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BACKGROUND: The prevalence of obesity has increased dramatically in children worldwide. Obesity has been recognized as a risk factor for more serious viral respiratory infections, mainly in adults. OBJECTIVE: To study the relationship between overnutrition (obesity and overweight) and clinical severity in children hospitalized with acute respiratory infections of viral origin. METHODS: One hundred and forty-three clinical records of children between 2 and 18 years old hospitalized for acute respiratory infection at Clínica Dávila (2014-2018) were analyzed, recording the respiratory viruses detected at the time of hospitalization, weight, and height. Nutritional status was estimated using Z score or body mass index, according to age. RESULTS: Eighty-tree3 children (58%) were positive for more than one respiratory virus. The main virus detected in monoinfection was adenovirus (9.8%), followed by respiratory syncytial virus (7.7%) and parainfluenza virus (7.7%). There were no deaths. Patients with obesity presented more days of hospitalization (P = .04), oxygen therapy (P = .03) and mechanical ventilation (P < .001), as well as a higher probability of requiring mechanical ventilation (P = .001) and of ICU admission (P = .003) compared with children with normal weight. Patients with overweight presented more days of mechanical ventilation (P < .001) than patients with normal weight. No significant differences were found between the presence of viral coinfection and nutritional status. CONCLUSION: Overnutrition is associated with greater severity of viral respiratory infection in hospitalized children.

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BACKGROUND: The respiratory microbiome is dynamic, varying between anatomical niches, and it is affected by various host and environmental factors, one of which is lifestyle. Few studies have characterized the upper respiratory tract microbiome profile according to lifestyle. We explored the association between lifestyles and microbiota profiles in the upper respiratory tract of healthy adults. METHODS: We analyzed nasal samples from 110 healthy adults who were living in Santiago, Chile, using 16S ribosomal RNA gene-sequencing methods. Volunteers completed a structured questionnaire about lifestyle. RESULTS: The composition and abundance of taxonomic groups varied across lifestyle attributes. Additionally, multivariate models suggested that alpha diversity varied in the function of physical activity, nutritional status, smoking, and the interaction between nutritional status and smoking, although the significant impact of those variables varied between women and men. Although physical activity and nutritional status were significantly associated with all indexes of alpha diversity among women, the diversity of microbiota among men was associated with smoking and the interaction between nutritional status and smoking. CONCLUSIONS: The alpha diversity of nasal microbiota is associated with lifestyle attributes, but these associations depend on sex and nutritional status. Our results suggest that future studies of the airway microbiome may provide a better resolution if data are stratified for differences in sex and nutritional status.

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Background: Little is known about the interaction between the nasopharyngeal bacterial profile and the nutritional status in children. In this study, our main goal was to evaluate the associations between overnutrition and the presence of four potentially pathogenic bacteria in the nasopharynx of infants with viral lower respiratory tract infections (LRTI). In addition, we determined whether changes in the nasopharyngeal bacterial profile were associated with mucosal and serum proinflammatory cytokines and with clinical disease severity. Methods: We enrolled 116 children less than 2 years old hospitalized for viral LRTI during two consecutive respiratory seasons (May 2016 to August 2017); their nutritional status was assessed, and nasopharyngeal and blood samples were obtained. S. aureus, S. pneumoniae, H. influenzae, M. catarrhalis, and respiratory viruses were identified in nasopharyngeal samples by qPCR. Cytokine concentrations were measured in nasopharyngeal and blood samples. Disease severity was assessed by the length of hospitalization and oxygen therapy. Results: Nasopharyngeal pathogenic bacteria were identified in 96.6% of the enrolled children, and 80% of them tested positive for two or more bacteria. The presence and loads of M. catarrhalis was higher (p = 0.001 and p = 0.022, respectively) in children with overnutrition (n = 47) compared with those with normal weights (n = 69). In addition, the detection of >2 bacteria was more frequent in children with overnutrition compared to those with normal weight (p = 0.02). Multivariate regression models showed that the presence and loads of S. pneumoniae and M. catarrhalis were associated with higher concentrations of IL-6 in plasma and TNF-α in mucosal samples in children with overnutrition. Conclusions: The nasopharyngeal profile of young children with overnutrition was characterized by an over representation of pathogenic bacteria and proinflammatory cytokines.

