The genus Orthopneumovirus consists of pathogens that target the upper respiratory tract within their specific hosts. Every orthopneumovirus is characterized as host specific, and has a range of diseases involved with respiratory illness. Orthopneumoviruses can cause diseases that range from a less-severe upper-respiratory illness to severe bronchiolitis or pneumonia. Orthopneumoviruses are found among sheep, cows, and most importantly humans. In humans, the orthopneumovirus that specifically impacts infants and small children is known as human respiratory syncytial virus. Pneumoviruses have been traced by researchers from the Center for Disease Control and Prevention and the University Medica Centre in Utrecht, Netherlands on how orthopneumoviruses attack infants and small children. The genus Orthopneumovirus consists of pathogens that target the upper respiratory tract within their specific hosts. Every orthopneumovirus is characterized as host specific, and has a range of diseases involved with respiratory illness. Orthopneumoviruses can cause diseases that range from a less-severe upper-respiratory illness to severe bronchiolitis or pneumonia. Orthopneumoviruses are found among sheep, cows, and most importantly humans. In humans, the orthopneumovirus that specifically impacts infants and small children is known as human respiratory syncytial virus. Pneumoviruses have been traced by researchers from the Center for Disease Control and Prevention and the University Medica Centre in Utrecht, Netherlands on how orthopneumoviruses attack infants and small children.