Cooling Holstein cows for 60 days prepartum in summer: effects on prepartum physiology, postpartum productivity, and calf growth.

Heat stress (HS) during the dry period of dairy cows in hot and dry conditions compromises the physiological status and mammary gland development of dairy cows, thereby negatively affecting milk component yield in the subsequent lactation. Our objective was to evaluate the effects of cooling Holstein cows under moderate or higher HS conditions (i.e., ambient temperature higher than 30 °C, with a temperature-humidity index of 78.2 units) during the dry period on prepartum physiological status, postpartum productivity, and calf growth. Twenty-four multiparous Holstein cows were divided into two groups: one with a cooling system based on spray and fans under a pen shade (CL, n = 12) and the other not-cooled (NC, n = 12). The cooling system operated 10 h/d (09:00-19:00 h) for 60 d prepartum. During the morning, rectal temperature and respiration frequency were lower in CL cows, but not in the afternoon, which was attributed to higher (P < 0.01) dry matter intake by CL cows. Total serum protein was higher (P < 0.01) in CL cows, but hemoglobin was higher in NC cows (P < 0.01), with no differences in other electrolytes, hormones, hematological components, and metabolites. Milk fat and fat and fat-protein corrected milk were higher (P < 0.05) in CL cows. Female and birth weight trended (P = 0.08) to be higher in CL cows. Cooling cows during the dry period had a limited effect on physiology prepartum but increased postpartum productivity of Holstein cows under hot and dry conditions.

Predicting carcass tissue composition in Blackbelly sheep using ultrasound measurements and machine learning methods.

This study aimed to predict Blackbelly sheep carcass tissue composition using ultrasound measurements and machine learning models. The models evaluated were decision trees, random forests, support vector machines, and multi-layer perceptrons and were used to predict the total carcass bone (TCB), total carcass fat (TCF), and total carcass muscle (TCM). The best model for predicting the three parameters, TCB, TCF, and TCM was random forests, with mean squared error (MSE) of 0.31, 0.33, and 0.53; mean absolute error (MAE) of 0.26, 0.29, and 0.53; and the coefficient of determination (R2) of 0.67, 0.69, and 0.76, respectively. The results showed that machine learning methods from in vivo ultrasound measurements can be used as determinants of carcass tissue composition, resulting in reliable results.

Epidemiological surveillance of chikungunya fever in Mexico since its introduction in 2014-2016 and identification of circulating genotypes.

In 2014, the chikungunya virus (CHIKV) was detected for the first time in Mexico, the identified strain was the one corresponding to the Asian genotype which was phylogenetically grouped with the strains that circulated in the British Virgin Islands outbreak and was later classified with lineages of Caribbean strains. In three years, 13,569 cases of chikungunya were registered in Mexico. Although the transmission and spread of the virus are now considered a moderate risk, the danger that the virus reemerges is not ruled out due to the infestation of Aedes mosquitoes. In this study, we reviewed the chikungunya fever (CHIKF) cases reported between 2014 and 2016 to reanalyze the data. Seventeen cases were selected from different states where the circulation of the virus had been reported. Statistical data were analyzed and a retrospective analysis was carried out. Nucleic acid sequences were determined of these 17 samples. 2015 was the year with the highest number of cases (92.8%) and they were detected in 28 states of the country. There is a predominance of females, and the most affected age group was between 25 and 44 years. In 2016, CHIKV genotypes were not known, in this study the presence of the Asian genotype of Caribbean lineage was confirmed. The presence of the West African and ECSA genotypes was phylogenetically ruled out. The sequences obtained were deposited in GeneBank.

Evaluation of serological diagnostic tests of human brucellosis for prevention and control in Mexico.

