Características clínico-etiológicas de pacientes pediátricos hospitalizados con diagnóstico de bronquiolitis. Ciudad de Santa Fe, Argentina

Introducción: La bronquiolitis constituye una de las principales causas de Infecciones Respiratorias Agudas Bajas en Pediatría, y es responsable de una proporción significativa de hospitalizaciones en lactantes, fundamentalmente, en menores de 1 año. Su diagnóstico es clínico, caracterizado por síntomas y signos de amplio grado de gravedad. Objetivo: Describir las características clínico-etiológicas de casos de bronquiolitis en menores de 1 año, internados en un hospital de niños de la ciudad de Santa Fe, durante un periodo de un año. Materiales y Métodos: Estudio observacional, transversal. Se analizaron datos demográficos, clínicos y de laboratorio de fichas médicas de vigilancia epidemiológica. Las técnicas diagnósticas usadas según el agente viral fueron RT-PCR en tiempo real, PCR-punto final e Inmunofluorescencia Indirecta. Resultados: Sobre un total de 108 casos, 90,7% tuvo de 1 a 6 meses de edad. La mediana de internación fue de 5 días, y el nacimiento prematuro fue la condición médica previa más frecuente. Un 78,7% (85) tuvo diagnóstico viral positivo, siendo Rinovirus (hRV) y Virus Sincicial Respiratorio (VSR) los agentes más prevalentes, tanto en infección única como en coinfección. El tiempo de oxigenoterapia fue mayor en los pacientes más graves (p<0,001). El 32,4% (35) recibió alguna medicación que fue, en mayor frecuencia, antibiótico. Se encontró asociación positiva y significativa entre la edad menor de 3 meses y una hospitalización mayor a 5 días (OR=2,5; IC: 1,1-5,8; p=0,02); y entre un diagnóstico VSR positivo y un cuadro grave (OR: 7,7; IC: 1,95-39,6; p<0,001). Conclusión: Las características y condiciones médicas consideradas por la literatura como factores de riesgo para el padecimiento y la gravedad de una IRAB, fueron halladas con mayor frecuencia en la población de estudio. El hRV y el VRS fueron los agentes de mayor rescate viral, encontrándose una asociación positiva entre la infección por VSR y la gravedad del cuadro.

Introduction: Bronchiolitis is one of the main causes of Acute Lower Respiratory Infections in pediatrics, and is responsible for a significant proportion of hospitalizations in infants, mainly in children under 1 year of age. Its diagnosis is clinical. The disease is characterized by a wide variety and degree of signs and symptoms. Objective: To describe the clinical-etiological characteristics of cases of bronchiolitis in children under 1 year of age, admitted to a children's hospital in the city of Santa Fe, over a period of one year. Materials and Methods: This was an observational and cross-sectional study. Demographic, clinical and laboratory data from epidemiological surveillance medical records were analyzed. The diagnostic techniques used, based on the viral agent, were real-time RT-PCR, end-point PCR and Indirect Immunofluorescence. Results: Out of a total of 108 cases, 90.7% were between 1 and 6 months old. The median hospital stay was 5 days, and premature birth was the most common prior medical condition. 78.7% (85) had a positive viral diagnosis, with Rhinovirus (hRV) and Respiratory Syncytial Virus (RSV) being the most prevalent agents, both in single infection and coinfection. Oxygen therapy time was longer in the most seriously ill patients (p<0.001). 32.4% (35) received some medication, which was, most frequently, antibiotics. A positive and significant association was found between age less than 3 months and hospitalization longer than 5 days (OR=2.5; CI: 1.1-5.8; p=0.02); and between a positive RSV diagnosis and a severe condition (OR: 7.7; CI: 1.95-39.6; p<0.001). Conclusions: The characteristics and medical conditions considered by the literature as risk factors for the morbidity and severity of a lower respiratory tract infection were found more frequently in the study population. hRV and RSV were the most commonly-detected viral agents. We found a positive association between RSV infection and the severity of the condition.

