A large TB outbreak of Beijing sub-lineage in a remand prison; recommendations to prevent recurrence in this vulnerable population Outbreak investigation details, whole genome sequencing results, recommendations based on this experience

In March 2011, Department of Public Health East in Ireland were notified of two cases of tuberculosis (TB), in two prisoners sharing a cell. We define the resulting outbreak and highlight the role of public health and laboratory-based molecular epidemiology in mapping and control of a prison outbreak. Cases were identified through clinical presentation, contact tracing, case-finding exercise or enhanced laboratory surveillance. Mycobacterium tuberculosis isolates were genotyped and underwent whole genome sequencing (WGS). Thirty-four cases of TB were linked to the outbreak: 27 prisoners (79%), 4 prison officers (12%) and 3 community cases (9%). M. tuberculosis was isolated from 31 cases (culture positivity 91%). A maximum of six single nucleotide polymorphisms separated the isolates, with 22 being identical; suggestive of a highly infectious 'super-spreader' within the prison. Isolates belonged to Beijing sub-lineage and were susceptible to first-line anti-tuberculous agents. A case-finding exercise incidentally detected a prisoner with multidrug-resistant TB. Of 143 prison officers screened, 52% had latent TB infection. Litigation costs exceeded five million euros. This constitutes the largest prison outbreak of TB in Western Europe investigated using WGS. A robust prison entry TB screening and education programme is required to effect better TB control, prevent future outbreaks, and attendant litigation.