RESUMEN
BACKGROUND: Population-based information regarding the impact of respiratory syncytial virus (RSV) and influenza on hospital admissions and mortality is scant for many countries. METHODS: Prospective testing of RSV and influenza virus was undertaken in patients <5 years old admitted to hospital with acute respiratory infection (ARI) between July, 2014 and June, 2015, and mortality rates for children living in 3 municipalities in the state of San Luis Potosí were calculated. RESULTS: During the 12-month study period, 790 children living in these municipalities were admitted with ARI. RSV was detected in 245 (31%) and influenza in 47 (5.9%). History of preterm birth was recorded for 112 children on admission. For children <5 years old, ARI-, RSV- and influenza-associated admission rates were 23.2, 7.2 and 1.4 (per 1000 population), respectively. The corresponding admission rates per 1000 infants <1 year old were 78, 25.2 and 4.4. Preterm infant admission rates were 2 times higher than those of term infants. Six children died; RSV was detected in 4 (66.6%) of the deceased, while no deaths were associated with influenza. ARI and RSV in-hospital mortality rates for children <5 years were 0.18 and 0.12 per 1000 population. ARI and RSV mortality rates in preterm infants were 7 and 14 times higher than in term infants, respectively. CONCLUSIONS: RSV was associated with both high admission and in-hospital mortality rates in children <5 years old. Specific interventions, such as active or passive immunization, to prevent RSV infections are required to reduce ARI-associated infant mortality.
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Mortalidad Hospitalaria , Hospitalización , Gripe Humana , Infecciones por Virus Sincitial Respiratorio , Humanos , Lactante , Infecciones por Virus Sincitial Respiratorio/mortalidad , Infecciones por Virus Sincitial Respiratorio/epidemiología , México/epidemiología , Hospitalización/estadística & datos numéricos , Preescolar , Gripe Humana/mortalidad , Gripe Humana/epidemiología , Femenino , Masculino , Estudios Prospectivos , Recién Nacido , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio/mortalidad , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/virologíaRESUMEN
Human Immunodeficiency virus (HIV) and its clinical entity, the Acquired Immunodeficiency Syndrome (AIDS) continue to represent an important health burden worldwide. Although great advances have been made towards determining the way viral genetic diversity affects clinical outcome, genetic association studies have been hindered by the complexity of their interactions with the human host. This study provides an innovative approach for the identification and analysis of epidemiological associations between HIV Viral Infectivity Factor (Vif) protein mutations and four clinical endpoints (Viral load and CD4 T cell numbers at time of both clinical debut and on historical follow-up of patients. Furthermore, this study highlights an alternative approach to the analysis of imbalanced datasets, where patients without specific mutations outnumber those with mutations. Imbalanced datasets are still a challenge hindering the development of classification algorithms through machine learning. This research deals with Decision Trees, Naïve Bayes (NB), Support Vector Machines (SVMs), and Artificial Neural Networks (ANNs). This paper proposes a new methodology considering an undersampling approach to deal with imbalanced datasets and introduces two novel and differing approaches (MAREV-1 and MAREV-2). As theses approaches do not involve human pre-determined and hypothesis-driven combinations of motifs having functional or clinical relevance, they provide a unique opportunity to discover novel complex motif combinations of interest. Moreover, the motif combinations found can be analyzed through traditional statistical approaches avoiding statistical corrections for multiple tests.
