Non-tuberculous mycobacteria are environmental organisms, distinct from the bacteria that cause tuberculosis and leprosy, that lurk in soil and municipal water systems. Several species are pathogenic to humans, and the most clinically prominent culprits include Mycobacterium avium complex, Mycobacterium abscessus, and Mycobacterium kansasii. When these organisms colonize damaged or vulnerable lungs, they can trigger a chronic pulmonary disease marked by persistent cough, fatigue, and progressive lung damage. Unlike tuberculosis, NTM infections are not spread from person to person, but they are exceptionally hard to eradicate: treatment regimens are long, success rates are often disappointing, and recurrence is frequent even after sputum cultures convert to negative.

The research team, led by investigators at The University of Texas at Tyler in collaboration with Vanderbilt University Medical Center, used the Texas Hospital Inpatient Discharge Public Use Data set as a proxy for disease burden. Because NTM pulmonary disease is not a reportable condition and diagnosis requires a complex combination of clinical symptoms, radiographic findings, and microbiological confirmation, large-scale surveillance is nearly impossible without administrative data. The researchers screened discharge records using ICD-10-CM codes A31.0, A31.2, A31.8, and A31.9, which capture pulmonary mycobacterial infection, disseminated Mycobacterium avium-intracellulare complex disease, and other or unspecified mycobacterial infections. The team acknowledged that this coding approach may include some non-pulmonary or non-specific NTM diagnoses, but argued that proxy-based studies are the most practical way to estimate the statewide disease burden.

The headline numbers are striking. Out of 23.33 million hospital discharge records analyzed across the eight-year window, the NTM diagnosis-coded inpatient discharge rate in Texas averaged 59.9 per 100,000 records, with an annual range of 46.1 to 62.6. The rate dipped in 2020 and 2021, a pattern the authors speculate may reflect disruptions in hospital utilization during the COVID-19 pandemic, before rebounding in subsequent years. Female patients consistently accounted for more than half of the NTM-coded discharges, comprising 46.2 percent of cases overall once masked gender records were accounted for. Among female patients with identifiable race data, 77.0 percent were Caucasian, reinforcing a well-documented demographic pattern in which middle-aged to elderly Caucasian women without a history of smoking or obvious risk factors constitute a large share of NTM pulmonary disease patients.

Age emerged as a dominant risk factor. Among the NTM-coded discharges, 3.3 percent of patients were aged 0 to 17 years, 19.5 percent were 18 to 44 years, 29.5 percent were 45 to 64 years, and 47.7 percent were 65 years or older. Within specific age bands, the female predominance was even more pronounced: women accounted for 48.6 percent of cases in the 65-to-74-year group and 67.2 percent in the 75-and-older group. The study also found that 70.3 percent of NTM cases in the 18-to-44-year age group were female, a figure that may reflect the higher proportion of female discharges in that age bracket overall. The authors note that because gender was masked or unknown for 2,204 of the 12,587 NTM-coded records, the true distribution may differ from what the data show.

Perhaps the most consequential finding is the stark regional variation within the state. The Gulf Coast region, comprising 13 counties and home to roughly 7.3 million people, recorded 4,203 NTM-coded discharges over the study period, with a regional rate of 74.4 per 100,000 records. Northeast Texas, a 35-county area with a population of approximately 1.6 million, logged 815 cases at a rate of 55.5 per 100,000. The Gulf Coast figure is notably higher than the statewide average, and the racial composition of female NTM patients also differed: 91.2 percent of female NTM patients in Northeast Texas were Caucasian, compared with 71.0 percent in the Gulf Coast region and 77.0 percent statewide. These patterns echo earlier national work, including a study by Spaulding and colleagues that documented geographic variation in NTM species distribution across the United States between 2009 and 2013, with Mycobacterium avium complex accounting for up to 61 percent of isolates in the West South Central region that includes Texas.

Mortality data add a sobering dimension to the picture. A total of 692 in-hospital deaths occurred among the NTM-coded discharges, representing 5.5 percent of all NTM cases over the eight years. Death rates climbed with age, reaching 6.18 percent in the 65-to-74-year group and 6.22 percent in the 75-and-older group. Male patients with NTM-coded discharges had a higher in-hospital mortality rate than female patients, at 6.44 percent versus 4.59 percent. The study found no statistically significant association between NTM pulmonary disease and length of hospital stay overall, though patients who died had a mean stay of 21.0 days compared with 11.4 days for those who survived, a difference the authors attribute to the severity of illness in the decedent group rather than to NTM disease itself.

The healthcare utilization patterns also carry policy implications. Among NTM-coded patients, 5,102 were covered under Medicare Part A and 1,521 were on Medicaid, reflecting the age distribution of the disease and its concentration among older adults. The authors note that while these figures underscore the financial weight of NTM disease on public insurance programs, the burden they measured was not as high as that reported in a previous Medicare-based study, which found that annual prevalence among beneficiaries increased roughly 2.5-fold between 1997 and 2007. The discrepancy likely reflects differences in methodology, population, and the inherent limitations of using discharge codes rather than confirmed clinical diagnoses.

Those limitations are substantial and the authors are candid about them. The data capture only hospitalized patients, whereas most NTM pulmonary disease is diagnosed and managed in outpatient settings, meaning the true community burden is almost certainly higher than what inpatient records suggest. The de-identified dataset prevented the researchers from identifying multiple hospitalizations for the same patient, so a single individual could appear multiple times in a given year, potentially inflating the case counts. The absence of microbiological information means the study cannot determine which NTM species dominate in Texas or whether the species profile differs between Northeast Texas and the Gulf Coast. Nor could the researchers examine comorbidities such as bronchiectasis or chronic obstructive pulmonary disease, which are known to accelerate disease progression in NTM patients.

Despite these caveats, the study delivers a clear message: NTM pulmonary disease is a significant and geographically uneven burden in Texas, concentrated among elderly Caucasian women in certain regions, and it imposes measurable costs on the healthcare system through hospitalizations and deaths. The authors call for further studies to systematically define the actual prevalence of NTM disease in non-hospitalized populations, to identify environmental exposures and host risk factors that drive susceptibility, and to clarify whether the dominant mycobacterial species differ across the state. As awareness of this emerging public health challenge grows, the Texas data provide a template for how administrative datasets can be harnessed to map the contours of a disease that has long flown under the surveillance radar.

Subject of Research: Epidemiology of non-tuberculous mycobacterial pulmonary disease in Texas using hospital discharge data

Article Title: Non-tuberculous mycobacteria pulmonary disease in Texas: an analysis of 8 years of hospital discharge data

Article References: Baham, A., Pasipanodya, J. G., Mehta, D., McBride, S., & Srivastava, S. (2026). Non-tuberculous mycobacteria pulmonary disease in Texas: an analysis of 8 years of hospital discharge data. Frontiers in Tuberculosis, 4, Article 1740382. https://doi.org/10.3389/ftubr.2026.1740382

Image Credits: AI Generated

DOI: 10.3389/ftubr.2026.1740382

Keywords: non-tuberculous mycobacteria, NTM pulmonary disease, Texas, hospital discharge data, epidemiology, Mycobacterium avium complex, healthcare utilization, regional variation, elderly women, in-hospital mortality, ICD-10-CM codes, public health surveillance