Background: Respiratory syncytial virus (RSV) is a leading etiological agent of acute respiratory tract infections and hospitalizations in children. However, little information is available regarding RSV infections in Latin American countries, particularly among adult patients.Objective: To describe the epidemiology of RSV infection and to analyze the factors associated with severe infections in children and adults in Mexico.Methods: Patients ≥1 month old, who presented with an influenza‐like illness (ILI) to six hospitals in Mexico, were eligible for participation in the study. Multiplex reverse‐transcriptase polymerase chain reaction identified viral pathogens in nasal swabs from 5629 episodes of ILI. Patients in whom RSV was detected were included in this report.Results: Respiratory syncytial virus was detected in 399 children and 171 adults. RSV A was detected in 413 cases and RSV B in 163, including six patients who had coinfection with both subtypes; 414 (72.6%) patients required hospital admission, including 96 (16.8%) patients that required admission to the intensive care unit. Coinfection with one or more respiratory pathogens other than RSV was detected in 159 cases. Young age (in children) and older age (in adults) as well as the presence of some underlying conditions were associated with more severe disease.Conclusions: This study confirms that RSV is an important respiratory pathogen in children in Mexico. In addition, a substantial number of cases in adults were also detected highlighting the relevance of this virus in all ages. It is important to identify subjects at high risk of complications who may benefit from current or future preventive interventions.

Several microorganisms produce nosocomial infections (NIs), among which Pseudomonas aeruginosa stands out as an opportunist pathogen with the capacity to develop multiresistance to first-choice antibiotics. From 2007 to 2013, forty-six NIs produced by P. aeruginosa were detected at a pediatric tertiary care hospital in Mexico with a significant mortality rate (17.39%). All isolates (n = 58/46 patients) were characterized by evaluating their response to several antibiotics as panresistant (PDR), extensively resistant (XDR), multiresistant (MDR) or sensitive (S). In addition, all isolates were typified through multilocus sequencing of seven genes: acsA, aroE, guaA, mutL, nuoD, ppsA and trpE. Furthermore, to establish the genetic relationships among these isolates, we carried out a phylogenetic inference analysis using maximum likelihood to construct a phylogenetic network. To assess evolutionary parameters, recombination was evaluated using the PHI test, and the ratio of nonsynonymous to synonymous substitutions was determined. Two of the strains were PDR (ST1725); 42 were XDR; four were MDR; and ten were S. Twenty-one new sequence types were detected. Thirty-three strains exhibited novel sequence type ST1725. The ratio of nonsynonym to synonym substitutions was 1:1 considering all genes. Phylogenetic analysis showed that the genetic relationship of the PDR, XDR and MDR strains was mainly clonal; however, the PHI test and the phylogenetic network suggest that recombination events occurred to produce a non-clonal population. This study aimed not only to determine the genetic diversity of clinical P. aeruginosa but also to provide a warning regarding the identification and spreading of clone ST1725, its ability to cause outbreaks with high mortality rates, and to remain in the hospital environment for over seven years. These characteristics highlight the need to identify clonal outbreaks, especially where high resistance to most antibiotics is observed, and control measures are needed. This study also represents the first report of the PDR ST1725.

Recent multidrug resistance in Pseudomonas aeruginosa has favoured the adaptation and dissemination of worldwide high-risk strains. In June 2018, 15 P. aeruginosa strains isolated from patients and a contaminated multi-dose meropenem vial were characterized to assess their association to an outbreak in a Mexican paediatric hospital. The strains were characterized by antibiotic susceptibility profiling, virulence factors’ production, and biofilm formation. The clonal relationship among isolates was determined with pulse-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) sequencing. Repressor genes for the MexAB-OprM efflux pump were sequenced for haplotype identification. Of the strains, 60% were profiled as extensively drug-resistant (XDR), 33% as multidrug-resistant (MDR), and 6.6% were classified as sensitive (S). All strains presented intermediate resistance to colistin, and 80% were sensitive to aztreonam. Pyoverdine was the most produced virulence factor. The PFGE technique was performed for the identification of the outbreak, revealing eight strains with the same electrophoretic pattern. ST235 and ten new sequence types (STs) were identified, all closely related to ST233. ST3241 predominated in 26.66% of the strains. Twenty-five synonymous and seventeen nonsynonymous substitutions were identified in the regulatory genes of the MexAB-OprM efflux pump, and nalC was the most variable gene. Six different haplotypes were identified. Strains from the outbreak were metallo-β-lactamases and phylogenetically related to the high-risk clone ST233.