Brucellosis is a zoonosis mainly present in developing countries. The WHO reports 500,000 new cases every year. From 2012 to 2016, 13,677 cases were reported in Mexico, with 2.00 to 2.64 rate per 100,000 inhabitants. To analyze the diagnostic algorithm of brucellosis in Mexico, we compared the commercial laboratory tests ELISA, Brucellacapt®, and lateral flow test (LFT) in a study of 473 individuals from two endemic Mexican populations. All patients were treated in first-level medical units for presenting brucellosis compatible symptoms and without a history of the disease. Clinical-epidemiological information was gathered and initial serum samples were obtained to react with anti-Brucella antibodies; subsequent samples were collected at follow-up treatment visits. Using the Rose Bengal screening, we found 165 negative samples and 308 positive reactive samples, of which 222 cases were confirmed and 234 were positive on at least one marker (IgG or IgM) or LFT. When Brucellacapt® was used, similar results to those observed with the conventional algorithm were found as judged by the Cohen's kappa coefficient (κ) (0.813, 95% CI 0.7788-0.8472). Similar κ indices between conventional algorithm and ELISA pair were found, 0.7038 (95% CI 0.6555-0.7521), representing high similarity between both groups of diagnosis. We conclude that conventional serodiagnoses, Brucellacapt® and LFT, presented inconclusive results and poor correlation between them. By contrast, ELISA test pair (IgG + IgM) presented high correlation with the conventional algorithm and greater capacity for correct positive and negative classification.

Complete genome sequence of a coxsackievirus type A24 variant causing an outbreak of acute haemorrhagic conjunctivitis in southeastern Mexico in 2017.

Cases of acute haemorrhagic conjunctivitis (AHC) caused by a coxsackie virus A24 variant (CV-A24v) in Mexico have been reported since 1987; however, no molecular data on the causative strains have been available. Here, we report the identification of the etiological agent responsible for the most recent AHC outbreak in southeastern Mexico (at the end of 2017) as well as the complete genome sequences of seven isolates, using next-generation sequencing (NGS). Phylogenomic analysis of the CV-A24v sequences reported here showed similarity to contemporary strains causing AHC outbreaks in French Guiana and Uganda, forming a novel clade related to genotype IV. Moreover, a specific mutational pattern in the non-structural proteins was identified in the 2017 isolates. This is the first report of genetic characterization of CV-A24v isolates obtained in Mexico.

Antimicrobial resistance and recurrent bacterial urinary tract infections in hospitalized patients following kidney transplantation: A single-center experience.

PURPOSE: The burden of urinary tract infections (UTIs) and risk factors for developing infections with multidrug resistant organisms (MDROs) post-kidney transplantation (KT) are poorly understood. METHODS: Single-center retrospective cohort study (January 2015-December 2017) evaluating first and recurrent episodes of bacteriuria and subsequent analysis of episodes caused by MDROs up to 6 months post-KT. Donor and recipient variables were reviewed. RESULTS: A total of 743 adults underwent single KT during the study period, and 106 patients were hospitalized with bacteriuria. 45% were asymptomatic in their first episode. 73.6% had a single episode, and 26.4% had 2 or more episodes. A total of 28 patients had recurrent episodes; 64.3% had an MDRO on the first episode and 78.6% on the second episode. Escherichia coli was the most common organism isolated, 88.5% were resistant to trimethoprim-sulfamethoxazole (TMP-SMX), 9.3% were extended-spectrum beta-lactamase (ESBL) producers, and 38.1% were MDROs. Body mass index ≥30 was significantly associated with the presence of MDROs in both univariate and multivariate analyses (RR 1.37, 95% CI 1.01-1.88; OR 3.26, CI 1.29-8.25). A total of 12 donors had bacteremia or bacteriuria and 6 (50%) with E coli. A total of 10 KT recipients received antibiotic prophylaxis to prevent donor-derived infections. CONCLUSIONS: Our results suggest that a significant proportion of patients develop recurrent bacteriuria post-transplantation; of those, more than half caused by MDROs. There is a possible association between obesity and MDROs in KT recipients that merits further investigation. With the global crisis in antimicrobial resistance, innovative strategies are needed to prevent and treat UTIs in KT patients.

Re-evaluating the role of phosphinic acid (DINHOP) adsorption at the photoanode surface in the performance of dye-sensitized solar cells.

