Viral lung disease due to herpesviridae in the intensive care unit

Abstract

Herpesviridae, including herpes simplex virus (HSV) and cytomegalovirus (CMV), are commonly detected in the respiratory tract of non-immunocompromised patients receiving mechanical ventilation. Although their detection usually involves viral reactivation without the involvement of pulmonary tissue, viral lung disease may occur in a particular population of patients. Although histological examination for specific cytopathic effects forms the basis of diagnosis, the use of modern virological tests (amplification using real-time polymerase chain reaction to estimate the vial load) should replace the histological tests in the near future. HSV bronchopneumonitis is associated with the reactivation of HSV in oropharyngeal and oral-labial lesions. It seems to clearly affect patients’ outcome due to prolonged mechanical ventilation and length of stay in the intensive care unit (ICU). However, only interventional studies will be able to determine its real impact. To date, use of acyclovir in these patients remains to be assessed. Although CMV reactivation in the blood is frequent in ICU patients, CMV pneumonia is difficult to diagnose because of the cumbersomeness of the procedure (open lung biopsies). Its true prognosis remains uncertain. The use of ganciclovir in this subset of patients also remains to be assessed.