Herpes Simplex Virus(HSV) causes tracheobronchitis and pneumonitis in critically ill patients. The characteristic endobronchial appearance is mucosal ulceration and membrane formation. We describe a series of critically ill patients with a normal endobronchial exam and cytopathic changes of HSV.
We reviewed all bronchoscopies performed in mechanically venilated patients in the medical ICU between October 2003 and March 2005 for evidence of mucosal lesions and cytopathic changes of HSV. Data including age, cause of respiratory failure, duration of mechanical ventilation and hospitalization prior to diagnosis, and level of HSV-1 IgG and IgM antibody(Ab)titers were recorded.
Of 52 bronchoscopies performed, 7 subjects with cytopathic changes of HSV were identified (13.5%) and one with bronchoscopic features of HSV. This patient was immunosupressed and was excluded. The average age was 64.9 yrs (49-84 yrs). The duration of ventilation prior to diagnosis was 9.4d (0-14) and of hospitalization was 15.1d (8-47). HSV-1 Ab titers were obtained in 4 of 7 subjects. The HSV-1 IgG Ab was elevated in 4 of 4 subjects(100%)with an average level of 31.0(normal<0.90). The HSV-1 IgM Ab titer was elevated in 2 of 4 subjects with an average level of 1.3 of those with elevated levels (normal<0.91). Respiratory failure (RF) was due to pneumonia or atelectasis in all but one patient, who had microscopic polyangiitis. Five patients received therapy with acyclovir. No specific clinical features were seen in the subjects with HSV cytopathic changes compared to the rest of the sample.
Cytopathic changes of HSV without obvious airway or parenchymal involvement are common in critically ill ventilated patients. To our knowledge, this has not been previously described in RF due to pneumonia or atelectasis. All cases occurred in fall and winter months (October to February).
The significance of HSV cytopathic changes in critically ill ventilated adults and whether antiviral treatment is beneficial remains unknown. This may represent true herpes infection or that of another etiologic agent. Further studies are indicated to define whether treatment is necessary.
Howard Weiss, None.