Influenza vs. COVID-19: Comparison of Clinical Characteristics and Outcomes in Pediatric Patients in Mexico City.

Introduction: Respiratory viruses are among the leading causes of disease and death among children. Co-circulation of influenza and SARS-CoV2 can lead to diagnostic and management difficulties given the similarities in the clinical picture. Methods: This is a cohort of all children hospitalized with SARS-CoV2 infection from March to September 3rd 2020, and all children admitted with influenza throughout five flu-seasons (2013-2018) at a pediatric referral hospital. Patients with influenza were identified from the clinical laboratory database. All hospitalized patients with confirmed SARS-CoV2 infection were followed-up prospectively. Results: A total of 295 patients with influenza and 133 with SARS-CoV2 infection were included. The median age was 3.7 years for influenza and 5.3 years for SARS-CoV2. Comorbidities were frequent in both groups, but they were more common in patients with influenza (96.6 vs. 82.7%, p < 0.001). Fever and cough were the most common clinical manifestations in both groups. Rhinorrhea was present in more than half of children with influenza but was infrequent in those with COVID-19 (53.6 vs. 5.8%, p < 0.001). Overall, 6.4% percent of patients with influenza and 7.5% percent of patients with SARS-CoV2 infection died. In-hospital mortality and the need for mechanical ventilation among symptomatic patients were similar between groups in the multivariate analysis. Conclusions: Influenza and COVID-19 have a similar picture in pediatric patients, which makes diagnostic testing necessary for adequate diagnosis and management. Even though most cases of COVID-19 in children are asymptomatic or mild, the risk of death among hospitalized patients with comorbidities may be substantial, especially among infants.

Amino acid changes in HA and determinants of pathogenicity associated with influenza virus A H1N1pdm09 during the winter seasons 2015-2016 and 2016-2017 in Mexico.

Biennial H1N1pdm09 influenza A virus (IAV) epidemics have been associated with major severity of respiratory disease in Mexico. Atypically and in contrast with what happened in USA, Canada and Europe during 2017, an increase of infections due to the H1N1pdm09 pandemic virus instead of H3N2 was observed. In order to determine the viral contribution to severe acute respiratory disease, we characterized the pathogenicity determinants of IAV in Mexico during the 2015-2016 and 2016-2017 seasons. The RNA segments of 20 IAV samples were sequenced by NGS platform and phylogenetic analysis was conducted. The analysis of the hemagglutinin (HA) sequences established that all virus samples, except one, belong to clade (6B.1). The IAVs presented the substitution S162 N, which introduces a new glycosylation site in the hemagglutinin. We also found the D222 G substitution, which has been associated with a higher tropism towards the lower respiratory tract, and a non-reported insertion of one Ile in NS1 (Ile113). The IAVs from 2016 to 2017 in Mexico belong to the new clade 6B.1. The new glycosylation site in HA (S162 N) is a major change that may affect the efficacy of the current vaccine. We detected in several patients pathogenicity determinants associated with the severity of the respiratory disease.

Healthcare-Associated Pneumonia: Don't Forget About Respiratory Viruses!

Introduction: Healthcare-associated infections are an important cause of morbidity and mortality, are among the most common adverse events in healthcare, and of them, pneumonia is the most commonly reported. Our objective was to evaluate the incidence and clinical outcome of respiratory viruses in hospital-acquired pneumonia (HAP). Methods: This was a prospective cohort study, include patients aged between 0 and 18 who fulfilled Centers for Diseases Control and Prevention (CDC) criteria for HAP. Demographic and clinical data were obtained, and a nasopharyngeal swab specimen was taken for the detection of respiratory viruses. All included patients were monitored until discharge to collect data on the need for mechanical ventilation, intensive care unit (ICU) admission, and mortality. All-cause 30-day mortality was also ascertained. Results: Four thousand three hundred twenty-seven patients were followed for 42,658 patient-days and 5,150 ventilator-days. Eighty-eight patients (2.03%) met the CDC criteria for HAP, 63 patients were included, and clinical and epidemiological characteristics showed no statistically significant differences between patients with virus associated healthcare-associated pneumonia (VAHAP) and those with non-viral healthcare-associated pneumonia (NVHAP). At least one respiratory virus was detected in 65% [95% CI (53-77)] of episodes of HAP, with a single viral pathogen observed in 53.9% and coinfection with 2 viruses in 11.1% of cases. The outcome in terms of ICU admission, mechanical ventilation and the 30-day mortality did not show a significant difference between groups. Conclusions: In two-thirds of the patients a respiratory virus was identified. There was no difference in mortality or the rest of the clinical outcome variables. About half of the patients required mechanical ventilation and 10% died, which emphasizes the importance of considering these pathogens in nosocomial infections, since their identification can influence the decrease in hospital costs and be taken into account in infection control policies.