During the Covid-19 pandemic, children and adolescents faced poverty, potentially dying from preventable causes, or missing out essential vaccines. The aim of this study was to assess potential environmental and individual factors associated to COVID-19 mortality in children and adolescents in Mexico. This cross-sectional study analysed the official data of 131,001 children under 10 years of age and adolescents between 10 and 19 years of age with COVID-19 disease, in Mexico. Participants were diagnosticated between March 2020 and June 13, 2021. The environmental variables such as malnutrition, vaccination coverage and social lag index were evaluated at the state level. Multilevel models were fitted to evaluate the association between environmental and individual factors and COVID-19 mortality. A total of 773 (0.6%) children and adolescents died due to COVID-19. Younger age (OR = 0.878, 95%CI: 0.869-0.888), diabetes (OR = 3.898, 95%CI: 2.596-5.851), immunosuppression (OR = 5.410, 95%CI: 4.088-7.158), obesity (OR = 1.876, 95%CI: 1.397-2.521), hypertension (OR = 1.906, 95%CI: 1.239-2.932), cardiovascular disease (OR = 2.288, 95%CI: 1.482-3.531), and chronic kidney disease (OR = 13.250, 95%CI: 9.066-19.350) were associated with mortality. COVID-19 mortality was directly associated with social lag index and malnutrition (OR_{very high} = 2.939, 95%CI: 1.111-7.775, and OR = 1.390, 95%CI: 1.073-1.802, respectively), and inversely associated with population density (OR = 0.374, 95%CI: 0.204-0.688). Finally, children and adolescents living in areas with a higher percentage of people with incomplete education (OR = 1.045, 95%CI: 1.011-1.081), of children of school age of 6–14 years who do not attend school (OR = 1.266, 95%CI: 1.032-1.554), and of illiterate population aged 15 and over (OR = 1.086, 95%CI: 0.999-1.179) were associated with a higher risk of COVID-19 mortality. Malnutrition, social lag index and population density are key factors to understand COVID-19 mortality in children and adolescents. Also, age and pre-existing comorbidities were also associated with worse COVID-19 prognosis. No funding was secured for this study.

Objetivo: Describir la supervivencia de los pacientes con insuficiencia cardiaca (IC) con seguimiento en atención primaria (AP) y analizar el efecto del sexo, edad, factores clínicos, de utilización de servicios y nivel de renta, en la supervivencia. Diseño: Estudio observacional longitudinal de una cohorte retrospectiva de pacientes a partir de la historia clínica electrónica. Emplazamiento: Área 7 de AP de la Comunidad de Madrid. Participantes: Pacientes mayores de 24 años con una consulta en AP en el año 2006. Mediciones principales Casos incidentes de IC desde 2006 a 2010 o hasta su fallecimiento. Análisis de supervivencia de Kaplan-Meier y de regresión multivariante de riesgos proporcionales de Cox. Resultados: Se identificaron 3.061 pacientes en una cohorte de 227.984. Su supervivencia fue del 65% a los 5 años. Fallecieron 519 pacientes con una supervivencia media de 49 meses. Los factores asociados a mayor riesgo de mortalidad fueron la edad (HR = 1,04; 1,03-1,05) y tener diagnóstico de cardiopatía isquémica (HR = 1,45; 1,15-1,78) o de diabetes (HR = 1,52; 1,17-1,95). Los factores con un efecto protector fueron ser mujer (HR = 0,72; 0,59-0,86), no pensionista (HR = 0,43; 0,23-0,84), haber recibido la vacunación de la gripe anualmente (HR = 0,01; 0,00-0,06), tener prescritos hipolipidemiantes (HR = 0,78; 0,61-0,99) o IECA (HR = 0,73; 0,60-0,88), así como que se le hubieran solicitado analíticas (HR = 0,98; 0,95-1), radiografías (HR = 0,81; 0,74-0,88) y electrocardiogramas (HR = 0,90; 0,81-0,99) en AP. Conclusiones: Los datos de los pacientes con IC seguidos en AP indican que su supervivencia es mejor que la obtenida en otros países, apoyando el argumento de la mejor evolución de la IC en los países mediterráneos. Objective: To describe survival of patients with chronic heart failure (HF) followed up in primary care (PC) and analyse the effect of sex, age, clinical and health services factors, and income levels on survival. Design: Longitudinal observational study of a retrospective cohort of patients with information extracted from electronic medical records. Setting: PC Area 7 of the Community of Madrid. Participants: Patients 24 year and older with at least one visit to PC in 2006. Principal measurement Incident cases of HF followed up from 2006 to 2010 or until death. Survival analysis with Kaplan-Meier and Cox proportional hazard multivariate regression. Results: A total of 3,061 cases were identified in a cohort of 227,984 patients. The survival rate was 65% at 5 years, with 519 patients dying with a median survival of 49 months. Factors associated with increased risk of mortality were, age (HR = 1.04, 1.03-1.05), and having a diagnosis of ischemic heart disease (HR = 1.45, 1.15- 1.78), or diabetes (HR = 1.52, 1.17-1.95). Factors with a significant protective effect were: female sex (HR = 0.72, 0.59-0.86), non-pensioner (HR = 0.43, 0.23-0.84), having received the influenza vaccine annually (HR = 0.01, 0.00-0.06), prescribed lipid-lowering drugs (HR = 0.78, 0.61-0.99) or ACE inhibitors (HR = 0.73, 0.60-0.88), and blood tests having been requested (HR = 0.97, 0.95-1.00), X-rays (HR = 0.81, 0.74-0.88), or electrocardiograms (HR = 0.90, 0.81-0.99) in PC. Conclusions: Data from patients with HF followed up in PC indicate that their survival is better than that obtained in other countries, supporting the argument of a better evolution of HF in Mediterranean countries.

