Background: Except for influenza pandemics, different observational studies have failed to demonstrate differences in mortality between various etiologies in adult patients hospitalized for respiratory infections. Aim: To compare clinical and mortality differences between different viral pathogens associated with severe acute respiratory infections (SARI) in hospitalized adults. Material and Methods: One-year prospective study in a sentinel center. We included 132 patients with SARI hospitalized for any of the nine viruses under study by PCR. Clinical variables were compared, excluding cases of coinfection. Results: A viral coinfection was identified in 12% and influenza infection in 56% of cases. Eighty percent of patients were aged ≥ 65 years, with a high frequency of comorbidities, 27% were bedridden. Twenty four percent were admitted to critical care units, 20% required ventilatory assistance and 16% died. Cases occurred throughout the year, with an expected seasonal peak between autumn and spring and a predominance of infections not associated with influenza during summer months. In the multivariate analysis, only being bedridden was significantly associated with mortality at discharge (Odds ratio 23.46; 95% confidence intervals 3.33-165.12, p < 0.01), without association with age, comorbidity, viral pathogen involved, laboratory parameters, clinical presentation or CURB65 score. No major clinical dissimilarities were found between different viral pathogens. Conclusions: In our series of patients, mostly elderly, only bedridden status was significantly associated with mortality at discharge in patients hospitalized for SARI. Viral pathogens were not relevant.

Los factores del huésped son más importantes que el tipo viral para predecir el desenlace en pacientes hospitalizados por infecciones respiratoria aguda grave. Exceptuando las pandemias de influenza, diferentes estudios observacionales no han logrado demostrar diferencias en mortalidad entre diferentes patógenos en pacientes adultos hospitalizados por infecciones respiratorias. Objetivo: Comparar diferencias clínicas y en mortalidad entre diferentes patógenos virales asociados a infección respiratoria aguda grave (IRAG) en adultos hospitalizados. Método: Estudio prospectivo durante un año en un centro centinela. Se incluyeron casos de IRAG hospitalizados por alguno de los 9 virus bajo estudio por RCP. Se compararon variables clínicas y desenlace. Resultados: Ingresaron 132 pacientes con IRAG. Se identificó coinfección viral en 12,1% e infección por influenza en 56,1%. La mayor parte era de la tercera edad (80,3%) con una alta frecuencia de comorbilidad y 27,3% estaba postrado. Veintitres coma cinco por ciento ingresó a unidad de cuidados críticos, 19,7% requirió asistencia ventilatoria y 15,9% fallecieron. Los casos ocurrieron todo el año, con un aumento estacional esperado entre otoño y primavera y predominio de infecciones no asociadas a influenza en verano. En el análisis multivariado, sólo la postración se asoció significativamente a mortalidad al egreso (ORa 23,46 IC95 3,33-165,12, p = 0,002), sin asociación con la edad, comorbilidad, patógeno viral involucrado, parámetros de laboratorio, presentación clínica o puntuación CURB65. No se encontraron discordancias clínicas mayores entre diferentes agentes virales. Conclusiones: En nuestra serie de pacientes, mayoritariamente de la tercera edad, sólo la postración se asoció significativamente a mortalidad al egreso en pacientes hospitalizados por IRAG. El patógeno viral no resultó ser relevante.

Acute renal failure (ARF) requiring hemodialysis is not common among patients affected by influenza. We report two unvaccinated adult patients with smoking habit, which were admitted with severe influenza A H1N1pdm09 that evolved with shock and required mechanical ventilation. Both patients developed progressive renal failure with oliguria/anuria, associated with urinary of inflammatory sediment with proteinuria, microhematuria and in one case also with hypocomplementemia, suggesting acute glomerulonephritis. Renal replacement therapy (RRT) was required in both cases. In one patient, who died of late complications, sequencing of the HA1 segment revealed the previously described D222N mutation associated to severe cases. ARF with RRT appears to be an uncommon complication of patients hospitalized for influenza A H1N1pdm09 and may be secondary to acute glomerulonephritis.

La insuficiencia renal aguda (IRA) que requiere hemodiálisis no es una complicación común entre los pacientes afectados por influenza. Se comunican los casos clínicos de dos pacientes adultos fumadores no vacunados, que se internaron por influenza A H1N1pdm09 grave por shock y necesidad de ventilación mecánica. Ambos desarrollaron una falla renal progresiva con oliguria/anuria, asociada a un sedimento de orina inflamatorio con proteinuria, microhematuria y en un caso además con hipocomplementemia, sugiriendo una glomerulonefritis aguda. Se requirió terapia de reemplazo renal (TRR) en ambos casos. En uno de los pacientes, que falleció por complicaciones tardías, la secuenciación del segmento HA1 reveló la mutación D222N previamente descrita en casos graves. La IRA con TRR parece ser una complicación infrecuente de los pacientes ingresados por influenza A H1N1pdm09 y puede ser secundaria a una glomerulonefritis aguda.

Human rhinovirus (HRV) is an emerging viral pathogen. Aim: To characterize a group of patients admitted due to infection by this agent in a general hospital in Chile. Methods: Cases were identified by RT-PCR for 1 year through active surveillance of patients admitted with severe respiratory illness. Diagnosis was not available during hospitalization. Thirty-two cases were identified, 90% were ≥60 years old or had co-morbid conditions. Human rhinovirus-related admissions represented 23.7% of hospitalization due to severe acute respiratory infections among adults and ranked second to influenza (37.8%). Patients presented with pneumonia (68.8%), decompensated chronic lung conditions (21.9%), heart failure or influenza-like illness (6.3% each). Admission to intensive or intermediate care units was required by 31.2% and in-hospital mortality reached 12.5%. A CURB-65 score ≥3 was significantly associated to in-hospital mortality (p < 0.05). Most patients received antibiotics (90%). Conclusions: Human rhinovirus infections in elderly patients with co-morbid conditions are associated with hospitalizations, requiring critical or semi-critical antibiotics use. A high CURB-65 score was associated to in-hospital mortality.

Background: Following the announcement of the Influenza A(H1N1) pandemic by the World Health Organization in April 2009, a surveillance program was carried out in Chile to detect the introduction of the virus in the country and to monitor its propagation and impact. Aim: To describe the onset of the outbreak and the genetic characterization of the pandemic H1N1 influenza virus in the first detected cases in Chile. Material and Methods: Analysis of18 clinical samples coming from suspicious patients, received in a National Reference Laboratory. RNA reverse transcription and real time influenza gene DNA amplification was carried out in a 7500 Fast and Step One Real Time PCR Systems of Applied Biosystems and MxPro-Mx3000P thermocycler from Stratagene. Super Script III Platinum One-Step Quantitative RT-PCR was used. Results: The virus was first detected in three persons returning from the Dominican Republic via Panamá and a child from the east zone of Santiago. Genetic characterization of the virus showed that the child was infected by a different variant of the pandemic virus than the three persons returning from the Caribbean. Conclusions: The onset of the Influenza outbreak in Chile apparently carne from two different epidemiological groups. The spread of the virus detected in the voyagers was limited immediately However the virus of the fourth case was found in different regions of Chile.