The Evaluation of Novel Approaches to TB Case Ascertainment and Management

Dr Martin Dedicoat PhDMrs Cathy Browne RGNPresented by Dr Christine Burt PhD

Trend in TB incidence in Birmingham and London 1990 - 2009

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Introduction- 70% of TB cases in Birmingham - people born overseas

- Each new case is reported to the Birmingham Chest Clinic

- Each new case of TB is allocated to a specialist nurse

- To improve the number of contacts identified for each new case of TB a service evaluation and improvement programme was undertaken by the Birmingham and Solihull TB service

- One of the aims of the evaluation was to use social network analysis to investigate clusters of TB patients

- This report contains preliminary results for the project

MethodsNew cases

Evaluation of the number of notifications and the outcome of their contacts was made by analysing anonymous data

Local database

National database

MethodsContact Tracing:

Extra Pulmonary TB – screening = close family only

Respiratory TB – screening = close family

>10% = active/latent TB wider screening

This method of contact tracing is known as ‘Stone in the Pond’ tracing

Methods continued

- Cluster definition and action taken is based on HPA guidance

- Conventional approaches to contact screening may miss cases

- Samples cultured and isolates typed using variable number tandem repeats (VNTR) of 24 loci

- Samples from all cases are sent to the HPA Labs for culture

- These 24 loci VNTR are used to identify clusters of TB patients

Methods continued

Many clusters have obvious links between different casesoften no link is found

Data from these interviews was used to construct network diagrams to illustrate links

In these cases a specialist nurse was tasked to visit and interview patients

Results- Between 1990 and 2012 = 43,968 contacts of TB

- 22,191 (50.5%) females mean age = 25

- Overall 42% did not complete their screening

- Outcomes were available for 92% of cases

- 20,759 (49.5%) males mean age = 19

- The proportion of smear positive contacts receiving chemoprophylaxix rose from 4.3% to 9.4%

Results continued- Clusters for further investigation were identified based on

several factors:

Links between patients were not known

- To date 15 clusters have been investigated

The cluster was growing

Pulmonary TB, smear positive Pulmonary TB, smear negative Non-pulmonary TB Latent TB No evidence of TB Failed to complete contact tracing Outcome unknown/pending

White British Recent migrant, 5 or less years in the UK Migrant, 6 or more years in the UK UK-born ethnic minority Status unknown/pending

Household contact Close contact Casual contact Epidemiological link, but typing link

not proven or available

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ConclusionAnalysis of the contact database revealed 42% of peopleIdentified as contacts

TB nursing team taking a more proactive approach in follow up:

The impact of this change will be assessed after one year

- Patents with latent TB who do not complete treatment

- Patients who start screening but do not complete it

Conclusion continued- Using the social network questionnaire a cluster of Eritrean

patients were found attending a single place of worship

- More still needs to be done

- An enhanced contact tracing service may contribute to reducing the incidence of TB in Birmingham

- More specific methods are becoming available

Acknowledgements

TB nurses investigating the clusters and managing patients

This service evaluation is funded by Heart of Birmingham Primary Care Trust

Health Protection Agency – Dr Grace Smith and Dr Jason Evans

The health protection unit in Birmingham - Helen Bagnall