Active case‐finding in contacts of people with TB

Abstract

BACKGROUND: Exposure to people with TB substantially elevates a person's risk of tuberculous infection and TB disease. Systematic screening of TB contacts enables the early detection and treatment of co‐prevalent disease, and the opportunity to prevent future TB disease. However, scale‐up of contact investigation in high TB transmission settings remains limited.METHODS: We undertook a narrative review to evaluate the evidence for contact investigation and identify strategies that TB programmes may consider when introducing contact investigation and management.RESULTS: Selection of contacts for priority screening depends upon their proximity and duration of exposure, along with their susceptibility to develop TB. Screening algorithms can be tailored to the target population, the availability of diagnostic tests and preventive therapy, and healthcare worker expertise. Contact investigation may be performed in the household or at communal locations. Local contact investigation policies should support vulnerable patients, and ensure that drop‐out during screening can be mitigated. Ethical issues should be anticipated and addressed in each setting.CONCLUSION: Contact investigation is an important strategy for TB elimination. While its epidemiological impact will be greatest in lower‐transmission settings, the early detection and prevention of TB have important benefits for contacts and their communities.

Association Studies of Serum Levels of TNF- α, IL-10, IFN-γ and CXCL 5 with Latent Tuberculosis Infection in Close Contacts

“…It is recommended that early screening for TB should be carried out in order to shift from a reactive to active screening, to detect patients at an early stage, to continuously strengthen the dissemination of core knowledge among patients and close contacts, and to enhance the awareness and behaviour of close contacts in terms of personal protection, so as to reduce the rate of infection and morbidity in this group. 26 …”

“…It is recommended that early screening for TB should be carried out in order to shift from a reactive to active screening, to detect patients at an early stage, to continuously strengthen the dissemination of core knowledge among patients and close contacts, and to enhance the awareness and behaviour of close contacts in terms of personal protection, so as to reduce the rate of infection and morbidity in this group. 26 The results of logistic regression and structural equation modelling are the influencing factors of LTBI include education, daily contact hours, eating animal liver, and drinking coffee, of which daily contact hours, eating animal liver, drinking coffee had direct effects on LTBI and education had indirect effects on LTBI. TB is an airborne transmission of germs from an infectious agent, and close contacts are exposed to an environment that provides favourable conditions for the survival of the germs, with the time of day spent in contact with the patient determining the degree of exposure to Mtb.…”

Surveillance of close contacts of patients with infectious tuberculosis: a prospective cohort study

“…Early identification and intervention for TB infections among close contacts decrease the likelihood of TB transmission within the community [ 16 ]. Conventional screening of contacts of people with infectious TB at baseline inevitably results in underestimation of TB infections due to time lags in developing adaptive immune responses against MTB.…”

Feasibility, enablers and challenges of using timeliness metrics for household contact tracing and TB preventive therapy in Pakistan

“…Household contacts of TB patients, especially infants and young children, are at high risk of contracting TB [ 25 – 27 ]. As explained earlier, TPT considerably reduces this risk with protective effects lasting for several years after a course of preventive therapy [ 28 , 29 ].…”