Background Cystic fibrosis patients are predisposed to pulmonary infections. Conditions associated with CF, like underweight, diabetes mellitus (CFRD), liver disease (CFLD) are favouring factors for tuberculosis (TB). The hypothesis of a potential comorbidity of TB in CF children occurred. The aim of the paper was to evaluate the prevalence of TB in children with complicated CF.

Methods Thirty-two patients (pts) with typical CF, associating complication like CFLD(27 pts), diabetes (3 pts) and 2 with both complication were considered for a prospective five years study. Biannual bacteriologic exam (TB specific also) were included, in addition to clinical examination and annual CT, to the patients evaluation.

Results Tuberculosis occurred in 6.25% (2 patients), both F508 del homozygous, with CFLD and poor nutritional status; one patient had also CFRD. His evolution was unfavourable; he developed portal hypertension and died from respiratory failure. The other patient was diagnosed with active TB, Pseudomonas positive and poor nutritional status, but good evolution after treatment. The rest of CFLD patients had a stationary evolution, except 4 of them (15.38%) developed diabetes. Tuberculin skin test was positive in 4 patients (12.5%), 3 of them received TB vaccine. Despite the mandatory vaccination for TB in our country, only 84% pts were vaccinated. 18.75% of patients (6 pts) were considered and treated as TB cases,without bacteriological confirmation, before being diagnosed with CF.

Conclusion Although TB is a frequent condition in our area, the prevalence among CF children is not as high as expected. It is possible that other factors, unknown so far, are implicated.