Two cases of severe bronchopneumonia due to influenza A (H3N2) virus: detection of influenza virus gene using reverse transcription polymerase chain reaction

Medical treatment of viral pneumonia including SARS in immunocompetent adult

Since no randomized controlled trials have been conducted on the treatment of viral pneumonia by antivirals or immunomodulators in immunocompetent adults, a review of such anecdotal experience are needed for the more rational use of such agents. Case reports (single or case series) with details on their treatment and outcome in the English literature can be reviewed for pneumonia caused by human or avian influenza A virus (50 patients), varicella zoster virus (120), adenovirus (29), hantavirus (100) and SARS coronavirus (SARS-CoV) (841). Even with steroid therapy alone, the mortality rate appeared to be lower when compared with conservative treatment for pneumonia caused by human influenza virus (12.5% vs. 42.1%) and hantavirus (13.3% vs. 63.4%). Combination of an effective antiviral, acyclovir, with steroid in the treatment of varicella zoster virus may be associated with a lower mortality than acyclovir alone (0% vs. 10.3%). Combination of interferon alfacon-1 plus steroid, or lopinavir/ritonavir, ribavirin plus steroid were associated with a better outcome than ribavirin plus steroid (0% vs. 2.3% vs. 7.7%, respectively). Combination of lopinavir/ritonavir plus ribavirin significantly reduced the virus load of SARS-CoV in nasopharyngeal, serum, stool and urine specimens taken between day 10 and 15 after symptom onset when compared with the historical control group treated with ribavirin. It appears that the combination of an effective antiviral and steroid was associated with a better outcome. Randomized therapeutic trial should be conducted to ascertain the relative usefulness of antiviral alone or in combination with steroid.

[Viral pneumonia in immunocompetent patients]

Les infections virales respiratoires communautaires sont fréquentes et le plus souvent bénignes. Beaucoup d'agents différents comme les virus influenza, ou para-influenza, le virus respiratoire syncitial, les rhinovirus, coronavirus, adénovirus et les herpès virus peuvent être isolés chez les patients immunocompétents. Parmi ces virus, le cytomégalovirus (CMV) peut être responsable de pneumonie nosocomiale en réanimation. Le diagnostic des infections virales est difficile car les signes cliniques sont non spécifiques et l'isolement du virus responsable difficile. Cependant, une symptomatologie clinique associant fièvre, myalgies, céphalées, pharyngite est fréquente dans les infections à Inflenza qui peuvent aboutir à des tableaux sévères. Enfin, le virus plus récent responsable d'infection respiratoire est un virus nouvellement découvert de la famille des coronavirus, le SRAS-CoV qui a été responsable d'une épidémie d'infections respiratoires sévères. Les pneumonies virales sont fréquentes mais probablement non diagnostiquées chez les patients immunocompétents. Cependant le diagnostic est nécessaire car pour la plupart des pathogènes il existe un traitement efficace. Le diagnostic repose sur l'histologie mais de nouvelles techniques comme la PCR doivent devenir d'utilisation courante pour améliorer le rendement diagnostique.