Diversity, composition, and networking of saliva microbiota distinguish the severity of COVID-19 episodes as revealed by an analysis of 16S rRNA variable V1-V3 region sequences.

Studies on the role of the oral microbiome in SARS-CoV-2 infection and severity of the disease are limited. We aimed to characterize the bacterial communities present in the saliva of patients with varied COVID-19 severity to learn if there are differences in the characteristics of the microbiome among the clinical groups. We included 31 asymptomatic subjects with no previous COVID-19 infection or vaccination; 176 patients with mild respiratory symptoms, positive or negative for SARS-CoV-2 infection; 57 patients that required hospitalization because of severe COVID-19 with oxygen saturation below 92%, and 18 fatal cases of COVID-19. Saliva samples collected before any treatment were tested for SARS-CoV-2 by PCR. Oral microbiota in saliva was studied by amplification and sequencing of the V1-V3 variable regions of 16S gene using an Illumina MiSeq platform. We found significant changes in diversity, composition, and networking in saliva microbiota of patients with COVID-19, as well as patterns associated with severity of disease. The presence or abundance of several commensal species and opportunistic pathogens were associated with each clinical stage. Patterns of networking were also found associated with severity of disease: a highly regulated bacterial community (normonetting) was found in healthy people whereas poorly regulated populations (disnetting) were characteristic of severe cases. Characterization of microbiota in saliva may offer important clues in the pathogenesis of COVID-19 and may also identify potential markers for prognosis in the severity of the disease. IMPORTANCE SARS-CoV-2 infection is the most severe pandemic of humankind in the last hundred years. The outcome of the infection ranges from asymptomatic or mild to severe and even fatal cases, but reasons for this remain unknown. Microbes normally colonizing the respiratory tract form communities that may mitigate the transmission, symptoms, and severity of viral infections, but very little is known on the role of these microbial communities in the severity of COVID-19. We aimed to characterize the bacterial communities in saliva of patients with different severity of COVID-19 disease, from mild to fatal cases. Our results revealed clear differences in the composition and in the nature of interactions (networking) of the bacterial species present in the different clinical groups and show community-patterns associated with disease severity. Characterization of the microbial communities in saliva may offer important clues to learn ways COVID-19 patients may suffer from different disease severities.

Breast cancer detection in Mexico City during 2017. / Detección del cáncer de mama en la Ciudad de México durante 2017.

BACKGROUND: Breast cancer is the leading cause of death of women in Mexico; its detection is among the priorities of Mexico City's (CDMX) Southern Local Office from the Instituto Mexicano del Seguro Social (IMSS: Mexican Institute for Social Security). OBJECTIVE: To describe the incidence and mortality related to breast cancer detection in the CDMX's Southern Local Office units from IMSS in 2017. MATERIAL AND METHODS: Databases from the Coordination of Prevention and Health Care (CPAS), Information and Strategic Analysis (CIAE) and the Breast Clinic (UDDC Mama) were analyzed. Among data, it was included age, study (mastography, ultrasound and biopsy), and histological type, incidence and mortality. For statistical analysis it was used Student's t, and Spearman correlation (p < 0.05). RESULTS: In a population of 589,683 women (40-69 years), 97,779 mastographs were performed. Out of these, there were 94,883 normal (BI-RADS 1) and 1933 suspicious (BIRADS 3-5). In 436 biopsies, infiltrating ductal carcinoma was the most frequent. The incidence rate was 39.3/100,000 and the mortality rate was 3.54/100,000 inhabitants (in 2015 and 2016 it was 6.84 and 7.02/100,000, respectively). CONCLUSIONS: An increase in the incidence and a decrease in breast cancer mortality has been observed, which is related to improvements in screening programs in 2017. It is important to maintain and optimize screening programs.

INTRODUCCIÓN: El cáncer de mama es la principal causa de muerte de mujeres en México; su detección se ubica entre las prioridades de la Delegación Sur de la Ciudad de México del Instituto Mexicano del Seguro Social (IMSS). OBJETIVO: Describir la incidencia y la mortalidad relacionadas con la detección del cáncer de mama en las unidades de la Delegación Sur de la Ciudad de México del IMSS en 2017. MATERIAL Y MÉTODOS: Se analizaron las bases de datos de las Coordinaciones de Prevención y Atención a la Salud (CPAS), de Información y Análisis Estratégico (CIAE) y de la Clínica de Mama (UDDC Mama). Entre los datos se incluyó edad, estudio (mastografía, ultrasonido y biopsia) y tipo histológico, incidencia y mortalidad. Para el análisis estadístico se empleó t de Student y correlación de Spearman (p ≤ 0.05). RESULTADOS: En una población de 589 683 mujeres (40-69 años), se realizaron 97 779 mastografías. De estas hubo 94 883 normales (BIRADS 1) y 1933 sospechosas (BIRADS 3-5). En 436 biopsias, el carcinoma ductal infiltrante fue el más frecuente. La tasa de incidencia fue 39.3/100 000 y de mortalidad de 3.54/100 000 habitantes (en 2015 y 2016 fue de 6.84 y 7.02/100 000, respectivamente). CONCLUSIONES: Se ha observado un incremento en la incidencia y disminución de mortalidad por cáncer de mama, el cual está relacionado con mejoras en programas de detección en 2017. Es importante mantener y optimizar los programas de detección.