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Control of the COVID-19 pandemic largely depends on the effectiveness of the vaccination process. An understanding of the factors that underlie the willingness to accept vaccination contributes pivotal information to controlling the pandemic. We analyzed the association between the willingness to accept the available COVID-19 vaccines and vaccine determinants amidst the Chilean vaccination process. Individual-level survey data was collected from 744 nationally representative respondents and multivariate regression models were used to estimate the association between outcome and explanatory variables. We found that trust in COVID-19 vaccines, scientists, and medical professionals significantly increased the willingness to: accept the vaccines and booster doses, as well as annual vaccinations and the vaccination of children. Our results are critical to understanding the acceptance of COVID-19 vaccines in the context of a country with one of the world's highest vaccination rates. We provide useful information for decision-making and policy design, in addition to establishing guidelines regarding how to effectively explain vaccination programs to citizens.

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RESUMEN La obesidad ha sido identificada como factor de riesgo de severidad de infecciones respiratorias. Apoyar la respuesta inmune en sujetos obesos es de interés. El presente trabajo evaluó el efecto del consumo de un extracto de calafate sobre marcadores de respuesta inmune en ratones delgados y obesos. Ratones C57BL/6J machos fueron expuestos por 82 días a dieta estándar (DE) y alta en grasas (DAG). A un subgrupo de ambos grupos, se les administró 50 y 100 mg [polifenoles totales]/kg peso de animal/día, de extracto, en las últimas dos semanas. Se evaluó expresión génica y secreción de marcadores de respuesta inmune, en tejido pulmonar y plasma. Se observó un efecto del tratamiento con extracto en la expresión de IFN-ϓ. Se observaron efectos inducidos por la DAG y el tratamiento con extracto de manera independiente, en la expresión de IL-12. Se observó un efecto global de la DAG sobre IFN-ϓ plasmático, específicamente una disminución en animales alimentados con DAG. Se observó una interacción entre la dieta y el tratamiento con extracto sobre IL-12 plasmática. El tratamiento utilizado modula marcadores que activan la respuesta inmune ante infecciones respiratorias principalmente de origen viral, en animales delgados y obesos.

ABSTRACT Obesity has been identified as a risk factor for severity of respiratory infections. Thus, the support of the immune response in obese subjects is of interest. The present work evaluated the effect of the consumption of a calafate extract on markers of the immune response in lean and obese mice. Male C57BL/6J mice were exposed for 82 days to a standard or a high-fat diet (HFD). A subgroup of both groups was given 50 and 100 mg [total polyphenols]/kg body weight/day of extract in the last two weeks. Gene expression and secretion of immune response markers were evaluated in lung tissue and plasma. An effect of extract treatment on IFN-ϓ expression was observed. Effects induced by the HFD and treatment with extract were observed independent of the expression of IL-12. An overall effect of the HF diet on plasma IFN-ϓ was observed, specifically a decrease in animals fed the HFD. An interaction between diet and extract treatment was observed over plasma IL-12. The treatment used modulates markers that activate the immune response to respiratory infections, mainly of viral origin, in lean and obese animals.

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We analyze the transmission routes, possible viral reservoirs in the oral cavity and considerations about dental care of SARS-CoV-2 virus infection. We also analyze the protocols required before and after a dental procedure, aiming to increase the awareness of dentists about the importance of virus spread prevention among health care workers and patients. The evaluation of symptoms associated with SARS- CoV-2 such as fever, fatigue, dry cough, myalgia, dyspnea, and the inquiry about possible contacts with infected people is of utmost importance. The tongue and oral mucosa are important viral reservoirs and the transmission of the virus occurs primarily by saliva droplets. Therefore, elective dental care should be postponed, attending only dental emergencies during this period, incorporating the use of protective personal equipment (PPE) and using manual instruments to prevent the production of aerosols.

