[Anti-SARS-CoV-2 seroprevalence in administrative staff of the Mexican Institute for Social Security]. / Seroprevalencia anti-SARS-CoV-2 en personal administrativo del Instituto Mexicano del Seguro Social.

Background: Asymptomatic subjects, the lack of diagnostic tests and, in countries like Mexico, the epidemiological surveillance method does not allow to establish the real number of infections in the COVID-19 pandemic. Frontline health personnel, as well as other groups related to priority activities are considered of high risk. We included administrative workers in contact with health personnel in the hospital units of the Mexican Institute for Social Security (IMSS, according to its initials in Spanish). Objective: To identify the seroprevalence of antibodies to SARS-CoV-2 in IMSS' administrative staff who does not treat patients. Material and methods: 76 volunteer participating individuals were incluided; IgG antibodies against the SARS-CoV-2 nucleoprotein were measured. A questionnaire was administered to the participants in order to identify possible risk factors. Results: 76 participants were included (39 men, 51.7%), with a median age of 42 years. 29 out of 76 subjects (38.2%), whose median age was 38 years (range 18-69 years); 15 men (51.7%), and 14 women (48.3%). A higher percentage of positive subjects under 45 years of age (n = 20, 84.2%) was observed than those aged 45 or over (n = 9, 25%), with an OR of 3 (95% CI 1.13-7.96, p = 0.03). No statistically significant difference was found regarding the type of comorbidity. Conclusions: The prevalence identified shows an important circulation of the virus in the administrative staff.

Introducción: los sujetos asintomáticos, la falta de pruebas diagnósticas y, en países como México, el método de vigilancia epidemiológica no permiten establecer el número real de contagios en la pandemia de COVID-19. El personal de salud de primera línea y otros grupos con actividades prioritarias son de alto riesgo. Se incluyeron trabajadores administrativos en contacto con personal de salud en las unidades hospitalarias del Instituto Mexicano del Seguro Social (IMSS). Objetivo: identificar la seroprevalencia de anticuerpos contra SARS-CoV-2 en personal administrativo del IMSS que no atiende a enfermos. Material y métodos: se incluyeron 76 individuos a los cuales se les midieron los anticuerpos IgG contra la nucleoproteína del SARS-CoV-2. También se les aplicó un cuestionario para identificar factores de riesgo. Resultados: se incluyeron 76 participantes (39 hombres, 51.7%), con una mediana de 42 años de edad. Fueron positivos 29 de 76 sujetos (38.2%), cuya mediana de edad fue de 38 años (rango 18-69 años); 15 hombres y 14 mujeres. Hubo mayor porcentaje de sujetos positivos menores de 45 años (n = 20, 84.2%) que aquellos de edad ≥ 45 años (n = 9, 25%), con una RM de 3 (IC 95% 1.13-7.96, p = 0.03). No hubo diferencia estadísticamente significativa respecto al tipo de comorbilidad. Conclusiones: la prevalencia identificada muestra una circulación importante del virus en el personal administrativo.

Clinical Effectiveness of Influenza Vaccination After Allogeneic Hematopoietic Stem Cell Transplantation: A Cross-sectional, Prospective, Observational Study.

BACKGROUND: Vaccination is the primary method for preventing influenza respiratory virus infection (RVI). Although the influenza vaccine is able to achieve serological responses in some allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients, its clinical benefits are still uncertain. METHODS: In this prospective, cross-sectional study, we retrospectively analyzed the effect of inactivated trivalent influenza vaccination on the prevalence of influenza RVI in a consecutive cohort of 136 allo-HSCT adult recipients who developed 161 RVI over 5 flu seasons (from 2013 to 2018). Respiratory viruses in upper- and/or lower-respiratory tract specimens were tested using multiplex polymerase chain reaction panel assays. RESULTS: Overall, we diagnosed 74 episodes (46%) of influenza RVI in 70 allo-HSCT recipients. Influenza RVI occurred in 51% of the non-vaccinated compared to 36% of the vaccinated recipients (P = .036). A multivariate analysis showed that influenza vaccination was associated with a lower prevalence of influenza RVI (odds ratio [OR] 0.39, P = .01). A multivariate risk factor analysis of lower-respiratory tract disease (LRTD) identified 2 conditions associated with the probability of influenza RVI progression: influenza vaccination (OR 0.12, 95% confidence interval [CI] 0.014-1, P = .05) and a high-risk immunodeficiency score (OR 36, 95% CI 2.26-575, P = .011). Influenza vaccination was also associated with a lower likelihood of an influenza-related hospital admission (14% vs 2%, P = .04). CONCLUSIONS: This study shows that influenza vaccination may have a clinical benefit in allo-HSCT recipients with virologically-confirmed RVI, in terms of a lower influenza RVI prevalence, slower LRTD progression, and lower likelihood of hospital admission.

Community-acquired respiratory virus lower respiratory tract disease in allogeneic stem cell transplantation recipient: Risk factors and mortality from pulmonary virus-bacterial mixed infections.