Rinovirus en pandemia. Ciudad de Santa Fe, Argentina. Bienio 2020-2021 / Rhinovirus in pandemic. Santa Fe city, Argentina. Biennium 2020-2021

En el contexto de la pandemia de COVID-19, a partir de 2020, la Unidad Centinela de Enfermedades Tipo Influenza (UC-ETI) (Santa Fe, Argentina) integró la vigilancia clínica y por laboratorio de SARS-CoV-2 y rinovirus (HRV) a la habitual vigilancia de influenza y otros virus respiratorios (OVR). El objetivo de este estudio transversal y retrospectivo fue describir las características clínico-epidemiológicas de casos de ETI de la ciudad de Santa Fe, con diagnóstico de HRV confirmado durante 2020-2021, en el marco de la UC-ETI. Del total de 600 casos de ETI cuyas muestras fueron analizadas, más del 50,0% fueron mujeres; y la mayor proporción se concentró en el grupo de 15 a 39 años (40,2%). El 33,7% registró al menos una comorbilidad o factor de riesgo, siendo la hipertensión arterial, asma, diabetes, obesidad y EPOC las más frecuentes. Además de fiebre y tos, los signos/síntomas predominantes fueron odinofagia, mialgia y cefalea. El porcentaje de positividad fue de 41,3% en 2020, 27,8% en 2021 y 35,5% en 2020-2021. De las muestras positivas del bienio (213), 59,0% fue SARS-CoV-2, 40,0% HRV y 1,0% OVR. La mayor proporción de diagnósticos positivos de SARS-CoV-2 se concentró en pacientes de 15 años y más, y la de HRV en menores de 15. Los periodos en los que predominó la circulación de HRV no lo hizo la de SARS-CoV-2, y viceversa. El aporte a la carga real de las infecciones virales respiratorias y su impacto en la salud pública destaca la importancia de sostener la vigilancia de HRV

In the context of the COVID-19 pandemic, in 2020, the influenza-like illness Sentinel Unit (ILI-SU) (Santa Fe, Argentina), integrated clinical and laboratory surveillance of SARS-CoV-2 and Rhinovirus (HRV) to the usual surveillance of Influenza and other respiratory viruses (ORV). The objective of this cross-sectional and retrospective study was to describe the clinical-epidemiological characteristics of ILI cases of Santa Fe city, who had a confirmed HRV diagnosis during 2020-2021, by the ILI-SU. Of a total of 600 ILI cases whose samples were analyzed, more than 50.0% were women; and the highest proportion was concentrated in the group between 15 and 39 years of age (40.2%). 33.7% of the cases registered at least one comorbidity or risk factor, among which arterial hypertension, asthma, diabetes, obesity and COPD were the most frequent. In addition to fever and cough, the predominant signs/symptoms were sore throat, myalgia and headache. The percentage of positivity was 41.3% in 2020, 27.8% in 2021, and 35.5% in 2020-2021. Of the biennium positive samples (213), 59.0% were SARS-CoV-2, 40.0% HRV, and 1.0% ORV. The highest proportion of SARS-CoV-2 positive diagnoses were concentrated in patients 15 years of age and older, while the highest proportion of HRV positive diagnoses were concentrated in patients under 15 years of age. The periods in which the circulation of HRV predominated did not predominated SARS-CoV-2, and vice versa. The contribution to the real burden of respiratory viral infections and its impact on public health, highlight the importance of sustaining HRV surveillance

Neuraminidase Inhibitors and Hospital Length of Stay: A Meta-analysis of Individual Participant Data to Determine Treatment Effectiveness Among Patients Hospitalized With Nonfatal 2009 Pandemic Influenza A(H1N1) Virus Infection.

BACKGROUND: The effect of neuraminidase inhibitor (NAI) treatment on length of stay (LoS) in patients hospitalized with influenza is unclear. METHODS: We conducted a one-stage individual participant data (IPD) meta-analysis exploring the association between NAI treatment and LoS in patients hospitalized with 2009 influenza A(H1N1) virus (A[H1N1]pdm09) infection. Using mixed-effects negative binomial regression and adjusting for the propensity to receive NAI, antibiotic, and corticosteroid treatment, we calculated incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Patients with a LoS of <1 day and those who died while hospitalized were excluded. RESULTS: We analyzed data on 18 309 patients from 70 clinical centers. After adjustment, NAI treatment initiated at hospitalization was associated with a 19% reduction in the LoS among patients with clinically suspected or laboratory-confirmed influenza A(H1N1)pdm09 infection (IRR, 0.81; 95% CI, .78-.85), compared with later or no initiation of NAI treatment. Similar statistically significant associations were seen in all clinical subgroups. NAI treatment (at any time), compared with no NAI treatment, and NAI treatment initiated <2 days after symptom onset, compared with later or no initiation of NAI treatment, showed mixed patterns of association with the LoS. CONCLUSIONS: When patients hospitalized with influenza are treated with NAIs, treatment initiated on admission, regardless of time since symptom onset, is associated with a reduced LoS, compared with later or no initiation of treatment.

[Parotitis and influenza: unusual association during 2017, in Santa Fe, Argentina]. / Parotiditis e influenza: inusual asociación durante 2017, en Santa Fe, Argentina.