Dineohexyl phosphinic acid (DINHOP) is a popular amphiphilic molecular insulator considered as the most efficient co-adsorbent (co-grafter) for the improvement of the photovoltaic performance of TiO2 based hybrid solar cells. Although the effect of its incorporation on the improvement of cell performance has been well demonstrated, the mechanisms through which it affects the photovoltaic and electrodynamic parameters of the cells are not yet clear. Here we re-examine the mechanism through which the DINHOP co-adsorbent affects the photovoltaic and electrodynamic parameters of dye-sensitized solar cells. Although DINHOP is widely believed to inhibit (passivate) recombination across the TiO2/electrolyte interface, we demonstrate that this is sublte, noticeable only for a very high concentration (e.g. 750 µM) of DINHOP, co-sensitized with a dye. For the most frequently used DINHOP concentrations (e.g. 75 µM and 375 µM), an observed increase of the diffusion coefficient and recombination rate could be directly associated with a decrease of total intra-gap states in TiO2. For a DINHOP concentration as low as 75 µM, the conduction band edge of TiO2 moves upward due to the combined effect of charge accumulation and a decrease in the total number of intra-gap states leading to an effective enhancement of the DCCS VOC, where the decrease in total intra-gap states does not contribute positively. The decrease of total intra-gap states enhances both the transport and recombination rates of charge carriers by the same fraction due to a transport-limited recombination process. On the other hand, adsorption of DINHOP molecules at higher concentrations such as 375 µM and 750 µM additionally modifies the distribution of intra-gap states, affecting the nonlinear recombination parameter of charge carriers at the anode-electrolyte interface, leading to an overall enhancement of the DSSC VOC. In all cases, incorporation of DINHOP results in an overall improvement of the solar cell efficiency (∼14% compared with the reference one), with a maximum for a concentration of 375 µM, where no inhibition of recombination was observed. Interestingly, for this DINHOP concentration, we estimate that 1 DINHOP molecule per every 12 molecules of dye occupies the intra-gap states of the TiO2 surface. The results presented in this work elucidate the physical phenomena involved in the interaction of co-adsorbents, pre-treatments or additives with the electrolyte at the surface of the TiO2 photoanode of dye-sensitized solar cells and can be easily adapted to study other electrochemical systems.

From ISET to InDRE. IV. Institute of Epidemiological Diagnosis and Reference: new orientation, 1990-2012.

From 1990 to 2012, the Sanitary and Tropical Diseases Institute experienced the most important changes. In 1989, its name and orientation were modified to become the National Institute of Epidemiological Diagnosis and Reference. Shortly before, it had been formalized as the apex of the National Network of Public Health Laboratories and had incorporated laboratories for preventive programs such as exfoliative cytology and rabies, malaria and tuberculosis diagnosis; subsequently, it would incorporate other networks that emerged as part of the response to major epidemic outbreaks and to the new epidemiological outlook. In this period, 27 priority diagnostic algorithms were defined, organized in 18 networks, some of which began to collaborate with global networks. In 2001, the Institute started working with pathogens related to bioterrorism. By then, space restrictions of the headquarter's building were evident; in 2008, starting the construction of new facilities was decided. The Institute and its diagnostic networks constitute a milestone in Latin American public health of the 21st century.

De 1990 a 2012, el Instituto de Salubridad y Enfermedades Tropicales experimentó los cambios más importantes desde su origen. En 1989 modificó su nombre y orientación a Instituto Nacional de Diagnóstico y Referencia Epidemiológicos. Poco antes se había formalizado como cúspide de la organización piramidal denominada Red Nacional de Laboratorios en Salud Pública y había incorporado los laboratorios de programas preventivos como el de citología exfoliativa y los de diagnóstico de rabia, paludismo, tuberculosis; posteriormente incorporaría otras redes que surgieron como parte de la respuesta a brotes epidémicos importantes (cólera, VIH-sida, sarampión, influenza) y al nuevo panorama epidemiológico (dengue, Chagas, rotavirus). En este periodo se definieron 27 algoritmos diagnósticos prioritarios organizados en 18 redes, algunas de las cuales comenzaron a colaborar con redes globales. En 2001, en el Instituto se empezó a trabajar con patógenos relacionados con el bioterrorismo. Para entonces, las severas restricciones de espacio del edificio construido en 1935 fueron evidentes; en 2008, las autoridades decidieron iniciar el diseño y construcción de las nuevas instalaciones. En conjunto, el InDRE y sus redes diagnósticas constituyen un hito en la salud pública latinoamericana del siglo XXI.

From the handling of an outbreak by an unknown pathogen in Wuhan to the preparedness and response in the face of the emergence of Covid-19 in Mexico.

