Duration of vaccine protection against breakthrough infections during five COVID-19 waves among healthcare workers primarily vaccinated with CoronaVac.

We aimed to characterise vaccine-induced protection against COVID-19 during five waves caused by Variants of Concern (VOCs). This is a nested case-control study of 3,972 HCW primarily vaccinated with CoronaVac (98%) that evaluated symptomatic SARS-CoV-2 breakthrough infections (BI) in almost two-years follow-up until the 3rd Omicron wave. Predictors of protection against SARS-CoV-2 BI were analysed using conditional logistic regression models. We included 1,491 SARS-CoV-2 breakthrough cases, mostly mild, and 2,962 controls. Most participants (90%) had received at least one booster before the onset of the Omicron waves, mainly BNT162b2. A multivariate logistic regression showed that vaccine-induced protection against BI wanes after six months regardless of the number of monovalent booster doses. Additionally, booster dose with BNT162b2 showed a trend for higher protection compared to CoronaVac during the Omicron waves. In conclusion, immunity of monovalent booster doses against SARS-CoV-2 is short-lasting. Individuals previously vaccinated with an inactivated vaccine should receive a BNT162B2 booster dose.

The effect of water molecules on paraquat salts: from physicochemical properties to environmental impact in the Brazilian Cerrado.

Introduction: The green revolution model that is followed in the Brazilian Cerrado is dependent on mechanization, chemical fertilization for soil dressing and correction, and the use of herbicides. Paraquat is a methyl viologen herbicide marketed as bipyridylium dichloride salts and used (in low doses) to combat weeds in their post-emergence stage. It is a non-selective pesticide that causes the peroxidation of the lipids that make up the cell membrane, and when it comes into contact with foliage, it results in the death of the plant. Methods: The effect of water molecules co-crystallized in Paraquat salt structures was analyzed in anhydrous, dihydrate, and trihydrate forms to understand those physicochemical properties in its redox activity. The frontier molecular orbitals were also carried out using DFT to obtain the chemical reactivity of the bipyridylium cation. Finally, the supramolecular arrangements were evaluated to analyze the physicochemical stability and acquire insights on superoxide anions. Results and discussion: The electronic structure indicated that the BP cation presents an acidic character due to its low ELUMO value, while the salt has a more basic character due to its high EHOMO value. For this reason, the BP ion is more susceptible to reduction during the weeds' photosynthesis process. During the process of plant photosynthesis, PQ is reduced to form a stable radical cation. In the supramolecular arrangement, the presence of water molecules increases the number of strong H-bonds, while the weak/moderate H-bonds are stabilized. PQ's toxic effects are observed in wildlife, domesticated animals, human populations, and ecosystems. The influence of PQ on the terrestrial environment is limited because of the soil adsorption capacity associated with good agricultural practices. The current use of good agricultural practices in the Cerrado seems not to prevent the environmental impacts of herbicides like PQ because it aims for the expansion and profitability of large-scale farming based on input-intensive practices instead of sustainable agriculture processes.

(E)-2-Benzylidenecyclanones: Part XVIII Study the Possible Link between Glutathione Reactivity and Cancer Cell Cytotoxic Effects of Some Cyclic Chalcone Analogs A Comparison of the Reactivity of the Open-Chain and the Seven-Membered Homologs.

Non-enzymatic thiol addition into the α,ß-unsaturated carbonyl system is associated with several biological effects. In vivo, the reactions can form small-molecule thiol (e.g., glutathione) or protein thiol adducts. The reaction of two synthetic (4'-methyl- and 4'-methoxy substituted) cyclic chalcone analogs with reduced glutathione (GSH) and N-acetylcysteine (NAC) was studied by (high-pressure liquid chromatography-ultraviolet spectroscopy) HPLC-UV method. The selected compounds displayed in vitro cancer cell cytotoxicity (IC50) of different orders of magnitude. The structure of the formed adducts was confirmed by (high-pressure liquid chromatography-mass spectrometry) HPLC-MS. The incubations were performed under three different pH conditions (pH 3.2/3.7, 6.3/6.8, and 8.0/7.4). The chalcones intrinsically reacted with both thiols under all incubation conditions. The initial rates and compositions of the final mixtures depended on the substitution and the pH. The frontier molecular orbitals and the Fukui function were carried out to investigate the effects on open-chain and seven-membered cyclic analogs. Furthermore, machine learning protocols were used to provide more insights into physicochemical properties and to support the different thiol-reactivity. HPLC analysis indicated diastereoselectivity of the reactions. The observed reactivities do not directly relate to the different in vitro cancer cell cytotoxicity of the compounds.

