RESPIRATORY SYNCYTIAL VIRUS-INFECTION ENHANCES THE RESPONSE TO LARYNGEAL CHEMOSTIMULATION AND INHIBITS AROUSAL FROM SLEEP IN YOUNG LAMBS

To evaluate the effect of respiratory syncytial virus (RSV) infection on the response to laryngeal chemostimulation (LCS) with water, five l ambs were inoculated with human RSV and three lambs were given control media at an age of 3-5 days. During RSV infection, LCS resulted in in creased inhibition of minute ventilation and delayed recovery of regul ar breathing. Sleep further increased the response, and arousal was le ss likely to occur in active sleep. Two of the five infected lambs nee ded resuscitation after LCS when arousal was absent. Histological stud ies showed bronchiolitis and pneumonitis. Laryngeal tastebud morpholog y was unchanged at 8 days after inoculation. However, infected lambs h ad disrupted tastebuds 4-6 weeks after infection. Failure to arouse an d to terminate reflex apnea may play a role in the pathogenesis of the sudden infant death syndrome associated with respiratory tract infect ion.