Systematic review of latent tuberculosis infection research to inform programmatic management in Ireland

Abstract

The World Health Organisation (WHO) End Tuberculosis (TB) Strategy and the WHO Framework Towards Tuberculosis Elimination in Low Incidence Countries state that latent tuberculosis infection (LTBI) screening and treatment in selected high-risk groups is a priority action to eliminate TB. The European Centre for Disease Prevention and Control (ECDC) advises that this should be done through high-quality programmatic management, which they describe as having six key components. The research aim was to systematically review the literature to identify what is known about the epidemiology of LTBI and the uptake and completion of LTBI screening and treatment in Ireland to inform the programmatic management of LTBI nationally. A systematic literature review was performed according to a review protocol and reported in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Twenty-eight studies were eligible for inclusion and described LTBI screening or treatment performed in one of five contexts, pre-biologic or other immunosuppression screening, people living with HIV, TB case contacts, other vulnerable populations, or healthcare workers. The risk of bias across studies with regard to prevalence of LTBI was generally high. One study reported a complete cascade of LTBI care from screening initiation to treatment completion. This systematic review has described what published research there is on the epidemiology and cascade of LTBI care in Ireland and identified knowledge gaps. A strategy for addressing these knowledge gaps has been proposed.

Evaluating the Quality of Latent Tuberculosis Infection Screening in Ireland: A Single-Centre Retrospective Cohort Study

“…The absolute number of patients tested using an IGRA (n = 1507), screened for LTBI using an IGRA (n = 1215), and subsequently treated for LTBI to completion (n = 27) over a three-year period was small, given that the population of the tertiary hospital catchment area is over 287,000 [33]. The prevalence of LTBI among the entire cohort was only 4%, consistent with that reported among patients screened due to immunosuppressive treatment use in other centres in Ireland [11]. Individually, the patients treated for LTBI had their risk of TB reduced because it is known to be highly effective [7,8].…”

“…The strengths of this study are that it included patients screened over three years. Although the sample size was small, it is larger than that of most previous similar studies conducted in Ireland [11]. This study has several limitations.…”

“…Other indications for LTBI treatment according to the Guidelines for the Prevention and Control of Tuberculosis 2010 [34], such as being from a country with a high incidence of TB, being homeless, or being a person who uses intravenous drugs were infrequent or did not feature at all among the indications for screening in this study, suggesting that these cohorts are not being screened for LTBI in this tertiary centre. Although there are few prevalence studies among such risk groups in Ireland [11], in England, IGRA positivity during programmatic screening was observed in 32% of immigrants from high-incidence countries, a group that contributed disproportionately to the national TB burden [14]. The TB service in this tertiary centre should expand screening to groups with a higher prevalence of LTBI, but it is unclear which population groups, and national guidance is lacking in this area.…”

“…Where deficits in screening quality are identified, health care providers can engage with their patients to understand why, and service quality can be improved. In Ireland, evaluations of LTBI screening are lacking across all at-risk groups, even at a local level [11]. There is a need for LTBI screening evaluations to be performed at service and national levels in Ireland.…”

Delayed Tuberculosis Treatment and Cost of Care in a Low-Incidence Country

“…Despite most patients in this evaluation having a risk factor for TB, few had a documented history of being screened for LTBI. This suggests that TB prevention should be improved, but guidance and support for TB services on programmatic LTBI management in Ireland are lacking [ 38 ]. This study adds to the literature on TB care in low-incidence countries where delays in treating TB are a well-recognized challenge [ 21–23 ], which has also been reported in other studies in Ireland [ 8 , 9 ].…”