BACKGROUND: Parotitis is an acute viral disease characterized by swelling and pain in one or both salivary glands, submaxillary or submental, fever, headache, muscle ache and/or fatigue. AIM: To investigate the occurrence of influenza virus infection in parotitis cases in a population of Santa Fe during 2017 and analyze clinical and epidemiological characteristics of the cases. METHODS: We studied patients with diagnosis of mumps without age restriction, who came for examination from week 26 to the network of clinicians forming the Sentinel Influenza Unit in Santa Fe. RESULTS: Between epidemiological weeks 26 and 44, 22 clinical parotitis cases we enrolled. The influenza virus was detected in 68.2%, influenza A (H3N2) 93%, and influenza B, 7%. The clinical signs of cases were mild, with an average swelling development of 5 days and no complications. 74% presented with influenza-like illness in tandem with parotitis. CONCLUSIONS: This study provides evidence that a proportion of children presenting with parotitis had influenza A(H3N2) virus infection. It is necessary to implement systematic surveillance of parotitis associated with influenza and differential diagnosis even in the absence of respiratory symptoms.

The epidemiological signature of influenza B virus and its B/Victoria and B/Yamagata lineages in the 21st century.

We describe the epidemiological characteristics, pattern of circulation, and geographical distribution of influenza B viruses and its lineages using data from the Global Influenza B Study. We included over 1.8 million influenza cases occurred in thirty-one countries during 2000-2018. We calculated the proportion of cases caused by influenza B and its lineages; determined the timing of influenza A and B epidemics; compared the age distribution of B/Victoria and B/Yamagata cases; and evaluated the frequency of lineage-level mismatch for the trivalent vaccine. The median proportion of influenza cases caused by influenza B virus was 23.4%, with a tendency (borderline statistical significance, p = 0.060) to be higher in tropical vs. temperate countries. Influenza B was the dominant virus type in about one every seven seasons. In temperate countries, influenza B epidemics occurred on average three weeks later than influenza A epidemics; no consistent pattern emerged in the tropics. The two B lineages caused a comparable proportion of influenza B cases globally, however the B/Yamagata was more frequent in temperate countries, and the B/Victoria in the tropics (p = 0.048). B/Yamagata patients were significantly older than B/Victoria patients in almost all countries. A lineage-level vaccine mismatch was observed in over 40% of seasons in temperate countries and in 30% of seasons in the tropics. The type B virus caused a substantial proportion of influenza infections globally in the 21st century, and its two virus lineages differed in terms of age and geographical distribution of patients. These findings will help inform health policy decisions aiming to reduce disease burden associated with seasonal influenza.

Parotiditis e influenza: inusual asociación durante 2017, en Santa Fe, Argentina / Parotitis and influenza: unusual association during 2017, in Santa Fe, Argentina

Resumen Introducción: La parotiditis es una enfermedad vírica aguda caracterizada por tumefacción y dolor en una o ambas glándulas salivales, submaxilar o submentoniana, fiebre, dolor de cabeza, dolor muscular y/o fatiga. Objetivos Investigar la ocurrencia de infección por el virus influenza en casos de parotiditis en una población de Santa Fe, durante 2017 y analizar las características clínicas y epidemiológicas de los casos. Materiales y Métodos: Se estudiaron pacientes con diagnóstico de parotiditis, que acudieron a la consulta desde la semana 26 en la red de médicos que forman la Unidad Centinela de Influenza en Santa Fe. Resultados: Entre las semanas epidemiológicas 26 y 44, se incluyeron 22 casos de parotiditis clínica. El virus influenza se detectó en 68,2%, influenza A (H3N2) 93% e influenza B 7%. Los síntomas clínicos de los casos fueron leves, con una tumefacción de cinco días y sin complicaciones. El 74% presentó una enfermedad tipo influenza en conjunto con la parotiditis. Conclusiones: Este estudio evidencia que niños que presentaban parotiditis tenían una infección por el virus de la influenza A (H3N2). Es necesario implementar una vigilancia sistemática de las parotiditis asociadas con influenza y el diagnóstico diferencial, incluso en ausencia de síntomas respiratorios.