The Onthophagus fuscus (Coleoptera: Scarabaeidae) species complex: an update and the description of a new species.

The Onthophagus fuscus Boucomont, 1932 (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini) species complex has a total of eight species, one of which is a new species (Onthophagus orizabensis new species) and three are elevated from the subspecies level (O. canescens Zunino Halffter, 1988 new rank; O. mycetorum Zunino Halffter, 1988 new rank; O. parafuscus Zunino Halffter, 2005 new rank). Onthophagus navarretorum Delgado Capistan, 1996 is included, while Onthophagus semiopacus has been removed from the species complex. The distribution map and key for the identification of species in this species complex are updated. Habitat preferences, ecological tolerance, and the restriction of this species complex to the mountains of the Mexican Transition Zone are discussed.

Simultaneous Detection of Beta and Gamma Human Herpesviruses by Multiplex qPCR Reveals Simple Infection and Coinfection Episodes Increasing Risk for Graft Rejection in Solid Organ Transplantation.

Herpesviruses are common components of the human microbiome that become clinically relevant when a competent immunosurveillance is compromised, such as in transplantation. Members of the beta and gamma subfamilies are associated with a wide diversity of pathologies, including end-organ disease and cancer. In this study, we developed a multiplex qPCR technique with high specificity, sensitivity, efficiency and predictability that allowed the simultaneous detection and quantification of beta and gamma human herpesviruses. The technique was tested in a cohort of 34 kidney- or liver-transplanted pediatric patients followed up for up to 12 months post-transplant. Viral load was determined in 495 leukocyte-plasma paired samples collected bi-weekly or monthly. Human herpesvirus (HHV) 7 was the herpesvirus most frequently found in positive samples (39%), followed by Epstein-Barr virus (EBV) (20%). Also, EBV and HHV7 were present in the majority of coinfection episodes (62%). The share of positive samples exclusively detected either in leukocytes or plasma was 85%, suggesting that these herpesviruses tended to take a latent or lytic path in an exclusive manner. Infection by human cytomegalovirus (HCMV) and HHV6, as well as coinfection by EBV/HHV7 and EBV/HHV6/HHV7, were associated with graft rejection (RR = 40.33 (p = 0.0013), 5.60 (p = 0.03), 5.60 (p = 0.03) and 17.64 (p = 0.0003), respectively). The routine monitoring of beta and gamma herpesviruses should be mandatory in transplant centers to implement preventive strategies.

Two new species of Ateuchus with remarks on ecology, distributions, and evolutionary relationships (Coleoptera, Scarabaeidae, Scarabaeinae).

Two new species of the genus Ateuchus Weber are described from the region of Los Chimalapas, Oaxaca, Mexico: A. benitojuarezisp. n. and A. colossussp. n. A diagnosis for distinguishing these new species from the other species of this genus in North America is included. This paper is illustrated with pictures of the dorsal habitus and the male genitalia of the new species. The evolutionary relationships of the species are discussed, as well as their distribution and ecology. It is considered that the species of the genus Ateuchus present in North and Central America correspond to the Typical Neotropical and Mountain Mesoamerican distribution patterns.

