Pathophysiology of chikungunya virus infection associated with fatal outcomes

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes acute, subacute, and chronic human arthritogenic diseases and, in rare instances, can lead to neurological complications and death. Here, we combined epidemiological, virological, histopathological, cytokine, molecular dynamics, metabolomic, proteomic, and genomic analyses to investigate viral and host factors that contribute to chikungunya-associated (CHIK) death. Our results indicate that CHIK deaths are associated with multi-organ infection, central nervous system damage, and elevated serum levels of pro-inflammatory cytokines and chemokines compared with survivors. The histopathologic, metabolite, and proteomic signatures of CHIK deaths reveal hemodynamic disorders and dysregulated immune responses. The CHIKV East-Central-South-African lineage infecting our study population causes both fatal and survival cases. Additionally, CHIKV infection impairs the integrity of the blood-brain barrier, as evidenced by an increase in permeability and altered tight junction protein expression. Overall, our findings improve the understanding of CHIK pathophysiology and the causes of fatal infections.

Norovirus in children under 2 years of age: an epidemiological study in Panama during the COVID-19 pandemic

Introduction

Norovirus infection is a common cause of acute gastroenteritis (AGE). Surveillance activities are important to aid investigation into effective norovirus control strategies, including vaccination. Here, we report ancillary findings related to the incidence, prevalence, and etiology of AGE caused by norovirus in Panama after adjustment of study methodology to comply with national coronavirus disease 2019 (COVID-19) mandates.

Methods

In January 2020, children aged <2 years began enrolling into an epidemiological study in Panama to estimate the burden of norovirus in preparation for evaluating upcoming prevention strategies. This included an observational, longitudinal, community-based AGE surveillance study and a hospital-based AGE surveillance study. For the longitudinal study, healthy children aged 5-18 months were enrolled from January 6 through March 23, 2020, with a follow-up of approximately 6 months. The last participant was contacted on September 23, 2020. For the hospital-based study, starting on January 21, 2020, children aged <2 years who were admitted to the Hospital del Niño Dr. José Renán Esquivel in Panama City due to AGE were evaluated. The last sample was collected on September 29, 2020. Collected stool samples were tested for norovirus as well as astrovirus, sapovirus, and various enteropathogens. Unfortunately, this study was disrupted by the subsequent implementation of disease transmission control procedures for the COVID-19 pandemic, and the study methodology was revised to comply with COVID-19 mandates.

Results

In the longitudinal surveillance cohort [N = 400 (Chiriquí, n = 239; Panama, n = 161)], a total of 185 AGE episodes were documented (Chiriquí, n = 85; Panama, n = 100) resulting in an overall AGE incidence of 11.6 (95% CI: 9.99-13.4) episodes per 100 child-months. The norovirus-related AGE incidence was 0.3 (95% CI: 0.10-0.73) episodes per 100 child-months (5/185 AGE episodes) and the prevalence of norovirus was 4.6% (13/282 stool samples collected). In the hospital-based surveillance cohort, at least one pathogen was detected in 50% of samples (44/88 stool samples collected) and norovirus prevalence was 6.8% (6/88 stool samples collected).

Discussion

This report demonstrates how the occurrence of the COVID-19 pandemic hindered the conduct of clinical trials. However, this also created unique research opportunities to investigate the potential impact of pandemic control measures on the etiology of infectious diarrheal disease.

Detection of parechovirus A in respiratory, gastrointestinal, and neurological clinical samples of pediatric patients from Panama (2014-2015)

Parechovirus A (PeV-A, Parechovirus, Picornaviridae) are human pathogens associated with mild to severe gastrointestinal and respiratory diseases in young children. While several studies have investigated the association of PeV-A with human disease, little is known about its epidemiology or detection in Latin America. Between the years 2014 and 2015, a total of 200 samples were collected from Panamanian pediatric patients aged < 16 years old exhibiting symptoms associated with respiratory (n = 64), gastrointestinal (n = 68), or neurological (n = 68) diseases. These samples were gathered from patients who had previously received negative diagnoses for the main respiratory viruses, rotavirus, and neurological viruses like herpes virus, enterovirus, and cytomegalovirus. The presence of PeV-A was analyzed by real time RT-PCR.Eight positive PeV-A infections (4.0%, 95% CI: 1.7 to 7.7) were detected: two in respiratory samples (3.0%, 95% CI: 0.3 to 10.8), five in gastrointestinal samples (7.3%, 95% CI: 2.4 to 16.3), and one in cerebrospinal fluid (1.5%, 95% CI: 1.4 to 7.9). The study provides evidence of PeV-A circulation in Panama and the data collectively, remarked on the importance of considering PeV-A in the Panamanian pediatric diagnostic landscape, especially when conventional testing for more common viruses yields negative results.

