Extending 'Contact Tracing' into the Community within a 50-Metre Radius of an Index Tuberculosis Patient Using Xpert MTB/RIF in Urban, Pakistan: Did It Increase Case Detection?

PLoS One. 2016 Nov 29;11(11):e0165813. doi: 10.1371/journal.pone.0165813. eCollection 2016.

Abstract

Background: Currently, only 62% of incident tuberculosis (TB) cases are reported to the national programme in Pakistan. Several innovative interventions are being recommended to detect the remaining 'missed' TB cases. One such intervention involved expanding contact investigation to the community using the Xpert MTB/RIF test.

Methods: This was a before and after intervention study involving retrospective record review. Passive case finding and household contact investigation was routinely done in the pre-intervention period July 2011-June 2013. Four districts with a high concentration of slums were selected as intervention areas; Lahore, Rawalpindi, Faisalabad and Islamabad. Here, in the intervention period, July 2013-June 2015, contact investigation beyond household was conducted: all people staying within a radius of 50 metres (using Geographical Information System) from the household of smear positive TB patients were screened for tuberculosis. Those with presumptive TB were investigated using smear microscopy and the Xpert MTB/RIF test was performed on smear negative patients. All the diagnosed TB patients were linked to TB treatment and care.

Results: A total of 783043 contacts were screened for tuberculosis: 23741(3.0%) presumptive TB patients were identified of whom, 4710 (19.8%) all forms and 4084(17.2%) bacteriologically confirmed TB patients were detected. The contribution of Xpert MTB/RIF to bacteriologically confirmed TB patients was 7.6%. The yield among investigated presumptive child TB patients was 5.1%. The overall yield of all forms TB patients among investigated was 22.3% among household and 19.1% in close community. The intervention contributed an increase of case detection of bacteriologically confirmed tuberculosis by 6.8% and all forms TB patients by 7.9%.

Conclusion: Community contact investigation beyond household not only detected additional TB patients but also increased TB case detection. However, further long term assessments and cost-effectiveness studies are required before national scale-up.

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Contact Tracing / methods*
  • Female
  • Geography
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Outcome Assessment, Health Care*
  • Pakistan / epidemiology
  • Retrospective Studies
  • Tuberculosis / diagnosis*
  • Tuberculosis / epidemiology*

Grants and funding

Mott MacDonald was contracted by Stop TB to provide independent monitoring and evaluation of TB REACH projects. Robert Stevens receives a salary from Mott MacDonald. We gratefully acknowledge the support from the TB REACH secretariat of Stop TB Partnership for funding the study and the Provincial TB Control Programme Pakistan. The specific roles of these authors are articulated in the ‘author contributions’ section. Mott MacDonald contributed professional services and opinion independently of the funder, Stop TB and the grantee, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.