On December 31, 2019, the Chinese health authorities informed the international community, through the mechanisms established by the World Health Organization (WHO), of a pneumonia epidemic of unknown etiology in Wuhan, Hubei Province. The first cases were reported early in that month and were linked to a history of having visited a market where food and live animals are sold. On January 7, 2020, isolation and identification of the culprit pathogen was achieved using next-generation sequencing, while the number of affected subjects continued to rise. The publication of full-genomes of the newly identified coronavirus (initially called 2019-nCoV, now called SARS-CoV2) in public and private databases, of standardized diagnostic protocols and of the clinical-epidemiological information generated will allow addressing the Public Health Emergency of International Concern (PHEIC), declared on January 30 by the WHO. With this document, we intend to contribute to the characterization of the pneumonia epidemic, now designated coronavirus disease (Covid-19) review the strengths Mexico has in the global health concert and invite health professionals to join the preparedness and response activities in the face of this emergency.

El 31 de diciembre de 2019, las autoridades chinas de salud informaron a la comunidad internacional, a través de los mecanismos establecidos por la Organización Mundial de la Salud (OMS), de una epidemia de neumonía con etiología desconocida en Wuhan, provincia de Hubei. Los primeros casos se notificaron a inicios de ese mes y se vincularon al antecedente de visitar un mercado de comida y animales vivos. El 7 de enero de 2020 se logró el aislamiento y reconocimiento del patógeno responsable mediante secuenciación de siguiente generación, mientras el número de afectados continuaba en ascenso. La publicación de genomas completos del nuevo coronavirus identificado (inicialmente denominado 2019-nCoV, ahora designado SARS-CoV2) en bases de datos públicas y privadas, de protocolos diagnósticos estandarizados y de la información clínica epidemiológica generada permitirá atender la Emergencia de Salud Pública de Importancia Internacional (ESPII) declarada el 30 de enero por la OMS. Con este documento pretendemos aportar a la caracterización de la epidemia de neumonía, ahora llamada enfermedad por coronavirus (Covid-19), revisar las fortalezas que tiene México en el concierto de la salud global e invitar a los profesionales de la salud a incorporarse a las actividades de preparación y respuesta ante esta emergencia.

From ISET to InDRE. V. Institute of Epidemiological Diagnosis and Reference. Global strategic position, 2012-2019.

This document describes the changes at the Institute of Epidemiological Diagnosis and Reference (InDRE) from 2012 to 2019, the administrative and equipment modifications, the new headquarters and the National System of Epidemiological Surveillance legal modifications. The process of relocation is mentioned, especially the careful transfer of the biological material protected by the Institute, and the new way of studying epidemic outbreaks, endemic diseases and the negative network is analyzed. At the international level, the promotion of links with global networks of the Pan American Health Organization, the World Health Organization (WHO) and other international organizations is described. The assignation to InDRE of four WHO collaborating centres is also mentioned. The Global Health Security Initiative Laboratory Network acknowledged InDRE's leadership, which co-chaired the working group during the study period.

En este documento se describen los cambios en el Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE) de 2012 a 2019, las modificaciones administrativas y de equipamiento, la nueva sede y las modificaciones jurídicas al Sistema Nacional de Vigilancia Epidemiológica. Se menciona el proceso de mudanza, en especial el cuidadoso traslado del material biológico que resguarda el Instituto y se analiza la nueva forma de estudiar los brotes epidémicos, los padecimientos endémicos y la red negativa. Respecto al ámbito internacional, se describe el fomento de la vinculación con redes globales de la Organización Panamericana de la Salud, la Organización Mundial de la Salud (OMS) y otros organismos internacionales. También se menciona la designación en el InDRE de cuatro centros colaboradores de la OMS. La Red de Laboratorios de la Iniciativa Global para la Seguridad en Salud reconoció el liderazgo del InDRE, cuyo director ocupó la copresidencia del grupo de trabajo en el periodo de estudio.

Mutational landscape and intra-host diversity of human papillomavirus type 16 long control region and E6 variants in cervical samples.