Risk factors (RFs) and mortality data of community-acquired respiratory virus (CARVs) lower respiratory tract disease (LRTD) with concurrent pulmonary co-infections in the setting of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is scarce. From January 2011 to December 2017, we retrospectively compared the outcome of allo-HSCT recipients diagnosed of CARVs LRTD mono-infection (n = 52, group 1), to those with viral, bacterial, or fungal pulmonary CARVs LRTD co-infections (n = 15, group 2; n = 20, group 3, and n = 11, group 4, respectively), and with those having bacterial pneumonia mono-infection (n = 19, group 5). Overall survival (OS) at day 60 after bronchoalveolar lavage (BAL) was significantly higher in group 1, 2, and 4 compared to group 3 (77%, 67%, and 73% vs 35%, respectively, P = .012). Recipients of group 5 showed a trend to better OS compared to those of group 3 (62% vs 35%, P = .1). Multivariate analyses showed bacterial co-infection as a RF for mortality (hazard ratio[HR] 2.65, 95% C.I. 1.2-6.9, P = .017). We identified other 3 RFs for mortality: lymphocyte count <0.5 × 109 /L (HR 2.6, 95% 1.1-6.2, P = .026), the occurrence of and CMV DNAemia requiring antiviral therapy (CMV-DNAemia-RAT) at the time of BAL (HR 2.32, 95% C.I. 1.1-4.9, P = .03), and the need of oxygen support (HR 8.3, 95% C.I. 2.9-35.3, P = .004). CARV LRTD co-infections are frequent and may have a negative effect in the outcome, in particular in the context of bacterial co-infections.

Epidemiologic and Clinical Characteristics of Coronavirus and Bocavirus Respiratory Infections after Allogeneic Stem Cell Transplantation: A Prospective Single-Center Study.

Epidemiologic data about coronaviruses (CoVs) and human bocavirus (HBoV) in the setting of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are scarce. We conducted a prospective longitudinal study on respiratory viral infections (RVIs) in allo-HSCT recipients with respiratory symptoms from December 2013 until June 2016. Respiratory virus in upper and/or lower respiratory tract (URT and LRT) specimens were tested using Luminex xTAG RVP Fast v1 assay. Seventy-nine consecutive allo-HSCT recipients developed a total of 192 virologically documented RVI episodes over 30 months. The median follow-up after RVI was 388 days (range, 5 to 923). CoV or HBoV was detected in 27 of 192 episodes (14%); 18 of 79 recipients (23%) developed a total of 21 CoV RVI episodes, whereas 6 recipients (8%) had 1 HBoV RVI episode each. Fourteen CoV RVI episodes were limited to the URT, whereas 7 affected the LRT. Co-pathogens were detected in 8 (38%) CoV cases. Type OC43 CoV was the dominant type (48%) followed by NL63 (24%), KHU1 (19%), and 229E (9%); the CoV hospitalization rate was 19%, whereas mortality was 5% (1 patient without any other microbiologic documentation). Among the 6 recipients with HBoV (3%), only 1 had LRT involvement and no one died from respiratory failure. In 5 cases (83%) HBoV was detected along with other viral co-pathogens. CoV RVIs are common after allo-HSCT, and in a significant proportion of cases CoV progressed to LRT and showed moderate to severe clinical features. In contrast, HBoV RVIs were rare and mostly presented in the context of co-infections.

A risk-adapted approach to treating respiratory syncytial virus and human parainfluenza virus in allogeneic stem cell transplantation recipients with oral ribavirin therapy: A pilot study.

Here we report the applicability of a protocol based on clinical conditions and risk factors (RFs) for managing 35 allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients who developed a total of 52 episodes of respiratory viral infections (RVIs) caused by respiratory syncytial virus (RSV; n=19), human parainfluenza virus (HPIV; n=29), or both (n=4) over a 2-year study period. Risk categories were classified as high risk (cat-1) when the immunodeficiency scoring index was ≥3 and/or ≥3 RFs and/or ≥1 co-infective virus(es) were present; the remaining cases were classified as low risk (cat-0). The presence of two or more signs or symptoms including fever (T>38 °C), sinusitis, otitis, sore throat, tonsillitis, or baseline C-reactive protein increased by >2-fold at the time of the RVI, was considered a clinically-intense episode (CIE). Overall, 34 out of 52 episodes (65%) were limited to upper respiratory tract infections (URTIs). Overall, 26 (50%) received oral ribavirin. Twenty-four of 40 (60%) cat-1 episodes were treated, compared to 2 of 12 (17%) cat-0 RVIs (P=.01), while 17 of the 25 (68%) CIEs were treated compared to 9 of the remaining 27 (33%) episodes (P=.02). Regardless of antiviral therapy, the overall resolution rate was 100% for URTI and 95% for lower respiratory tract infection; the virus-related mortality was low (4%). In conclusion, the use of a risk-adapted protocol to guide therapeutic decisions for allo-HSCT recipients with RSV or HPIV RVIs is feasible and may limit unnecessary antiviral therapy.

High vancomycin MICs within the susceptible range in Staphylococcus aureus bacteraemia isolates are associated with increased cell wall thickness and reduced intracellular killing by human phagocytes.

Vancomycin minimum inhibitory concentrations (MICs) at the upper end of the susceptible range for Staphylococcus aureus have been associated with poor clinical outcomes of bloodstream infections. We tested the hypothesis that high vancomycin MICs in S. aureus bacteraemia isolates are associated with increased cell wall thickness and suboptimal bacterial internalisation or lysis by human phagocytes. In total, 95 isolates were evaluated. Original vancomycin MICs were determined by Etest. The susceptibility of S. aureus isolates to killing by phagocytes was assessed in a human whole blood assay. Internalisation of bacterial cells by phagocytes was investigated by flow cytometry. Cell wall thickness was evaluated by transmission electron microscopy. Genotypic analysis of S. aureus isolates was performed using a DNA microarray system. Vancomycin MICs were significantly higher (P=0.006) in isolates that were killed suboptimally (killing index <60%) compared with those killed efficiently (killing index >70%) and tended to correlate inversely (P=0.08) with the killing indices. Isolates in both killing groups were internalised by human neutrophils and monocytes with comparable efficiency. The cell wall was significantly thicker (P=0.03) in isolates in the low killing group. No genotypic differences were found between the isolates in both killing groups. In summary, high vancomycin MICs in S. aureus bacteraemia isolates were associated with increased cell wall thickness and reduced intracellular killing by phagocytes.