Background: Parotitis is an acute viral disease characterized by swelling and pain in one or both salivary glands, submaxillary or submental, fever, headache, muscle ache and/or fatigue. Aim: To investigate the occurrence of influenza virus infection in parotitis cases in a population of Santa Fe during 2017 and analyze clinical and epidemiological characteristics of the cases. Methods: We studied patients with diagnosis of mumps without age restriction, who came for examination from week 26 to the network of clinicians forming the Sentinel Influenza Unit in Santa Fe. Results: Between epidemiological weeks 26 and 44, 22 clinical parotitis cases we enrolled. The influenza virus was detected in 68.2%, influenza A (H3N2) 93%, and influenza B, 7%. The clinical signs of cases were mild, with an average swelling development of 5 days and no complications. 74% presented with influenza-like illness in tandem with parotitis. Conclusions: This study provides evidence that a proportion of children presenting with parotitis had influenza A(H3N2) virus infection. It is necessary to implement systematic surveillance of parotitis associated with influenza and differential diagnosis even in the absence of respiratory symptoms.

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

BACKGROUND: Influenza disease burden varies by age and this has important public health implications. We compared the proportional distribution of different influenza virus types within age strata using surveillance data from twenty-nine countries during 1999-2014 (N=358,796 influenza cases). METHODS: For each virus, we calculated a Relative Illness Ratio (defined as the ratio of the percentage of cases in an age group to the percentage of the country population in the same age group) for young children (0-4 years), older children (5-17 years), young adults (18-39 years), older adults (40-64 years), and the elderly (65+ years). We used random-effects meta-analysis models to obtain summary relative illness ratios (sRIRs), and conducted meta-regression and sub-group analyses to explore causes of between-estimates heterogeneity. RESULTS: The influenza virus with highest sRIR was A(H1N1) for young children, B for older children, A(H1N1)pdm2009 for adults, and (A(H3N2) for the elderly. As expected, considering the diverse nature of the national surveillance datasets included in our analysis, between-estimates heterogeneity was high (I2>90%) for most sRIRs. The variations of countries' geographic, demographic and economic characteristics and the proportion of outpatients among reported influenza cases explained only part of the heterogeneity, suggesting that multiple factors were at play. CONCLUSIONS: These results highlight the importance of presenting burden of disease estimates by age group and virus (sub)type.

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

INTRODUCTION: The increased availability of influenza surveillance data in recent years justifies an actual and more complete overview of influenza epidemiology in Latin America. We compared the influenza surveillance systems and assessed the epidemiology of influenza A and B, including the spatio-temporal patterns of influenza epidemics, in ten countries and sub-national regions in Latin America. METHODS: We aggregated the data by year and country and characteristics of eighty-two years were analysed. We calculated the median proportion of laboratory-confirmed influenza cases caused by each virus strain, and compared the timing and amplitude of the primary and secondary peaks between countries. RESULTS: 37,087 influenza cases were reported during 2004-2012. Influenza A and B accounted for a median of 79% and, respectively, 21% of cases in a year. The percentage of influenza A cases that were subtyped was 82.5%; for influenza B, 15.6% of cases were characterized. Influenza A and B were dominant in seventy-five (91%) and seven (9%) years, respectively. In half (51%) of the influenza A years, influenza A(H3N2) was dominant, followed by influenza A(H1N1)pdm2009 (41%) and pre-pandemic A(H1N1) (8%). The primary peak of influenza activity was in June-September in temperate climate countries, with little or no secondary peak. Tropical climate countries had smaller primary peaks taking place in different months and frequently detectable secondary peaks. CONCLUSIONS: We found that good influenza surveillance data exists in Latin America, although improvements can still be made (e.g. a better characterization of influenza B specimens); that influenza B plays a considerable role in the seasonal influenza burden; and that there is substantial heterogeneity of spatio-temporal patterns of influenza epidemics. To improve the effectiveness of influenza control measures in Latin America, tropical climate countries may need to develop innovative prevention strategies specifically tailored to the spatio-temporal patterns of influenza in this region.

Impact of influenza in the post-pandemic phase: Clinical features in hospitalized patients with influenza A (H1N1) pdm09 and H3N2 viruses, during 2013 in Santa Fe, Argentina.

It is important to characterize the clinical and epidemiological pattern of the influenza A (H1N1) pdm09 virus and compare it with influenza A (H3N2) virus, as surveyed in just a few studies, in order to contribute to the implementation and strengthening of influenza control and prevention strategies. The aims in this study were to describe influenza clinical and epidemiological characteristics in hospitalized patients, caused by influenza A (H1N1)pdm09 and influenza A (H3N2) viruses during 2013, in Santa Fe, Argentina. A retrospective study was conducted over 2013 among hospitalized patients with laboratory-confirmed influenza diagnosis. In contrast to patients with influenza A (H3N2) (20.5%), a higher proportion of hospitalizations associated with influenza H1N1pdm were reported among adults aged 35-65 years (42.8%). Of all patients, 73.6% had an underlying medical condition. Hospitalized patients with H1N1pdm were subject to 2.6 (95%CI, 1.0-6.8) times higher risk of severity, than those hospitalized with influenza A (H3N2). This results demonstrate the impact in the post-pandemic era of H1N1pdm virus, with increased risk of severe disease, in relation to H3N2 virus, both viruses co-circulating during 2013.

