1. Contact Investigation for Tuberculosis Control
Tim Epps & Bill White
Division of Disease Prevention-TB
Virginia Department of Health
10 January 2007

2. 10 January 2007
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
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4. Investigating the index patient and sites of transmission
10 January 2007
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
10 January 2007
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
10 January 2007
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
10 January 2007
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”)
10 January 2007
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
10 January 2007
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
10 January 2007
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
10 January 2007
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
10 January 2007
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
10 January 2007
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
10 January 2007
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
10 January 2007
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?
10 January 2007
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?
10 January 2007
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
10 January 2007
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 PRIORTY CONTACTS Children < 5 years of age
10 January 2007
HIGH PRIORTY CONTACTS
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?
10 January 2007
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
10 January 2007
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
10 January 2007
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
10 January 2007
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
10 January 2007
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
10 January 2007
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 Transmission probability assessment
10 January 2007
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
10 January 2007
Person Characteristics
Clinical Data
High Likelihood of Transmission
Low Likelihood of Transmission
Disease location
Laryngeal
Pulmonary
Extrapulmonary alone
Smear Status
Positive
Negative
Smear source
Spontaneous specimen
Induced or clinical (bronchoscopy, etc.)
Chest X-ray
Cavitary
Non-cavitary
Symptoms
Cough
No cough
Anti-TB Drugs No
Yes (2 weeks or more)

28. Contact Characteristics
10 January 2007
Contact Characteristics
Age
Health status
Lifestyle

29. Time Characteristics Duration of Exposure Frequency of exposure
10 January 2007
Time Characteristics
Duration of Exposure
Frequency of exposure

30. Evaluation of Contacts
10 January 2007
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. 10 January 2007
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
Evidence of recent transmission is provided by any of the following factors:
A high infection rate among contacts [The percentage of contacts who have a newly identified positive skin test reaction]
Infection in a young child [suggests recent transmission]
A TST conversion in a contact [Increase in measurement of 10 mm or more within 2 years is standard; for contacts, it is a change from less than 5 mm on the initial skin test to a reaction of greater than or equal to 5 mm on the second test, 10 to 12 weeks after exposure…evaluate this person for treatment for LTBI]
A secondary case of TB disease [warrants a contact investigation around this new case; indicates ongoing transmission]

32. Treatment and Follow-Up of Contacts
10 January 2007
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. 10 January 2007
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
10 January 2007
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
10 January 2007
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. 10 January 2007
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
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Patient Confidentiality
Assure the patient that all information, including the patient’s name, will be kept confidential

38. Success of a Contact Investigation
10 January 2007
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
10 January 2007
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
10 January 2007
Other Topics
Cultural competence
Social network analysis
Use of blood tests for detection of LTBI
Quanti-FERON-TB test

41. 10 January 2007
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:
10 January 2007

43. 10 January 2007
Questions?