ResumenDescribimos dos especies nuevas del género Ateuchus Weber, de la región de Los Chimalapas, Oaxaca, México: A. benitojuarezisp. n. y A. colossussp. n. Incluimos diagnosis para distinguir a estas especies nuevas del resto de especies del género presentes en Norteamérica. Presentamos ilustraciones del hábito dorsal y la genitalia masculina de las nuevas especies. Discutimos las relaciones evolutivas de las especies, así como también su distribución y ecología. Consideramos que las especies del género Ateuchus corresponden con los patrones de distribución Neotropical Típico y Mesoamericano de Montaña.

Surveillance for the identification of cases of acute respiratory infection by enterovirus D68 in children in a tertiary level care hospital during 2014-2016. / Vigilancia epidemiológica para la identificación de casos de infección respiratoria aguda por enterovirus D68 en niños en un hospital de tercer nivel de atención durante 2014-2016

Background: The reemergence of enterovirus D68 (EV-D68) infections in the United States was reported from August-October 2014 (691 cases). In Mexico, an outbreak at the National Institute of Respiratory Diseases was reported (24 cases). The results of epidemiological surveillance of Enterovirus sp. (EV) and other respiratory viruses in a national pediatric tertiary care level hospital are presented. Methods: Following the alert issued by the reemergence of EV-D68 in 2014, epidemiological surveillance -which only detected respiratory viruses by PCR in patients with influenza-like illness using nasopharyngeal swabs- expanded to include children with asthma exacerbation or acute respiratory distress. Positive samples to EV were confirmed and typed by sequencing. Subsequent sequencing was used to obtain the complete viral genome. Results: Of 1705 samples, 13 were positive to EV. Patients with EV presented the following comorbidities: chronic lung disease (7.7%), neoplastic disease (15.4%), allergic asthma/rhinitis (23%), recurrent pneumonia (23%), and other (23%). Of the 13 samples positive for EV, three were positive for EV-D68. These cases required invasive mechanical ventilation, presented no neurological involvement and survived. Conclusions: The impact of the population studied by EV-D68 was lower than that reported in Mexico during the same period. Cases of EV-D68 infection had multiple comorbidities, but few pulmonary comorbidities, which could explain the low attack rate. The epidemiological surveillance and infection prevention system may have contained the outbreak.

Introducción: La reemergencia de las infecciones por Enterovirus D68 (EV-D68) se reportó en los EE.UU. desde agosto-octubre de 2014 (691 casos). En México, un brote se reportó en el Instituto Nacional de Enfermedades Respiratorias (24 casos). Se presentan los resultados de la vigilancia epidemiológica en un hospital pediátrico nacional de tercer nivel para Enterovirus sp. (EV) y otros virus respiratorios. Método: Tras la alerta emitida por la reemergencia del EV-D68 en 2014, la vigilancia epidemiológica ­que solo detectaba virus respiratorios mediante PCR en pacientes con enfermedad tipo influenza mediante toma de hisopados nasofaríngeos­ se expandió para incluir niños con exacerbación de asma o dificultad respiratoria aguda. Las muestras positivas para EV fueron confirmadas y tipificadas por secuenciación. Posteriormente, se utilizó secuenciación de siguiente generación para obtener el genoma viral completo. Resultados: De 1705 muestras, 13 fueron positivas para EV. Los pacientes con EV presentaron la siguiente comorbilidad: enfermedad pulmonar crónica (7.7%), enfermedad neoplásica (15.4%), asma/rinitis alérgica (23%), neumonías de repetición (23%), y otras (23%). De las 13 muestras positivas para EV, tres resultaron positivas para EV-D68. Dichos casos requirieron ventilación mecánica invasiva, no tuvieron afectación neurológica y sobrevivieron. Conclusiones: La afectación por EV-D68 de la población estudiada fue menor que lo reportado en México durante el mismo periodo. Los casos de infección por EV-D68 presentan diversa comorbilidad, aunque escasas enfermedades pulmonares, lo cual pudiera explicar la baja tasa de ataque. La presencia del sistema de vigilancia epidemiológica establecido y la prevención de infecciones pudieron haber contenido el brote.

Influenza-like illness in healthcare personnel at a paediatric referral hospital: Clinical picture and impact of the disease.