Healthcare-associated infections on the intensive care unit in 21 Brazilian hospitals during the early months of the coronavirus disease 2019 (COVID-19) pandemic: An ecological study.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has caused a global health crisis and may have affected healthcare-associated infection (HAI) prevention strategies. We evaluated the impact of the COVID-19 pandemic on HAI incidence in Brazilian intensive care units (ICUs). METHODS: In this ecological study, we compared adult patients admitted to the ICU from April through June 2020 (pandemic period) with the same period in 2019 (prepandemic period) in 21 Brazilian hospitals. We used the Wilcoxon signed rank-sum test in a pairwise analysis to compare the following differences between the pandemic and the prepandemic periods: microbiologically confirmed central-line-associated bloodstream infection (CLABSI) and ventilator-associated pneumonia (VAP) incidence density (cases per 1,000 central line and ventilator days, respectively), the proportion of organisms that caused HAI, and antibiotic consumption (DDD). RESULTS: We detected a significant increase in median CLABSI incidence during the pandemic: 1.60 (IQR, 0.44-4.20) vs 2.81 (IQR, 1.35-6.89) (P = .002). We did not detect a significant difference in VAP incidence between the 2 periods. In addition, we detected a significant increase in the proportion of CLABSI caused by Enterococcus faecalis and Candida spp during the pandemic, although only the latter retained statistical significance after correction for multiple comparisons. We did not detect a significant change in ceftriaxone, piperacillin-tazobactam, meropenem, or vancomycin consumption between the studied periods. CONCLUSIONS: There was an increase in CLABSI incidence in Brazilian ICUs during the first months of COVID-19 pandemic. Additionally, we detected an increase in the proportion of CLABSI caused by E. faecalis and Candida spp during this period. CLABSI prevention strategies must be reinforced in ICUs during the COVID-19 pandemic.

Risk factors for reduction in adherence to protective measures following coronavirus disease 2019 (COVID-19) vaccination and vaccine perceptions among healthcare workers, in São Paulo, Brazil.

A survey evaluated 2,300 healthcare workers following the first dose of a coronavirus disease 2019 (COVID-19) vaccine in a tertiary-quaternary hospital in São Paulo, Brazil. Adherence to protective measures following vaccination was compared to previous non-work-related behaviors. Younger age, previous COVID-19, and burnout symptoms were associated with reduced adherence to mitigation measures.

Insights into chalcone analogues with potential as antioxidant additives in diesel-biodiesel blends.

Biodiesel production is one of the promising strategies to reduce diesel consumption and an important contribution to climate change. However, biodiesel stability remains a challenging problem in biofuel use in the global energy matrix. In this context, organic additives have been investigated to minimize these problems and reduce harmful emissions to comply with fuel requirement standards. In this study, we discuss a comprehensive structural description, a behavior of B15 [85% volume of diesel and 15% volume of biodiesel (B100)] stability in the presence of antioxidants (chalcone analogues), and a theoretical calculation to pave the way for clarifying and expanding the potential of title compounds as an antioxidant additive for diesel-biodiesel blends. Finally, a systematic description of the oxidation stability was undertaken using a specialized machine learning computational pySIRC platform.

New Insights on Glutathione's Supramolecular Arrangement and Its In Silico Analysis as an Angiotensin-Converting Enzyme Inhibitor.

Angiotensin-converting enzyme (ACE) inhibitors are one of the most active classes for cardiovascular diseases and hypertension treatment. In this regard, developing active and non-toxic ACE inhibitors is still a continuous challenge. Furthermore, the literature survey shows that oxidative stress plays a significant role in the development of hypertension. Herein, glutathione's molecular structure and supramolecular arrangements are evaluated as a potential ACE inhibitor. The tripeptide molecular modeling by density functional theory, the electronic structure by the frontier molecular orbitals, and the molecular electrostatic potential map to understand the biochemical processes inside the cell were analyzed. The supramolecular arrangements were studied by Hirshfeld surfaces, quantum theory of atoms in molecules, and natural bond orbital analyses. They showed distinct patterns of intermolecular interactions in each polymorph, as well as distinct stabilizations of these. Additionally, the molecular docking study presented the interactions between the active site residues of the ACE and glutathione via seven hydrogen bonds. The pharmacophore design indicated that the hydrogen bond acceptors are necessary for the interaction of this ligand with the binding site. The results provide useful information for the development of GSH analogs with higher ACE inhibitor activity.