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Infecciones por VIH , VIH-1 , Humanos , Secuencias de Aminoácidos , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/metabolismo , Teorema de Bayes , Mutación , Aprendizaje Automático , VIH-1/metabolismoRESUMEN
Understanding the evolution of the SARS-CoV-2 virus in various regions of the world during the Covid-19 pandemic is essential to help mitigate the effects of this devastating disease. We describe the phylogenomic and population genetic patterns of the virus in Mexico during the pre-vaccination stage, including asymptomatic carriers. A real-time quantitative PCR screening and phylogenomic reconstructions directed at sequence/structure analysis of the spike glycoprotein revealed mutation of concern E484K in genomes from central Mexico, in addition to the nationwide prevalence of the imported variant 20C/S:452R (B.1.427/9). Overall, the detected variants in Mexico show spike protein mutations in the N-terminal domain (i.e. R190M), in the receptor-binding motif (i.e. T478K, E484K), within the S1-S2 subdomains (i.e. P681R/H, T732A), and at the basis of the protein, V1176F, raising concerns about the lack of phenotypic and clinical data available for the variants of interest we postulate: 20B/478K.V1 (B.1.1.222 or B.1.1.519) and 20B/P.4 (B.1.1.28.4). Moreover, the population patterns of single nucleotide variants from symptomatic and asymptomatic carriers obtained with a self-sampling scheme confirmed the presence of several fixed variants, and differences in allelic frequencies among localities. We identified the mutation N:S194L of the nucleocapsid protein associated with symptomatic patients. Phylogenetically, this mutation is frequent in Mexican sub-clades. Our results highlight the dual and complementary role of spike and nucleocapsid proteins in adaptive evolution of SARS-CoV-2 to their hosts and provide a baseline for specific follow-up of mutations of concern during the vaccination stage.
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COVID-19/virología , Proteínas de la Nucleocápside de Coronavirus/genética , Filogenia , SARS-CoV-2/genética , COVID-19/epidemiología , COVID-19/inmunología , COVID-19/prevención & control , Vacunas contra la COVID-19/administración & dosificación , Portador Sano/prevención & control , Portador Sano/virología , Genoma Viral , Humanos , México , Mutación , Fosfoproteínas/genética , SARS-CoV-2/clasificación , SARS-CoV-2/inmunología , SARS-CoV-2/aislamiento & purificación , VacunaciónRESUMEN
BACKGROUND: We identified a global chemical pattern of volatile organic compounds in exhaled breath capable of discriminating between COVID-19 patients and controls (without infection) using an electronic nose. METHODS: The study focused on 42 SARS-CoV-2 RT-qPCR positive subjects as well as 42 negative subjects. Principal component analysis indicated a separation of the study groups and provides a cumulative percentage of explanation of the variation of 98.3%. RESULTS: The canonical analysis of principal coordinates model shows a separation by the first canonical axis CAP1 (r2 = 0.939 and 95.23% of correct classification rate), the cut-off point of 0.0089; 100% sensitivity (CI 95%:91.5-100%) and 97.6% specificity (CI 95%:87.4-99.9%). The predictive model usefulness was tested on 30 open population subjects without prior knowledge of SARS-CoV-2 RT-qPCR status. Of these 3 subjects exhibited COVID-19 suggestive breath profiles, all asymptomatic at the time, two of which were later shown to be SARS-CoV-2 RT-qPCR positive. An additional subject had a borderline breath profile and SARS-CoV-2 RT-qPCR positive. The remaining 27 subjects exhibited healthy breath profiles as well as SARS-CoV-2 RT-qPCR test results. CONCLUSIONS: In all, the use of olfactory technologies in communities with high transmission rates as well as in resource-limited settings where targeted sampling is not viable represents a practical COVID-19 screening approach capable of promptly identifying COVID-19 suspect patients and providing useful epidemiological information to guide community health strategies in the context of COVID-19.
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COVID-19 , SARS-CoV-2 , Humanos , Tamizaje Masivo , Sensibilidad y Especificidad , TecnologíaRESUMEN
The study of infectious disease behavior has been a scientific concern for many years as early identification of outbreaks provides great advantages including timely implementation of public health measures to limit the spread of an epidemic. We propose a methodology that merges the predictions of (i) a computational model with machine learning, (ii) a projection model, and (iii) a proposed smoothed endemic channel calculation. The predictions are made on weekly acute respiratory infection (ARI) data obtained from epidemiological reports in Mexico, along with the usage of key terms in the Google search engine. The results obtained with this methodology were compared with state-of-the-art techniques resulting in reduced root mean squared percentage error (RMPSE) and maximum absolute percent error (MAPE) metrics, achieving a MAPE of 21.7%. This methodology could be extended to detect and raise alerts on possible outbreaks on ARI as well as for other seasonal infectious diseases.