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Objective: To investigate the relationship of overnutrition (obese and overweight) with severity of illness in children hospitalized with acute lower respiratory infections (ALRIs), frequency of viral coinfections and leptin levels. Methods: We studied 124 children <2 years old that were hospitalized for ALRI. Nutritional status was calculated by z-scores according to weight-for-age z-scores, length or height-for-age z-scores, and weight-for-height z-scores. Nasopharyngeal aspirates (NPAs) were obtained and viral respiratory pathogens were identified using reverse transcription polymerase chain reactions (RT-PCR). Respiratory syncytial virus (RSV) load was assessed using quantitative RT-PCR. NPA and plasma leptin level were measured. Clinical data and nutritional status were recorded, and patients were followed up until hospital discharge. Viral coinfection was defined as the presence of two or more viruses detected in the same respiratory sample. Severity of illness was determined by length of hospitalization and duration of oxygen therapy. Results: Children with overnutrition showed a greater frequency of viral coinfection than those with normal weight (71% obese vs. 37% normal weight p = 0.013; 68% overweight vs. 37% normal weight p = 0.004). A lower RSV load was found in obese (5.91 log10 copies/mL) and overweight children (6.49 log10 copies/mL) compared to normal weight children (8.06 log10 copies/mL; p = 0.021 in both cases). In multivariate analysis, obese, and overweight infants <6 months old were associated with longer hospital stays (RR = 1.68; CI: 1.30-2.15 and obese: RR = 1.68; CI: 1.01-2.71, respectively) as well as a greater duration of oxygen therapy (RR = 1.80; IC: 1.41-2.29 and obese: RR = 1.91; CI: 1.15-3.15, respectively). Obese children <6 months showed higher plasma leptin level than normal weight children (7.58 vs. 5.12 ng/µl; p <0.046). Conclusions: In infants younger than 6 months, overnutrition condition was related to increased severity of infections and high plasma leptin level. Also, children with overnutrition showed a greater frequency of viral coinfection and low RSV viral load compared to normal weights children. These findings further contribute to the already existent evidence supporting the importance of overnutrition prevention in pediatric populations.

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We analyze the transmission routes, possible viral reservoirs in the oral cavity and considerations about dental care of SARS-CoV-2 virus infection. We also analyze the protocols required before and after a dental procedure, aiming to increase the awareness of dentists about the importance of virus spread prevention among health care workers and patients. The evaluation of symptoms associated with SARS- CoV-2 such as fever, fatigue, dry cough, myalgia, dyspnea, and the inquiry about possible contacts with infected people is of utmost importance. The tongue and oral mucosa are important viral reservoirs and the transmission of the virus occurs primarily by saliva droplets. Therefore, elective dental care should be postponed, attending only dental emergencies during this period, incorporating the use of protective personal equipment (PPE) and using manual instruments to prevent the production of aerosols.

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Obesity has a high prevalence among children. On the other hand, acute respiratory infections especially of viral origin, are an important cause of morbidity and mortality in this age group. During the recent pandemic of influenza A (H1N1) virus, obesity was identified as a novel independent risk factor for severity multiple markers of the disease. We reviewed the evidence associating obesity with a worse course of respiratory diseases in children. Nine out of 40 retrieved articles, were chosen to be reviewed. We concluded that there is evidence suggesting that immunomodulatory effects of obesity could be considered as a novel risk factor. Thus, bearing in mind the drastic rise in obesity prevalence around the world and in Chile, and the latent possibility of new respiratory pandemics caused by viruses, studying the possible effect of obesity aggravating viral respiratory infections will become important.

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Obesity has a high prevalence among children. On the other hand, acute respiratory infections especially of viral origin, are an important cause of morbidity and mortality in this age group. During the recent pandemic of influenza A (H1N1) virus, obesity was identified as a novel independent risk factor for severity multiple markers of the disease. We reviewed the evidence associating obesity with a worse course of respiratory diseases in children. Nine out of 40 retrieved articles, were chosen to be reviewed. We concluded that there is evidence suggesting that immunomodulatory effects of obesity could be considered as a novel risk factor. Thus, bearing in mind the drastic rise in obesity prevalence around the world and in Chile, and the latent possibility of new respiratory pandemics caused by viruses, studying the possible effect of obesity aggravating viral respiratory infections will become important.

