LTBEx – a new model for management of TB incidents in metropolitan areas

London TB Extended contact tracing (LTBEx) pilot project works with local HPTs and TB Services in order to enhance the coordination, and timely and complete follow up of contact investigation for TB incidents in congregate settings, by improving collaboration with clinical and diagnostic services for contacts of TB cases and supporting mass screening exercises, where possible. Specific objectives are:

1). To develop, share and use consistent criteria across London for declaring a TB incident

2). To develop, share and implement a consistent approach to risk assessment of TB cases and TB incidents (1.6.3 in NICE NG33).

3). To work with HPTs and TB services to ensure appropriate management of TB incidents through:

• Identifying at risk contacts

• Supporting the NHS with screening of contacts where necessary (e.g. gathering details of the contacts, inviting them for screening and performing TST and/or phlebotomy) NICE recommendations 1.6.1.2 - 1.6.1.5).

• Collecting and collating screening outcome results, including number of contacts identified & screened, identified cases of latent and active TB

• Providing local HPTs and other stakeholders with data on incident screening outcomes

4). To provide support for extended screening following cluster investigation

5). To inform future London and national policies for the management of TB incidents and outbreaks by providing robust evidence

6). To strengthen the pathway of communication between the PHE and the NHS.

7). To include within this service a robust centralized contact screening database where information on risk assessment of TB incidents, contacts identified, screening method used and outcome of screening is collated and analysed.

8). To monitor and evaluate the effectiveness and efficiency of LTBEx by analysing systematically collected data and develop recommendations for improvement of the service identified by the evaluation.

9). Where support is provided by LTBEx to NHS TB services (e.g. admin support, screening support, follow up of DNA contacts) a summary report of activities to be provided to the local HPTs and NHS services. This report can then be used to inform local commissioners of this service provision and the resources needed to continue it into the future.

10). To use the collected data on contact screening and evidence emerging from screening of specific subgroups. Additionally, to make appropriate recommendations on implementation of NICE guidance on screening of contacts

In 2014, 2,572 cases of tuberculosis were reported among London residents, a rate of 30.1 per 100,000 population and the largest share of cases (39.4%) amongst English regions. TB contact tracing is an important element of TB control and NICE recommends those who had close and prolonged contact with cases of infectious TB should be offered screening (Recommendation 1.2.1.1). Where significant TB exposure occurs outside of household, for example at a school, workplace or healthcare setting, it is called a TB incident.

Prior to the launch of LTBEx project in January 2013, TB incidents were managed by the 4 HPTs and approximately 30 TB clinics in London.

There were some shortcomings and gaps including:

• Variations in risk assessment and contact screening: The execution of the contact tracing and screening process was subject to wide variation, depending on the interpretation of national guidance, personal judgements and availability of resources.

• Geographical boundaries: Local TB services are restricted by geographical boundaries, and some only provide contact screening for the areas that they cover. However contacts of the same case may often live across a wider area, and would generally need to be referred to different TB clinics in the areas where they live. This had resulted in contacts being assessed and screened differently, depending on their area of residence and follow up of screening outcomes becoming more difficult and time consuming.

• Difficulties in arranging on-site screening: Due to considerable pressure to manage their case load, or contractual restrictions, it had not always been possible for clinics to offer on-site screening, or for screening to be arranged in a timely manner. Where on-site screening was not possible, contacts would have been referred to their local clinics.

• Poor uptake of screening: contacts referred to TB clinics are less likely to attend compared to those who are offered on-site screening. This could be due to having to negotiate time off work or school, fear of hospital or not being able to afford the transport. On site screening overcomes these barriers and is particularly important for children, young people and other vulnerable groups as it offers screening in a familiar environment with support from those they know and trust.

The idea for LTBEx was first developed and proposed in 2010 and was recommended in a London TB needs assessment. The proposal’s aim was to improve contact tracing which is in line with NICE guidance recommendations 1.8.2.5 and 1.6.1.2. However, there were many challenges to implement the proposal, including agreement on funding, clinical governance structure, supervision of projects and receiving support from London HPTs and TB services. 