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Enfermedades Transmisibles , Epidemias , Enfermedades Respiratorias , Brotes de Enfermedades , Predicción , Humanos , México , Enfermedades Respiratorias/epidemiologíaRESUMEN
In 2016 WHO member states endorsed the 69th World Health Assembly's Global Health Sector Strategies (GHSS) towards eliminating Hepatitis B (HBV) infections by 2030. Substantial progress has been made in Mexico regarding HBV vaccination, blood safety and health-care setting injection safety but minor progress has been identified regarding timely HBV birth-dose coverage, access to diagnostic testing and treatment. Most importantly, Mexico's lack of a national plan for the fight against viral hepatitis was identified as a major obstacle for the development and implementation of actions and procuring funding. Insight of these deficiencies, we propose six actions that are in line with GHSS strategic directions to better allow Mexico to reach the goal of eliminating viral hepatitis by 2030. 1) the creation of a National Viral Hepatitis Task Group capable of providing direction, recommendations as well as innovative solutions in the fight against viral hepatitis in Mexico; 2) the drafting of a National Plan for viral hepatitis; 3) establishing a national viral hepatitis information database; 4) development of Clinical Practice Guidelines; 5) appeal for governmental responsibility and accountability; 6) promote basic, applied science projects as well as clinical research to determine the viral, epidemiological, genomic, ethnic and cultural peculiarities of viral hepatitis infections in Mexico. These basic actions will better equip Mexico to meet GHSS targets, lead to high-impact health interventions and ultimately enhance the cascade of care, from diagnosis to chronic care. Political commitment is a requirement to the implementation of these actions but civil society involvement is also seen to be crucial.
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Erradicación de la Enfermedad , Política de Salud , Hepatitis B/prevención & control , Comités Consultivos , Transfusión Sanguínea/normas , Infección Hospitalaria/prevención & control , Salud Global , Objetivos , Accesibilidad a los Servicios de Salud , Vacunas contra Hepatitis B/uso terapéutico , Hepatitis C/tratamiento farmacológico , Hepatitis C/prevención & control , Hepatitis Viral Humana/prevención & control , Humanos , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , México , Guías de Práctica Clínica como AsuntoRESUMEN
Protease is one of three enzymes encoded within HIV's pol gene, responsible for the cleavage of viral Gag-Pol polypeptide into mature viral proteins and a target of current anti-retroviral therapy. Protease diversity analysis in Latin America has been lacking in spite of extensive studies of protease-inhibitor resistance mutations. We studied the diversity of 777 Mexican protease sequences and found that all were subtype B except one (CRF02_AG). Phylogenetic analysis suggested the existence of six different clades with geospecific contributions. Thirty-three percent of sites were conserved, 25% had conservative substitutions, and 41% exhibited physicochemical changes. The most conserved regions surrounded the active site, most of the flap domain, and a region between the 60's loop and C-terminal triad. A single sequence exhibited an active site mutation (T26S). Variable sites were mapped to a crystallographic structure, providing further insight into the distribution and functional relevance of variable sites among Mexican isolates.