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Paralytic shellfish poisoning (PSP) toxins are a group of naturally occurring neurotoxic alkaloids produced among several genera of primarily freshwater cyanobacteria and marine dinoflagellates. Although saxitoxin (STX) and analogs are all potent Na(+) channel blockers in vertebrate cells, the functional role of these compounds for the toxigenic microorganisms is unknown. Based upon the known importance of monovalent cations (such as sodium) in the maintenance of cellular homeostasis and ion channel function, we examined the effect of high extracellular concentrations of these ions on growth, cellular integrity, toxin production and release to the external medium in the filamentous freshwater cyanobacterium, Raphidiopsis brookii D9; a gonyautoxins (GTX2/3) and STX producing toxigenic strain. We observed a toxin export in response to high (17 mM) NaCl and KCl concentrations in the growth medium that was not primarily related to osmotic stress effects, compared to the osmolyte mannitol. Addition of exogenous PSP toxins with the same compositional profile as the one produced by R. brookii D9 was able to partially mitigate this effect of high Na⁺ (17 mM). The PSP toxin biosynthetic gene cluster (sxt) in D9 has two genes (sxtF and sxtM) that encode for a MATE (multidrug and toxic compound extrusion) transporter. This protein family, represented by NorM in the bacterium Vibrio parahaemolyticus, confers resistance to multiple cationic toxic agents through Na⁺/drug antiporters. Conserved domains for Na⁺ and drug recognition have been described in NorM. For the D9 sxt cluster, the Na⁺ recognition domain is conserved in both SxtF and SxtM, but the drug recognition domain differs between them. These results suggest that PSP toxins are exported directly in response to the presence of monovalent cations (Na⁺, K⁺) at least at elevated concentrations. Thus, the presence of both genes in the sxt cluster from strain D9 can be explained as a selective recognition mechanism by the SxtF/M transporters for GTX2/3 and STX. We propose that these toxins in cyanobacteria could act extracellularly as a protective mechanism to ensure homeostasis against extreme salt variation in the environment.

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The outbreak of pandemic influenza A (H1N1) 2009 virus caused the first influenza pandemic disease of the 21st century. In August 2010, the pandemic moved into the post-pandemic period. However, localized outbreaks of various magnitudes continued with a higher rate of disease severity. The aim of this study was to assess a new polymerase chain reaction (PCR)-oligochromatographic assay (Speed-Oligo) in the diagnosis of novel influenza A (H1N1) 2009. A total of 405 nasopharyngeal aspirate specimens from 400 pediatric and adults patients with suspected infection of pandemic influenza A (H1N1) 2009 were analyzed. The sensitivity and specificity values of the Speed-Oligo assay in comparison to reverse transcriptase-PCR assay developed by the Centers for Disease Control and Prevention were 86.5% and 92.2%, respectively. The new assay is simple, rapid, and provides a good sensitivity for detection of influenza A (H1N1) 2009. This assay might be a good alternative to real-time PCR assays for laboratories not equipped with real-time PCR instruments.

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Two commercial polymerase chain reaction (PCR) assays (a real-time PCR [Cepheid] and an oligochromatographic test [Speed-oligo]) and 1 serology test (Serodia-Myco II) for detecting Mycoplasma pneumoniae in nasopharyngeal aspirates and serum samples were studied. Among the 145 samples, 32 serum pairs were serologically positive for M. pneumoniae. Of these, in 30 nasopharyngeal aspirates, M. pneumoniae was detected using the real-time PCR assay and 25 using Speed-oligo, corresponding to a sensitivity of 93.7% and 78.1%, respectively. Among the 94 samples with negative serology, we only obtained 1 positive result by real-time PCR assay. In the group of samples from healthy children, no positive results were obtained.

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We have evaluated the quantitative T-cell response after specific Mycobacterium tuberculosis antigen stimulation in active tuberculosis (TB) and latent TB infection (LTBI) patients. In adults, the median number of T cells after RD1 antigen stimulation was significantly higher in active TB patients than in LTBI patients. In children, the number of responder T cells against the specific antigens was higher in active TB than in LTBI patients, although the differences were not significant. In summary, in patients with suspected clinical TB, although there is overlapping in the number of responder T cells between both groups, a T-cell count above the described threshold could suggest active TB, especially in patients with a high probability of having active TB and low probability of having LTBI. In addition, the results are consistent with the current evidence that T-cell response may indicate mycobacterial burden and disease activity.

