Chronic Achromobacter Infections Lead to Worse Cystic Fibrosis Outcomes, Study Shows

The risk of cystic fibrosis patients with chronic Achromobacter infections dying or having to have a lung transplant is twice as high than in patients who don’t have the bacteria, a study indicates.

Researchers published the study, titled “Clinical Outcomes Associated with Achromobacter Species Infection in Patients with Cystic Fibrosis,” in the journal Annals of the American Thoracic Society.

The primary cause of premature death in CF is progressive airway disease caused by recurring infections. The most common bacteria involved are Pseudomonas aeruginosa and Staphylococcus aureus. But in the past few decades, additional species have been discovered in CF patients’ lungs, including Achromobacter species.

In fact, studies have discovered Achromobacter in 3 to 30 percent of CF patients. Little of the research has dealt with the species’ effects on CF patients, however.

So a research team decided to investigate the connection between Achromobacter and CF patient outcomes. The study covered 1,103 patients in Toronto between 1997 and 2014.

Researchers focused on the risk of patients dying or needing a transplant. They grouped patients into three categories: (1) no history of infection, (2) intermittent infections or (3) chronic infections.

They discovered 7.3 percent of patients with an Achromobacter infection. They also found that those with chronic Achromobacter infections were twice as likely to die or need a transplant than those with no history of infection.

The average age of death or a transplant among those with a chronic Achromobacter infection was 21.5 years. It was 29.5 years for patients with intermittent Achromobacter infections, and 30.3 years for those with no history of infection.

Researchers also discovered that pulmonary disease exacerbations were more common in patients with chronic infection, but the results were not significant once they were adjusted for other factors.

Patients with chronic Achromobacter infections also had poorer scores on a measure of lung capacity known as FEV₁%, but their scores did not decrease further after they developed the chronic infection.

Because neither pulmonary exacerbations nor lung function worsened with a chronic Achromobacter infection, the team hypothesized that other factors are playing a role in patients’ higher death rates.

While the study demonstrated that patients with chronic Achromobacter infections are at higher risk of dying or needing a transplant, it failed to answer the question of whether the infections occur in sicker patients or whether infections contribute to more severe lung disease.

To answer this question, the team called for a study of whether the use of anti-microbial drugs to treat the infections can change patient outcomes.