A TB outbreak at a Cork primary school where 40 people have been infected has exhibited “an extraordinarily high rate of attack” and confounded public health officials who have been unable to identify the source.
In light of the seriousness of the outbreak, the Health Service Executive (HSE) has taken the unusual step of offering a second round of screening of close to 200 pupils who attend Scoil Iósaf Naofa, at Crab Lane, Ballintemple, in the suburbs of Cork city.
This is to cater for the possibility that children who tested negative for TB in the initial round of screening may test positive in a subsequent Mantoux (skin) test.
In a letter to parents on Tuesday, chairwoman of the outbreak control team Dr Margaret O’Sullivan said the situation they are dealing with is rare in terms of the number of people infected and the fact that they have been unable to find the source.
“It is an extremely unusual event in the scientific literature in terms ofpotential source exposure, lack of confirmation of a definitive infectious source and the degree of spread which has been recorded,” Dr O’Sullivan wrote.
The strain of TB has yet to be identified.
Dr O’Sullivan said the school outbreak revealed “an extraordinarily high attack rate in terms of overall numbers of active TB cases and of latent TB infection in the school”.
In total, six children have active or full-blown TB, 31 have latent infection, and three staff have also been diagnosed with latent TB, bringing the overall level of infection to 40.
Latent TB is not infectious and children on treatment for active TB are not infectious, according to their treating paediatricians.
The school remains open, and last night the HSE declined to comment on whether this would continue to be the case. However, Dr O’Sullivan stressed that other children, or staff, or close contacts are not at risk from contact with either the cases of active TB or latent TB.
The HSE did confirm that children who test negative for TB on the second round screening, which commences on the week of September 27, will be offered the BCG vaccine on the same day and will not need to be referred to the BCG vaccination service.
The Department of Public Health has also requested that new junior infant classes at Scoil Iósaf Naofa be prioritised for the vaccine.
This request was made on August 23, but the HSE was last night unable to say if it had been acceded to.
© Irish Examiner Ltd. All rights reserved