Contact Investigation for Tuberculosis Control

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Contact Investigation for Tuberculosis Control

• Tim Epps Bill White
• Division of Disease Prevention-TB
• Virginia Department of Health

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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

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Decision to Initiate a Contact Investigation





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Investigating the index patient and sites of
transmission

• Pre-interview phase
• Determination of infectious period
• Interviewing the patient
• Field investigation
• Specific investigation plan

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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
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Interviewing the Patient

• Language of patients choice interpreter if
  required
• Assurance of confidentiality and privacy
• Review and verify information gathered from other
  sources
• Infectious period
• Potential transmission settings patients 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

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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 lt 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

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Assigning Priorities (First things first)

• Priority of contact investigation (smear positive
  pulmonary gt smear negative pulmonary gt
  extra-pulmonary)
• Priority of investigation of contacts (close,
  small children, immunocompromised gt gt less
  close, older, healthy)

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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

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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

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Source Patient Definition

• A person with infectious TB disease who is
  responsible for transmitting M. tuberculosis to
  another person or persons

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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

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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. gt 8 hrs./day.
• More likely to become infected with TB than
  contacts who see the patient less often

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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

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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

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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

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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

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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.

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HIGH PRIORTYCONTACTS

• Children lt 5 years of age
• Immune compromised individuals
• Those exposed during medical procedures
• Exposure gt 8 hrs per day
• Those exhibiting TB symptoms

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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

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Organizing a Contact Investigation

• Prioritization of field activities
• Consideration of geography
• Prior knowledge of patients likely whereabouts
  at specific times of the day

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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

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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

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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)

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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

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Interview

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

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Person Characteristics
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Contact Characteristics

• Age
• Health status
• Lifestyle

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Time Characteristics

• Duration of Exposure
• Frequency of exposure

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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)

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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

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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

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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

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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

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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

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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

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Patient Confidentiality

• Assure the patient that all information,
  including the patients name, will be kept
  confidential

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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

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Communicating through the media

• Involve your PIO early and routinely
• Media can help in a large investigation

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Other Topics

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

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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.

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CDC Contact Investigation Slideset Link

• http/www.cdc.gov/nchstp/tb/pubs/slidesets/contact
  inv/default.htm

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Questions?