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

10 January 2007

Contact Investigation for Tuberculosis ControlContact Investigation for Tuberculosis Control

Tim Epps & Bill White

Division of Disease Prevention-TB

Virginia Department of Health

10 January 2007

Learning ObjectivesLearning Objectives

At the end of this lecture, the participants will be able to:1. Describe the situations in which a contact

investigation should be done; 2. Describe how to prioritize a contact

investigation; 3. Describe the steps in a contact investigation; 4. Determine the infectious period, and;5. Identify the contacts who should be

considered high-priority

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Decision to Initiate a Decision to Initiate a Contact InvestigationContact Investigation

* * * **

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Investigating the index Investigating the index patient and sites of patient and sites of

transmissiontransmissionPre-interview phase *Determination of infectious period *Interviewing the patient *Field investigation *Specific investigation plan *

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Determining the Infectious Determining the Infectious PeriodPeriod

Above

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.

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Interviewing the Patient 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

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Field investigation – site Field investigation – site visitsvisits

• 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

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Assigning Priorities (“First things first”)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)

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Specific Investigation Specific Investigation PlanPlan

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 - DefinitionIndex 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 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 – DefinitionContact – DefinitionContact

– 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 – DefinitionClose 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

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Contact Investigation – Contact Investigation – DefinitionDefinition

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 Importance of a Contact InvestigationInvestigation

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 When to Do a Contact Investigation?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 How Quickly Should a Contact Investigation be Done?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 InvestigationsPrioritizing 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 PRIORTYHIGH PRIORTYCONTACTSCONTACTS

Children < 5 years of ageImmune compromised individualsThose exposed during medical

proceduresExposure > 8 hrs per dayThose exhibiting TB symptoms

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Who Is Responsible for a CI?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 Organizing a Contact InvestigationInvestigation

Prioritization of field activities

Consideration of geography

Prior knowledge of patient’s likely whereabouts at specific times of the day

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Steps in a Contact InvestigationSteps in a Contact Investigation1. Medical record review2. Patient interview3. Field investigation4. Risk assessment for M. tuberculosis transmission5. Decision about priority of contacts6. Evaluation of contacts7. Treatment and follow-up for contacts8. Decision about whether to expand testing9. Evaluation of contact investigation activities

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Records SearchRecords 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 CollectedInformation 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 CollectedInformation 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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InterviewInterview 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 CharacteristicsPerson CharacteristicsClinical Data High Likelihood

of TransmissionLow Likelihood of Transmission

Disease location

Laryngeal

PulmonaryExtrapulmonary 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)

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Contact CharacteristicsContact Characteristics

Age

Health status

Lifestyle

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Time CharacteristicsTime Characteristics

Duration of Exposure

Frequency of exposure

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Evaluation of ContactsEvaluation of ContactsEvaluated 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 TestingWhen To Expand TestingEvidence 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 ContactsTreatment 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 TBSecondary Case of TBWhen 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 ThoroughnessProfessional ThoroughnessUtilize 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 CommunicationEffective 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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PersistencePersistence 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 ConfidentialityPatient Confidentiality

Assure the patient that all information, including the patient’s name, will be kept confidential

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Success of a Contact Success of a Contact InvestigationInvestigation

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 Communicating through the mediathe media

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

investigation

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Other TopicsOther TopicsCultural competenceSocial network analysisUse of blood tests for detection of

LTBI– Quanti-FERON-TB test

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Required DocumentsRequired 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:CDC Contact Investigation Slideset Link:

http:/www.cdc.gov/nchstp/tb/pubs/slidesets/contactinv/default.htm

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Questions?Questions?