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Variación Genética , Infecciones por VIH/virología , Proteasa del VIH/genética , VIH-1/enzimología , VIH-1/genética , Antirretrovirales/farmacología , Farmacorresistencia Viral/genética , Infecciones por VIH/epidemiología , VIH-1/efectos de los fármacos , Humanos , México , Modelos Moleculares , Mutación Missense , Filogenia , Análisis de Secuencia de ProteínaRESUMEN
Adenoviruses are important pathogens known to infect vertebrate hosts, including a wide range of primates. Despite its importance, data on the diversity of these viruses in non-human primates living in their natural habitat remain scarce. In this study, we conducted a surveillance of adenoviral infection in wild black howler monkeys from two protected natural areas in Mexico. This was achieved by analyzing 67 fecal samples using a nested PCR that targets the adenovirus DNA polymerase gene. Adenoviral DNA was detected in 12 samples from both study sites, with an overall prevalence of 17.9%. The amplified DNA sequences shared 100% nucleotide identity and phylogenetic analyses revealed that the haplotype detected was novel, and clustered with Platyrrhini mastadenovirus A, which was previously described in captive New World monkeys. Our data, along with the previous evidence, confirm that monkeys native to the Americas are the original hosts of these adenoviruses.
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Infecciones por Adenoviridae/veterinaria , Adenoviridae/genética , Alouatta/virología , Enfermedades de los Monos/diagnóstico , Enfermedades de los Monos/virología , Adenoviridae/clasificación , Animales , Femenino , Masculino , Enfermedades de los Monos/epidemiología , FilogeniaRESUMEN
This study set out to determine the frequency of antiretroviral drug resistance mutations in treatment-naive subjects of the north central Mexican state of San Luis Potosí. Mexican studies of antiretroviral drug resistance mutations have focused mainly on large metropolitan areas and border towns subjected to intense international migrations. This study set forth to describe the frequency of these mutations in a Mexican region less subjected to such migratory influences and more representative of smaller Mexican cities. Thirty-eight full-length pol sequences spanning the protease, reverse-transcriptase, and integrase-encoding regions were obtained from 42 treatment-naive human immunodeficiency virus (HIV)-infected subjects. Most exhibited subtype B homology, but CRF02_AG was also detected. Evidence of APOBEC3 hypermutation was seen in two samples. Calibrated population analysis revealed a surveillance drug resistance mutation prevalence of 4.9% for protease inhibitors, of 2.7% for nucleoside reverse transcriptase inhibitors, of 8.1% for non-nucleoside reverse transcriptase inhibitors, and an overall prevalence of 9.5%. This corresponds to an intermediate level of transmitted drug resistance according to the World Health Organization. The identification of integrase mutations suggests that transmitted drug mutations are being imported, as inhibitors targeting integrase have not been widely used in Mexico. Our results provide a greater understanding of HIV diversity in Mexico and highlight the way internal migrations allow HIV mutations and genetic features to permeate regions less subjected to international migrations. The implications of these findings will become more evident as Mexico hosts increased repatriations of migrants in the coming years.
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Farmacorresistencia Viral , Infecciones por VIH/virología , Integrasa de VIH/genética , Proteasa del VIH/genética , Transcriptasa Inversa del VIH/genética , VIH/genética , Mutación Missense , Adolescente , Adulto , Femenino , Frecuencia de los Genes , VIH/efectos de los fármacos , VIH/enzimología , Humanos , Masculino , México , Análisis de Secuencia de ADN , Adulto JovenRESUMEN
Human cytomegalovirus (HCMV) infection in children and young adults has been associated with changes in the innate immune system. We herein analyzed the possible effect of very long term HCMV infection on the expression of several NK cell receptors. Ninety HCMV-seropositive individuals were included and classified as young adults (n=30), elderly (n=30) and very elderly subjects (n=30). A peripheral blood sample was obtained and the expression of NK cell receptors (NKG2A, NKG2C, ILT2, CD161, KIR2DL1, KIR3DL1, and KIR3DL2) by NK and other lymphocyte subsets was assessed by flow cytometry. In addition, the frequency of the sixteen KIR genes was analyzed by polymerase chain reaction. We found a significant increase in the number of NKG2C+ NK and T cells in elderly individuals compared to young adults accompanied by an opposite trend in the number of NKG2A+ lymphocytes, and ILT2+ cells were also increased in elderly individuals. A significant increase in the levels of CD3-CD56+NKG2C+CD57+ cells was also detected in the elderly groups. Finally, KIR gene analysis revealed that the KIR genotype 2 was significantly less frequent in the elderly individuals. Our results support that long-term infection by HCMV exerts a significant progressive effect on the innate immune system.