Real-time RT-PCR for Venezuelan equine encephalitis complex, Madariaga, and Eastern equine encephalitis viruses: application in human and mosquito public health surveillance in Panama

Eastern equine encephalitis virus (EEEV), Madariaga virus (MADV), and Venezuelan equine encephalitis virus complex (VEEV) are New World alphaviruses transmitted by mosquitoes. They cause febrile and sometimes severe neurological diseases in human and equine hosts. Detecting them during the acute phase is hindered by non-specific symptoms and limited diagnostic tools. We designed and clinically assessed real-time reverse transcription polymerase chain reaction assays (rRT-PCRs) for VEEV complex, MADV, and EEEV using whole-genome sequences. Validation involved 15 retrospective serum samples from 2015 to 2017 outbreaks, 150 mosquito pools from 2015, and 118 prospective samples from 2021 to 2022 surveillance in Panama. The rRT-PCRs detected VEEV complex RNA in 10 samples (66.7%) from outbreaks, with one having both VEEV complex and MADV RNAs. VEEV complex RNA was found in five suspected dengue cases from disease surveillance. The rRT-PCR assays identified VEEV complex RNA in three Culex (Melanoconion) vomerifer pools, leading to VEEV isolates in two. Phylogenetic analysis revealed the VEEV ID subtype in positive samples. Notably, 11.9% of dengue-like disease patients showed VEEV infections. Together, our rRT-PCR validation in human and mosquito samples suggests that this method can be incorporated into mosquito and human encephalitic alphavirus surveillance programs in endemic regions.

Detection of Leishmania RNA Virus 1 in Leishmania (Viannia) panamensis Isolates, Panama

We detected Leishmania RNA virus 1 (LRV1) in 11 isolates of Leishmania (Viannia) panamensis collected during 2014-2019 from patients from different geographic areas in Panama. The distribution suggested a spread of LRV1 in L. (V.) panamensis parasites. We found no association between LRV1 and an increase in clinical pathology.

Decreased oxytocin plasma levels and oxytocin receptor expression in borderline personality disorder

INTRODUCTION

Borderline personality disorder (BPD) is characterized by intense affective reactions with underlying social and interpersonal cognitive deficits. Oxytocin has largely been associated with both stress regulation and social cognition in psychiatric patients and in non-clinical populations in previous studies. Finally, abnormal oxytocin levels have been preliminary reported in BPD patients.

METHODS

53 patients with moderate-severe BPD and 31 healthy control subjects were investigated for plasma levels of oxytocin and protein expression of oxytocin receptor in blood mononuclear cells. Clinical assessments were made for severity, functionality, and comorbidity with axis I and II conditions.

RESULTS

Oxytocin plasma levels were significantly lower in BPD patients compared with controls. In addition, protein expression of oxytocin receptor was significantly reduced in the BPD group. A positive correlation was found between plasma oxytocin levels and the activity index score of the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ). Oxytocin receptor protein expression, on the contrary, had a negative correlation with the ZKPQ sociability index score.

CONCLUSIONS

Results support the evidence of a dysfunction of the oxytocin system in borderline personality disorder, which could be involved in emotional dysregulation and interpersonal disturbances in these patients.

Expansion and Refinement of Deep Sequence-Coupled Biopanning Technology for Epitope-Specific Antibody Responses in Human Serum

Identifying the specific epitopes targeted by antibodies elicited in response to infectious diseases is important for developing vaccines and diagnostics. However, techniques for broadly exploring the specificity of antibodies in a rapid manner are lacking, limiting our ability to quickly respond to emerging viruses. We previously reported a technology that couples deep sequencing technology with a bacteriophage MS2 virus-like particle (VLP) peptide display platform for identifying pathogen-specific antibody responses. Here, we describe refinements that expand the number of patient samples that can be processed at one time, increasing the utility of this technology for rapidly responding to emerging infectious diseases. We used dengue virus (DENV) as a model system since much is already known about the antibody response. Sera from primary DENV-infected patients (n = 28) were used to pan an MS2 bacteriophage VLP library displaying all possible 10-amino-acid peptides from the DENV polypeptide. Selected VLPs were identified by deep sequencing and further investigated by enzyme-linked immunosorbent assay. We identified previously described immunodominant regions of envelope and nonstructural protein-1, as well as a number of other epitopes. Our refinement of the deep sequence-coupled biopanning technology expands the utility of this approach for rapidly investigating the specificity of antibody responses to infectious diseases.