Human papillomavirus genotype 16 (HPV16) is the most frequent high-risk HPV (HR-HPV) identified in cervical precursor lesions and cervical cancer (CC) worldwide. The oncogenic potential of HPV16 is partly dependent on the lineage involved in the infection and the presence of clinically relevant mutations. In this report, we present the distribution of HR-HPV and the mutational profile and intra-host variability of HPV16 lineages, based on analysis of the long control region (LCR) and the E6 gene in samples with normal cytology (n = 39), squamous intraepithelial lesions (n = 25), and CC (n = 39). HR-HPV genotyping was performed using multiplex real-time PCR. HPV16 lineage assignments and mutation frequencies were determined by conventional PCR and Sanger DNA sequencing, and intra-patient viral populations were analyzed using next-generation sequencing (NGS). The most frequent HR-HPV type was HPV16, followed by HPV31 and HPV18. The frequency of HPV16 sublineages was A1/A2 > D2 > D3 and B1. Moreover, the most frequent mutations, both in samples from this study and in the available sequences from Mexican isolates in the GenBank database were LCR-G7518A, which is involved in carcinogenesis, and E6-T350G (producing L83V), associated with persistence of infection. Otherwise, deep sequencing revealed high conservation of viral lineages and mutations, independently of the stages studied. In conclusion, the high frequency and stability of these molecular markers, as well as the circulating viral lineages, could be related to the incidence of CC associated with HPV16. Hence, they deserve a broader analysis to determine the risk of specific populations for progression of the disease.

Desde el ISET al InDRE. I. Instituto de Salubridad y Enfermedades Tropicales: génesis y primeros años, 1934-1940.

Lázaro Cárdenas government vision, and the process to create the Sanitary and Tropical Diseases Institute, which is considered strategic for public health, were consistent with the actions that were carried out: the Department of Public Sanitary asked the most relevant scientist of those days, Eliseo Ramírez, to design and follow-up the Institute's project. A commission of the Higher Education and Scientific Research Council reviewed and approved the project and conferred this institution its nature of research center with social and humanistic vocation since its foundation. Sanitary and Tropical Diseases Institute became the first post-revolutionary health institution that was born with well-remunerated job positions to conduct full-time research in Mexico, offering clinical services, teaching and supporting disease prevention and control campaigns. It was with no doubt a milestone in Mexican public health and crystalized the expectations of several generations of physicians and health researchers about having a high-level institution. It is the most significant public health institution of the country, with a new phase as Institute of Epidemiological Diagnosis and Reference. Without it, Mexican modern public health cannot be understood.

La visión del gobierno cardenista y el proceso para crear el Instituto de Salubridad y Enfermedades Tropicales, considerado estratégico para la salud pública, fueron congruentes con las acciones llevadas a cabo: el Departamento de Salubridad Pública encargó al científico más relevante de la época, Eliseo Ramírez, el diseño y seguimiento del Instituto, que una comisión del Consejo Nacional de Educación Superior y la Investigación Científica revisó, aprobó y desde su inicio le confirió el carácter de investigación con vocación social y humanística. El Instituto de Salubridad y Enfermedades Tropicales se convirtió en el primer organismo posrevolucionario que nació con plazas bien remuneradas para realizar investigación de tiempo completo en México, ofreciendo servicio clínico y enseñanza y apoyando las campañas sanitarias en la prevención y control de las enfermedades. Sin duda fue un parteaguas en la salud pública mexicana y cristalizó las expectativas de varias generaciones de médicos e investigadores en salud para tener una institución de alto nivel. Es la más significativa institución de salud pública del país, con una nueva etapa como Instituto de Diagnóstico y Referencia Epidemiológicos; sin ella no se entiende la moderna salud pública de México.

Desde el ISET al InDRE. II. Instituto de Salubridad y Enfermedades Tropicales: madurez y consolidación, 1940-1964.

The period that starts in 1940 is crucial for the creation of Mexico's modern health system. The Institute of Sanitary and Tropical Diseases is the pioneer institution in health research and on its first two decades it achieved maturity and consolidated lines of research expressed in almost 1700 publications. It also obtained notorious international visibility and was selected as a regional reference for epidemiological surveillance of influenza, streptococcus and salmonella. Its evolution took place with an innovation rhythm that would be decreasing by the end of this period. It faced limitations to renew lines of research, researchers and laboratory equipment. However, its role in public health decisions of the country remained central.