Bromine Substitution Effect on Structure, Reactivity, and Linear and Third-Order Nonlinear Optical Properties of 2,3-Dimethoxybenzaldehyde.

The structural and electronic properties of 2,3-dimethoxybenzaldehyde (2,3-DMB), 5-bromo-2,3-dimethoxybenzaldehyde (5-BRB), and 6-bromo-2,3-dimethoxybenzaldehyde (6-BRB) were extensively discussed with emphasis on linear and nonlinear optical responses. The intermolecular interactions were comparatively studied by Hirshfeld surfaces, quantum theory of atoms in molecules (QTAIM), and natural bond orbitals (NBOs), indicating that bromine substitution decreases the H···H and C···H contacts and increases H···Br and Br···Br closed-shell interactions on crystalline arrangements. The frontier molecular orbitals and molecular electrostatic potential map, carried out at the CAM-B3LYP/6-311++G(d,p) level of theory, showed that the kinetic stability occurs in the increasing order 6-BRB < 5-BRB < 2.3-DMB. The bromine atom has a beneficial effect on the nonlinear third-order susceptibility of 2,3-DMB, with theoretical predictions of 89.54 ×10-22 and 83.15 ×10-22 (m/V)2 for 6-BRB and 5-BRB, respectively. These findings were favorably compared with available theoretical and experimental data of other organic crystals that may be promising as NLO materials.

Theoretical analysis of the effects of counterions on the supramolecular arrangement of sulfamethoxazole.

Active pharmaceutical ingredients are formulated as the salt form, aiming to modulate their physicochemical properties. In this regard, the optimization and choice of the salt former have a strong influence on toxicity, therapeutic efficiency, and bioavailability. Sulfamethoxazole (SMZ) salts with Na+, Cl-, and Br- counterions influence in the supramolecular arrangement as well as in their thermodynamic and kinetic parameters. Herein, we analyzed the interactions of the Na+, Cl-, and Br- counterions on the supramolecular arrangement of the sulfamethoxazole salts by Hirshfeld surfaces, fingerprint plots, and theoretical methods-quantum theory of atoms in molecules and natural bond orbitals. Moreover, we evaluated their electronic structure by density functional theory using calculation of the frontier molecular orbitals. Molecular electrostatic potential maps were also obtained to predict the interactions of the counterions along crystalline arrangements. We observed that the structures of [SMZ]+ and [SMZ]- ions differ slightly from the SMZ. The chemical reactivity indices show that the SMZ is kinetically more stable than its respective ions, while its anion is more polarizable, and its cation has a higher global electrophilicity index. The molecular electrostatic potential maps show high charge density in the sulfonyl group (nucleophilic region) and the heterocyclic amino group (electrophilic region). Although the molecular skeleton is identical among the three SMZ species and the presence of different counterions in the formation of the crystalline structure of the salts results in supramolecular arrangements with different patterns of intermolecular interactions, despite being very similar in terms of intensities.

Characterization of Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Variant Shedding and Predictors of Viral Culture Positivity on Vaccinated Healthcare Workers With Mild Coronavirus Disease 2019.

In this prospective cohort of 30 vaccinated healthcare workers with mild Omicron variant infection, we evaluated viral culture, rapid antigen test (RAT), and real-time reverse-transcription polymerase chain reaction (RT-PCR) of respiratory samples at days 5, 7, 10, and 14. Viral culture was positive in 46% (11/24) and 20% (6/30) of samples at days 5 and 7, respectively. RAT and RT-PCR (Ct ≤35) showed 100% negative predictive value (NPV), with positive predictive values (PPVs) of 32% and 17%, respectively, for predicting viral culture positivity. A lower RT-PCR threshold (Ct ≤24) improved culture prediction (PPV = 39%; NPV = 100%). Vaccinated persons with mild Omicron infection are potentially transmissible up to day 7. RAT and RT-PCR might be useful tools for shortening the isolation period.

Impact of Discontinuing Levofloxacin Prophylaxis on Bloodstream Infections in Neutropenic Hematopoietic Stem Cell Transplantation Patients.

