| human parainfluenza virus type 4 infection in chinese children with lower respiratory tract infections: a comparison study. | background: human parainfluenza viruses (hpivs) are a leading cause of acute respiratory tract infections (artis). although hpiv-4 has been associated with mild artis for years, recent investigations have also associated hpiv-4 infection with severe respiratory syndromes and with outbreaks of artis in children. objectives: to characterize the role of hpiv-4 and its clinical features in children with acute lower respiratory tract infections (alrtis) in beijing, china. study design: nasopharyngeal ... | 2011 | 21636318 |