Zika Virus-Associated Cerebellitis with Complete Clinical Recovery

Zika virus (ZIKV) was first detected in the Americas in Brazil in 2015, with a rapid spread to surrounding countries. In Panama, the outbreak began in November 2015 in an indigenous community located on the Caribbean side of the country. Zika virus is typically associated with a diffuse rash, fever, and conjunctivitis. It can rarely cause neurologic manifestations, most commonly microcephaly and Guillain-Barré syndrome. Encephalitis and acute encephalomyelitis are known complications, but ZIKV-associated cerebellitis has yet to be reported in the literature. Herein, we report a case of cerebellitis in a patient infected with ZIKV. This patient developed severe frontal headache and vertigo on the third day of illness, and dysarthria and ataxia on the fifth day. After 1 week of hospitalization, the patient completely recovered. The laboratory serological diagnosis was complicated because of the detection of antibodies against dengue, suggesting a secondary flavivirus infection.

Effectiveness of an intervention in multicomponent exercise in primary care to improve frailty parameters in patients over 70 years of age (MEFAP-project), a randomised clinical trial: rationale and study design

Background

Physical activity may reverse frailty in the elderly, but we encounter barriers to the implementation of exercise programs in this population. Our main aim is to evaluate the effect of a multicomponent physical activity program, versus regular medical practice, on reverting pre-frailty status among the elderly, 12 months post-intervention.

Methods

Randomized parallel group multicenter clinical trial located in primary care setting, among non-dependent and pre-frail patients > 70 years old, including 190 patients (95 intervention, 95 control group). Intervention: Multicomponent physical activity program (MEFAP, for its acronym in Spanish) with twelve 1.5 h-weekly sessions comprised of: 1. Informative session; 2. Exercises for improving aerobic resistance, muscle strength, propioception-balance and flexibility; and 3. Handing out of at-home exercise chart (twice/week). Main variable: pre-frailty according to the Fried phenotype. Secondary variables: sociodemographic, clinical and functional variables; exercise program adherence, patient satisfaction with the program and quality of life. We will perform an intention-to-treat analysis by comparing the retrogression from pre-frailty (1 or 2 Fried criteria) to robust status (0 Fried criteria) by the end of the intervention, 6 months and 12 months post-intervention. The accumulated incidence in each group will be calculated, as well as the relative risk (RR) and the number needed to treat (NNT) with their corresponding 95% confidence intervals. Protocol was approved by the Ethics Committee Hospital la Paz.

Discussion

Within the context of regular clinical practice, our results will provide evidence regarding the effects of exercise interventions on frailty among pre-frail older adults, a key population given their significant potential for functional, physical, and mental health improvement.

Trial registration

NCT03568084. Registered 26 June 2018. Date of enrollment of the first participant to the trial: July 2nd 2018.

Bulk Ti nitride prepared from rutile TiO2 for its application as stimulation electrode in neuroscience

Bulk titanium nitride (TiN) was synthesized by nitridation of TiO₂ rutile substrates. TiN pellets were successfully achieved at 1100 °C in ammonia stream; these materials were characterized by the evaluation of their microstructure, surface, chemical composition and electrical and electrochemical properties, concluding that the synthesis promotes the creation of a TiN_xO_y surface, which shows high metallic conductivity (close to 10² S/cm) and a microstructure with micro- and nano-features. Electrochemical studies reveal high storage capacities which are delivered through an injection mechanism that involves the double charge layer and EIS show a high capacitive contribution to the mechanism. Neuron cell cultures assessed the biocompatibility of the sample prepared and put forward this material as a promising candidate for implantable stimulation electrode in neuroscience.

CHARACTERIZATION OF FLUORESCENT NUCLEAR TRACK DETECTORS AS CRITICALITY DOSIMETERS II

Fluorescent nuclear track detectors (FNTDs) as criticality dosimeters for both neutrons and gamma are further characterized in terms of angular dependence and quick dose assessment. The power spectrum integral depth profiles obtained from stacks of fluorescent images acquired within FNTDs exposed to a broad spectrum neutron field at various angles are analyzed to determine a calibration curve for angular dependence. MCNPX simulations were shown to be in good agreement with experimental results. A prototype triage reader was also designed and tested for quick assessment of dose. An unfolding technique incorporating both energy dependence and angular dependence is discussed. The advantages and shortcomings of using FNTDs in the event of a criticality excursion accident are analyzed.

ENERGY RESPONSE OF FLUORESCENT NUCLEAR TRACK DETECTORS OF VARIOUS COLORATIONS TO MONOENERGETIC NEUTRONS

The neutron-energy dependence of the track-counting sensitivity of fluorescent nuclear track detectors (FNTDs) at two ranges of Mg doping, resulting in different crystal colorations, was investigated. The performance of FNTDs was studied with the following converters: Li-glass for thermal to intermediate-energy neutrons, polyethylene for fast neutrons, and polytetrafluoroethylene (Teflon™) for photon- and radon-background subtraction. The irradiations with monoenergetic neutrons were performed at the National Physics Laboratory (NPL), UK. The energy range was varied from 144 keV to 16.5 MeV in the personal dose equivalent range from 1 to 3 mSv. Monte Carlo simulations were performed to model the response of FNTDs to monoenergetic neutrons. A good agreement with the experimental data was observed suggesting the development of a basic model for future MC studies. Further work will focus on increasing FNTD sensitivity to low-energy neutrons and developing a faster imaging technique for scanning larger areas to improve counting statistics.

