Investigators from Trinity College Dublin, the Irish Mycobacteria Reference Laboratory, St. James’s Hospital, and the Department of Public Health HSE East believe tuberculosis (TB) care in Irish Prisons should be supported, considering the findings of their study which is published in the International Journal of Tuberculosis and Lung Disease.

The study describes an investigation into a large outbreak of tuberculosis which occurred in an Irish prison in 2011. This resulted in 34 people contracting active TB from a single infectious case. The use of whole genome sequencing enabled the investigators to track the course of onward transmission, and to link TB cases identified as recently as 2019 to the 2011 outbreak.

The outbreak resulted in litigation costs to the State of more than €5 million euro. The study found that in addition to the active TB cases, 50% of the prison staff tested as close contacts of cases may have developed Latent TB as a result of occupational exposure. This is an asymptomatic, non-infectious form of TB, which may progress to the active form of TB at a future date, in a small number of cases.

“This report demonstrates the power of whole genome sequencing to enhance epidemiological investigations of TB outbreaks over prolonged periods of time,” says Professor Tom Rogers, Clinical Microbiology, Trinity, and formerly Clinical Director, Irish Mycobacteria Reference Laboratory (IMRL) based at St. James’s Hospital. “The IMRL has created a national database of TB genomes which will facilitate future public health investigations of TB in Ireland.”

A PDF version of the paper ‘The largest prison outbreak of TB in Western Europe investigated using whole-genome sequencing‘ is available upon request to [email protected].