INTRODUCTION: Healthcare personnel (HP) are frequently exposed to influenza and can be a source of transmission to patients and other workers, resulting in high-cost outbreaks for healthcare institutions. OBJECTIVES: To analyse the presentation of HP with influenza-like illness (ILI) and the differences between individuals with influenza confirmed by polymerase chain reaction (PCR) and those with a negative test. The secondary objective was to evaluate the duration of symptomatology and work absenteeism as well as the vaccination rate of HP at a paediatric referral hospital. METHODS: A cross-sectional, descriptive study was conducted at a paediatric referral hospital. Clinical and epidemiological data on HP with ILI were collected between January and April 2016. Nasopharyngeal swab for influenza PCR was obtained from one in every three workers with ILI. Telephone follow-up was conducted to document duration of symptoms, complications and absenteeism. RESULTS: A total of 164 ILI episodes were evaluated in 162 HP. A swab was obtained in 59 cases, and influenza was detected in 30 cases. The clinical picture of HP with confirmed influenza was similar to that of HP with a negative PCR. Arthralgia was more common in those with influenza (90% vs 58%), with a tendency towards statistical significance. No HP required hospitalization, and 78.5% were absent from work at least 1 day. CONCLUSIONS: Influenza causes significant morbidity and absenteeism among HP. Influenza infection was confirmed in only half of HP with an ILI on whom a PCR was performed, suggesting that other respiratory viruses can cause a similar pattern.

Vigilancia epidemiológica para la identificación de casos de infección respiratoria aguda por enterovirus D68 en niños en un hospital de tercer nivel de atención durante 2014-2016 / Surveillance for the identification of cases of acute respiratory infection by enterovirus D68 in children in a tertiary level care hospital during 2014-2016

Resumen Introducción: La reemergencia de las infecciones por Enterovirus D68 (EV-D68) se reportó en los EE.UU. desde agosto-octubre de 2014 (691 casos). En México, un brote se reportó en el Instituto Nacional de Enfermedades Respiratorias (24 casos). Se presentan los resultados de la vigilancia epidemiológica en un hospital pediátrico nacional de tercer nivel para Enterovirus sp. (EV) y otros virus respiratorios. Método: Tras la alerta emitida por la reemergencia del EV-D68 en 2014, la vigilancia epidemiológica -que solo detectaba virus respiratorios mediante PCR en pacientes con enfermedad tipo influenza mediante toma de hisopados nasofaríngeos- se expandió para incluir niños con exacerbación de asma o dificultad respiratoria aguda. Las muestras positivas para EV fueron confirmadas y tipificadas por secuenciación. Posteriormente, se utilizó secuenciación de siguiente generación para obtener el genoma viral completo. Resultados: De 1705 muestras, 13 fueron positivas para EV. Los pacientes con EV presentaron la siguiente comorbilidad: enfermedad pulmonar crónica (7.7%), enfermedad neoplásica (15.4%), asma/rinitis alérgica (23%), neumonías de repetición (23%), y otras (23%). De las 13 muestras positivas para EV, tres resultaron positivas para EV-D68. Dichos casos requirieron ventilación mecánica invasiva, no tuvieron afectación neurológica y sobrevivieron. Conclusiones: La afectación por EV-D68 de la población estudiada fue menor que lo reportado en México durante el mismo periodo. Los casos de infección por EV-D68 presentan diversa comorbilidad, aunque escasas enfermedades pulmonares, lo cual pudiera explicar la baja tasa de ataque. La presencia del sistema de vigilancia epidemiológica establecido y la prevención de infecciones pudieron haber contenido el brote.