Distribution of influenza virus types by age using case-based global surveillance data from twenty-nine countries, 1999-2014

Background

Influenza disease burden varies by age and this has important public health implications. We compared the proportional distribution of different influenza virus types within age strata using surveillance data from twenty-nine countries during 1999-2014 (N=358,796 influenza cases).

Methods

For each virus, we calculated a Relative Illness Ratio (defined as the ratio of the percentage of cases in an age group to the percentage of the country population in the same age group) for young children (0-4 years), older children (5-17 years), young adults (18-39 years), older adults (40-64 years), and the elderly (65+ years). We used random-effects meta-analysis models to obtain summary relative illness ratios (sRIRs), and conducted meta-regression and sub-group analyses to explore causes of between-estimates heterogeneity.

Results

The influenza virus with highest sRIR was A(H1N1) for young children, B for older children, A(H1N1)pdm2009 for adults, and (A(H3N2) for the elderly. As expected, considering the diverse nature of the national surveillance datasets included in our analysis, between-estimates heterogeneity was high (I²>90%) for most sRIRs. The variations of countries’ geographic, demographic and economic characteristics and the proportion of outpatients among reported influenza cases explained only part of the heterogeneity, suggesting that multiple factors were at play.

Conclusions

These results highlight the importance of presenting burden of disease estimates by age group and virus (sub)type.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3181-y) contains supplementary material, which is available to authorized users.

A study of the application of permeable pavements as a sustainable technique for the mitigation of soil sealing in cities: A case study in the south of Spain

The use of 'Sustainable Urban Drainage Systems' (SuDS) has become a more sustainable alternative for managing stormwater, greatly reducing the effects of soil sealing. However, the lack of monitored projects is a barrier to their implementation, as the companies which manage sewer systems cannot quantify the impact and cost-efficiency of SuDS. This paper presents a project developed in the south of Spain, in which the hydrological performance of 3 types of permeable pavements has been analyzed. The efficiencies obtained (over 70%), are higher than or similar to the efficiencies of vegetated SuDS, demonstrating the capacity of these pavements for delaying catchment area response and slow flow velocities, reducing the operating costs of sewer systems and the flood risk, while also ensuring service conditions for cities and safety for pedestrian and vehicular circulation. This pilot site has generated results which are sufficiently consistent so as to be representative, and serve as a reference for other cities with a similar climate.

The reintroduction of DENV-2 in 2011 in Panama and subsequent outbreak characteristic

The circulation of the South-east Asian/American (AS/AM) dengue 2 virus (DENV-2) genotype in the Americas has been associated with a high rate of severe disease. From 1993, the year DENV was reintroduced in Panama, until 2011 there were 29 dengue-associated deaths, 17 of which occurred in 2011, the most severe outbreak with a case fatality rate (CFR) of 44% (17 deaths out of 38 severe dengue cases). During this outbreak DENV-2 was reintroduced into the country, whereas over the prior five years DENV-1 and -3 were predominant. Herein, we describe the 2011 Panama outbreak and genetically characterize the Panamanian DENV-2 strains, which were associated with severe dengue disease in Panama. Our results suggest that the DENV-2 isolates from this outbreak belonged to the AS/AM genotype sub-clade 2BI and were genetically close to viruses described in the outbreaks in Nicaragua, Honduras, Guatemala and Mexico from 2006-2011. Sub-clade 2BI has previously been associated with severe disease in Nicaragua during outbreaks from 2005-2007.

Scavenging activity of Magnéli phases as a function of Ti4+/Ti3+ ratios

TiO₂ is able to scavenge reactive oxygen and nitrogen species (ROS and RNS) in the absence of light. The scavenging mechanism has been related to the chemistry of defects (oxygen vacancy reduced oxidation states of Ti) but it is still unknown. This study describes the ROS scavenging activity of different titanium oxide phases and relates their scavenging activities with the Ti⁴⁺/Ti³⁺ molar ratio as well as the band gap value. The Ti₅O₉ phase, with a mixture of both oxidation states, presented a substantially higher percentage of 2,2-diphenyl-1-picrylhydracyl radicals (DPPH˙) eliminated per m² of specific surface area in comparison to phases with predominant oxidation states Ti⁴⁺ or Ti³⁺ such as TiO₂ and Ti₂O₃, respectively. The obtained results indicate that the DPPH˙ scavenging mechanism corresponds to a catalytic process on the Ti₅O₉ surface which is facilitated by the presence of charges that can easily move through the material. The mobility of charges and electrons in the semiconductor surface, related to the presence of oxidation states Ti⁴⁺ and Ti³⁺ and a small band gap, could create an attractive surface for radical species such as DPPH˙. This puts forward Ti₅O₉ as a promising candidate coating for implantable biomedical devices, as an electrode, since it can cushion inflammatory processes which could lead to device encapsulation and, consequently, failure.

