2.2.3 Key implementation steps in contact investigation

In addition to planning and budgeting, NTPs should consider the following key implementation steps in contact investigation:

  1. Provide standard guidance and approaches to reach contacts and undertake investigations to ensure uniformity in implementation.
  2. Provide national guidance that:
    • defines priority populations for contact investigation (household and beyond);
    • defines the model of care (facility- or community-based);
    • ensures the human rights of index patients, contacts and communities are respected;
    • defines the roles and responsibilities of programme personnel, HCWs and community health workers (CHWs) in reaching contacts, symptom screening and provision of CXR if available, referral for testing and clinical evaluation (e.g. cadre of HCWs responsible for contact investigation and inclusion in respective job descriptions, or HCWs responsible for supervision of personnel conducting contact investigation if community-based model is implemented);
    • defines data elements to be captured with the index patient’s record (with or without use of digital tools);
    • includes the necessary tools to identify contacts, to record the outcomes of TB screening, and to refer identified people with presumptive TB for further diagnostic workup if the community-based model is implemented;
    • provides locally tested messages for demand generation and education.
  3. Leverage existing human resources and mechanisms across multiple disease programmes (e.g. public health response model and differentiated service delivery (DSD) models for people living with HIV) to implement contact investigation and ensure sustainability and efficiency. TB and HIV screening could be integrated throughout the process.
  4. Implement contact investigation as follows:
    • The index patient should be interviewed as soon as possible after diagnosis, preferably within a week, to elicit details about household and other close contacts. Health providers should explain clearly and sensitively the urgency of initiating contact investigation to the index patient, considering the increased risk of progression to TB disease with recent exposure. A second interview may be required to elicit additional contacts and to complete any missing information.
    • Ideally, the interview should be conducted by a person who speaks the same language as the index patient and is familiar with their social and cultural context.
    • Education of the index patient and household members regarding the benefits of taking TPT and the risks of not taking it should be central to the contact investigation process. The overall aim should be to enable informed decision by the individuals to receive a complete course of TPT.
    • Appropriate disclosure counselling of the index TB patient is important to secure their support and to reach all relevant contacts for investigation.
    • Contact investigation can be implemented in the community or at the health facility. Where the community-based model is implemented, it is desirable to seek approval from the index patient for a home visit. In addition to counselling of the index patient, arrangements should be made to counsel contacts before starting TPT.
    • Preferably, the health provider (trained CHW or professional health provider) conducting the contact investigation should visit the home or workplace of the index patient; conduct interviews and underscore the importance of identifying and evaluating contacts; perform symptom screening and documentation; gather more accurate information about the likely intensity and duration of exposure; and ensure all symptomatic contacts are referred for further evaluation and treatment decision and all asymptomatic contacts are assessed for TPT eligibility (see Box 2.3) (20). Home visits may need to be done outside working hours since contacts may be at work or school during these times.
    • Home visits by health providers provide the opportunity to identify needs for social support, nutritional support and information on infection control measures. The health provider may refer the index patient and contacts to relevant social and nutritional support programmes.
    • During the home visit, the health provider should provide counselling and education to family members on TB symptoms and infection control (see Annex 1 for a list of resources, including counselling and education materials). If required, prompt medical attention and referrals should be made, especially for child contacts and people living with HIV, in whom TB could progress rapidly. HIV testing and counselling should be offered as part of this process, including to biological children of any adults living with HIV.
    • If the home or workplace cannot be visited, the index patient may be interviewed at a health facility and their contacts listed. The index patient’s full address should be obtained and modality for future communication mutually agreed with them (e.g. telephone, email, contact of an intermediary or treatment provider). Health workers should systematically follow up with the index patient, intermediary and treatment providers and mobilize all relevant contacts to the health facility for symptom screening and CXR where relevant, testing for TB and TB infection when indicated and available, and evaluation for eligibility for TPT. Transport vouchers may be needed if this is done at a clinic.
    • The focus of the contact investigation should be on household members, but contacts at workplaces, residential care facilities, residential schools, long-term care facilities, prisons, correctional facilities and acute medical care facilities should also be considered as per national guidelines for evaluation, especially when exposure is likely to have been prolonged and the index case is likely to be highly infectious (prolonged cough, medium or high semiquantitative results via rapid molecular testing, or extensive cavities on CXR).
    • Maintaining confidentiality during contact investigation is a challenge because of the social connections between index patients and their contacts. All people should be treated with respect, and confidentiality should be maintained as much as possible. National programme guidelines on data protection, confidentiality, privacy and informed consent should be adhered to. Contact screening is generally experienced in a positive light if the community appreciates this is done to keep vulnerable people and the whole community safe (21).
    • When the index patient is reluctant to give information regarding household and social contacts, counselling efforts should continue over time to gain the patient’s trust. The index patient should not be coerced, and their TB treatment should not be linked with the success of the contact investigation.
    • Information from the interview should be recorded in the patient’s medical notes or file (22).
    • If not already done, contact investigation is also important among family members and close contacts of a person who has died from TB.
  5. Provide guidance on monitoring and evaluation:
    • Use standard recording and reporting tools and a protocol for data collection during contact investigation, data entry and analysis.
    • Monitor the yield of contact investigations and the number and proportion of people with TB disease and TB infection detected to inform programme adjustments. Information should be recorded on the number of contacts identified and those who complete the contact investigation process.


Box 2.3 Key steps in contact investigation

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