[Detection of human bocavirus in children from Tucuman and Santa Fe, Argentina]. / Detección de bocavirus humano en la población infantil de Tucumán y Santa Fe, Argentina.

BACKGROUND: A large proportion of acute respiratory tract infections (ARTI) remain without etiologic diagnosis, reason why new pathogens are investigated continuously. Human bocavirus (HBoV) was discovered in 2005, as a new member of Parvoviridae family and proposed to cause ARTI. AIM: To know the prevalence of HBoV among pediatric populations hospitalized for ARTI in two provinces of Argentina: Santa Fe and Tucuman; and to describe epidemiological and clinical aspects associated to its detection. MATERIALS AND METHODS: We studied nasopharyn-geal aspirates of patients younger than 5 years old that were hospitalized during 2013 due ARTI. HBoV DNA was assayed using PCR described by Allander et al. Traditional virnses were studied by immunofluorescence. Personal, clinical and epidemiological data were collected in a standardized form. RESULTS: The HBoV was detected in 7% of the samples and was prevalent in spring and summer and in children younger of 2 years old. Other respiratory viruses were detected in 22% of HBoV positive samples. DISCUSSION: We detected HBoV in these two provinces of Argentina. Further studies should be performed to determine if it's a recent infection or prolonged viral shedding.

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

INTRODUCTION: Determining the optimal time to vaccinate is important for influenza vaccination programmes. Here, we assessed the temporal characteristics of influenza epidemics in the Northern and Southern hemispheres and in the tropics, and discuss their implications for vaccination programmes. METHODS: This was a retrospective analysis of surveillance data between 2000 and 2014 from the Global Influenza B Study database. The seasonal peak of influenza was defined as the week with the most reported cases (overall, A, and B) in the season. The duration of seasonal activity was assessed using the maximum proportion of influenza cases during three consecutive months and the minimum number of months with ≥80% of cases in the season. We also assessed whether co-circulation of A and B virus types affected the duration of influenza epidemics. RESULTS: 212 influenza seasons and 571,907 cases were included from 30 countries. In tropical countries, the seasonal influenza activity lasted longer and the peaks of influenza A and B coincided less frequently than in temperate countries. Temporal characteristics of influenza epidemics were heterogeneous in the tropics, with distinct seasonal epidemics observed only in some countries. Seasons with co-circulation of influenza A and B were longer than influenza A seasons, especially in the tropics. DISCUSSION: Our findings show that influenza seasonality is less well defined in the tropics than in temperate regions. This has important implications for vaccination programmes in these countries. High-quality influenza surveillance systems are needed in the tropics to enable decisions about when to vaccinate.

Detección de bocavirus humano en la población infantil de Tucumán y Santa Fe, Argentina / Detection of human bocavirus in children from Tucuman and Santa Fe, Argentina

Background: A large proportion of acute respiratory tract infections (ARTI) remain without etiologic diagnosis, reason why new pathogens are investigated continuously. Human bocavirus (HBoV) was discovered in 2005, as a new member of Parvoviridae family and proposed to cause ARTI. Aim: To know the prevalence of HBoV among pediatric populations hospitalized for ARTI in two provinces of Argentina: Santa Fe and Tucuman; and to describe epidemiological and clinical aspects associated to its detection. Materials and Methods: We studied nasopharyn-geal aspirates of patients younger than 5 years old that were hospitalized during 2013 due ARTI. HBoV DNA was assayed using PCR described by Allander et al. Traditional virnses were studied by immunofluorescence. Personal, clinical and epidemiological data were collected in a standardized form. Results: The HBoV was detected in 7% of the samples and was prevalent in spring and summer and in children younger of 2 years old. Other respiratory viruses were detected in 22% of HBoV positive samples. Discussion: We detected HBoV in these two provinces of Argentina. Further studies should be performed to determine if it’s a recent infection or prolonged viral shedding.

