing plan • Becomes part of the permanent record

10. Index Case - Definition • A person with suspected or confirmed TB disease who is the initial case reported to the health department is called the index patient

11. Source Patient – Definition • A person with infectious TB disease who is responsible for transmitting M. tuberculosis to another person or persons

12. Contact – Definition • Contact • People exposed to someone with infectious TB disease, generally including family members, roommates or housemates, close friends, coworkers, classmates, and others • A high-priority group for treatment for LTBI because they are at high risk of being infected with M. tuberculosis, and if infected, they are at high risk of developing disease

13. Close Contact – Definition • Close Contact • A person who had prolonged, frequent, or intense contact with a person with TB while he or she was infectious. > 8 hrs./day. • More likely to become infected with TB than contacts who see the patient less often

14. Contact Investigation – Definition • A procedure for identifying people exposed to someone with infectious TB, evaluating them for latent TB infection (LTBI) and TB disease, and providing appropriate treatment for LTBI or TB disease

15. Importance of a Contact Investigation • Important to find contacts who: • Have TB disease so that they can be given treatment, and further transmission can be stopped • Have LTBI so that they can be given treatment for LTBI • Are at high risk of developing TB disease and may need treatment for LTBI until it becomes clear whether they have TB infection

16. When to Do a Contact Investigation? • Whenever a patient is found to have or is suspected of having infectious TB disease • When TB is confirmed or there is a high clinical suspicion of TB

17. How Quickly Should a Contact Investigation be Done? • Close contacts should be examined within 7 working days after the index case has been diagnosed • The sooner contacts are identified and evaluated, and can begin appropriate therapy, the less likely it is that transmission will continue

18. Prioritizing Contact Investigations • Laryngeal TB or positive sputum smear pulmonary TB most infectious. CI immediately required. • Negative sputum smear pulmonary TB CI recommended. • Extrapulmonary TB does not carry any risk for transmission and contact investigations are not performed. • CI not performed for people with diseases caused by nontuberculous mycobacteria only, such as M. avium.

19. HIGH PRIORTYCONTACTS • Children < 5 years of age • Immune compromised individuals • Those exposed during medical procedures • Exposure > 8 hrs per day • Those exhibiting TB symptoms

20. Who Is Responsible for a CI? • The health department is legally responsible for ensuring that a complete contact investigation is done for the TB cases reported in its area • Identifying and evaluating contacts • Treating any contacts found to have TB disease • Offering treatment for LTBI to infected contacts • Monitoring adherence to prescribed regimens and ensuring a system is in place to assess completion of treatment

21. Organizing a Contact Investigation • Prioritization of field activities • Consideration of geography • Prior knowledge of patient’s likely whereabouts at specific times of the day

22. Steps in a Contact Investigation • Medical record review • Patient interview • Field investigation • Risk assessment for M. tuberculosis transmission • Decision about priority of contacts • Evaluation of contacts • Treatment and follow-up for contacts • Decision about whether to expand testing • Evaluation of contact investigation activities

23. Records Search • Saves valuable time and effort in the field • Medical records should be checked for prior visits or locating information • Referrals done by a colleague could provide information

24. Information To Be Collected • Site of TB disease • TB symptoms and approximate date symptoms began • Sputum smear and culture results, including the dates of specimen collection • Results of nucleic acid amplification testing (if available) • Chest x-ray results and date • TB treatment (medications, dosage, and date treatment was started) • Method of treatment administration (DOT or self administered)

25. Information To Be Collected • For suspected TB cases the following information should also be collected: • Medical risk factors that may increase the risk for development of TB disease • History of tuberculin skin test results • History of previous treatment for TB disease or TB infection

26. Interview • Infectious period • Brings focus to the interview • Start/end point of probable transmission • Transmission probability assessment • Identifies contact tracing priorities • Person • Place • Time

27. Person Characteristics

28. Contact Characteristics • Age • Health status • Lifestyle

29. Time Characteristics • Duration of Exposure • Frequency of exposure

30. Evaluation of Contacts • Evaluated for LTBI and TB disease. • This evaluation includes at least: • A medical history • A Mantoux tuberculin skin test (unless there is a previous documented positive reaction)

31. When To Expand Testing • Evidence of recent transmission, the next highest-priority group should be evaluated • Expand to the next group of contacts each time there is evidence of transmission in the group being tested

32. Treatment and Follow-Up of Contacts • Treatment for LTBI: • Contacts who have a positive tuberculin skin test reaction and no evidence of TB disease • High-risk contacts who have a negative tuberculin skin test reaction, such as children under 5 years of age, HIV-infected people, and other high-risk contacts who may develop TB disease very quickly after infection

33. Secondary Case of TB • When a contact develops TB disease as a result of transmission from an index patient • Conduct a contact investigation immediately around any source case or secondary case or cases discovered during another investigation

34. Professional Thoroughness • Utilize all locating resources available to you • Motivate patients to seek medical attention • Ensure that patient receives medical care • Follow-up with patients to reinforce their compliance with medical recommendations

35. Effective Communication • Be specific and efficient when communicating • Have ability to problem solve when speaking • Use open-ended questions • Be assertive, not aggressive • Have ability to “sense” problems and address them immediately

36. Persistence • Make multiple attempts to locate patient, if patient not found in first attempt • Recognize that patients may not respond to first referral to visit the clinic • Be prepared to make necessary additional actions (i.e., visits, telephone calls, referrals, etc.) • Be level-headed and calm when dealing with difficult patients

37. Patient Confidentiality • Assure the patient that all information, including the patient’s name, will be kept confidential

38. Success of a Contact Investigation • Infected contacts should begin and complete a regimen of treatment for LTBI • Interrupt transmission and prevent future cases of disease

39. Communicating through the media • Involve your PIO early and routinely • Media can help in a large investigation

40. Other Topics • Cultural competence • Social network analysis • Use of blood tests for detection of LTBI • Quanti-FERON-TB test

41. 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.

42. CDC Contact Investigation Slideset Link: http:/www.cdc.gov/nchstp/tb/pubs/slidesets/contactinv/default.htm

43. Questions?