Changes in TB contact tracing during the COVID-19 pandemic. An Irish single centre experience

Abstract Contact tracing following the diagnosis of tuberculosis (TB) is a crucial process in the identification and treatment of both secondary TB cases and also infected contacts who may require treatment for latent TB infection. During the COVID-19 pandemic, Public Health and Respiratory teams in the St Vincent’s University Hospital (SVUH) TB clinic in Dublin, Ireland, noted anecdotally that there appeared to be fewer contacts screened by public health services per index active TB case identified. To investigate this, we performed a retrospective review of the TB contact tracing service in SVUH, examining and comparing contact tracing of active TB cases in the 3 years prior to the pandemic (2017-2019) and four years thereafter (2020-2023). Results from 2017-2019 calendar years, prior to the COVID-19 pandemic noted an average of 4.77 contacts per index TB case (total 107 index cases and 510 contacts). In comparison, our data from 2020-2022 noted an average of 3.03 contacts per index TB case (total 59 index cases and 179 contacts). As pandemic restrictions were lifted again, we found our 2023 data to be more comparable to that of pre-pandemic times, noting 4.54 contacts per index case (total 22 index cases and 100 contacts). The reduction in TB contacts per index cases noted during the COVID-19 pandemic may reflect work and lifestyle changes over that time, particularly an increase in remote work but also social distancing. It is interesting that as the population emerged from the isolation measures of the pandemic, contact numbers returned quickly to pre-pandemic levels. In line with global concerns, our data highlights the ongoing workload of TB contact tracing locally and the importance of resource allocation for these services. Key messages • Our Irish centre experienced a notable but temporary reduction in contacts requiring screening by public health services, per index active TB case, during the COVID-19 pandemic. • In line with global concerns, our data highlights the ongoing workload of TB contact tracing locally and the importance of resource allocation for these services.