Co-infecção de rinovírus e alguns outros vírus respiratórios em crianças apresentando doença do trato respiratório inferior, em Uberlândia, MG, Brasil

Abstract

Human rhinoviruses (HRV) are commonly associated with mild respiratory symptoms of children. However, some studies have detected these viruses in lower respiratory tract illness (LRTI), often in coinfection with other respiratory agents. So, both investigated simultaneous infections of these agents with other respiratory viruses as a possible association with LRTI, in rhinovirus-positive samples of children attended at a public health service in Uberlândia, MG, Brazil. The presence of RNA of these viruses was researched by polymerase chain reaction (PCR), preceded by reverse transcription (RT), in 321 nasopharyngeal aspirates (NPAs) samples from children <5 yo. with acute respiratory disease (ARD), which presented negative or inconclusive results for seven respiratory viruses by immunofluorescence assay. Of these total, 90 specimens with positive results for HRV and presenting LRTI diagnose, were selected to be tested by PCR for presence of respiratory syncytial virus (RSV) types A and B, influenzaviruses (FLU) A and B, human metapneumovirus (hMPV) and parainfluenzaviruses (PIV) 1, 2 and 3. The LRTI were classified into: bronchiolitis, pneumonia and acute bronchitis. Bronchiolitis and pneumonia were considered more severe than acute bronchitis. In 64.4% of samples any other investigated viruses were detected. In the remaining of clinical specimens, a second virus were found, including RSV in 22.2%, followed by hMPV in 6.7%, and PIV in 6.7%. A higher incidence of bronchiolitis was observed in children that had HRV coinfection with hMPV or PIV, compared with those presenting only HRV (p = 0.0364). Younger children were the most frequently identified with dual infection, and also presented higher rates of hospitalization. The relation between HRV coinfection with certain viruses and a higher frequency of bronchiolitis suggests that HRV could cause more severe clinical syndromes, when associated with some other respiratory viral agents. The fact that younger children had been more often coinfected suggests that age has an important role in the simultaneous infection of HRV with other respiratory viruses.