Multidrug-resistant pathogens have emerged worldwide. We have driven the hypothesis that the non-use of fluoroquinolone prophylaxis during neutropenia could reduce antibiotic resistance in Gram-negative bacteria that cause bloodstream infections (BSIs) in hematopoietic stem cell transplantation (HSCT) patients and that this change in resistance pattern could lead to an impact on BSI mortality. This is a quasi-experimental study comparing BSI incidence, resistance patterns of bacteria that cause BSI, and BSI mortality when levofloxacin prophylaxis was routine for neutropenic HSCT patients (2016-2018) to when fluoroquinolone prophylaxis was discontinued in our center (2019). Bivariate comparisons and multivariate logistic regression models were used for analyses. A total of 310 HSCTs (66 (21%) allogeneic and 244 (79%) autologous) were performed during the study period. Sixty (19%) patients had BSIs, 30 in each evaluated period. The discontinuation of levofloxacin prophylaxis was associated with an increase in BSI incidence and a decrease in the resistance rates of causative BSI bacteria and in BSI 30-day mortality. The increase in the rate of resistant bacteria causing BSI and in BSI mortality might outweigh the benefits of a decrease in BSI incidence caused by fluoroquinolone prophylaxis in neutropenic HSCT patients. We suggest that the routine use of fluoroquinolone in this context be revisited.

SARS-Cov-2 seroprevalence and risk factors among health care workers: Estimating the risk of COVID-19 dedicated units.

We evaluated the seroprevalence of SARS-CoV-2 and risk factors among 1,996 oligo/asymptomatic health care workers. The seroprevalence was 5.5% and risk factors associated with being infected with SARS-CoV-2 was professional category of cleaning (adj odds ratio 2.22, 95% confidence interval: 1.12-4.44, P: .023) and male gender (adj odds ratio: 1.54, 95% confidence interval: 1.03-2.32, P: .035).Working at dedicated COVID-19 units (high-risk group) was not an independent risk factor for seropositivity.

Seasonality of distinct respiratory viruses in a tropical city: implications for prophylaxis.

OBJECTIVE: The frequency and seasonality of viruses in tropical regions are scarcely reported. We estimated the frequency of seven respiratory viruses and assessed seasonality of respiratory syncytial virus (RSV) and influenza viruses in a tropical city. METHODS: Children (age ≤ 18 years) with acute respiratory infection were investigated in Salvador, Brazil, between July 2014 and June 2017. Respiratory viruses were searched by direct immunofluorescence and real-time polymerase chain reaction for detection of RSV, influenza A virus, influenza B virus, adenovirus (ADV) and parainfluenza viruses (PIV) 1, 2 and 3. Seasonal distribution was evaluated by Prais-Winsten regression. Due to similar distribution, influenza A and influenza B viruses were grouped to analyse seasonality. RESULTS: The study group comprised 387 cases whose median (IQR) age was 26.4 (10.5-50.1) months. Respiratory viruses were detected in 106 (27.4%) cases. RSV (n = 76; 19.6%), influenza A virus (n = 11; 2.8%), influenza B virus (n = 7; 1.8%), ADV (n = 5; 1.3%), PIV 1 (n = 5; 1.3%), PIV 3 (n = 3; 0.8%) and PIV 2 (n = 1; 0.3%) were identified. Monthly count of RSV cases demonstrated seasonal distribution (b3 = 0.626; P = 0.003). More than half (42/76 [55.3%]) of all RSV cases were detected from April to June. Monthly count of influenza cases also showed seasonal distribution (b3 = -0.264; P = 0.032). Influenza cases peaked from November to January with 44.4% (8/18) of all influenza cases. CONCLUSIONS: RSV was the most frequently detected virus. RSV and influenza viruses showed seasonal distribution. These data may be useful to plan the best time to carry out prophylaxis and to increase the number of hospital beds.

Effect of ortho- and para-chlorine substitution on hydroxychlorochalcone.

This work describes a comparative molecular structure of two hydroxychlorochalcones with an emphasis on their planarity. Hirshfeld surface analysis investigates the effect of ortho- and para-chlorine substitution on supramolecular arrangement and physical chemical properties. The molecular conformation of 2'-hydroxy-4',6'-dimethyl-2-chlorochalcone and 2'-hydroxy-4',6'-dimethyl-4-chlorochalcone chalcones was obtained through DFT with the exchange-correlation functional M06-2X and the 6-311++G(2d,2p) basis set, and the results were compared with the experimental X-ray data in order to get insights on the effect of ortho- and para-chlorine substitution. The charge transfer into entire main carbon chain was also investigated using frontier molecular orbitals (HOMO and LUMO), NBO, and MEP map in order to describe the comparative conformational stability due to the resonance effect produced by π electron displacements. Finally, the intermolecular observed interactions were analyzed by QTAIM, with the M06-2X/6-311G++(d,p) theory level.