Abstract Background: The reemergence of enterovirus D68 (EV-D68) infections in the United States was reported from August-October 2014 (691 cases). In Mexico, an outbreak at the National Institute of Respiratory Diseases was reported (24 cases). The results of epidemiological surveillance of Enterovirus sp. (EV) and other respiratory viruses in a national pediatric tertiary care level hospital are presented. Methods: Following the alert issued by the reemergence of EV-D68 in 2014, epidemiological surveillance -which only detected respiratory viruses by PCR in patients with influenza-like illness using nasopharyngeal swabs- expanded to include children with asthma exacerbation or acute respiratory distress. Positive samples to EV were confirmed and typed by sequencing. Subsequent sequencing was used to obtain the complete viral genome. Results: Of 1705 samples, 13 were positive to EV. Patients with EV presented the following comorbidities: chronic lung disease (7.7%), neoplastic disease (15.4%), allergic asthma/rhinitis (23%), recurrent pneumonia (23%), and other (23%). Of the 13 samples positive for EV, three were positive for EV-D68. These cases required invasive mechanical ventilation, presented no neurological involvement and survived. Conclusions: The impact of the population studied by EV-D68 was lower than that reported in Mexico during the same period. Cases of EV-D68 infection had multiple comorbidities, but few pulmonary comorbidities, which could explain the low attack rate. The epidemiological surveillance and infection prevention system may have contained the outbreak.

Two new species of the Phanaeus endymion species group (Coleoptera, Scarabaeidae, Scarabaeinae).

Phanaeus bravoensissp. n. is described from the coniferous-oak forests in the state of Guerrero, and P. huicholsp. n. from coniferous-oak forests and cloud forests in Jalisco and Nayarit. The new species are closely related to P. halffterorum and P. zoque respectively. Morphological trait combination, geographic distribution, and trophic habits show important differences among the studied species. A distribution map and an updated key to separate the species are included.

ResumenDescribimos a Phanaeus bravoensissp. n. proveniente de los bosques de coníferas y encino del estado de Guerrero, y a P. huicholsp. n. de los bosques de coníferas y encino y bosques de niebla de Jalisco y Nayarit. Las nuevas especies están cercanamente relacionadas con P. halffterorum y P. zoque, respectivamente. Las combinaciones de caracteres morfológicos, áreas de distribución geográfica y los hábitos alimenticios muestran diferencias importantes entre las especies estudiadas. Incluimos un mapa de distribución y una clave actualizada para separar a las especies.

Correlation between viral load of cytomegalovirus and tacrolimus and sirolimus levels in transplanted pediatric patients / Correlación entre la carga viral de citomegalovirus y los niveles de tacrolimus y sirolimus en pacientes pediátricos trasplantados

Abstract: Introduction: Survival of transplant patients and grafts depends largely on the use of immunosuppressive drugs. However, a balance remains to be established among immunosuppression, transplant rejection and cytomegalovirus (CMV) infection, which results in a high rate of morbidity and mortality. The aim of this study was to define a better strategy for monitoring transplanted patients based on the analysis of the blood concentration of sirolimus and tacrolimus and the burden of CMV. Methods: Fifty five post-transplant (kidney and liver) pediatric patients, nine treated with sirolimus and 46 treated with tacrolimus, were included. A total of 541 measurements were obtained. In each measurement the concentration of immunosuppressant in whole blood and CMV viral load in plasma and whole blood was quantified by real-time PCR. Pearson correlation coefficient (r) was estimated. Results: Values of r ≤ 0.0747 were found for the relationship between dose and concentration of immunosuppressant; r = 0.9406 for the relationship between viral load in whole blood and plasma, and r ≤ 0.4616 for the relationship between concentration of immunosuppressant and viral load. Conclusions: These data support that the doses of immunosuppressive drugs do not correlate with the levels of the same in whole blood. Therefore, systemic levels of immunosuppressant should be constantly monitored together with CMV load. Meanwhile, a high correlation between viral load measured in whole blood and plasma was found.