Introducción: Un alto porcentaje de las infecciones respiratorias agudas (IRA) permanece sin diagnostico etiológico, por lo cual se investigan nuevos patógenos continuamente. Bocavirus humano (HBoV) fue descubierto en 2005, como un nuevo miembro de la familia Parvoviridae y propuesto como causante de IRA. Objetivos: Investigar la prevalencia de HBoV en niños bajo 5 años de edad, hospitalizados por IRA en dos provincias de Argentina: Santa Fe y Tucumán y describir aspectos epidemiológicos y clínicos asociados a su detección. Materiales y Métodos: Se estudiaron retrospectivamente los aspirados nasofaríngeos (ANF) de pacientes bajo 5 años de edad, con diagnóstico de IRA, hospitalizados durante el año 2013. La presencia de HBoV se detectó mediante la RPC de punto final descripta por Allander y cols. Los virus tradicionales se estudiaron mediante inmunofluorescencia. Datos personales, clínicos y epidemiológicos se recolectaron en una planilla estandarizada. Resultados: HBoV fue detectado en 7% de las muestras con prevalencia en primavera y verano; y principalmente en pacientes bajo 2 años de edad. Se registró co-detecciones en 22% de los casos. Discusión: Hemos detectado HBoV en estas dos provincias de Argentina; estudios posteriores deberán efectuarse para determinar si se trata de una infección reciente o una excreción prolongada del virus.

Impact of neuraminidase inhibitors on influenza A(H1N1)pdm09-related pneumonia: an individual participant data meta-analysis.

BACKGROUND: The impact of neuraminidase inhibitors (NAIs) on influenza-related pneumonia (IRP) is not established. Our objective was to investigate the association between NAI treatment and IRP incidence and outcomes in patients hospitalised with A(H1N1)pdm09 virus infection. METHODS: A worldwide meta-analysis of individual participant data from 20 634 hospitalised patients with laboratory-confirmed A(H1N1)pdm09 (n = 20 021) or clinically diagnosed (n = 613) 'pandemic influenza'. The primary outcome was radiologically confirmed IRP. Odds ratios (OR) were estimated using generalised linear mixed modelling, adjusting for NAI treatment propensity, antibiotics and corticosteroids. RESULTS: Of 20 634 included participants, 5978 (29·0%) had IRP; conversely, 3349 (16·2%) had confirmed the absence of radiographic pneumonia (the comparator). Early NAI treatment (within 2 days of symptom onset) versus no NAI was not significantly associated with IRP [adj. OR 0·83 (95% CI 0·64-1·06; P = 0·136)]. Among the 5978 patients with IRP, early NAI treatment versus none did not impact on mortality [adj. OR = 0·72 (0·44-1·17; P = 0·180)] or likelihood of requiring ventilatory support [adj. OR = 1·17 (0·71-1·92; P = 0·537)], but early treatment versus later significantly reduced mortality [adj. OR = 0·70 (0·55-0·88; P = 0·003)] and likelihood of requiring ventilatory support [adj. OR = 0·68 (0·54-0·85; P = 0·001)]. CONCLUSIONS: Early NAI treatment of patients hospitalised with A(H1N1)pdm09 virus infection versus no treatment did not reduce the likelihood of IRP. However, in patients who developed IRP, early NAI treatment versus later reduced the likelihood of mortality and needing ventilatory support.

Epidemiological and virological characteristics of influenza B: results of the Global Influenza B Study.

INTRODUCTION: Literature on influenza focuses on influenza A, despite influenza B having a large public health impact. The Global Influenza B Study aims to collect information on global epidemiology and burden of disease of influenza B since 2000. METHODS: Twenty-six countries in the Southern (n = 5) and Northern (n = 7) hemispheres and intertropical belt (n = 14) provided virological and epidemiological data. We calculated the proportion of influenza cases due to type B and Victoria and Yamagata lineages in each country and season; tested the correlation between proportion of influenza B and maximum weekly influenza-like illness (ILI) rate during the same season; determined the frequency of vaccine mismatches; and described the age distribution of cases by virus type. RESULTS: The database included 935 673 influenza cases (2000-2013). Overall median proportion of influenza B was 22·6%, with no statistically significant differences across seasons. During seasons where influenza B was dominant or co-circulated (>20% of total detections), Victoria and Yamagata lineages predominated during 64% and 36% of seasons, respectively, and a vaccine mismatch was observed in ≈25% of seasons. Proportion of influenza B was inversely correlated with maximum ILI rate in the same season in the Northern and (with borderline significance) Southern hemispheres. Patients infected with influenza B were usually younger (5-17 years) than patients infected with influenza A. CONCLUSION: Influenza B is a common disease with some epidemiological differences from influenza A. This should be considered when optimizing control/prevention strategies in different regions and reducing the global burden of disease due to influenza.

The role of rhinovirus in children hospitalized for acute respiratory disease, Santa Fe, Argentina.