El periodo que comienza en 1940 es crucial para la creación del moderno sistema de salud de México. El Instituto de Salubridad y Enfermedades Tropicales es la institución pionera en investigación en salud y en sus primeras dos décadas logra madurez y consolida líneas de investigación expresadas en casi 1700 publicaciones. También obtiene notoria visibilidad internacional y fue seleccionado como referencia regional para la vigilancia epidemiológica de influenza, estreptococo y salmonela. Su evolución se produjo con ritmo de innovación que iría disminuyendo para el final de ese periodo. Enfrentó limitaciones para renovar líneas de trabajo, investigadores y equipo de laboratorio, sin embargo, su papel en las decisiones de la salud pública del país siguió siendo central.

Desde el ISET al InDRE. III. Instituto de Salubridad y Enfermedades Tropicales: crisis y renovación, 1965-1989.

This paper analyzes the situation and the changes made in the Institute of Sanitary and Tropical Diseases between 1965 and 1989 to become the National Institute of Epidemiological Diagnosis and Reference. Three major stages are identified during this period: crisis, transition and renewal. The factors that led to the crisis, the decisions made to overcome it and to harmonize the work of laboratories with epidemiological and public health criteria are discussed. The recognition obtained by researchers of the Institute despite the crisis is described, as well as the way the institution managed to continue with projects despite the changing global situation. The transition included the arrival of a new generation of professionals with modern computer-based and conceptual tools and the remarkably well met challenge of participating in national surveys with rigorous criteria. All this moved the institution to define its profile towards diagnosis and reference.

El artículo analiza la situación y los cambios efectuados en el Instituto de Salubridad y Enfermedades Tropicales entre 1965 y 1989 para transformarse en el Instituto Nacional de Diagnóstico y Referencia Epidemiológicos. Se identifican tres grandes etapas en el periodo: crisis, transición y renovación. Se señalan los elementos que llevaron a la crisis, las decisiones que se tomaron para salir de ella y armonizar el trabajo de los laboratorios con criterios epidemiológicos y de salud pública. Se citan las distinciones obtenidas por investigadores del Instituto a pesar de la crisis y se describe cómo la institución logró seguir con proyectos a pesar de la cambiante situación mundial. La transición incluyó la llegada de una nueva generación de profesionales con modernas herramientas informáticas y conceptuales y el desafío de participar en encuestas nacionales con criterios rigurosos. Todo ello movió a la institución a definir su perfil hacia el diagnóstico y la referencia.

Algoritmo diagnóstico para la confirmación de casos de sarampión y rubéola en México.

Due to the successful implementation of measles and rubella elimination strategies, Mexico announced the interruption of endemic transmission of measles in 1996 and that of rubella in 2008. After a verification process, the region of the Americas was declared free of rubella and congenital rubella syndrome in 2015 and of measles in 2016. In order to maintain the elimination status in Mexico, it is essential to continue laboratory surveillance within the framework of the Global Measles and Rubella Laboratory Network. The Institute of Epidemiological Diagnosis and Reference, through the National Network of Public Health Laboratories, guarantees timely and reliable results in view of the possible reintroduction of these and other emerging pathogens.

Debido a la implementación exitosa de las estrategias de eliminación del sarampión y la rubéola, México enunció la interrupción de la transmisión endémica del sarampión en 1996 y de la rubéola en 2008. Después de un proceso de verificación, la región de las Américas fue declarada libre de rubéola y del síndrome de rubéola congénita en 2015 y del sarampión en 2016. Para mantener el estatus de eliminación en México es esencial continuar con la vigilancia por laboratorio en el marco de la Red Mundial de Laboratorios de Sarampión y Rubéola. El Instituto de Diagnóstico y Referencia Epidemiológicos, a través de la Red Nacional de Laboratorios de Salud Pública, garantiza resultados oportunos y confiables ante la posible reintroducción de estos y otros patógenos emergentes.

Diagnostic algorithm for the confirmation of cases of measles and rubella in Mexico.

Due to the successful implementation of measles and rubella elimination strategies, Mexico announced the interruption of endemic transmission of measles in 1996 and that of rubella in 2008. After a verification process, the region of the Americas was declared free of rubella and congenital rubella syndrome in 2015 and of measles in 2016. In order to maintain the elimination status in Mexico, it is essential to continue laboratory surveillance within the framework of the Global Measles and Rubella Laboratory Network. The Institute of Epidemiological Diagnosis and Reference, through the National Network of Public Health Laboratories, guarantees timely and reliable results in view of the possible reintroduction of these and other emerging pathogens.

