Epidemiological, clinical and laboratorial aspects of respiratory syncytial virus infection in hospitalized infants / Aspectos epidemiologicos, clinicos e laboratoriais da infecção pelo virus sincicial respiratorio em crianças menores de um ano, internadas com doeça respiratoria aguda

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

In pediatrics, acute respiratory infections are the most common cause of hospitalization. The Respiratory Syncytial Virus (RSV) is the main agent responsible for these infections that are clinically manifested as bronchiolitis or pneumonia Severe cases occur mostly in premature patients who have chronic pneumopathies, cardiopathies and immunodeficiencies. Some of the hospitalized patients require invasive mechanical ventilation (IMV) Follow up after the acute phase often demonstrates recurring respiratory obstruction. Objectives: to describe the epidemiological and clinical characteristics of infants under the age of 12 months hospitalized with acute lower respiratory tract infections, determine factors related to mechanical ventilation and RSV as well as delayed evolutional characteristics of this population. Methods and Cases: This was a prospective cohort study conducted from 2001 April to 2001 September at two university hospitals in the region of Campinas, Sao Paulo. An evaluation was performed of 152 infants aged 0 to 12 months, hospitalized with an initial diagnosis of acute lower respiratory tract diseases Direct Immunofluorescence Assay (DFA) was used to perform a clinical research and assess RSV in the nasopharyngeal secretion. The patients were divided into two groups according to the need for IMV as well as the presence of RSV and their prognostic factors were compared. Six to twelve months after hospitalization, patients with DFA positive for RSV as well as patients who were subjected to IMV were recalled and checked for the presence of recurrent wheezing. The relation between risk factors and outcome was analyzed by applying Relative Risk (RR) and Confidence Intervals (CI 95%). The chi-square test and the Fisher Exact test were used for comparing proportions. Continuous measures were compared using the Mann Whitney test. The significance level adopted for statistical tests was 5%. Results: RSV research was conducted on 149 infants, revealing 17.4% positivity (26 patients). Twenty-one patients (13 8%) were subjected to IMV and factors significantly associated were age below three months (RR=2.35, IC 95%: 1.06-5.22) and breastfeeding period less than one month (RR=3.15; IC95%: 1.35-7.35). When both groups were compared with and without the presence of RSV, the factors associated with infection were: gestational age less than 35 weeks (RR=4 17, IC95%: 2.21-7.87), birth weight less than 2,500g (RR=2.69, 1C95%: 1.34 -5.37) and maternal education less than five years (RR=2 28, IC 95%: 1 13-4.59). Only 26 (63.4%) out of 41 patients reported for follow up of clinical evolution. Of these, 19.2% were non-sibilants, 57.7% were intermittent sibilants and 23.1% were persistent sibilants When the non-sibilant groups were compared with the intermittent sibilants, a significant difference was observed in relation to the variable - hospitalization after discharge, which only occurred in the second group. No significant difference was observed regarding the variables analyzed when non-sibilant groups were compared with moderate/mild persistent sibilants. Conclusions: The incidence of RSV was 17.5% in infants hospitalized with acute lower respiratory tract infections. Factors associated with IMV were age below three months and breastfeeding period less than one month Factors associated with acquisition of RSV were: gestational age less than 35 weeks, birth weight below 2,500 gm; maternal education level less than five years. Delayed clinical evolution revealed that infants who were positive for RSV and infants subjected to IMV demonstrated intermittent wheezing with no need for inhalation corticotherapy and also a higher number of hospitalizations after discharge.

ASSUNTO(S)

risk factors respiratory syncytial viruses virus sincicial respiratorio fatores de risco respiratory tract infections artificial respiração artificial respiration infecções respiratorias

ACESSO AO ARTIGO

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