Nontuberculous mycobacterial infection in a tertiary care center in Mexico, 2001-2017

ABSTRACT Introduction: Nontuberculous mycobacteria (NTM) comprise several pathogens with a complex profile of virulence, diverse epidemiological and clinical patterns as well as host specificity. Recently, an increase in the number of NTM infections has been observed; therefore, the objective of this study was to evaluate the clinical characteristics and outcomes of these infections. Methods: We included patients with NTM infections between 2001-2017 and obtained risk factors, clinical features and outcomes; finally, we compared this data between slowly growing (SGM) and rapidly growing mycobacteria (RGM). Results: A total of 230 patients were evaluated, 158 (69%) infected and 72 (31%) colonized/pseudoinfected. The average annual incidence in the first 11 years of the study was 0.5 cases per 1000 admissions and increased to 2.0 cases per 1000 admissions later on. The distribution of NTM infections was as follows: bloodstream and disseminated disease 72 (45%), lung infection 67 (42%), skin and soft tissue infection 19 (12%). Mycobacterium avium complex was the most common isolate within SGM infections, and HIV-infected patients were the most affected. Within RGM infections, M. fortuitum was the most common isolate from patients with underlying conditions such as cancer, type-2 diabetes mellitus, presence of invasive devices, and use of immunosuppressive therapy. We did not find significant differences in deaths and persistent infections between disseminated SGM infection when compared to disseminated RGM infection (42% vs. 24%, p = 0.22). However, disseminated SGM infection required a longer duration of therapy than disseminated RGM infection (median, 210 vs. 42 days, p = 0.01). NTM lung disease showed no significant differences in outcomes among treated versus non-treated patients (p = 0.27). Conclusions: Our results show a significant increase in the number of Non-tuberculosis-mycobacteria infections in our setting. Patients with slow-growing-mycobacteria infections were mainly persons living with human immunodeficiency virus . Older patients with chronic diseases were common among those with rapidly-growing-mycobacteria infections. For non-tuberculosis-mycobacteria lung infection, antibiotic therapy should be carefully individualized.

Mycobacterium tuberculosis complex bacteremia among HIV and non-HIV patients in a Mexican tertiary care center

ABSTRACT Objectives: To determine the factors associated with Mycobacterium tuberculosis complex-positive blood culture. Methods: Case-control study. Sociodemographic, clinical and laboratory data were collected from 2000 to 2015. Results: We reviewed medical records of 533 patients with culture-proven tuberculosis, of whom 27.2% (145/533) had blood culture available. Patients with mycobacteremia presented more frequently with abdominal tuberculosis, body mass index <18 kg/m2, and had lower hemoglobin and albumin levels. No differences were observed regarding HIV status. Conclusions: Few studies have reported on the characteristics associated with Mycobacterium tuberculosis complex bacteremia, especially among Human Immunodeficiency Virus-negative patients. Out of 145 tuberculosis-infected patients with blood culture results available, 21 turned out positive. Anemia, hypoalbuminemia, and a body mass index < 18 kg/m2 were associated with mycobacteremia.

Seroprevalence of brucellosis among dairy farm workers in Mexico / Seroprevalencia de brucelosis entre trabajadores de una cuenca lechera en México

Abstract: Objective: To describe the seroprevalence and associated factors for brucellosis among dairy farm workers. Materials and methods: We performed a secondary analysis of a data set and sera from a previous cross-sectional study in a dairy farm. Sera were tested for Brucella spp. antibodies by the slide agglutination test. Seropositivity was defined as a titer ≥1:40; recent infection was titers ≥1:160. Results: We tested 331 human sera. Seroprevalence of brucellosis was 18.1% (60/331; 95% CI 14.1-22.7); 13.3% of them (8/60; 95% CI 5.9 24.5) corresponded to recent infection. Highexposure occupation (calf caretaker; OR 3.3; 95%CI 1.1 - 9.7), daily hours in contact with cows (OR 1.1; 95%CI 1.03 - 1.2), and living on-site (OR 2.2; 95% CI 1.1 - 4.4) remained independently associated with seropositivity. Conclusions: We found a high seroprevalence of brucellosis among dairy farm workers, as well as a significant association among those with prolonged and close contact with cattle.

Resumen: Objetivos: Describir la seroprevalencia y factores asociados con la brucelosis en los trabajadores de una cuenca lechera. Material y métodos: Se realizó un análisis secundario de datos y sueros obtenidos en una cuenca lechera. Se buscaron anticuerpos contra Brucella spp. en los sueros por medio de la prueba de aglutinación en placa. Se definió seropositividad a partir de un título ≥1:40, e infección reciente con títulos ≥1:160. Resultados: Se analizaron 331 sueros humanos. La seroprevalencia de brucelosis fue de 18.1% (60/331; IC 95% 14.1-22.7); el 13.3% (8/60; IC 95% 5.9 24.5) correspondieron a infección reciente. Alta exposición (becerrero; RM 3.3; IC 95% 1.1 - 9.7), horas diarias en contacto con vacas (RM 1.1; IC 95% 1.03 - 1.2), y vivir en el establo (RM 2.2; IC 95% 1.1 - 4.4) estuvieron asociadas independientemente con seropositividad. Conclusiones: Se encontró alta seroprevalencia de brucelosis en trabajadores de una cuenca lechera, y asociación en aquellos con contacto cercano y prolongado con vacas.