Abstract
Background We aimed to evaluate the effectiveness of contact investigation in comparison to passive case-detection alone and estimated the yield of co-prevalent and incident tuberculosis (TB), and latent tuberculosis infection (LTBI) among contacts of patients with TB.
Methods A systematic search was undertaken of studies published between January 1, 2011 and October 1, 2019 in the English language. The proportion of contacts diagnosed with co-prevalent TB, incident TB and/or LTBI was estimated. Evaluation of the effectiveness of contact investigation included randomised trials, while the yield of contact investigation (co-prevalent and incident TB and LTBI) was assessed in non-randomised studies.
Results Data were extracted from 244 studies, of which 187 studies measured the proportion of contacts diagnosed with TB disease and 135 studies measured LTBI prevalence. Individual randomised trials demonstrated that contact investigation increased TB case notification (RR 2.5 [95% CI: 2.0–3.2]), TB case detection (OR 1.34 [95% CI: 0.43–4.24]) and decreased mortality (RR 0.6 [95% CI: 0.4–0.8]) and population TB prevalence (risk ratio 0.82 [95% CI: 0.64–1.04]).
The overall pooled prevalence of TB was 3.6% (95% CI: 3.3–4.0%; I2=98.9%, 181 studies). The pooled prevalence of microbiologically-confirmed TB was 3.2% (95% CI: 2.6–3.7%; I2=99.5%, 106 studies). The pooled incidence of TB was highest in the first year after exposure to index patients (2.0%, 95% CI: 1.1–3.3%; I2=96.2%, 14 studies) and substantially lower five years after exposure to index patient (0.5%, 95% CI: 0.3–0.9%; 1 study). The pooled prevalence of LTBI among contacts was 42.4% (95% CI: 38.5–46.4%; I2=99.8%, 135 studies).
Conclusions and Relevance This systematic review and meta-analysis found that contact investigation was effective in high-burden settings. The higher pooled prevalence estimates of microbiologically-confirmed TB compared to previous reviews suggests newer rapid molecular diagnostics contribute to increased case detection.
Footnotes
This manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.
Conflict of interest: Dr. Velen has nothing to disclose.
Conflict of interest: Dr. Shingde has nothing to disclose.
Conflict of interest: Dr. Ho has nothing to disclose.
Conflict of interest: Dr. Fox has nothing to disclose.
- Received January 28, 2021.
- Accepted April 29, 2021.
- Copyright ©The authors 2021. For reproduction rights and permissions contact permissions{at}ersnet.org