Clinical Manifestations of Punta Toro Virus Species Complex Infections, Panama, 2009

An investigation in Panama found that Punta Toro virus species complex (PTVs) may contribute to febrile illnesses with symptoms mirroring those of dengue fever. However, further studies are needed to determine if PTV infection causes only a mild disease or if it can have more serious manifestations in some patients.

Genetic variability of human respiratory syncytial virus group B in Panama reveals a novel genotype BA14

In Panama, human respiratory syncytial virus (HRSV) is responsible of 20-40% of acute respiratory infections in children under 5 years old. Currently, little is known about the genetic variability of HRSV in Central America and the Caribbean. Recently, we reported the genetic variability of HRSV-A, however; no studies on HRSV-B in Panama have been described yet. In this study, 24 sequences of Panamanian HRSV-B, from children (<5 years) with acute respiratory infections (ARI), collected from July 2008 to November 2012 were analyzed. All sequences share the characteristic 60-nt duplication of the BA strains. Six Panamanian strains grouped with the BA10 genotype and 12 samples clustered together in a separate monophyletic clade with an aLRT support value of 0.92 and an intra-group p-distance less than 0.07. This fulfills the criteria to consider a new genotype in HRSV, which we named BA14 genotype. Another six strains remain unclassified, but closely related to BA9, BA11, or the new BA14 genotypes, according to their genetic p-distance. Different amino acid substitutions in the Panamanian HRSV-B strains were observed, some previously described and others found only on Panamanian strains. This study contributes to the knowledge of the genetic variability and evolution of HRSV in Central America.

TiO2 surfaces support neuron growth during electric field stimulation

TiO₂ is proposed here for the first time as a substrate for neural prostheses that involve electrical stimulation. Several characteristics make TiO₂ an attractive material: Its electrochemical behaviour as an insulator prevents surface changes during stimulation. Hydration creates -OH groups at the surface, which aid cell adhesion by interaction with inorganic ions and macromolecules in cell membranes. Its ability to neutralize reactive oxygen and nitrogen species that trigger inflammatory processes confers biocompatibility properties in dark conditions. Here, physicochemical characterization of TiO₂ samples and their surfaces was carried out by X-ray diffraction, X-ray photoelectronic emission spectroscopy, scanning electron microscopy, atomic force microscopy and by contact angle measurements. Its properties were related to the growth parameters and morphology of amphibian spinal neurons cultured on TiO₂ samples. Neurons adhered to and extended neurites directly on TiO₂ surfaces without pre-coating with adhesive molecules, indicating that the material permits intimate neuron-surface interactions. On TiO₂ surfaces the distal tips of each extending neurite and the neurite shafts themselves showed more complex filopodial morphology compared with control cultures on glass. Importantly, the ability of TiO₂ to support neuron growth during electric field exposure was also tested. The extent of growth and the degree of neurite orientation relative to the electric field on TiO₂ approximated that on glass control substrates. Collectively, the data suggest that TiO₂ materials support neuron growth and that they have potential utility for neural prosthetic applications incorporating electric field stimulation, especially where intimate contact of neurons with the material is beneficial.

Characteristics of seasonal influenza A and B in Latin America: Influenza surveillance data from ten countries

Introduction

The increased availability of influenza surveillance data in recent years justifies an actual and more complete overview of influenza epidemiology in Latin America. We compared the influenza surveillance systems and assessed the epidemiology of influenza A and B, including the spatio-temporal patterns of influenza epidemics, in ten countries and sub-national regions in Latin America.

Methods

We aggregated the data by year and country and characteristics of eighty-two years were analysed. We calculated the median proportion of laboratory-confirmed influenza cases caused by each virus strain, and compared the timing and amplitude of the primary and secondary peaks between countries.

Results

37,087 influenza cases were reported during 2004–2012. Influenza A and B accounted for a median of 79% and, respectively, 21% of cases in a year. The percentage of influenza A cases that were subtyped was 82.5%; for influenza B, 15.6% of cases were characterized. Influenza A and B were dominant in seventy-five (91%) and seven (9%) years, respectively. In half (51%) of the influenza A years, influenza A(H3N2) was dominant, followed by influenza A(H1N1)pdm2009 (41%) and pre-pandemic A(H1N1) (8%). The primary peak of influenza activity was in June-September in temperate climate countries, with little or no secondary peak. Tropical climate countries had smaller primary peaks taking place in different months and frequently detectable secondary peaks.