Predictors of mortality in patients with yellow fever: an observational cohort study

BACKGROUND: Yellow fever virus infection results in death in around 30% of symptomatic individuals. The aim of this study was to identify predictors of death measured at hospital admission in a cohort of patients admitted to hospital during the 2018 outbreak of yellow fever in the outskirts of São Paulo city, Brazil. METHODS: In this observational cohort study, we enrolled patients with yellow fever virus from two hospitals in São Paolo­the Hospital das Clínicas, University of São Paulo and the Infectious Diseases Institute "Emilio Ribas". Patients older than 18 years admitted to hospital with fever or myalgia, headache, arthralgia, oedema, rash, or conjunctivitis were consecutively screened for inclusion in the present study. Consenting patients were included if they had travelled to geographical areas in which yellow fever virus cases had been previously confirmed. Yellow fever infection was confirmed by real-time PCR in blood collected at admission or tissues at autopsy. We sequenced the complete genomes of yellow fever virus from infected individuals and evaluated demographic, clinical, and laboratory findings at admission and investigated whether any of these measurements correlated with patient outcome (death). FINDINGS: Between Jan 11, 2018, and May 10, 2018, 118 patients with suspected yellow fever were admitted to Hospital das Clínicas, and 113 patients with suspected yellow fever were admitted to Infectious Diseases Institute "Emilio Ribas". 95 patients with suspected yellow fever were included in the study, and 136 patients were excluded. Three (3%) of 95 patients with suspected yellow fever who were included in the study were excluded because they received a different diagnosis, and 16 patients with undetectable yellow fever virus RNA were excluded. Therefore, 76 patients with confirmed yellow fever virus infection, based on detectable yellow fever virus RNA in blood (74 patients) or yellow fever virus confirmed only at the autopsy report (two patients), were included in our analysis. 27 (36%) of 76 patients died during the 60 day period after hospital admission. We generated 14 complete yellow fever virus genomes from the first 15 viral load-detectable samples. The genomes belonged to a single monophyletic clade of the South America I genotype, sub-genotype E. Older age, male sex, higher leukocyte and neutrophil counts, higher alanine aminotransferase, aspartate transaminase (AST), bilirubin, and creatinine, prolonged prothrombin time, and higher yellow fever virus RNA plasma viral load were associated with higher mortality. In a multivariate regression model, older age, elevated neutrophil count, increased AST, and higher viral load remained independently associated with death. All 11 (100%) patients with neutrophil counts of 4000 cells per mL or greater and viral loads of 5·1 log10 copies/mL or greater died (95% CI 72­100), compared with only three (11%) of 27 (95% CI 2­29) among patients with neutrophil counts of less than 4000 cells per mL and viral loads of less than 5·1 log10 copies/mL. INTERPRETATION: We identified clinical and laboratory predictors of mortality at hospital admission that could aid in the care of patients with yellow fever virus. Identification of these prognostic markers in patients could help clinicians prioritise admission to the intensive care unit, as patients often deteriorate rapidly. Moreover, resource allocation could be improved to prioritise key laboratory examinations that might be more useful in determining whether a patient could have a better outcome. Our findings support the important role of the virus in disease pathogenesis, suggesting that an effective antiviral could alter the clinical course for patients with the most severe forms of yellow fever

Impact of human immunodeficiency virus infection on mortality of patients who acquired healthcare associated-infection in critical care unit.

