Progressive immune damage associated with Human Immunodeficiency Virus (HIV) alters mucosal homeostasis, favouring oral microbial imbalance and the development of opportunistic infections. The aim of this study was to characterize the composition and structure of the oral microbiota in different clinical conditions of HIV infection. A cross-sectional study was conducted in 99 Mexican men divided into five groups: HIV-negative controls, newly diagnosed without antiretroviral treatment, virally suppressed, with oral candidiasis, and with HPV infection. Metagenomic DNA was obtained from salivary samples, and the V1–V3 region of the 16S rRNA gene was massively sequenced. Taxonomic profiles, alpha/beta diversity, differential abundance, microbial co-occurrence networks and degree of dysbiosis were analysed. The results showed distinctive profiles between the groups. Alpha and beta diversity was significantly higher in the groups with oral Candida and HPV lesions, reflecting a disturbance of microbial balance. Differential abundance analysis revealed an increase in Streptococcus, Veillonella, Lactobacillus and Actinomyces genera in HIV patients, while healthy subjects showed higher abundance of Neisseria, Treponema, and Rothia, associated with a eubiotico state. The group of patients with HPV lesions had the highest number of taxa with differential abundance, suggesting an ecological environment altered by the lesion. Analysis of co-occurrence networks revealed a progressive pattern of microbial complexity: controls presented simple networks with weak positive correlations, while HIV groups showed increased connection density and appearance of structured nuclei. The group of patients with HPV lesions presented the highest connectivity, with multiple strongly correlated cores and core nodes such as Prevotella melaninogenica and Shuttleworthia. The dysbiosis score increased progressively from healthy subjects to those with HPV lesions, indicating a gradient of oral microbial disruption. These findings suggest that HIV immunosuppression and the presence of oral lesions are associated with enhanced dysbiosis, although their individual contributions could not be independently assessed due to the absence of non-HIV lesion controls. The integration of microbial networks and dysbiosis scores could be useful for assessing mucosal and immune health in people with HIV and used as biomarkers of clinical progression.

The increasing burden of dengue represents a growing global public health concern. Among the factors associated with rising dengue incidence, climate change, particularly increasing temperatures, has been frequently highlighted, alongside other environmental, biological, and social determinants. The emergence of dengue in previously non-endemic areas and its sustained increase in incidence have become increasingly common in recent decades. Objective: The aim of this study was to describe national dengue case trends in Mexico from 1990 to 2023 and to assess their association with temperature over the same period using a descriptive, retrospective analysis of epidemiological surveillance and temperature data. Methods: Epidemiological data on confirmed dengue cases and incidence were obtained from the Morbidity Yearbook of the General Directorate of Epidemiology (DGE) of the Mexican Ministry of Health. These data were used to construct epidemic curves and to analyze the geographic distribution of incidence using quartiles. Temperature data were derived from the national annual mean calculated from monthly reports issued by the National Water Commission (CONAGUA). Associations between temperature and dengue cases and incidence were explored over the study period. Results: Temporal analysis revealed a significant increase in both dengue cases and incidence in Mexico, with a positive association with temperature during the same period. Quartile-based geographic analysis showed that state-level classifications remained relatively stable across periods, with several states clustering within or tending toward the group considered endemic. Conclusions: The results of this study show an increase in cases and incidence of dengue over time, as well as a positive association between cases/incidence of dengue in Mexico and the increase in the national average temperature during the study period; however, due to its descriptive and retrospective design, causal inference is not possible. Dengue transmission is inherently multifactorial, and the observed trends likely reflect the combined influence of climatic conditions, historical expansion of transmission cycles, vector establishment, and unmeasured socio-epidemiological factors. The absence of entomological indicators, additional climatic variables, and spatially or seasonally disaggregated analyses limits the ability to capture localized dynamics. Overall, temperature should be interpreted as a contributing factor within a complex system rather than as the sole driver of dengue trends, underscoring the need for integrated surveillance and control strategies in both endemic and non-endemic regions.

Healthcare-associated infections remain a central hospital challenge, particularly in critical areas where invasive procedures and microbial contamination overlap. The hospital environment, including air and high-touch surfaces, acts as a persistent microorganism source that favors stability and spread. UV-C disinfection systems have become complementary tools to conventional cleaning. This study evaluated the disinfectant efficacy of a 254 nm multiemitter UV-C system under in situ and in vitro conditions. A 254 nm UV-C multiemitter system was deployed to eight hospital areas selected for epidemiological relevance. Air and surface sampling were conducted before and after standardized UV-C cycles. The bacterial and fungal aerobiome was quantified (CFU/m³) and surfaces were characterized by MALDI-TOF mass spectrometry. In vitro assays tested efficacy against planktonic cultures and mature biofilms of clinical ESKAPE isolates and C. albicans. The UV-C intervention achieved mean aerobiome reductions above 91.5%, with complete elimination in multiple critical zones. Surface contamination was reduced by 96.1%, including total disinfection across several sampled points. In vitro testing showed ≥99.99% to 100% elimination of planktonic microorganisms. Mature biofilms exhibited full loss of viability after UV-C exposure, independent of biofilm architecture and structural complexity. Therefore, the 254 nm UV-C multiemitter system significantly reduced environmental microbial burden in critical hospital areas, supporting its integration within infection-prevention programs and reinforcing environmental biosafety through the control of the microbial sources involved in transmission dynamics.

Introduction: The coronavirus disease 2019 (COVID-19) pandemic is a global health concern and has persisted through the emergence of variants that have caused subsequent waves of COVID-19 due to the high dispersion and contagiousness of the virus. The aim of this work was to analyze the epidemiology of the cases of reinfection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants during the third and fourth wave of the COVID-19 pandemic at the Hospital Juárez de México (HJM). Methodology: A prospective study of the cases of SARS-CoV-2 reinfection, variants detected, symptoms, and associated comorbidities was carried out on 1,347 patients who attended the HJM from September 2021 to July 2022. Results: 760 (56.4%) and 587 (43.6%) patients were negative and positive for SARS-CoV-2, respectively. The Omicron variant was the most frequent and the most common symptoms were: cough (80%), headache (61.32%), fever (51.6%), and dyspnea (40%). A higher proportion of females were vaccinated, ranging from one dose to the complete schedule. The factors that were associated with a greater risk of death from complications of SARS-CoV-2 reinfection were male gender, diabetes mellitus, and arterial hypertension. Conclusions: Females were the most susceptible to an Omicron reinfection event, even though they were vaccinated. However, the risk of death was higher when the patient was male; being male was a potential risk factor for death from COVID-19 and comorbidities.