Conclusions

We found that good influenza surveillance data exists in Latin America, although improvements can still be made (e.g. a better characterization of influenza B specimens); that influenza B plays a considerable role in the seasonal influenza burden; and that there is substantial heterogeneity of spatio-temporal patterns of influenza epidemics. To improve the effectiveness of influenza control measures in Latin America, tropical climate countries may need to develop innovative prevention strategies specifically tailored to the spatio-temporal patterns of influenza in this region.

Unusual pattern of chikungunya virus epidemic in the Americas, the Panamanian experience

Background

Chikungunya virus (CHIKV) typically causes explosive epidemics of fever, rash and polyarthralgia after its introduction into naïve populations. Since its introduction in Panama in May of 2014, few autochthonous cases have been reported; most of them were found within limited outbreaks in Panama City in 2014 and Puerto Obaldia town, near the Caribbean border with Colombia in 2015. In order to confirm that Panama had few CHIKV cases compared with neighboring countries, we perform an epidemiological analysis of chikungunya cases reported from May 2014 to July 2015. Moreover, to understand this paucity of confirmed CHIKV cases, a vectorial analysis in the counties where these cases were reported was performed.

Methods

Chikungunya cases were identified at medical centers and notified to health authorities. Sera samples were analyzed at Gorgas Memorial Institute for viral RNA and CHIKV-specific antibody detection.

Results

A total of 413 suspected cases of CHIKV infections were reported, with incidence rates of 0.5 and 0.7 per 100,000 inhabitants in 2014 and 2015, respectively. During this period, 38.6% of CHIKV cases were autochthonous with rash and polyarthralgia as predominant symptoms. CHIKV and DENV incidence ratios were 1:306 and 1:34, respectively. A phylogenetic analysis of E1/E2 genomic segment indicates that the outbreak strains belong to the Asian genotype and cluster together with CHIKV isolates from other American countries during the same period. Statistical analysis of the National Vector Control program at the district level shows low and medium vector infestation level for most of the counties with CHIKV cases. This index was lower than for neighboring countries.

Conclusions

Previous training of clinical, laboratory and vector workers allowed a good caption and detection of the chikungunya cases and fast intervention. It is possible that low/medium vector infestation level could explain in part the paucity of chikungunya infections in Panama.

Chikungunya virus (CHIKV) is a mosquito borne pathogen that causes fever with rash and arthralgia, which are often confused with Dengue virus (DENV) infections. It has been reported that when CHIKV colonizes regions without previous circulation, it generally results in explosive human epidemics. In Panama, the first CHIKV infections were detected in May 2014. However, unlike many countries in the Americas, Panama presented with few autochthonous cases during the outbreak. In this study, we investigated the likely reason for the paucity of cases. Low vector infestation level, along with the surveillance programs, preparedness and early outbreak response possibly influenced the low number of cases observed during the Panamanian CHIKV outbreak.

Pathogen-specific deep sequence-coupled biopanning: A method for surveying human antibody responses

Identifying the targets of antibody responses during infection is important for designing vaccines, developing diagnostic and prognostic tools, and understanding pathogenesis. We developed a novel deep sequence-coupled biopanning approach capable of identifying the protein epitopes of antibodies present in human polyclonal serum. Here, we report the adaptation of this approach for the identification of pathogen-specific epitopes recognized by antibodies elicited during acute infection. As a proof-of-principle, we applied this approach to assessing antibodies to Dengue virus (DENV). Using a panel of sera from patients with acute secondary DENV infection, we panned a DENV antigen fragment library displayed on the surface of bacteriophage MS2 virus-like particles and characterized the population of affinity-selected peptide epitopes by deep sequence analysis. Although there was considerable variation in the responses of individuals, we found several epitopes within the Envelope glycoprotein and Non-Structural Protein 1 that were commonly enriched. This report establishes a novel approach for characterizing pathogen-specific antibody responses in human sera, and has future utility in identifying novel diagnostic and vaccine targets.

Note. Effect of trisodium phosphate on mesophilic and psychrotrophic bacterial flora attached to the skin of chicken carcasses during refrigerated storage Nota. Efecto del fosfato trisódico en los microorganismos mesófilos y psicrotrofos presentes en la piel de canales de pollo durante su almacenamiento en refrigeración

The potential for using trisodium phosphate (TSP) to reduce mesophilic and psychrotrophic popula tions on the skin of chicken carcasses was explored. Skin samples were immersed in sterile tap water (control) or an 8%, 10% or 12% solution of TSP at 20 °C for 15 min. Surface pH values and mesophilic and psychrotrophic plate counts were determined after 0, 1, 3 and 5 days of storage at 2° C. After washing, bacterial populations were significantly smaller in the samples treated with TSP than in the controls. The concentration of the TSP solution was a significant factor in reducing the populations of the bacteria on chicken skin. Before storage, the reduction in the presence of bacteria achieved in treated samples with respect to controls ranged between 0.95 log10 cycles and 1.78 log10 cycles in the case of mesophilic microorganisms, and 0.92 log10 cycles and 1.94 log10 cycles in the case of psychrotrophic strains. These differences between the concentrations of bacteria in samples immersed in water and those treated with TSP increased over time, ranging from 2.35 log 10 cycles to 3.08 log10 cycles (mesophilic microorganisms), and from 2.79 log10 cycles to 4.09 log10 cycles (psychrotrophic microorganisms) on day 5 of storage. The pH of the skin remained more or less constant throughout the study period, ranging between 8 and 9 in skin treated with TSP, depending on the concentration, while it was two units lower in the control samples.