In 2012, the Health Protection Agency (HPA) Development Fund awarded funding to start the LTBEx pilot project, with supervision by the HPA London Regional Office. The funding and supervision was subsequently provided by Public Health England, London Region. The multidisciplinary team has been recruited, trained and developed skills in clinical and public health TB care. HPTs and TB clinics were consulted throughout the process and were invited to join the advisory group. One of the biggest challenges faced by LTBEx when it was launched was working with 4 different health protection and over 30 TB Services, each team often having different ways of doing things and some adverse to change. However, LTBEx has created an adaptive model to work in partnership with HPTs and TB Services and gradually introduce a more standardised and consistent approach based on NICE and other national guidelines.

The LTBEx produced a suite of materials for TB incident risk assessment and communication with TB services and those offered screening. Another main challenge for the LTBEx team is lack of a clinical governance to allow the team to work independently. We therefore arranged for honorary contracts for the clinical team members and we always work with at least one TB nurse from the local TB Services.

The LTBEx team created a unique database for TB incident contacts, which records details of exposure to the index case, medical and social risk factors for TB, screening methods and results for each contact. This information would allow assessment of TB screening exercise compared to NICE and other national guidelines and provide evidence on effectiveness of screening. The cost of the project is mainly towards staff salaries, training and work-related staff expenses, such as travel.

Since January 2013 LTBEx has responded to 117 TB incidents of which 78 screening completed, 4 screening is planned and 35 did not require screening or support from LTBEx. The LTBEx is currently undergoing formal evaluation by an independent team at an academic centre. Provisional LTBEx data and a comparison with a previous audit show the following benefits:

• LTBEx has improved the overall uptake of screening from 50% to 73%, with LTBEx on-site screening showing an even higher uptake of 80%. This is due to convenience for service users as the screening is offered at their place of work or education or other venues they frequently visit.
• LTBEx has improved patients experiences, by providing timely and effective onsite screening. This has removed some of the barriers that prevent patients accessing healthcare, such as having to negotiate time off work or school, or not being able to afford the transport. This demonstrates implementation of recommendation 1.7.1.6 in NICE guidance.
• Onsite screening is particularly important where screening of children and young people is required, as they can be screened in a familiar environment, with the additional support of family or staff who they know and trust.
• Onsite screening offers the opportunity for awareness raising activities and health promotion. In addition to written information, the team offers question and answer sessions or school assemblies to address the potential misconceptions around TB or the stigma sometimes associated with it.
• Of 1494 contacts, 15 (1%) were diagnosed with active TB and 203 (13.6%) with latent TB infection, giving an overall yield of 14.6% (218/1494). This is comparable to other TB screenings such as household and close contact screening carried out by TB clinics.
• Of the contacts identified by LTBEx, only 40.9% were resident in the same borough as the incident location, while 44.0% lived in another London borough and 15.1% lived elsewhere. Screening exercises carried out by LTBEx have been able to overcome cross-boundary issues, remove the necessity for complicated and time-consuming referrals between London clinics, and thereby improve the efficiency of screening pathways and overall screening uptake rates.
• The LTBEx contact database is the first database in the UK that systematically collect demographic and clinical information on TB contacts. This unique dataset will influence evidence-based TB contact tracing. LTBEx is well received by stakeholders and the feedback.

Funding for a cross-boundary project which combines public health and clinical work has been the biggest challenge for the project as there are no clear commissioning pathways. The new NHS 5 year Forward View might provide an opportunity for similar projects to overcome these issues.

There are many stakeholders involved in projects like and their support is essential to ensure the success of the project. LTBEx stakeholders include TB Services, Health Protection Teams, TB Control Board and Clinical Commissioning Groups. Regular updates and feedback to stakeholders are vital in maintaining their support and interest.