Risk factors for Mycobacterium abscessus infection in cystic fibrosis patients; a case-control study.

Mycobacterium abscessus is a nontuberculous mycobacterium that is increasingly recognized as an opportunistic pathogen in cystic fibrosis (CF) patients. Factors that predispose CF patients to infection by this environmental bacterium remain unknown. In a case-control study of 22 CF patients with M. abscessus infection and 22 CF controls, we investigated risk factors for MAB infection as well as the positioning of MAB infection in relation to the other pathogens infecting CF patients. No clear risk factors were found; steroid treatment and CF related diabetes were equally common among cases and controls. M. abscessus disease affects CF patients of varying age, lung function and co-morbidities. Antimicrobial maintenance therapy did not prevent M. abscessus infection. A history of Stenotrophomonas maltophilia infection was significantly more frequent among cases than among controls and there may be a relation with Aspergillus fumigatus infection, or both may be signs of advanced lung damage that predisposes to MAB disease. The absence of clear risk factors and the omnipresence of MAB in the environment suggest that MAB infection in CF patients is a random event. Its symptoms and impact on lung function seem to warrant treatment.