The epidemiology of nontuberculous mycobacteria (NTM) infections is not well described. In this study, we determined the incidence and prevalence of NTM infections and focused on social risk factors. Additionally, we described persons suffering from pulmonary and extrapulmonary NTM. What is the incidence and prevalence of NTM and what are the characteristics of the affected patients? This is a nationwide retrospective register-based cohort study in Denmark. Adult patients with NTM diagnosis in the Danish national registers from 2000-2017 were classified as having either pulmonary or extrapulmonary NTM disease. We identified 1,146 adults with an NTM diagnosis. 661 patients had pulmonary NTM of which 50.4% were male, while 485 had extrapulmonary NTM of which 59.6% were male. The median age (Interquartile range), was 66 years (18) and 57 years (32), respectively. The yearly incidence rate per 100,000 increased between 2000 and 2017 for both pulmonary (0.4 to 1.3) and extrapulmonary NTM (0.3 to 0.6). The annual prevalence per 100,000 increased from 0.4 to 3.5 for pulmonary and 0.3 to 1.0 for extrapulmonary NTM. The incidence rate increased with age. The incidence of pulmonary NTM was highest in 70+ year-olds (19.3 per 100,000). Compared to pulmonary NTM patients, extrapulmonary NTM patients were more likely to be employed and had a higher educational level. The prevalence of NTM disease in Denmark increased between 2000 and 2017. Pulmonary and extrapulmonary NTM patients are two distinct groups that differ in age, gender, education, and employment status. Increased suspicion of pulmonary NTM disease is warranted in the elderly after exclusion of more common lung infections.

Strongyloidiasis is a disease caused by the intestinal helminth Strongyloides stercoralis. When the immune system of infected individuals is compromised, larvae may migrate from the gastrointestinal tract to other tissues, causing S. stercoralis hyperinfection syndrome, which has a reported mortality of 71%. In this case, we report a patient with S. stercoralis hyperinfection syndrome with central nervous system (CNS) involvement. An elderly South East Asian male tourist presented with pulmonary symptoms, fever and infiltrates on chest X-ray. He later developed symptoms of CNS infection. S. stercoralis larvae were found in a stool sample. Microbiological examination of cerebrospinal fluid revealed S. stercoralis-specific DNA. The patient was treated with oral and rectal ivermectin and albendazole. The condition was complicated by sepsis, bacteraemia and hypereosinophilia. Unfortunately, the patient eventually died from pulmonary oedema and insufficiency. This case highlights the global importance of Strongyloides CNS infection in endemic and non-endemic regions.

Objectives: To investigate age, sex, and geographical differences in nontuberculous mycobacteria (NTM) incidence in Denmark.Methods: A nationwide register-based study of all patients with NTM isolates in Denmark from 1991 through 2022 based on centralised microbiological data from The International Reference Laboratory of Mycobacteriology, Statens Serum Institut, Copenhagen, Denmark. A Poisson regression model was used to calculate incidence rates (IRs) and rate ratios (IRRs).Results: 4123 patients had NTM isolated for the first time. Their median age was 59 years (Interquartile range 33–72), which increased over time. Males were younger than females. The proportion of female patients increased significantly over time. The type of NTM and patient age were closely associated. Pulmonary NTM isolation was increasingly common with higher age, while extra-pulmonary NTM isolation was mainly seen in small children. Pulmonary NTM IRs were almost twice as high for females in 2008–2022 compared to 1991–2007 (IRR 1.9, 95% confidence interval [CI] 1.7–2.1, p<0.001), with increases mainly seen in older age groups. The increase was less pronounced for males (IRR 1.3, 95%CI 1.1–1.4, p<0.001). There were considerable geographical differences, with age- and sex-adjusted NTM IRs being 10–40% higher in countryside, provincial, and catchment municipalities than in the capital.Conclusion: Age, sex, and geography are essential determinants in NTM epidemiology. We found that rates of pulmonary NTM have been increasing, particularly in older females, while changes for males were less pronounced. Finally, we observed considerable geographical differences in NTM IRs in Denmark, with higher rates in less populated municipalities.

Pulmonary disease caused by Mycobacterium abscessus is difficult to treat, as there is currently no reliable evidence-based treatment. Treatment is long, complex and has many side effects. In this case, we report a patient with treatment-refractory pulmonary M. abscessus disease, treated with inhaled tigecycline. Treatment with inhaled tigecycline lasted 15 months with comparably limited side effects. There were no positive mycobacterial cultures in the follow-up period of 2 years. Inhaled tigecycline is an option in the treatment of pulmonary M. abscessus when first-line treatment fails. Additional research should investigate this further.

Nontuberculous Mycobacteria Infection, Denmark

Background: Nontuberculous mycobacterial pulmonary disease (NTM-PD) is associated with a significant economic burden due to complex diagnostics, prolonged multidrug treatments and hospitalisations. However, cost data are limited, particularly from countries with universal healthcare. We evaluated the economic burden of NTM-PD in Denmark. Methods: We conducted a nationwide cost analysis of all adults diagnosed with NTM-PD between 2005 and 2017, identified through International Classification of Diseases, 10th Revision codes. Each case was matched 1:4 to comparators by age, sex, marital/cohabitation status and municipality of residence. We assessed direct healthcare costs (primary and secondary care, and medications) and indirect costs (foregone earnings and public benefits for those aged 18–64 years) 3 years before and after the diagnosis. Annual costs were estimated using a generalised linear model with a gamma distribution and log link. Results: We included 545 NTM-PD patients and 2150 comparators. Patients had lower education levels and employment rates. Direct healthcare costs peaked in the diagnosis year at EUR 24 454 (95% CI 22 378–26 723) for patients versus EUR 4233 (95% CI 4057–4417) for comparators. Employment income declined before diagnosis and remained significantly lower (EUR 9547 versus 18 720), while public benefit payments were higher (EUR 18 005 versus 8978). Net costs peaked at EUR 29 394 (95% CI 27 523–31 408) in the diagnosis year, with comorbidity-adjusted direct healthcare costs being 4.8 times higher for patients (p<0.001). Conclusion: NTM-PD is associated with a substantial economic burden in Denmark, with nearly 5-fold higher direct healthcare costs, reduced income, increased public benefit payments and with net costs exceeding EUR 29 000 in the diagnosis year.