Feasibility study of the prevalence of latent tuberculosis infection for Māori in the Waikato region, Aotearoa New Zealand

Abstract

Objective: This study aimed to assess the feasibility of conducting a representative tuberculin skin test (TST) survey for Māori in Aotearoa New Zealand and to estimate the prevalence of latent tuberculosis (TB) infection. Methods: Participants were Māori in the Waikato region, recruited by a Māori nurse, through: 1) random household selection from the Electoral Roll; 2) randomly selected prison inmates; and 3) community and health settings. A TB history and symptoms questionnaire was completed, TST performed and investigation of those with TST induration ≥10mm. Results: Random household selection was resource intensive and only contributed 14 participants. Repeated random selection of prison lists were required to recruit 207 participants and there were no positive TST cases. Community and health settings yielded the highest participation (n=370) and the three people (0.5%) with TST ≥10mm. Age ≥45 years and history of contact with a TB case were associated with TST induration ≥5mm (n=39; 6.6%). Conclusions: The community and health settings were the only feasible options for recruitment. The overall prevalence of a positive TST in the study population was low. A 5mm cut-off may be best to maximise sensitivity for future studies. Implications for public health: A mixture of sample selection processes that are more targeted are needed to identify Māori with latent TB infection.