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Infecciones por Citomegalovirus/inmunología , Citomegalovirus/inmunología , Células Asesinas Naturales/inmunología , Receptores de Células Asesinas Naturales/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Células Cultivadas , Citomegalovirus/fisiología , Infecciones por Citomegalovirus/genética , Infecciones por Citomegalovirus/virología , Femenino , Citometría de Flujo , Frecuencia de los Genes , Genotipo , Haplotipos , Interacciones Huésped-Patógeno/inmunología , Humanos , Células K562 , Células Asesinas Naturales/metabolismo , Células Asesinas Naturales/virología , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa/métodos , Receptores de Células Asesinas Naturales/clasificación , Receptores de Células Asesinas Naturales/genética , Adulto JovenRESUMEN
The viral infectivity factor (Vif) is an HIV accessory protein that counteracts host antiviral proteins of the APOBEC3 family. Accumulating evidence highlights the pivotal role that accessory HIV proteins have on disease pathogenesis, a fact that has made them targets of interest for novel therapeutic and preventive strategies. Little is known about Vif sequence diversity outside of African or white populations. Mexico is home to Americas' third largest HIV-affected population and Mexican Hispanics represent an ever-increasing U.S. minority. This study provides a detailed analysis of the diversity seen in 77 Mexican Vif protein sequences. Phylogenetic analysis shows that most sequences cluster with HIV-1 subtype B, while less than 10% exhibit greater similarity to subtype D and A subtypes. Although most functional motifs are conserved among the Mexican sequences, substantial diversity was seen in some APOBEC binding sites, the nuclear localization inhibitory signal, and the CBFß interaction sites.
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Variación Genética , Genotipo , Infecciones por VIH/virología , VIH-1/clasificación , VIH-1/genética , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/genética , Análisis por Conglomerados , Infecciones por VIH/epidemiología , VIH-1/aislamiento & purificación , Humanos , México/epidemiología , FilogeniaRESUMEN
Killer-cell immunoglobulin-like receptors (KIRs) are membrane proteins expressed by cells of innate and adaptive immunity. The KIR system consists of 17 genes and 614 alleles arranged into different haplotypes. KIR genes modulate susceptibility to haematological malignancies, viral infections, and autoimmune diseases. Molecular epidemiology studies rely on traditional statistical methods to identify associations between KIR genes and disease. We have previously described our results by applying support vector machines to identify associations between KIR genes and disease. However, rules specifying which haplotypes are associated with greater susceptibility to malignancies are lacking. Here we present the results of our investigation into the rules governing haematological malignancy susceptibility. We have studied the different haplotypic combinations of 17 KIR genes in 300 healthy individuals and 43 patients with haematological malignancies (25 with leukaemia and 18 with lymphomas). We compare two machine learning algorithms against traditional statistical analysis and show that the "a priori" algorithm is capable of discovering patterns unrevealed by previous algorithms and statistical approaches.