Human Bocaviruses (HBoV) can cause acute respiratory tract infections. High coinfection rates cloud its pathogenicity. This study sought to describe the clinical features of HBoV1 disease in children and adults with Influenza-like illness (ILI), exploring associations between viral load, clinical features, and seasonality. Patients who tested positive for HBoV1 by polymerase chain reaction, enrolled from April 2010 to March 2014 in the ILI002 prospective observational cohort study were included in this cross-sectional nested study. Participants were included in ILI002 if they presented with signs and/or symptoms suggestive of influenza-like illness. Samples were tested for viral load, and NP1 and VP1/VP2 phylogenetic analyses, except for the samples lacking suitable and viable clinical material for genotyping. We identified HBoV1 in 157 (2.8%) of participants. Prevalence was 4.5% in children and 1.8% in adults. Single HBoV1 detection occurred in 41.1% and 46.3% of children and adults, respectively. Children commonly experienced fever (83.3%), cough with sputum (74.4%), and shortness of breath (72.2%). In the multivariate analysis of children, significant positive associations were detected between viral loads and age (0.20 [95% CI: 0.07, 0.33]), and the presence of fever (2.64 [95% CI: 1.35, 3.94]), nasal congestion (1.03 [95% CI: 0.07, 1.99]), dry cough (1.32 [95% CI: 0.42, 2.22]), chest congestion (1.57 [95% CI: 0.33, 2.80]), red eyes (1.25 [95% CI: 0.35, 2.14]), cough with sputum (1.79 [95% CI: 0.80, 2.78]), and other signs and symptoms such as chills, dizziness, and diaphoresis (1.73 [95% CI: 0.19, 3.27]). In contrast, significant negative associations were found between viral loads and percent neutrophils on the blood count (−0.04 [95% CI: −0.06, −0.02]), fatigue (−1.60 [95% CI: −2.46, −0.74]) and the presence of other symptoms or signs, including adenopathy and rash (−1.26 [95% CI: −2.31, −0.21]). Adults commonly experienced sore throat (73.1%), fatigue (77.4%), and headache (73.1%). In the multivariate analysis of adults, significant positive associations were detected between viral load and body mass index (0.13 [95% CI: 0.04, 0.21]), and the presence of confusion (1.54 [95% CI: 0.55, 2.53]), and sore throat (1.03 [95% CI: 0.20, 1.85]), and significant negative associations were detected between viral load and chest congestion (−1.16 [95% CI: −2.07, −0.24]). HBoV1 was detected throughout the year irrespective of season, temperature, and humidity. This study demonstrated the importance of detecting HBoV1 in patients with influenza-like illness either as single infection or co-infection, in both adults and children, and improves the characterization of HBoV1 seasonality, clinical features, and viral load. Phylogenetic analyses show a high conservation. The Mexican Emerging Infectious Diseases Clinical Research Network (LaRed), 10.13039/501100003141 CONACYT (Fondo Sectorial SSA/IMSS/ISSSTE, Projects No. 71260 and No. 127088), Fondos federales no. HIM/2015/006, 10.13039/100000060 NIAID , 10.13039/100000002 NIH through a contract with Westat, Inc. (HHSN2722009000031, HHSN27200002), 10.13039/100000054 NCI , 10.13039/100000002 NIH (75N91019D00024, 75N91019F00130). Additional information at the end of the manuscript.