Resumen: Introducción: La supervivencia de pacientes trasplantados y de los injertos depende en gran medida del uso de fármacos inmunosupresores. Sin embargo, aún no se ha logrado establecer un balance entre la inmunosupresión, el rechazo al trasplante y la infección por citomegalovirus (CMV), lo cual deriva en una alta tasa de morbilidad y mortalidad. El objetivo de este trabajo fue definir una mejor estrategia de seguimiento de los pacientes trasplantados a partir del análisis de la concentración en sangre de sirolimus y tacrolimus y la carga de CMV. Métodos: Se incluyeron 55 pacientes pediátricos post-trasplante (riñón e hígado), nueve en tratamiento con sirolimus y 46 en tratamiento con tacrolimus. Se obtuvieron 541 mediciones en total. En cada medición se cuantificó la concentración de inmunosupresor en sangre total y la carga viral de CMV en plasma y sangre total mediante PCR en tiempo real. Se calculó el coeficiente de correlación de Pearson (r). Resultados: Se encontraron valores de r ≤ 0.0747 para la relación entre dosis y concentración del inmunosupresor; de r = 0.9406 para la relación de la carga viral entre suero y sangre total y de r ≤ 0.4616 para la relación entre concentración de inmunosupresor y carga viral. Conclusiones: Estos datos apoyan que la dosis de los fármacos inmunosupresores no correlaciona con los niveles de los mismos en sangre total. Por ello, deben ser constantemente monitoreados junto con la carga viral. Por su parte, se encontró alta correlación entre la carga viral medida en sangre total y plasma.

Correlation between viral load of cytomegalovirus and tacrolimus and sirolimus levels in transplanted pediatric patients.

INTRODUCTION: Survival of transplant patients and grafts depends largely on the use of immunosuppressive drugs. However, a balance remains to be established among immunosuppression, transplant rejection and cytomegalovirus (CMV) infection, which results in a high rate of morbidity and mortality. The aim of this study was to define a better strategy for monitoring transplanted patients based on the analysis of the blood concentration of sirolimus and tacrolimus and the burden of CMV. METHODS: Fifty five post-transplant (kidney and liver) pediatric patients, nine treated with sirolimus and 46 treated with tacrolimus, were included. A total of 541 measurements were obtained. In each measurement the concentration of immunosuppressant in whole blood and CMV viral load in plasma and whole blood was quantified by real-time PCR. Pearson correlation coefficient (r) was estimated. RESULTS: Values of r ≤0.0747 were found for the relationship between dose and concentration of immunosuppressant; r = 0.9406 for the relationship between viral load in whole blood and plasma, and r ≤0.4616 for the relationship between concentration of immunosuppressant and viral load. CONCLUSIONS: These data support that the doses of immunosuppressive drugs do not correlate with the levels of the same in whole blood. Therefore, systemic levels of immunosuppressant should be constantly monitored together with CMV load. Meanwhile, a high correlation between viral load measured in whole blood and plasma was found.

Frecuencia de virus respiratorios y características clínicas de niños que acuden a un hospital en México / Frequency of respiratory viruses and clinical characteristics in children attending a care center in Mexico City

OBJETIVO. Describir la frecuencia de virus respiratorios y características clínicas en niños con cuadros respiratorios de un hospital de tercer nivel en México. MATERIAL Y MÉTODOS. Se incluyeron niños con diagnóstico de infección respiratoria y un resultado positivo por inmunofluorescencia de enero 2004 a octubre 2006. RESULTADOS. De 986 muestras nasofaríngeas, 138 (14 por ciento) fueron positivas. La frecuencia fue: 80 por ciento virus sincicial respiratorio (VSR), 8 por ciento parainfluenza 1, 5 por ciento parainfluenza3, 2 por ciento adenovirus, 2 por ciento influenza A, 1 por ciento parainfluenza 2 y 1 por ciento influenza B. CONCLUSIONES. La frecuencia de virus respiratorios fue de 14 por ciento. El VSR se identificó asociado con más frecuencia, a neumonía y bronquiolitis en menores de 3 años.

OBJECTIVE. To describe the frequency of respiratory viruses and clinical characteristics in children with respiratory signs and symptoms in a tertiary care center in Mexico. MATERIAL AND METHODS. Patients with a clinical diagnosis of respiratory infection and a positive immunofluorescence result (Light Diagnostics) from January 2004 to October 2006 were included. RESULTS. From the 986 nashopharyngeal samples, 138 (14 percent) were positive by immunofluorescence. The frequency was: 80 percent RSV, 8 percent parainfluenza 1, 5 percent parainfluenza 3, 2 percent adenovirus, 2 percent influenza A, 1 percent parainfluenza 2 and 1 percent influenza B. CONCLUSIONS. Respiratory viruses were detected in 14 percent of samples tested. RSV was the most frequently identified virus and was associated with pneumonia and bronchiolitis in children younger than 3 years old.