Disseminated Mycobacterium avium subsp. avium infection in a pet Korean squirrel (Sciuris vulgaris coreae)

A disseminated Mycobacterium avium subsp. avium infection was diagnosed in a pet Korean squirrel. Grossly, multiple small nodules in the lung, liver, spleen, and skin were observed. Adrenal glands were very enlarged. The only tissue exhibiting necrosis and calcification was a very enlarged bronchial lymph node. The remaining lymph nodes were slightly enlarged. Moderate ascites was also observed. Microscopically, a disseminated granulomatous inflammation with numerous lymphocytes was seen. Acid-fast bacilli were detected in macrophages, in giant cells, free in the interstitium, and in some lymphatic vessels, both within cells and free in the lumen. M. avium subsp. avium was isolated and identified by polymerase chain reaction-restriction endonuclease analysis.

Correction: Temporal Patterns of Influenza A and B in Tropical and Temperate Countries: What Are the Lessons for Influenza Vaccination?

[This corrects the article DOI: 10.1371/journal.pone.0152310.].

Epidemiology of Emergent Madariaga Encephalitis in a Region with Endemic Venezuelan Equine Encephalitis: Initial Host Studies and Human Cross-Sectional Study in Darien, Panama

Background

Neurotropic arboviral infections are an important cause of encephalitis. A zoonotic, vector-borne alphavirus, Madariaga virus (MADV; formerly known as South American eastern equine encephalitis virus), caused its first documented human outbreak in 2010 in Darien, Panama, where the genetically similar Venezuelan equine encephalitis virus (VEEV) is endemic. We report the results of a seroprevalence survey of animals and humans, illustrating contrasting features of MADV and VEEV ecology and epidemiology.

Methods

Small mammals were trapped in 42 sites in Darien, Panama, using Sherman traps, Tomahawk traps, and mist nets for bats. Blood was tested for the presence of neutralizing antibodies to MADV and VEEV. In addition, bird sera collected in 2007 in Chagres, Panama, were tested for MADV and VEEV neutralizing antibodies. Viremia was ascertained by RT-PCR. Human exposure to these two viruses was determined by IgG ELISA, followed by plaque reduction neutralization tests. To identify relevant risk factors for MADV or VEEV exposure, logistic regression analysis was performed, and the most parsimonious model was selected based on the Akaike information criterion.

Results

The animal survey yielded 32 bats (16 species), 556 rodents (12 species), and 20 opossums (4 species). The short-tailed cane mouse (Zygodontomys brevicauda) found abundantly in pasture and farms, had the highest MADV seroprevalence (8.3%). For VEEV, the shrub and forest-dwelling long-whiskered rice rat (Transandinomys bolivaris) had the highest seroprevalence (19.0%). Viremia was detected in one animal (Z. brevicauda). Of the 159 bird sera (50 species) tested, none were positive for either virus. In humans (n = 770), neutralizing antibodies to MADV and VEEV were present in 4.8% and 31.5%, respectively. MADV seropositivity was positively associated with cattle ranching, farming, and fishing. Having VEEV antibodies and shrubs near the house diminished risk. Age, forest work, farming and fishing were risk factors for VEEV, while having MADV antibodies, glazed windows, waste pick-up and piped water were protective.

Conclusion

Our findings suggest that the short-tailed cane mouse and the long-whiskered rice rat serve as hosts for MADV and VEEV, respectively. The preferred habitat of these rodent species coincides with areas associated with human infection risk. Our findings also indicate that MADV emerged recently in humans, and that the transmission cycles of these two sympatric alphaviruses differ spatially and in host utilization.

Arthropod-borne viruses are important causes of encephalitis. In 2010, the first documented human outbreak of the mosquito-borne, zoonotic Madariaga virus (MADV) occurred in the Darien region of Panama. Neither its epidemiology nor its transmission cycle is understood. In this study, the authors searched for possible animal hosts of this virus, and sought to describe its epidemiology. They contrast the findings with those for Venezuelan equine encephalitis virus (VEEV), an endemic, genetically similar virus. Zygodontomys brevicauda, the short-tailed cane mouse, had the highest seroprevalence for MADV. This rodent species is most often found in pasture and farm land. Indeed, the risk factors for human MADV exposure were cattle ranching and farming. The animal with highest seroprevalence for VEEV, the long-whiskered rice rat (Transandinomys bolivaris), commonly occurs in forest, and the epidemiological risk factors included working in the forest. Farming and fishing were risk factors for exposure to both viruses, and having antibodies to one virus diminished the risk of being positive for the other. Increasing prevalence with age was seen for VEEV, confirming that VEEV is endemic in the region. This association was absent for MADV, suggesting that this virus emerged recently to infect humans.

