Contact investigation is the most effective means of active case detection due to the fact that the people closest to a recently diagnosed case of sputum smear-positive TB are the most likely to be infected or themselves have active disease. The investigation may identify the person from whom the disease was contracted who may be unaware of their condition and therefore remain untreated and infectious. Although always a possibility, sources of adult TB are not often detected as the patient could have been infected at any previous time in their lives.  If however the patient is a child it is likely that they have recently been infected by an adult with active disease, such as a member of their household, close relative or family friend.

The investigation of at least the household contacts provides a valuable opportunity to educate people who have potentially been infected with TB so they can recognise signs and symptoms and seek the necessary help and treatment if they develop the disease in the future. This is also important where resources are not available to investigate any further than the patient’s household. Patients themselves need to be equipped and encouraged to discuss their condition with others who have been in contact with them and are showing signs and symptoms of disease.

Treatment of latent TB infection to prevent the development of active disease is most effective for children and other vulnerable people who have been infected by the patient. Any possibility of active disease must be ruled out before preventive treatment is started in order to avoid the possibility of partial treatment, which could lead to the development of drug resistance.
Where available, tuberculin skin testing can identify latent TB and preventive treatment can be offered to those at highest risk of developing disease. Where tuberculin is not available, The Union recommends that in the absence of active disease, preventive therapy should be offered to all children aged under 5 living in the same household as a smear-positive case of TB.

For details of the treatment of infected children preventive see Chapter 8 of Management of the child with cough or difficult breathing

Read more: TB medicines for children WHO 2008

For more information on Tuberculin test – see Identifying TB

Contact tracing can often be a traumatic experience for the patient, who may feel very exposed and vulnerable due to the stigmatising nature of TB, so it is vital that the whole process is handled with as much sensitivity and discretion as possible. Every effort must be made to maintain the patient’s confidentiality.

Consider the need to be sensitive when addressing a patient’s need for confidentiality with their family, while trying to encourage them to gain support from their family as well as to prepare them for potential investigation for TB

Learn more: About stigma

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