References in the content below refer to the PBMEF Guide.
Definitions
Percent of contacts of people with bacteriologically confirmed pulmonary TB (index cases) who were screened for active TB disease, among all contacts identified during the reporting period.
Contact investigation (CI) is a systematic process to identify people (contacts) who were exposed to active pulmonary TB disease, assess contacts for signs or symptoms of active TB disease, provide diagnostic testing to confirm or exclude active disease or diagnose TB infection, and provide contacts with treatment for TB disease or infection. CI consists of identification of contacts, prioritization of contact at highest risk, clinical evaluation and diagnostic testing, and treatment as clinically indicated.
Calculation: (Numerator/Denominator) x 100
Numerator
Denominator
Ref # |
CON_SCRN
(Previously CI-1) |
Tier Level |
Core Indicator
|
Category |
Reach
|
Type |
Core Outcome
|
Unit of Measure |
Percent of contacts
|
Data Type |
Percentage
|
Disaggregations |
Age (0–4, 5–14, 15+)
Sex
|
Reporting Level |
All Core PBMEF indicators should be reported at the national level; data may also be collected subnationally for more granular monitoring.
|
Reporting Frequency |
This indicator should be reported on a semiannual basis at a minimum. More frequent monitoring on a quarterly or monthly basis is recommended. Performance plans and reports (PPRs) for this indicator are based on calendar year (CY) periodicity to reflect national level attainment and align with the USAID congressional reporting requirements.
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This indicator is reported on National TB Program (NTP) official records, such as contact registers. If these registers do not exist, data can be collected from implementing partners (IPs) supporting CI interventions. The denominator can also be estimated by taking the estimated average household size, assuming the index cases come from different households. See indicator CI-2 for more information.
This indicator was introduced in the World Health Organization (WHO) 2020 Global Data Collection Form and can be calculated using the WHO database. The variable for the numerator is newinc_con_screen and the denominator is newinc_con.
CI is an important first step both for active case finding and TB preventive treatment (TPT). CI identifies people recently exposed to TB with a high risk of developing TB disease or TB infection (TBI) and can help reduce the spread of TB in a community. As much as 5% of the contacts of people with TB can have active TB disease. This indicator measures the ability of NTPs to systematically identify and evaluate contacts of bacteriologically confirmed pulmonary TB patients for active TB and TBI.
CI coverage is one of the top 10 indicators of the WHO End TB Strategy with a recommended target level of 90% by 2025.
Increases in CI coverage will result in greater detection of people with TB and provision of appropriate anti-TB therapy (for people with confirmed TB) or TPT (for those without TB disease). Moreover, CI is a good public health practice and essential for tracking several infectious diseases with similar routes of transmission (such as COVID-19).
The total number of contacts identified can be compared to the number of contacts investigated to determine the gap in overall CI coverage among identified contacts. This is something that can be analyzed as a trend over time or compared between regions to better understand contact-tracing performance. Comparisons with a country’s CI targets will provide the impetus to further strengthen the implementation of CI strategies within an NTP. This trend should be considered in the context of the percentage of bacteriologically confirmed TB cases for whom contacts were identified (national level indicator “TB cases with contact investigations initiated”). For example, a country that reaches 100% CI coverage but only conducts CI for 20% of bacteriologically confirmed cases may not be performing as well as a country that achieves 75% CI coverage and conducts CI for 50% of people with bacteriologically confirmed TB.
Another comparison could be made between the number of contacts investigated per index case. Charting the trend of the average number of contacts investigated per index case can also give an understanding about how effective CI efforts are.
Data on CI coverage will also help countries monitor efforts to initiate eligible contacts on TPT. For example, CI coverage among contacts data can be viewed in conjunction with the number of people with active TB detected among the contacts (contact yield) and the number of eligible contacts put on TPT. Data can also be collected at the subnational level and used to learn from the geographic distribution of contacts. Data should be reported annually at a minimum but semiannual or quarterly reporting will improve the timeliness of data for decision making.