Child overweight and obesity are associated with reduced executive cognitive performance and brain alterations: a magnetic resonance imaging study in Mexican children

BACKGROUND

Overweight and obesity in childhood is associated with negative physical and psychological effects. It has been proposed that obesity increase the risk for developing cognitive deficits, dementia and Alzheimer's disease and that it may be associated with marked differences in specific brain structure volumes.

OBJECTIVE

The purpose of this study was a neurobiopsychological approach to examine the association between overweight and obesity, brain structure and a paediatric neuropsychological assessment in Mexican children between 6 and 8 years of age.

METHODS

We investigated the relation between the body mass index (BMI), brain volumetric segmentation of subcortical gray and white matter regions obtained with magnetic resonance imaging and the Neuropsychological Assessment of Children standardized for Latin America. Thirty-three healthy Mexican children between 6 and 8 years of age, divided into normal weight (18 children) and overweight/obese (15 children) groups.

RESULTS

Overweight/obese children showed reduced executive cognitive performance on neuropsychological evaluations (i.e. verbal fluidity, P = 0.03) and presented differences in brain structures related to learning and memory (reduced left hippocampal volumes, P = 0.04) and executive functions (larger white matter volumes in the left cerebellum, P = 0.04 and mid-posterior corpus callosum, P = 0.03). Additionally, we found a positive correlation between BMI and left globulus pallidus (P = 0.012, ρ = 0.43) volume and a negative correlation between BMI and neuropsychological evaluation scores (P = 0.033, ρ = -0.37).

CONCLUSIONS

The findings contribute to the idea that there is a relationship between BMI, executive cognitive performance and brain structure that may underlie the causal chain that leads to obesity in adulthood.

[What would you do with a 29-weeks pregnant woman with generalised pruritus?]

Intrahepatic cholestasis of pregnancy is a reversible disease of variable frequency. The pathophysiology involves an increase of the bile acids in the fetal blood of the mother and the fetus. The high concentrations of the bile acids cause maternal pruritus and high perinatal morbimortality. Primary Care physicians in close contact with the patient must have a high index of suspicion when faced with typical symptoms of cholestasis, such as generalized pruritus in women in the second or third trimester of gestation to be able to act on the consequences.

Staphylococcal growth and enterotoxin production in the presence of meat cultures (non LAB)

The effect of meat cultures (non lactic acid bacteria) on the growth and production of enterotoxins and thermonuclease by Staphylococcus aureus was studied. Micrococcus varians did not affect growth nor the synthesis of metabolites. Levels of enterotoxins A, B and D produced by the respective S. aureus strains were reduced by S. xylosus, S. saprophyticus and S. carnosus. The two latter species prevented production of enterotoxin C(1) and S. xylosus markedly reduced the amount produced. The three coagulase-negative staphylococci showed little inhibitory effect on the growth of S. aureus. Penicillium nalgiovense did not show inhibitory activity against the four S. aureus strains. Debaryomyces hansenii slightly inhibited growth of the enterotoxin A-producing strain, but reduced enterotoxin synthesis at 30 °C. Thermonuclease was detected whenever enterotoxins were detected though the influence of the effector organism was dependent on the test strain.

Simple, specific molecular typing of dengue virus isolates using one-step RT-PCR and restriction fragment length polymorphism

A one-step RT-PCR and one-enzyme RFLP was used to detect and distinguish among flaviviruses, including the four serotypes of dengue and the St. Louis Encephalitis, West Nile and Yellow Fever viruses in cultured virus samples or acute-phase human serum. Using a previously described RT-PCR, but novel RFLP procedure, results are obtained in 24 h with basic PCR and electrophoresis equipment. There is 95% agreement between RT-PCR/RFLP results and those achieved by indirect immunofluorescence assays, and 100% agreement between RT-PCR/RFLP results and gene sequencing. This method is more rapid than tests of cytopathic effect based on virus isolation in tissue culture, and simpler than real-time PCR. It does not require specialized equipment, radioisotopes or computer analysis and is a method that can be applied widely in the developing world. It allows for prompt determination of whether a flavivirus is the cause of illness in a febrile patient, rapid identification of dengue serotypes in circulation, and improved patient management in cases where prior dengue exposure make dengue hemorrhagic fever or dengue shock syndrome a risk.