Human metapneumovirus infection in hematopoietic stem cell transplant recipients.

UNLABELLED: Human metapneumovirus (hMPV) was described in 2001 and has been associated with both upper and lower respiratory tract infection (URTI and LRTI, respectively), especially in children, the elderly, and in immunocompromised patients. The objective of this study was to identify hMPV as the etiological agent of acute respiratory infection in hematopoietic stem cell transplant (HSCT) patients and to determine the clinical features of hMPV infection in these patients. METHODS: The study was performed retrospectively in 769 respiratory samples obtained from immunocompromised patients submitted to HSCT over a period of 6 years. RNA was extracted by the guanidinium thiocyanate method, and reverse transcription polymerase chain reaction assay was performed to amplify a 928pb fragment of the hMPV N gene. RESULTS: hMPV was present in 19 (2.5%) samples. The mean age of infected patients was 18.3+/-10.8 (range, 3-41). Sixty-six percent of hMPV infections occurred during autumn, winter, and spring months. Three episodes showed co-infection with more than 1 virus. Two patients (11.1%) were infected a few days into the conditioning period and 9 (50%) in the first 3 months after the transplant. The majority of patients (72.2%) presented URTI alone with flu-like symptoms (cough, fever, headache, wheezing), while 5 patients (27.8%) had LRTI (pneumonia). No patient died from complications associated with the hMPV infection. CONCLUSIONS: hMPV has been reported as a respiratory pathogen in HSCT patients. We suggest that hMPV infection should be routinely investigated in this population, mainly in children, to prevent nosocomial transmission during transplant proceedings and to avoid the risk of progressing to complications due to LRTI.

Impact of respiratory infections by influenza viruses A and B in pediatrics patients from Federal University of Paraná, Brazil.

The objective of the present study was to determine the impact of influenza virus on pediatric hospitalized patients. We retrospectively reviewed records of children with laboratory diagnoses, by cell culture and/or indirect immunofluorescence assay, of influenza virus seen in a period of 6 years. A total of 1,033 samples were analyzed, 45 (4.3%) of them being reactive to influenza virus. Thirty-one samples were positive to influenza A virus and 14 to influenza B. The frequency of hospitalization in intensive care and medical emergency was found to be high. Three (8.6%) patients died, two of them due to respiratory failure. Low frequency of influenza virus infection was observed in the study. The data suggest the need of more efficient epidemiological surveillance measures in order to obtain reliable information to better assess the impact of the virus on our region and determine the need of preventive measures, such as immunization.

Impact of respiratory infections by influenza viruses A and B in pediatrics patients from Federal University of Paraná, Brazil

The objective of the present study was to determine the impact of influenza virus on pediatric hospitalized patients. We retrospectively reviewed records of children with laboratory diagnoses, by cell culture and/or indirect immunofluorescence assay, of influenza virus seen in a period of 6 years. A total of 1,033 samples were analyzed, 45 (4.3 percent) of them being reactive to influenza virus. Thirty-one samples were positive to influenza A virus and 14 to influenza B. The frequency of hospitalization in intensive care and medical emergency was found to be high. Three (8.6 percent) patients died, two of them due to respiratory failure. Low frequency of influenza virus infection was observed in the study. The data suggest the need of more efficient epidemiological surveillance measures in order to obtain reliable information to better assess the impact of the virus on our region and determine the need of preventive measures, such as immunization.

Padronizaçäo da técnica antigenemia para a detecçäo do citomegalovirus / Padronization of antigenemia metodology for detection of citomegalovirus

Antigenemia para citomegalovirus (CMV) é um importante marcador de evoluçäo de doença e eficácia de tratamento em pacientes imunocomprometidos. O objetivo desse estudo foi comparar diferentes técnicas de processamentos e de imunomarcaçäo para a detecçäo da proteína da matrix do CMV pp65 em leucócitos do sangue periférico. Amostras de sangue coletadas de pacientes submetidos ao transplante de medula óssea (TMO) foram processadas e imunomarcadas por diferentes metodologias. Separou-se leucócitos de sangue periférico, utilizando-se duas técnicas, sedimentaçäo espontânea a 37§C (Processamento 1) e a sedimentaçäo com Dextran (Processamento 2), após a lise eritrocitária procedeu-se a contagem dos leucócitos, ajuste da densidade celular e o preparo das lâminas que continham (2x10 a quinta potência) células, por citocentrifugaçäo. As lâminas, obtidas através das diferentes técnicas de processamentos, foram coradas, utilizando-se a metodologia de Imunoperoxidase (IP) e os resultados obtidos foram analisados de acordo com parâmetros qualitativos e quantitativos. Também avaliou-se duas diferentes técnicas de imunomarcaçäo: IFI Imunofluorescência Indireta) e IP onde comparou-se o número de células positivas. Obteve-se lâminas de melhor qualidade pelo processamento 1 e um maior número de célu;as positivas com técnica de IP

Modulation detection, modulation masking, and speech understanding in noise in the elderly.

Temporal processing of suprathreshold sounds was examined in a group of young normal-hearing subjects (mean age of 26.0 years), and in three groups of older subjects (mean ages of 54.3, 64.8, and 72.2 years) with normal hearing or mild sensorineural hearing loss. Three experiments were performed. In the first experiment (modulation detection), subjects were asked to detect sinusoidal amplitude modulation (SAM) of a broadband noise, for modulation frequencies ranging from 2-1024 Hz. In the second experiment (modulation masking), the task was to detect a SAM signal (modulation frequency of 8 Hz) in the presence of a 100%-modulated SAM masker. Masker modulation frequency ranged from 2-64 Hz. In the final experiment, speech understanding was measured as a function of signal-to-noise ratio in both an unmodulated background noise and in a SAM background noise that had a modulation frequency of 8 Hz and a modulation depth of 100%. Except for a very modest correlation between age and modulation detection sensitivity at low modulation frequencies, there were no significant effects of age once the effect of hearing loss was taken into account. The results of the experiments suggest, however, that subjects with even a mild sensorineural hearing loss may have difficulty with a modulation masking task, and may not understand speech as well as normal-hearing subjects do in a modulated noise background.

Overshoot in normal-hearing and hearing-impaired subjects.

Overshoot was measured in both ears of four subjects with normal hearing and in five subjects with permanent, sensorineural hearing loss (two with a unilateral loss). The masker was a 400-ms broadband noise presented at a spectrum level of 20, 30, or 40 dB SPL. The signal was a 10-ms sinusoid presented 1 or 195 ms after the onset of the masker. Signal frequency was 1.0 or 4.0 kHz, which placed the signal in a region of normal (1.0 kHz) or impaired (4.0 kHz) absolute sensitivity for the impaired ears. For the normal-hearing subjects, the effects of signal frequency and masker level were similar to those published previously. In particular, overshoot was larger at 4.0 than at 1.0 kHz, and overshoot at 4.0 kHz tended to decrease with increasing masker level. At 4.0 kHz, overshoot values were significantly larger in the normal ears: Maximum values ranged from about 7-26 dB in the normal ears, but were always less than 5 dB in the impaired ears. The smaller overshoot values resulted from the fact that thresholds in the short-delay condition were considerably better in the hearing-impaired subjects than in the normal-hearing subjects. At 1.0 kHz, overshoot values for the two groups of subjects more or less overlapped. The results suggest that permanent, sensorineural hearing loss disrupts the mechanisms responsible for a large overshoot effect.