Respiratory viruses in the pediatric intensive care unit: prevalence and clinical aspects

A survey was conducted in two pediatric intensive care units in hospitals in Porto Alegre, Brazil, in order to monitor the main respiratory viruses present in bronchiolitis and/or pneumonia and their involvement in the severity of viral respiratory infections. Viral respiratory infection prevalence was 38.7 percent. In bronchiolitis, respiratory syncytial virus (RSV) was detected in 36 percent of the cases. In pneumonia, the prevalence rates were similar for adenovirus (10.3 percent) and RSV (7.7 percent). There was a difference among the viruses detected in terms of frequency of clinical findings indicating greater severity. Frequency of crackles in patients with RSV (47.3 percent) showed a borderline significance (p = 0.055, Fisher's exact test) as compared to those with adenovirus (87.5 percent). The overall case fatality rate in this study was 2.7 percent, and adenovirus showed a significantly higher case fatality rate (25 percent) than RSV (2.8 percent) (p = 0.005). Injected antibiotics were used in 49 percent of the children with RSV and 60 percent of those with adenovirus. Adenovirus was not detected in any of the 33 children submitted to oxygen therapy.

Viral etiology of acute respiratory infections among children in Porto Alegre, RS, Brazil

Although acute respiratory infections (ARIs) are a major cause of child morbidity and mortality in Southern Brazil, little information is available on their seasonality and viral etiology. This study was conducted on children under 5 years of age with ARI to assess viral etiology in the State of Rio Grande do Sul, from 1990 to 1992. A total of 862 nasopharyngeal secretion (NPS) samples were tested using indirect immunofluorescence. The results showed that 316 (36.6) NPS samples were positive: 26.2 for RSV, 6 for adenovirus, 1.7 for influenza viruses, 1.5 for parainfluenza viruses, and 1.2 for mixed infection. The mean viral prevalence rates in out-patient services, emergency wards, and in-patient hospital wards were 26.7, 53 and 42.3, respectively. Respiratory syncytial virus (RSV) and adenovirus accounted for 91.4 of the viral diagnoses. RSV was more frequent in children under one year of age at the three levels of health care and was prevalent in infants under six months. Adenovirus was the most prevalent pathogen in hospitalized children, in 1992. Influenza A virus showed an increased prevalence with age among out-patient children. This study shows the annual occurrence of viral respiratory infections in the coldest months, with a significant annual variation in the frequency of RSV infection.

Respiratory syncytial virus groups A and B in Porto Alegre, Brazil, from 1990 to 1995 and 1998

We analyzed the respiratory syncytial virus (RSV) groups and their epidemiological pattern that were detected over the course of seven years in southern Brazil. The two RSV groups co-circulated each year, but frequencies of groups A and B varied both between and within yearly outbreaks. In 1991, group A predominated over group B (p=0.0016). RSV outbreaks analyzed showed a temperature-dependent pattern and no association with rainfall, similarly to other countries from southern South America. Knowledge of the variants is important in terms of both diagnosis and definition of a vaccine composition

Respiratory syncytial virus (RSV) bronchiolitis: comparative study of RSV groups A and B infected children

The grouping characteristics of 29 respiratory syncytial virus (RSV) present in nasopharyngeal cells collected from hospitalized children with bronchiolitis during the 1990 RSV season in Porto Alegre, RS, were analysed. Twenty-two were grouped as belonging to group A and 7 to group B. Cyanosis, oxygen therapy, cough, length of hospitalization and atelectasis were observed to be more frequently found within group B infected children. Other clinical signs and symptoms were similarly found in both groups