A new European study indicates the financial burden and mortality associated with non-tuberculosis mycobacterium pulmonary disease (NTM-PD) is higher than previously suspected.

The study reporting the findings, “Burden of non-tuberculous mycobacterial lung disease in Germany,” was recently published in the European Respiratory Journal.

NTM-PD is a relatively uncommon bacterial infection caused by mycobacteria — a ubiquitous bacteria often found in soil and water. There are over 150 subtypes of non-tuberculosis mycobacterium with mycobacterium avid complex (MAC) being the most common cause of NTM-PD worldwide.

The global incidence, hospitalization rate, and mortality associated with NTM-PD has been increasing, particularly in susceptible individuals, such as those with immunosuppression or with predisposing chronic pulmonary conditions like chronic obstructive pulmonary disease (COPD) or bronchiectasis.

Because symptoms can be similar to those found in patients with chronic lung conditions, the diagnosis of NTM-PD is often difficult and may be delayed until patients are severely ill.

To further investigate the cost and mortality associated with NTM-PD infections, researchers compared 125 patients with newly diagnosed NTM-PD against 1,250 control patients over 39 months.

The study revealed that all-cause mortality was four times higher in the NTM-PD group compared to controls. And, all-cause mortality in patients who had both COPD and NTM-PD was 41% compared to only 15% in patients who had COPD only.

The study also found that healthcare costs were almost four times higher in the NTM-PD group compared to the control group. Most of the increased cost was attributed to hospitalizations, which alone were three times higher in the NTM-PD group.

Additionally, researchers found a high degree of variability in terms of treatment of NTM-PD infections. A total of 29 different drug combinations were observed throughout the study with only 54% of patients receiving antibiotics when they were diagnosed and 26% never receiving antibiotics at all.

“Although NTM-PD is considered rare, these findings highlight that the burden of the disease is high,” Dr. Michael Loebinger of the Royal Brompton Hospital in London, the study’s author, said in a press release. “Treatment can be hard to tolerate and may be unsuccessful, making treatment decisions complex. To help with this challenge, the British Thoracic Society will be releasing new guidelines this year.”