An investigation is under way after a "cluster" of tuberculosis (TB) cases were identified among men at a Welsh prison.
Public Health Wales (PHW) has confirmed there were four cases of the potentially fatal condition in men held at HMP Parc in Bridgend over the last nine months.
The NHS trust said it was now working closely with Cwm Taf Morgannwg University Health Board , HMP Parc, and Her Majesty’s Prison & Probation Service to investigate the matter further.
Screening sessions will take place in January for prisoners, staff, and visitors who were in closest contact with those diagnosed.
Siôn Lingard, consultant in health protection at Public Health Wales, said: "TB is difficult to catch and requires close and prolonged contact with an infectious individual for a person to become infected.
"Nevertheless, due to some prison staff being in close contact with prisoners with TB, we will be screening staff at the prison early in the new year.
"We regret any concern that this causes but it is obviously important that any cases of TB are identified and treated.
"The infection can be treated with antibiotics and complete cure is possible in most instances."
Public Health Wales added the men diagnosed with TB have responded well to treatment.
No outbreak has been declared at this time but the situation is being kept under active review.
TB is an infection usually affecting the lungs but any part of the body can be affected.
Anyone can catch TB by breathing in the bacteria in tiny droplets sneezed or coughed out by someone who has TB in their lungs. But this requires prolonged and close contact.
The most common symptom of TB in adults is a persistent cough. Other symptoms can include weight loss, a high temperature, and sweating, particularly at night.
Anyone who is concerned about their health should speak to their GP or contact NHS Direct Wales on 0845 46 47.
More information on tuberculosis is available from the Public Health Wales website at http://www.wales.nhs.uk/sitesplus/888/page/43877
