Incidence of TB by country of origin - Estrie region

The identification and treatment of latent tuberculosis infection (LTBI)
among immigrants from high-incidence regions who move to low-incidence
countries is generally considered an ineffective strategy because only
≈14% of them comply with the multiple steps of the ‘cascade of care’ and
complete treatment. In the Estrie region of Canada, a refugee clinic was
opened in 2009. One of its goals is LTBI management. Between 2009-2020,
5131 refugees were evaluated. To determine the efficacy and benefit-cost
ratio of this intervention, records of refugees seen in 2010-14 (n=1906)
and 2018-19 (n=1638) were reviewed. Cases of tuberculosis (TB) among our
foreign-born population occurring before (1997-2008) and after (2009-2020)
setting up the clinic were identified. All costs associated with TB or
LTBI were measured. Out of 441 patients offered LTBI treatment, 374 (85%)
were compliant. Adding other losses, overall compliance was 69%. To
prevent one case of TB, 95.1 individuals had to be screened and 11.9
treated, at a cost of $16,056. After discounting, each case of TB averted
represented $32,631, for a benefit-cost ratio of 2.03. Among nationals of
the 20 countries where refugees came from, incidence of TB decreased from
68.2 (1997-2008) to 26.3 per 100,000 person-years (2009-2020). Incidence
among persons from high-incidence countries not targeted by the
intervention did not change (12.4 vs 12.8 per 100,000) Among refugees
settling in our region, 69% completed the LTBI cascade of care, leading to
a 61% reduction in TB incidence. This intervention was cost-beneficial.
Key factors for this satisfactory compliance included: close collaboration
with community organizations, its integration within a comprehensive
package of medical care for the whole family, its delivery shortly after
arrival, shorter rifampicin-based treatment, and risk-based selection of
patients to be treated. Management of LTBI among migrants should not be
considered a lost cause.