Abstract:
Background: Tuberculosis (TB) case finding is an important component of TB control
because it can reduce transmission of Mycobacterium tuberculosis (MTB) through
prompt detection and treatment of infectious patients.
Methods: Using population-based infectious disease surveillance (PBIDS) platforms with
links to health facilities in Kenya we implemented intensified TB case finding in the
community and at the health facilities, as an adjunct to routine passive case finding
conducted by the national TB program. From 2011 to 2014, PBIDS participants ≥15
years were screened either at home or health facilities for possible TB symptoms which
included cough, fever, night sweats or weight loss in the preceding 2 weeks. At home,
participants with possible TB symptoms had expectorated sputum collected. At the
clinic, HIV-infected participants with possible TB symptoms were invited to produce
sputum. Those without HIV but with symptoms lasting 7 days including the visit day had
chest radiographs performed, and had sputum collected if the radiographs were
abnormal. Sputum samples were tested for the presence of MTB using the Xpert
MTB/RIF assay. TB detection rates were calculated per 100,000 persons screened.
Results: Of 11,191 participants aged ≥15 years screened at home at both sites, 2695
(23.9%) reported possible TB symptoms, of whom 2258 (83.8%) produced sputum
specimens. MTB was detected in 32 (1.4%) of the specimens resulting in a detection rate
of 286/100,000 persons screened. At the health facilities, a total of 11,762 person were
screened, 7500 (63.8%) had possible TB symptoms of whom 1282 (17.1%) produced
sputum samples. MTB was detected in 69 (5.4%) of the samples, resulting in an overall
detection rate of 587/100,000 persons screened. The TB detection rate was higher in
persons with HIV compared to those without at both home (HIV-infected - 769/100,000,
HIV-uninfected 141/100,000, rate ratio (RR) - 5.45, 95% CI 3.25-22.37), and health
facilities (HIV-infected 3399/100,000, HIV-uninfected 294/100,000, RR 11.56, 95% CI
6.18-18.44).
Conclusion: Facility-based intensified TB case finding detected more TB cases per the
number of specimens tested and the number of persons screened, including those with
HIV, than home-based TB screening and should be further evaluated to determine its
potential programmatic impact.