Human rhinoviruses (HRVs) were historically considered upper airway pathogens. However, they have recently been proven to cause infections in the lower respiratory tract, resulting in hospitalization of children with pneumonia, bronchiolitis, and chronic pulmonary obstruction. In this report, HRV frequency and seasonality are described together with patient clinical-epidemiological aspects. From a total of 452 surveyed samples, the HRV nucleic acids was detected in 172 (38.1%) and found in every month of the study year. 60% of inpatients with acute respiratory infection (ARI) associated with HRV were under 6 months of age and 31% had a clinical history, being preterm birth and recurrent wheezing the prevailing conditions. The most frequent discharge diagnoses were pneumonia (35.2%), bronchiolitis (32.4%), and bronchitis (12.4%). Fifteen point nine percent of patients required admission into intensive care units. The results obtained in this study demonstrated the association between HRV and children hospitalizations caused by ARI.

[Epidemiologic and clinical characteristics of children with disease due to Bordetella pertussis in Santa Fe, Argentina]. / Características clínicas y epidemiológicas de niños con enfermedad por Bordetella pertussis en Santa Fe, Argentina.

INTRODUCTION: Pertussis, a vaccine-preventable respiratory disease, remains a public health problem. OBJECTIVE: The goal of this study is to describe epidemiological and clinical patterns of B. pertussis-caused respiratory infection over the period 2006-2010 in Santa Fe, Argentina. METHODS: Inpatients and outpatients < 14 years of age, meeting pertussis case definition criteria were included. Household family contacts of confirmed cases with compatible symptoms were also surveyed. RESULTS: 1074 patients were evaluated, 102 (9.49%) were confirmed through PCR. The proportion of confirmed cases was: in 2006, 35.5%; 2007, 21.2%; 2008, 4.9%. In 2009 and 2010 no cases were detected. 94.2% of hospitalized patients and 42.8% of outpatients were less than six months of age. Of all patients, 67.6% required hospitalization as they had a moderate to severe illness. The length of stay for these patients was over six days. 27.5% had pre-existing medical conditions, the most frequent being prematurity and malnutrition. The outcome was severe in 23.1% of cases, all of whom hadn't started the vaccination schedule. Severe pulmonary hypertension was present in five patients. Fatality rate was 4.9%. CONCLUSIONS: Pertussis mainly affected children < 6 months, non-vaccinated or with less than 3 doses. The bacterium was also detected among adults and teenagers.

Características clínicas y epidemiológicas de niños con enfermedad por Bordetella pertussis en Santa Fe, Argentina / Epidemiologic and clinical characteristics of children with disease due to Bordetella pertussis in Santa Fe, Argentina

Introduction: Pertussis, a vaccine-preventable respiratory disease, remains a public health problem. Objective: The goal of this study is to describe epidemiological and clinical patterns of B. pertussis-caused respiratory infection over the period 2006-2010 in Santa Fe, Argentina. Methods: Inpatients and outpatients < 14 years of age, meeting pertussis case definition criteria were included. Household family contacts of confirmed cases with compatible symptoms were also surveyed. Results: 1074 patients were evaluated, 102 (9.49%) were confirmed through PCR. The proportion of confirmed cases was: in 2006, 35.5%; 2007, 21.2%; 2008, 4.9%. In 2009 and 2010 no cases were detected. 94.2% of hospitalized patients and 42.8% of outpatients were less than six months of age. Of all patients, 67.6% required hospitalization as they had a moderate to severe illness. The length of stay for these patients was over six days. 27.5% had pre-existing medical conditions, the most frequent being prematurity and malnutrition. The outcome was severe in 23.1% of cases, all of whom hadn't started the vaccination schedule. Severe pulmonary hypertension was present in five patients. Fatality rate was 4.9%. Conclusions: Pertussis mainly affected children < 6 months, non-vaccinated or with less than 3 doses. The bacterium was also detected among adults and teenagers.