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Neoplasias Hematológicas/genética , Neoplasias Hematológicas/inmunología , Receptores KIR/genética , Adulto , Algoritmos , Estudios de Casos y Controles , Femenino , Predisposición Genética a la Enfermedad , Haplotipos , Humanos , Aprendizaje Automático , Masculino , Cómputos Matemáticos , Modelos Genéticos , Análisis Multivariante , Biología de Sistemas , Adulto JovenRESUMEN
Certain genotypic combinations of killer-cell immunoglobulin-like receptors (KIR) and human leukocyte antigens (HLA) have been associated with favourable outcomes after exposure to human immunodeficiency virus in Caucasoid and African populations. Human immunodeficiency virus (HIV) infection is characterized by a rapid exhaustion of CD4 cells, which results in impaired cellular immunity. During this early phase of infection, it is thought that the natural killer (NK) cells represent the main effector arm of the host immune response to HIV. This study investigates whether KIR and HLA factors are associated to CD4 T cell numbers after HIV infection in Mexican mestizos as assessed at the time of initial medical evaluation and subsequent clinical follow-up. KIR and HLA-B gene carrier frequency differences were compared between groups of patients stratified by CD4 T cell numbers as assessed during their first medical evaluation (a point in time at which all patients were anti-retroviral therapy naïve). In addition, the influence that these genetic factors have on averaged historical CD4 cell counts in patients subjected to follow-up (mostly therapy-experienced) was also evaluated. Our results suggest a protective role for the HLA-Bw4 and KIR3D + Bw4 combination in both therapy-naïve and therapy-experienced patients. This report furthers our understanding on the way that immune genes modulate HIV disease progression in less-studied human populations such as the Mexican mestizos with a special focus on CD4 T cell number and behaviour.
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Linfocitos T CD4-Positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Antígenos HLA-B/inmunología , Americanos Mexicanos/genética , Receptores KIR3DL1/genética , Receptores KIR3DS1/genética , Adolescente , Adulto , Anciano , Progresión de la Enfermedad , Femenino , Genotipo , Infecciones por VIH/genética , Infecciones por VIH/virología , Humanos , Células Asesinas Naturales/inmunología , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
OBJECTIVE: Cytomegalovirus (CMV) is widely distributed and constitutes the main cause of congenital infections worldwide. CMV transmission during pregnancy represents one of the major impacts of this virus on public health. This study aimed at assessing glycoprotein B (gB) CMV genotypes in Mexican children and pregnant women, since there is limited information regarding CMV genomic diversity in Mexico. METHODS: We analyzed CMV strains detected in Mexican children (n = 38) and women (n = 38) between 2001 and 2012. A fragment of the gB gene was amplified and sequenced, and genotypes were defined based on prototype sequences. RESULTS: The gB1 genotype was detected more frequently in children (68.4%) compared to women (31.6%; p = 0.0028), while genotype 2 was more common in women (65.8%) compared to children (26.3%, p = 0.0012). Genotype 3 was uncommon in both groups (5.3 and 2.6%). Nucleotide sequences exhibited a high degree of similarity to prototype strains. However, we identified 17 distinct sequences that resulted in changes in the encoded amino acid sequence in four strains. CONCLUSIONS: gB1 and gB2 are the most common strains associated with CMV infection in Mexican children and women. In addition, we found that the frequency for each genotype differed amongst them, possibly due to variability in transmission or reactivation dynamics.
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Infecciones por Citomegalovirus/virología , Citomegalovirus/genética , Citomegalovirus/aislamiento & purificación , Complicaciones Infecciosas del Embarazo/virología , Proteínas del Envoltorio Viral/genética , Adulto , Secuencia de Aminoácidos , Infecciones por Citomegalovirus/congénito , ADN Viral/genética , Femenino , Genotipo , Humanos , Lactante , Recién Nacido , México , Filogenia , Reacción en Cadena de la Polimerasa , Embarazo , Alineación de Secuencia , Análisis de Secuencia , Factores de Tiempo , Proteínas del Envoltorio Viral/químicaRESUMEN
Introduction of a novel influenza virus into the human population leads to the occurrence of pandemic events, such as the one caused by pandemic influenza A (H1N1) 2009 virus. The severity of infections caused by this virus in young adults was greater than that observed in patients with seasonal influenza. Fatal cases have been associated with an abnormal innate, proinflammatory immune response. A critical role for natural killer cells during the initial responses to influenza infections has been suggested. In this study, we assessed the association of killer-cell immunoglobulin-like receptors (KIRs) with disease severity by comparing KIR gene content in patients with mild and severe pandemic influenza virus infections to a control group. We found that activator (KIR3DS1 and KIR2DS5) and inhibitory (KIR2DL5) genes, encoded in group B haplotypes containing the cB01, cB03 and tB01 motifs, are associated with severe pandemic influenza A (H1N1) 2009 infections. Better understanding of how genetic variability contributes to influenza virus pathogenesis may help to the development of immune intervention strategies aiming at controlling the severity of disease.