Expresión atípica en la detección y cuantificación del virus de Epstein-Barr utilizando PCR en tiempo real / Atypic expression in the detection and quantification of Epstein-Barr virus using real-time PCR

Introducción. La carga viral del virus de Epstein-Barr (VEB) no solamente sirve para detectar una infección activa, sino también como marcador tumoral de ciertas formas malignas. En los pacientes inmunocomprometidos está relacionado con el síndrome linfoproliferativo postrasplante (SLPT) y la incidencia se encuentra en el orden de 1 a 20%. Se recomienda la determinación de la carga viral del VEB en sangre total y plasma para dar seguimiento a los pacientes en riesgo de padecer el SLPT; para esto, se utiliza como herramienta la reacción en cadena de la polimerasa en tiempo real (PCR-TR). El objetivo de este trabajo es describir los hallazgos de las variaciones identificadas en el genoma del VEB al realizar la detección y cuantificación en muestras de pacientes pediátricos, utilizando la tecnología de PCR-TR. Métodos. Se analizaron retrospectivamente los resultados de 352 pacientes pediátricos a los que se les había realizado la detección y cuantificación del VEB en sangre periférica y plasma por medio de PCR-TR. Se amplificó un fragmento de 166 pb del genoma, utilizando un diseño de la compañía TIB MOLBIOL y el equipo LightCycler®, con una temperatura específica de desnaturalización (Tm) de 68 °C. Resultados. De los 352 pacientes estudiados, se detectó la presencia del VEB en 132 (37.5%) y se cuantificó la carga viral. En 5 de los pacientes positivos (3.8%), se identificó un cambio de la Tm. Por medio de electroforesis en gel de agarosa, se comprobó que el amplificado obtenido corresponde al fragmento de 166 pb. Conclusiones. Consideramos que puede existir una disminución en la concentración de guanina-citosina (G-C) en la secuencia blanco, ya que la Tm sufrió una disminución en todos los casos reportados. Sin embargo, se requiere la secuenciación de los amplificados para determinar con precisión la causa de disminución en la Tm.

Background. Epstein-Barr virus (EBV) viral load is useful not only for detection of an active infection but also as a tumor marker for certain malignant forms. In immunocompromised patients it is related to postransplant lymphoproliferative syndrome (PTLS) with an incidence on the order of 1 to 20%. It is recommended to determine viral load in whole blood and plasma to monitor patients at risk for developing PTLS. Real-time polymerase chain reaction (RT-PCR) is a useful tool for this determination. In these determinations the melting curve (Tm) plays an important role because changes in Tm suggest that the target sequence has suffered mutations, although the selected regions for detection and quantification of EBV are highly conserved. We undertook this study to describe the findings of the variations identified in the EBV genome and to perform the detection and quantification in samples of pediatric patients using RT-PCR. Methods. Results from 352 pediatric patients were analyzed retrospectively in whom investigation of the EBV was performed in peripheral blood and plasma by RT-PCR. For detection and quantification of EBV, a 166-bp fragment of the genome was amplified using a design of TIB MOLBIOL and the LightCycler® equipment with a Tm of 68 °C. Results. Of the 352 patients studied, in 132 (37.5%) presence of EBV was detected and quantified the viral load. In five (3.8%) of the positive patients, a change of the Tm was identified Using electrophoresis running in agarose gel, it was proved that the obtained amplification corresponds to the 166-bp fragment. Conclusion. The specific product and size of the amplified remained unchanged; therefore, we there is a high probability of decrease in the concentration of guanine-cytosine in the target sequence because the Tm showed a decrease in all the reported cases. It is required the sequence of the amplification is required to precisely determine the cause of the decrease in the Tm.

