Viral Pneumonias

Viral pneumonia is usually community acquired and caused by influenza, parainfluenza , respiratory syncytial virus , human metapneumovirus , and adenovirus. Many of these infections are airway centric and chest imaging demonstrates bronchiolitis and bronchopneumonia , With the exception of adenovirus infections , the presence of lobar consolidation usually suggests bacterial coinfection. Community-acquired viral pathogens can cause more severe pneumonia in immunocompromised hosts , who are also susceptible to CMV and varicella infection. These latter 2 pathogens are less likely to manifest the striking airway-centric pattern. Airway-centric pattern is distinctly uncommon in Hantavirus pulmonary syndrome , a rare environmentally acquired infection with high mortality.