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Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/genética , Receptores KIR2DL5/genética , Receptores KIR3DS1/genética , Receptores KIR/genética , Adolescente , Adulto , Anciano , Secuencias de Aminoácidos , Niño , Preescolar , Femenino , Frecuencia de los Genes , Genotipo , Haplotipos , Humanos , Gripe Humana/epidemiología , Gripe Humana/patología , Masculino , México/epidemiología , Persona de Mediana Edad , Pandemias , Isoformas de Proteínas/genética , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
OBJETIVO: Determinar la prevalencia de infección congénita por citomegalovirus en recién nacidos participantes en el programa de tamiz neonatal de los Servicios de Salud de San Luis Potosí. MATERIAL Y MÉTODOS: Se evaluó la presencia de citomegalovirus en muestras de sangre almacenadas en papel filtro. RESULTADOS. Se detectó la presencia de citomegalovirus en 10 (0.68 por ciento) de 1 457 muestras estudiadas. No se encontraron diferencias en las características de los recién nacidos con infección congénita en comparación con aquéllos sin infección. CONCLUSIONES: Es necesario concientizar a los profesionales de la salud sobre la prevalencia e impacto de la infección congénita por citomegalovirus.
OBJECTIVE: To determine the prevalence of congenital cytomegalovirus infection in newborn infants included in the neonatal screening program coordinated by the State Health Services in San Luis Potosí. MATERIAL AND METHODS: We evaluated the presence of cytomegalovirus in blood samples stored in filter paper. RESULTS: Cytomegalovirus was detected in 10 (0.68 percent) of the 1 457 samples included in the study. There were no differences in the characteristics of infants with congenital infection compared to those without infection. CONCLUSIONS: It is necessary to increase awareness of health professionals regarding the prevalence and impact of congenital cytomegalovirus infection.
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Femenino , Humanos , Recién Nacido , Masculino , Infecciones por Citomegalovirus/congénito , Infecciones por Citomegalovirus/epidemiología , Peso al Nacer , Intervalos de Confianza , Citomegalovirus/aislamiento & purificación , México/epidemiología , Tamizaje Neonatal , PrevalenciaRESUMEN
Natural killer (NK) cell function is regulated by different types of membrane-bound receptors of which killer-cell immunoglobulin-like receptors (KIRs) are the most complex and diverse. KIRs are encoded by 17 different genes located within the leukocyte receptor complex (19q13.4). The frequency with which KIR gene features are present in different human populations differs. Here, we present our results on the KIR gene diversity observed in a large group of mestizos from the central Mexican city of San Luis Potosí. In total, 53 different KIR genotypes were observed, 47 with previously described gene profiles and six harboring novel KIR gene combinations. Group A homozygous haplotypes were seen in 102 individuals (34%), while group B homozygous haplotypes were present in 45 (15%). Heterozygous combinations of groups A and B haplotypes were seen in 153 individuals (51%). Haplotype frequency estimations based on a true content of 600 chromosomes showed a relatively balanced proportion of group A (59.5%) and group B (40.5%) haplotypes in our study population. A homozygous combination of the cA01|tA01 haplotype was present in 33% of the population with other frequent combinations being cA01|tA01, cB03|tB01 in 14.7% and cA01|tA01, cB02|tA01 in 12%. The dendrogram derived from activating KIR gene phylogenetic analysis revealed five clearly distinct clades corresponding to African, East Asian, Arab/Caucasoid, Mexican mestizo/Amerindian and South Asian populations. Our results illustrate the genetic contribution that Caucasoid and Amerindian populations have made toward present-day Mexicans and suggest an important Southeast Asian genetic contribution to native Amerindian populations.