Introducción: Tos convulsiva es una enfermedad respiratoria prevenible por vacuna, que continúa siendo un problema de salud pública. Objetivo: Describir el patrón clínico y epidemiológico de la infección respiratoria por Bordetella pertussis durante el período 2006-2010 en Santa Fe, Argentina. Material y Métodos: Se incluyeron pacientes internados y ambulatorios menores de 14 años, que cumplieron con los criterios de definición de caso de coqueluche y los contactos de casos confirmados. Resultados: Se evaluaron 1.074 pacientes, 102 (9,49%) fueron confirmados por RPC. La proporción de casos confirmados fue: en 2006: 35,5%; 2007: 21,2%; 2008: 4,9%. En los años 2009 y 2010 no se detectaron casos. El 67,6% requirió internación con una duración de 6 días. El 94,2% de los pacientes hospitalizados fue menor de 6 meses y en los ambulatorios el 42,8%. El 27,5% presentaba condiciones médicas pre-existentes, siendo prematuridad y desnutrición las más frecuentes. La evolución de la enfermedad fue grave en 23,1% de los casos, los cuales no habían iniciado el calendario de vacunaciones. Se presentó hipertensión pulmonar grave en 5 pacientes. La letalidad fue de 4,9%. Discusión: La enfermedad afectó principalmente a lactantes < 6 meses, no vacunados o con menos de 3 dosis. La bacteria también se detectó entre adultos y adolescentes.

[Monitoring of activity of influenza in Santa Fe, Argentina, 2005-2010]. / Monitoreo de la actividad de influenza en Santa Fe, Argentina, 2005-2010.

BACKGROUND: Influenza viruses have a relevant public health impact. OBJECTIVE: To describe the activity of influenza and assess the morbidity and mortality impact during 2005 to 2010 in Santa Fe, Argentina. METHODS: Epidemiological and virological indicators were calculated based on sentinel surveillance. Mortality data from patients over and under the age of 65 were analyzed using the integrated autoregressive moving average model and an excess of mortality attributable to influenza was determined. RESULTS: The viral circulation effect on morbidity was measured through the evolution in the proportion of influenza-like illness (ILI) patients. Peak incidence was observed between weeks 23 and 33. An excess of deaths was identified in 2007 among patients over 65 and among those under 65 in 2009, which was related with influenza A(H3N2) and A(H1N1)pandemic virus circulation respectively, associated with a higher proportion of virus recovery and a higher ILI percentage. CONCLUSIONS: The sentinel surveillance of influenza is a simple and efficient methodology that identifies influenza trends. Our study showed that the virus has caused a rise of mortality in patients > 65 in epidemic periods associated with the H3N2 subtype and in patients < 65 in the pandemic period with the circulation ofA(HIN1)pandemic virus.

Effectiveness of neuraminidase inhibitors in reducing mortality in patients admitted to hospital with influenza A H1N1pdm09 virus infection: a meta-analysis of individual participant data.

BACKGROUND: Neuraminidase inhibitors were widely used during the 2009-10 influenza A H1N1 pandemic, but evidence for their effectiveness in reducing mortality is uncertain. We did a meta-analysis of individual participant data to investigate the association between use of neuraminidase inhibitors and mortality in patients admitted to hospital with pandemic influenza A H1N1pdm09 virus infection. METHODS: We assembled data for patients (all ages) admitted to hospital worldwide with laboratory confirmed or clinically diagnosed pandemic influenza A H1N1pdm09 virus infection. We identified potential data contributors from an earlier systematic review of reported studies addressing the same research question. In our systematic review, eligible studies were done between March 1, 2009 (Mexico), or April 1, 2009 (rest of the world), until the WHO declaration of the end of the pandemic (Aug 10, 2010); however, we continued to receive data up to March 14, 2011, from ongoing studies. We did a meta-analysis of individual participant data to assess the association between neuraminidase inhibitor treatment and mortality (primary outcome), adjusting for both treatment propensity and potential confounders, using generalised linear mixed modelling. We assessed the association with time to treatment using time-dependent Cox regression shared frailty modelling. FINDINGS: We included data for 29,234 patients from 78 studies of patients admitted to hospital between Jan 2, 2009, and March 14, 2011. Compared with no treatment, neuraminidase inhibitor treatment (irrespective of timing) was associated with a reduction in mortality risk (adjusted odds ratio [OR] 0·81; 95% CI 0·70-0·93; p=0·0024). Compared with later treatment, early treatment (within 2 days of symptom onset) was associated with a reduction in mortality risk (adjusted OR 0·48; 95% CI 0·41-0·56; p<0·0001). Early treatment versus no treatment was also associated with a reduction in mortality (adjusted OR 0·50; 95% CI 0·37-0·67; p<0·0001). These associations with reduced mortality risk were less pronounced and not significant in children. There was an increase in the mortality hazard rate with each day's delay in initiation of treatment up to day 5 as compared with treatment initiated within 2 days of symptom onset (adjusted hazard ratio [HR 1·23] [95% CI 1·18-1·28]; p<0·0001 for the increasing HR with each day's delay). INTERPRETATION: We advocate early instigation of neuraminidase inhibitor treatment in adults admitted to hospital with suspected or proven influenza infection. FUNDING: F Hoffmann-La Roche.