To evaluate 30-day mortality in human immunodeficiency virus (HIV) and non-HIV patients who acquired a healthcare-associated infection (HAI) while in an intensive care unit (ICU), and to describe the epidemiological and microbiological features of HAI in a population with HIV.This was a retrospective cohort study that evaluated patients who acquired HAI during their stay in an Infectious Diseases ICU from July 2013 to December 2017 at a teaching hospital in Brazil.Data were obtained from hospital infection control committee reports and medical records. Statistical analysis was performed using SPSS and a multivariate model was used to evaluate risk factors associated with 30-day mortality. Epidemiological, clinical, and microbiological characteristics of HAI in HIV and non-HIV patients and 30-day mortality were also evaluated.Among 1045 patients, 77 (25 HIV, 52 non-HIV) patients acquired 106 HAI (31 HIV, 75 non-HIV patients). HIV patients were younger (45 vs 58 years, P = .002) and had more respiratory distress than non-HIV patients (60.0% vs 34.6%, P = .035). A high 30-day mortality was observed and there was no difference between groups (HIV, 52.0% vs non-HIV, 54.9%; P = .812). Ventilator-associated pneumonia (VAP) was more frequent in the HIV group compared with the non-HIV group (45.2% vs 26.7%, P = .063), with a predominance of Gram-negative organisms. Gram-positive agents were the most frequent cause of catheter associated-bloodstream infections in HIV patients. Although there was a high frequency of HAI caused by multidrug-resistant organisms (MDRO), no difference was observed between the groups (HIV, 77.8% vs non-HIV, 64.3%; P = .214). Age was the only independent factor associated with 30-day mortality (odds ratio [OR]: 1.05, 95% confidence interval [CI]: 1.01-1.1, P = .017), while diabetes mellitus (OR: 3.64, 95% CI: 0.84-15.8, P = .085) and the Sequential Organ-Failure Assessment (SOFA) score (OR: 1.16, 95% CI: 0.99-1.37, P = .071) had a tendency to be associated with death.HIV infection was not associated with a higher 30-day mortality in critical care patients with a HAI. Age was the only independent risk factor associated with death. VAP was more frequent in HIV patients, probably because of the higher frequency of respiratory conditions at admission, with a predominance of Gram-negative organisms.

Predictors of mortality in patients with yellow fever: an observational cohort study.

BACKGROUND: Yellow fever virus infection results in death in around 30% of symptomatic individuals. The aim of this study was to identify predictors of death measured at hospital admission in a cohort of patients admitted to hospital during the 2018 outbreak of yellow fever in the outskirts of São Paulo city, Brazil. METHODS: In this observational cohort study, we enrolled patients with yellow fever virus from two hospitals in São Paolo-the Hospital das Clínicas, University of São Paulo and the Infectious Diseases Institute "Emilio Ribas". Patients older than 18 years admitted to hospital with fever or myalgia, headache, arthralgia, oedema, rash, or conjunctivitis were consecutively screened for inclusion in the present study. Consenting patients were included if they had travelled to geographical areas in which yellow fever virus cases had been previously confirmed. Yellow fever infection was confirmed by real-time PCR in blood collected at admission or tissues at autopsy. We sequenced the complete genomes of yellow fever virus from infected individuals and evaluated demographic, clinical, and laboratory findings at admission and investigated whether any of these measurements correlated with patient outcome (death). FINDINGS: Between Jan 11, 2018, and May 10, 2018, 118 patients with suspected yellow fever were admitted to Hospital das Clínicas, and 113 patients with suspected yellow fever were admitted to Infectious Diseases Institute "Emilio Ribas". 95 patients with suspected yellow fever were included in the study, and 136 patients were excluded. Three (3%) of 95 patients with suspected yellow fever who were included in the study were excluded because they received a different diagnosis, and 16 patients with undetectable yellow fever virus RNA were excluded. Therefore, 76 patients with confirmed yellow fever virus infection, based on detectable yellow fever virus RNA in blood (74 patients) or yellow fever virus confirmed only at the autopsy report (two patients), were included in our analysis. 27 (36%) of 76 patients died during the 60 day period after hospital admission. We generated 14 complete yellow fever virus genomes from the first 15 viral load-detectable samples. The genomes belonged to a single monophyletic clade of the South America I genotype, sub-genotype E. Older age, male sex, higher leukocyte and neutrophil counts, higher alanine aminotransferase, aspartate transaminase (AST), bilirubin, and creatinine, prolonged prothrombin time, and higher yellow fever virus RNA plasma viral load were associated with higher mortality. In a multivariate regression model, older age, elevated neutrophil count, increased AST, and higher viral load remained independently associated with death. All 11 (100%) patients with neutrophil counts of 4000 cells per mL or greater and viral loads of 5·1 log10 copies/mL or greater died (95% CI 72-100), compared with only three (11%) of 27 (95% CI 2-29) among patients with neutrophil counts of less than 4000 cells per mL and viral loads of less than 5·1 log10 copies/mL. INTERPRETATION: We identified clinical and laboratory predictors of mortality at hospital admission that could aid in the care of patients with yellow fever virus. Identification of these prognostic markers in patients could help clinicians prioritise admission to the intensive care unit, as patients often deteriorate rapidly. Moreover, resource allocation could be improved to prioritise key laboratory examinations that might be more useful in determining whether a patient could have a better outcome. Our findings support the important role of the virus in disease pathogenesis, suggesting that an effective antiviral could alter the clinical course for patients with the most severe forms of yellow fever. FUNDING: São Paulo Research Foundation (FAPESP).

