In humans, the most common types of infection are respiratory tract infections, among which viral infections predominate. Viruses can also infect the low respiratory tract, causing bronchiolitis, bronchitis and pneumonia. The objective of this review article was to show epidemiological, pathophysiological, clinical and therapeutic aspects of viral community-acquired pneumonia. These types of pneumonia are commonly caused by influenza A and B; parainfluenza 1, 2 and 3; respiratory syncytial virus; or adenovirus. We also address the types of pneumonia caused by hantaviruses, metapneumoviruses and rhinoviruses.Keywords: Pneumonia, viral; Influenza, human; Respiratory syncytial virus infections; Hantavirus.
ResumoAs infecções do trato respiratório são as formas de infecção mais comuns que afetam o homem e, dentre essas, predominam as de causa viral. Os vírus também podem acometer o trato respiratório baixo, causando bronquiolite, bronquite e pneumonia. Neste artigo de revisão, objetivamos mostrar aspectos epidemiológicos, fisiopatológicos, clínicos e do tratamento das pneumonias comunitárias por vírus. Essas pneumonias costumam ser causadas por vírus influenza A e B; parainfluenza 1, 2 e 3; vírus respiratório sincicial; e adenovírus. Também são apresentados aqui os hantavírus, metapneumovírus e rinovírus causando pneumonia. can actively inhibit or delay such responses. In addition, hantaviruses have an inhibiting effect on the cell receptors responsible for the maintenance of vascular integrity. More severe clinical profiles have also been associated with high viral loads. Inversely, neutralizing antibodies seem to have a protective effect against the severe forms.
Descritores(6) Furthermore, in severe RSV pneumonia, high local viral replication, an exacerbated proinflammatory response and a high level of T cell activation have been observed. (7) In patients with pneumonia, there are no clinical criteria that suggest, with proven safety, the viral etiology. In addition, there are difficulties in establishing the general etiologic diagnosis of pneumonia, especially of viral pneumonia, which limits the knowledge about this disease and its causative agents. The classical description of severe viral pneumonia is based on that of the influenza A virus. Patients present with cough that is initially dry but can evolve to the production of pinkish mucous sputum, and respiratory failure, characterized by cyanosis and hypoxia. At examination, patients are found to be acutely ill, showing increased respiratory rate and crackles disseminated through the lung parenchyma projection area, as well as eventually presenting rhinitis and conjunctivitis. In RSV pneumonia, bronchitis and bronchiolitis associated with necrotic mucosal lesion and mucus plugging take on added importance.(3) In adults, high fever, leukocytosis with neutrophilia and radiological findings of lobar pneumonia do not predict the viral etiology. Similarly, in children, clinical alterations, such as an axillary temperature > 39°C, and altered complementary...