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Variación Genética , Indígenas Norteamericanos/genética , Receptores KIR/genética , Pueblo Asiatico/etnología , Pueblo Asiatico/genética , Frecuencia de los Genes , Haplotipos/genética , Humanos , Indígenas Norteamericanos/etnología , Leucocitos , México/etnología , Filogenia , Receptores KIR2DL2/genética , Receptores KIR2DL4/genética , Receptores KIR3DL2/genética , Población Blanca/etnología , Población Blanca/genéticaRESUMEN
BACKGROUND: Acute respiratory infections are a leading cause of morbidity and mortality worldwide. Starting in 2009, pandemic influenza A(H1N1) 2009 virus has become one of the leading respiratory pathogens worldwide. However, the overall impact of this virus as a cause of mortality has not been clearly defined. OBJECTIVES: To determine the impact of pandemic influenza A(H1N1) 2009 on mortality in a Mexican population. METHODS: We assessed the impact of pandemic influenza virus on mortality during the first and second outbreaks in San Luis Potosí, Mexico, and compared it to mortality associated with seasonal influenza and respiratory syncytial virus (RSV) during the previous winter seasons. RESULTS: We estimated that, on average, 8·1% of all deaths that occurred during the 2003-2009 seasons were attributable to influenza and RSV. During the first pandemic influenza A(H1N1) 2009 outbreak, there was an increase in mortality in persons 5-59 years of age, but not during the second outbreak (Fall of 2009). Overall, pandemic influenza A (H1N1) 2009 outbreaks had similar effects on mortality to those associated with seasonal influenza virus epidemics. CONCLUSIONS: The impact of influenza A(H1N1) 2009 virus on mortality during the first year of the pandemic was similar to that observed for seasonal influenza. The establishment of real-time surveillance systems capable of integrating virological, morbidity, and mortality data may result in the timely identification of outbreaks so as to allow for the institution of appropriate control measures to reduce the impact of emerging pathogens on the population.
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Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/mortalidad , Pandemias , Adolescente , Adulto , Anciano , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Gripe Humana/epidemiología , México/epidemiología , Persona de Mediana Edad , Factores de TiempoRESUMEN
Epigenetic mechanisms are crucial to regulate the expression of different genes required for neuronal plasticity. Neurotoxic substances such as arsenic, which induces cognitive deficits in exposed children before any other manifestation of toxicity, could interfere with the epigenetic modulation of neuronal gene expression required for learning and memory. This study assessed in Wistar rats the effects that developmental arsenic exposure had on DNA methylation patterns in hippocampus and frontal cortex. Animals were exposed to arsenic in drinking water (3 and 36ppm) from gestation until 4 months of age, and DNA methylation in brain cells was determined by flow cytometry, immunohistochemistry and methylation-specific polymerase chain reaction (PCR) of the promoter regions of reelin (RELN) and protein phosphatase 1 (PP1) at 1, 2, 3 and 4 months of age. Immunoreactivity to 5 methyl-cytosine was significantly higher in the cortex and hippocampus of exposed animals compared to controls at 1 month, and DNA hypomethylation was observed the following months in the cortex at high arsenic exposure. Furthermore, we observed a significant increase in the non-methylated form of PP1 gene promoter at 2 and 3 months of age, either in cortex or hippocampus. In order to determine whether this exposure level is associated with memory deficits, a behavioral test was performed at the same age points, revealing progressive and dose-dependent deficits of fear memory. Our results demonstrate alterations of the methylation pattern of genes involved in neuronal plasticity in an animal model of memory deficit associated with arsenic exposure.