Introduction: Measuring trough serum levels of vancomycin is recommended by current guidelines for monitoring treatment, with values between 15-20 mg/L for severe infections. Various variables are associated with failing to reach effective levels, which this study seeks to determine. This study aimed to identify factors associated with subtherapeutic serum levels, their relationship with hemato-oncological diseases, and other pharmacokinetic variables. Materials and methods: This was an observational case-control study of hospitalized adults in whom serum vancomycin levels were measured. A total of 857 medical records were analyzed, of which 377 met the inclusión criterio of this study. A random selection of 92 cases and 202 controls was made at a 1:2 ratio without matching. Results: The median age was 59 years, and 56.8% of the patients were male. Hemato-oncological diagnoses were present in 23.1% of patients, with non-Hodgkin lymphoma and acute leukemia being the most frequent. Four variables were statistically associated with subtherapeutic levels: hemato-oncological disease (OR 2.12; 95% CI 1.53–4.88; p=0.004), BMI >25 kg/m² (OR 1.15; 95% CI 1.07–1.21; p<0.001), age >75 years (OR 0.96; 95% CI 0.93–0.96; p<0.001), and creatinine >0.7 mg/dL (OR 0.08; 95% CI 0.01–0.11; p<0.001). Discussion: Hemato-oncological disease and increased body mass index were significantly associated with subtherapeutic vancomycin levels. In contrast, older age and higher creatinine levels acted as protective factors, possibly due to reduced renal clearance. These findings support the need for therapeutic drug monitoring and dose adjustment in oncologic patients.

La infeccion por micobacterias no tuberculosas, específicamente por Mycobacterium kansasii, no suele ser una entidad frecuente, por lo que representa un reto a nivel diagnóstico y terapéutico, sin tener un esquema de manejo totalmente establecido en la población pediátrica; lo anterior teniendo un impacto en el curso clínico y complicaciones asociadas. En el presente artículo realizamos el abordaje del caso de una paciente lactante con antecedente de prematuridad y de trisomía 21, cardiopatía congénita, hipotiroidismo, displasia broncopulmonar e inmunodeficiencia asociada a síndrome de Down quien cursó con sepsis de origen pulmonar con múltiples complicaciones y adenitis cervical, con reporte biopsia de ganglio con presencia de Mycobacterium kansasii. La paciente representó un desafío médico para su equipo tratante, dado el curso no esperado de la enfermedad y la información limitada en la literatura sobre el manejo dirigido, considerando su edad, comorbilidades y resistencia intrínseca de esta micobacteria a ciertos medicamentos.

Introduction: Latent tuberculosis infection (LTBI) is characterized by a sustained immune response to Mycobacterium tuberculosis antigens without clinical, radiographic, or microbiological evidence of active disease. The aim of this study was to assess medical and social risk factors for progression of latent tuberculosis infection (LTBI) to active pulmonary tuberculosis in children with household TB contact. Materials and methods: A prospective study (2022–2024) involved 120 children aged 4–12 with LTBI. Two groups were formed: children who developed active TB (LTBI-to-TB group) and those who remained latent. Inclusion required consent. Clinical, immunological (IL-2, IgM), and social factors were analyzed. Risk was evaluated via relative risk (RR) and 95% confidence intervals. Results: Progression to active TB was linked to bacillary TB contact (RR=6.5), maternal TB (RR=5.2), anemia (RR=3.8), >5 ARI episodes/year (RR=26.0), ineffective BCG (RR=3.0), single-parent homes (RR=11.0), territorial TB (RR=4.5), helmintiasis (RR=10.0), chickenpox (RR=5.0), genitourinary diseases (RR=8.0), ENT pathology (RR=5.7), isoniazid monotherapy (RR=2.7), COVID-19 or HIV exposure (RR=8.0), IL-2 >311.1 ng/ml, and IgM >1.18 IU/ml. Discussions: Immunological and social factors increase LTBI progression risk. High-risk children need tailored monitoring.