Seroprevalence of Poliomyelitis Antibodies Among Children Aged 1 to 4 Years Old and Factors Associated With Poliovirus Susceptibility; Mexican Health and Nutrition Survey, 2012.

Background: An essential component of the "Polio Eradication and Endgame Strategic Plan 2013-2018" is the evaluation of population immunity. Mexico introduced the inactivated polio vaccine (IPV) into its routine immunization schedule in 2007 but continued to give trivalent oral polio vaccine OPV twice a year during National Health Weeks through 2016. Methods: To describe the seroprevalence of poliomyelitis among children one to four years old in Mexico and analyze risk factors for susceptibility. We detected antibodies to poliovirus type 1 by microneutralization test in 966 serum samples randomly selected from the National Health and Nutrition Survey, 2012. We assessed variables associated with susceptibility using multivariable logistic regression. Results: The overall weighted seroprevalence of the general population was 98.39% (95% confidence interval [CI] 96.76-99.21). We found significant differences of prevalence according to age (94.39%, 95% CI 87.56-97.58; 99.02%, 95% CI 95.68-99.79; 99.82%, 95% CI 98.77-99.98; and 100% among children 1, 2, 3, and 4 years old respectively) and number of IPV doses (96.91%, 95% CI 90.55-99.44; 100%; 97.85%, 95% CI 94.46-99.18; and 99.92%, 95% CI 99.45-99.98 for 1 2, 3, and 4 number of doses, respectively). Multivariate analyses showed that susceptibility was associated with younger age, fewer doses of IPV, and certain socioeconomic levels. Conclusions: Overall seroprevalence was high. However, we found susceptible children among younger ages and children with fewer or unknown IPV doses belonging to certain socioeconomic strata. Results are relevant for countries transitioning from OPV to IPV and underline the importance of achieving high coverage with IPV.

Effects of Oxidizing/Reducing Agent Ratio on Phase Purity, Crystallinity, and Magnetic Behavior of Solution-Combustion-Grown BiFeO3 Submicroparticles.

Fabrication of phase-pure well-crystalline BiFeO3 submicroparticles in large scale is of great importance for the utilization of this rhombohedrally distorted perovskite material in applications such as memory storage and spintronic devices and visible photocatalyst for the degradation of organic pollutants. In fact, because of the narrow temperature range of phase stabilization, the fabrication of phase-pure BiFeO3 in large scale remained elusive. We present the synthesis of phase-pure BiFeO3 particles of submicrometric dimensions (246-330 nm average size) through the adjustment of oxidizing/reducing agent ratio in solution combustion process utilizing glycine as reducing agent and nitrate precursors as oxidizing agent. Utilizing X-ray diffraction and Raman spectroscopy, we demonstrate that the BiFeO3 submicroparticles synthesized at equivalence ratio (Φe) close to 0.5 do not contain undesired impurities such as Bi2Fe4O9 and Bi24Fe2O39. Moreover, the submicroparticles are highly crystalline, possessing high room temperature magnetic moment and stable antiferromagnetic behavior across a wide temperature range. The superparamagnetic behavior at low magnetic field manifested by impurities attached to the BiFeO3 submicroparticles might lead to their use as effective magnetically separable photocatalysts.

Full genome and phylogenetic analysis of hepatitis B virus genotype F in Mexican isolates.

Hepatitis B virus genotype F (HBV/F) is endemic in Central and South America with a minor proportion in Mexico and North America. HBV/F is divided into subgenotypes and subtypes with particular geographic circulation patterns. Here, we report the complete genome sequence and molecular characterization of HBV/F from three isolates. Phylogenetic analysis with all available HBV/F sequences showed that our sequences belonged to the F1b subtype and, in addition, the absence of the previously reported F1a subtype in Mexican isolates. Our findings suggest the circulation of HBV/F1b, the first phylogenomic study of HBV/F in Mexico.

Genotypic variability analysis of DENV-1 in Mexico reveals the presence of a novel Mexican lineage.

Here, we report for the first time the circulation of dengue virus type 1 (DENV-1) belonging to the lineage IV of genotype V (African American genotype) based on phylogenetic analysis of nucleotide sequences from 10 DENV-1-positive samples obtained in Mexico between 2012 and 2014. Our data revealed that the lineages III and IV of DENV-1 genotype V were found circulating during the same period, probably explaining the rise in the number of cases of severe dengue during that period.