Comparison of serological assays using pneumococcal proteins or polysaccharides for detection of Streptococcus pneumoniae infection in children with community-acquired pneumonia.

The aim of this study was to compare the results of serological assays using pneumococcal proteins or polysaccharides for the detection of pneumococcal infection in childhood pneumonia. Serological assays measured IgG against eight pneumococcal proteins (Ply,CbpA,PspA1,PspA2,PcpA,PhtD,StkP-C,PcsB-N), C-polysaccharide [in the whole study population, n = 183], or 19 pneumococcal capsular polysaccharides (1,2,4,5,6B,7F,8,9 V,10A,11A,12F,14,15B,17F,18C,19F,20,23F,33F) [only in a subgroup of patients, n = 53] in paired serum samples of children aged <5 years-old hospitalized with clinical and radiological diagnosis of community-acquired pneumonia. We also performed an inhibition of binding test with the anti-capsular polysaccharide assay in order to confirm the specificity of the antibody responses detected. Invasive pneumococcal pneumonia was investigated by blood culture and PCR (ply-primer). Among 183 children, the anti-protein assay detected antibody response in 77/183(42.1%) patients and the anti-C-polysaccharide assay in 28/183(15.3%) patients. In a subgroup of 53 children, the anti-protein assay detected response in 32/53(60.4%) patients, the anti-C-polysaccharide assay in 11/53(20.8%) patients, and the anti-capsular polysaccharide in 25/53(47.2%) patients. Simultaneous antibody responses against ≥2 different capsular polysaccharides were detected in 11/53(20.8%) patients and this finding could not be explained by cross-reactivity between different serotypes. Among 13 patients with invasive pneumococcal pneumonia, the sensitivity of the anti-protein assay was 92.3%(12/13), of the anti-C-polysaccharide assay 30.8%(4/13), and of the anti-capsular polysaccharide assay 46.2%(6/13). The serological assay using pneumococcal proteins is more sensitive for the detection of pneumococcal infection in children with pneumonia than the assay using pneumococcal polysaccharides. Future studies on childhood pneumonia aetiology should consider applying serological assays using pneumococcal proteins.

Antibody responses against Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in children with acute respiratory infection with or without nasopharyngeal bacterial carriage.

BACKGROUND: We studied Immunoglobulin G (IgG) antibody responses against Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in young children with acute viral type respiratory infection and analyzed the findings in a multivariate model including age, nasopharyngeal carriage of the tested bacteria and pneumococcal vaccination. METHODS: We included 227 children aged 6-23 months with acute respiratory infection. Nasopharyngeal aspirates were tested for bacterial carriage through detection of messenger RNA (mRNA) transcript with nCounter analysis. Acute and convalescent serum samples were tested for IgG antibody response against eight pneumococcal proteins, three proteins from H. influenzae and five proteins from M. catarrhalis in a fluorescent multiplex immunoassay. RESULTS: A two-fold or greater increase in antibodies to S. pneumoniae, H. influenzae and M. catarrhalis was detected in 27.8, 9.7 and 14.1%, respectively. Nasopharyngeal carriage of each of the studied bacteria was not associated with antibody response detection against each respective bacterium. Furthermore, neither age nor pneumococcal vaccination were independently associated to detection of antibody response against the studied bacteria. Children who carried H. influenzae had higher frequency of colonization by M. catarrhalis (175 [80.3%] vs. 2 [22.2%]; p < .001) than those without H. influenzae. Also, children with acute otitis media tended to have higher frequency of antibody response to S. pneumoniae. CONCLUSION: Nasopharyngeal colonization by S. pneumoniae, H. influenzae and M. catarrhalis did not induce significant increases in antibody levels to these bacteria. Carriage of pathogenic bacteria in the nasopharynx is not able to elicit antibody responses to protein antigens similar to those caused by symptomatic infections.