[Frequency of respiratory viruses and clinical characteristics in children attending a care center in Mexico City]. / Frecuencia de virus respiratorios y características clínicas de niños que acuden a un hospital en México.

OBJECTIVE: To describe the frequency of respiratory viruses and clinical characteristics in children with respiratory signs and symptoms in a tertiary care center in Mexico. MATERIAL AND METHODS: Patients with a clinical diagnosis of respiratory infection and a positive immunofluorescence result (Light Diagnostics) from January 2004 to October 2006 were included. RESULTS: From the 986 nashopharyngeal samples, 138 (14%) were positive by immunofluorescence. The frequency was: 80% RSV, 8% parainfluenza 1, 5% parainfluenza 3, 2% adenovirus, 2% influenza A, 1% parainfluenza 2 and 1% influenza B. CONCLUSIONS: Respiratory viruses were detected in 14% of samples tested. RSV was the most frequently identified virus and was associated with pneumonia and bronchiolitis in children younger than 3 years old.

Coexistencia de las mutaciones C677T y A1298C en la enzima 5,10 metilentetrahidrofolato reductasa en pacientes pediátricos con trombosis / Coexistence of C677T and A1298C mutations in the 5,10 methylenetetrahydrofolate reductase enzyme in pediatric patients with thrombosis

Introducción. Una de las alteraciones genéticas que predisponen a trombosis, y que ha sido ampliamente estudiada, es la mutación C677T en el gen que codifica para la enzima 5,10 metilentetrahidrofolato reductasa (MTHFR). Así también, la presencia de la mutación A1298C en el mismo gen es considerada como un factor genético que predispone a trombosis. Métodos. Estudio realizado a 9 pacientes pediátricos con diagnóstico de trombofilia, 7 de sexo masculino y 2 del femenino, con edades de 1 mes a 13 años, a los cuales se les realizó, mediante la reacción en cadena de la polimerasa en tiempo real, el estudio de las mutaciones C677T y A1298C en la enzima MTHFR, la mutación G1691A (Leiden) del factor V y la mutación G20210A de la protrombina. Por métodos convencionales se realizó el fenómeno de resistencia a la proteína C activada (RPCa) y las proteínas C y S de la coagulación, así como la antitrombina (AT). Resultados. Todos los pacientes presentaron la coexistencia de las mutaciones C677T y A1298C en la MTHFR; solamente uno de ellos presentó un estado homocigoto para C677T y heterocigoto para A1298C, los otros 8 pacientes presentaron estados heterocigotos para ambas mutaciones; en los 9 pacientes no se demostró la presencia de las mutaciones G1691A del factor V (Leiden) y la G20210A de la protrombina, ni alteraciones en la RPCa, AT y las proteínas C y S de la coagulación. Conclusiones. La coexistencia de las mutaciones C677T y A1298C debe considerarse para su investigación en todos los pacientes que presenten un estado de trombofilia.

Introduction. One of the thrombophilic conditions that has been widely studied is the C677T mutation in the gene encoding the 5,10 methylenetetrahydrofolate reductase (MTHFR) enzyme. The presence of mutation A1298C in the same gene is also considered as one factor that predisposes thrombosis. Methods. We report on 9 pediatric patients diagnosed with thrombophilia, 7 males and 2 females with ages ranging from 1 month to 13 years. Real-time polymerase chain reaction was performed along with the study of the C677T and A1298C mutations in the MTHFR enzyme, G1691A mutation (Leiden) and factor V, prothrombin mutation G20210A. Conventional methods were used for activated protein C (APC) resistance and protein C and S coagulation, as well as antithrombin (AT). Results. All patients had coexisting mutations C677T and A1298C in MTHFR. Only 1 patient was homozygous for C6 7 7T and heterozygous for A1298C. The other 8 patients presented heterozygous mutations and in the 9 patients the presence of mutations of G 1691A factor V (Leiden) and G20210A prothrombin was not demonstrated, as well as alterations in APC, AT and proteins C and S. Conclusions. Coexistence of the C677T and A1298C mutations should be considered for investigation in all patients presenting thrombophilia.