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The aim of the study was to assess a new latex agglutination (LA) stool antigen assay (PYLOGEN; CerTest Biotec, Zaragoza, Spain) in the diagnosis of Helicobacter pylori infection and to monitor its eradication after treatment. The LA test has been approved for sale in Europe, and its approval from the US Food and Drug Administration is still pending. The individuals enrolled were classified into 3 groups of patients: Group 1 consisted of 38 patients who are H. pylori positive. The diagnosis of H. pylori infection was established if there was concordance between 2 test results (urea breath test [UBT], rapid urease test, and histopathologic study) or if the culture alone was positive. Patients with only 1 positive test were considered indeterminate and were excluded from the study. Group 2 comprised 9 patients without positive tests and who were considered to be H. pylori negative. Group 3 consisted of 57 patients who received eradication treatment. The sensitivity and specificity of the test were 78.9% and 100%, respectively. The results of the UBT of the patients were studied 6 weeks after eradication therapy. The sensitivity and specificity of the LA test relative to UBT for patients after treatment were 75% and 93.3%, respectively.

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Nine hundred cases of seafood related diarrhea were reported in the region of Puerto Montt, Chile during the austral summer of 2006. This is the continuation of the large outbreaks associated with the consumption of seafood containing the Vibrio parahaemolyticus serovar O3:K6 pandemic clonal group that arose last decade in Chile. The initial outbreaks occurred during the summer of 1998 in Antofagasta (23 degrees 39'S 70 degrees 24'W). Subsequently, outbreaks there were rare, but since 2004 outbreaks have been frequent farther south in Puerto Montt (41 degrees 29'S 72 degrees 24'W). The large outbreaks in Puerto Montt and their rarity in Antofagasta is atypical because the seawater temperature at Puerto Montt is 5 degrees C lower than at Antofagasta and the presence of V. parahaemolyticus in seafood has been associated with higher water temperatures. To better understand the role of seafood in outbreak occurrences in these regions, we analyzed the V. parahaemolyticus populations in clinical cases and shellfish from Puerto Montt during diarrhea outbreaks in 2006 and in shellfish from Antofagasta, where no cases were observed. Enrichment culture from shellfish yielded no V. parahaemolyticus from samples from the north, but its presence was detected in 80% of the samples from the south. Grouping of the V. parahaemolyticus isolates by the fragment restriction pattern of their DNA showed that all pathogenic (tdh+) isolates obtained from Puerto Montt shellfish corresponded to the serovar O3:K6 South East Asian pandemic clone, while the non-pathogenic (tdh-) isolates corresponded to at least six discrete groups. The possible causes for the disappearance of the pandemic strain from the north and its persistence in the south are discussed.

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Large epidemics of diarrhoea associated with seafood consumption and Vibrio parahaemolyticus occurred during the austral summers of 2004 and 2005 in the environs of Puerto Montt, Chile (41 degrees 29'S 72 degrees 24'W). There are no reports of V. parahaemolyticus infections before 2004 in this region, their absence being explained by the low ocean temperatures which seldom reach 16 degrees C. We analysed V. parahaemolyticus obtained from shellfish and clinical samples during epidemics. Isolates were examined using conventional protocols and an improved method for restriction enzyme analysis using total bacterial DNA which permits direct genome restriction enzyme analysis by conventional gel electrophoresis (DGREA) with a similar discrimination index as restriction fragment length polymorphism-pulsed field gel electrophoresis (RFLP-PFGE). Analysis of clinical samples showed that the epidemics were caused by the V. parahaemolyticus O3:K6 pandemic clonal group. On the other hand, analysis of shellfish samples during both epidemics showed that 53% contained V. parahaemolyticus (3-93 g(-1)). Detailed analysis of 50 positive shellfish samples showed that only three contained detectable levels of the pandemic clone. Most V. parahaemolyticus isolates obtained from shellfish corresponded to non-pandemic clones differentiated into 14 groups by DGREA. In summary, the causative agent during epidemics was only a minor component of a small but diverse population of V. parahaemolyticus in shellfish.

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