We read with interest the article published by Caylà and Caminero,1 and in line with their proposal to update and implement a national program for the control of tuberculosis (TB) for Spain, we would like to contribute to this effort from Castile-Leon and emphasize the importance of epidemiological surveillance, microbiological control, and diagnosis and treatment of this disease.

TB generates a high burden of morbidity and mortality worldwide, and it is estimated that 1.7 billion (23%) of the world's population is infected with Mycobacterium tuberculosis.2 The distribution of the disease burden varies significantly depending on the region, and it was estimated that in 2017, 44% of cases occurred in the World Health Organization (WHO) South-East Asia region, 25% in Africa, 18% in the Western Pacific region, and 7.7% in the Eastern Mediterranean region. Incidence is lower in the Americas (2.8%) and Europe (2.7%).3

In total, 1419 new cases of TB were reported to the Epidemiological Surveillance Network of Castile-Leon in the 5-year period between 2012 and 2016.4 Incidence rates have remained steady, ranging from 10.5 new cases per 100000 inhabitants reported in 2012 to 10.1 TB cases per 100000 inhabitants in 2016. The incidence of confirmed cases shows a declining trend, from 11.7 cases per 100000 inhabitants in 2012 to 8.6 cases per 100000 in the year 2016. Median age in men is 58 years and 48 years in women, with a male/female ratio ranging between 1.54 in 2014 and 1.94 in 2016.

Etiology from bacteriological diagnosis identifies Mycobacterium tuberculosis as the most frequently isolated microorganism, detected in 71% of cases. Antibiotic sensitivity testing of the series found 83 resistance patterns, of which 32 (39%) involve pyrazinamide resistance and 21 (25%) isoniazid resistance. Analysis of the follow-up results shows that in 2015, 67% had received satisfactory treatment, defined as cure and completed treatment.4

The increasing prevalence of resistance in Castile-Leon since the beginning of this decade (1.2% to streptomycin; 3.2% to isoniazid; 0.3% to rifampicin; 0.1% to ethambutol; and 0.5% to pyrazinamide)5 underlines the need for maintaining active surveillance and performing sensitivity studies, particularly when in Europe it is estimated that 17% (95% CI: 16%–18%) are new cases and 53% (95% CI: 46%–61%) of previously treated cases have methicillin-resistant and/or multidrug-resistant TB.3

Our view, reflected by other authors,6 is that the rational and sequential use of antituberculous drugs is of utmost importance when designing TB treatment, be it sensitive or resistant.

Follow-up indicators and compliance with the criteria of the Plan for the Prevention and Control of Tuberculosis, agreed by the autonomous communities and approved by the Public Health Commission in June 2013, have improved in the years under study. However, it is essential that registries also improve, including the recording of appropriate microbiological data, if we are to achieve the proposed objectives and accelerate progress toward the global goals and milestones set down by the WHO for reducing the burden of TB disease, scheduled for 2020, 2025, 2030 and 2035.3