Leila Christina Sahni, The University of Texas School of Public Health


Respiratory diseases are an important contributor to global morbidity and mortality, causing more than 2.5 million deaths each year. These diseases are a leading cause of death in children less than 5 years of age and disproportionately affect children in low- and middleincome countries, where poverty, malnutrition, and lack of access to care result in increased risk of infection and death. Although the burden of disease is lower in the United States, respiratory disease, in particular acute respiratory illness (ARI) caused by viruses, remains a substantial cause of morbidity. The epidemiology of many of the commonly detected respiratory viruses (ex. respiratory syncytial virus, influenza virus, rhinovirus/enterovirus, human metapneumovirus, and parainfluenza virus) has been well-described in children <5 years of age where disease burden is>highest, but less is known about the contribution of these viruses in children ≥5 years of age. Emerging respiratory viruses, for which little to no population immunity exists, have the potential to substantially impact children’s health globally. Identification and characterization of emerging respiratory viruses is a public health priority.

This dissertation analyzed data collected by the New Vaccine Surveillance Network (NVSN), a network of 7 pediatric hospitals established to conduct active, population-based surveillance for ARI and acute gastroenteritis. The first manuscript describes the epidemiology of well-recognized respiratory viruses in children 5-17 years of age hospitalized with ARI, with an emphasis on symptoms associated with infection treatment received during hospitalization, and clinical outcomes. Although these viruses have been well characterized in younger pediatric populations, data are lacking for older children. The second manuscript describes the detection of 2 novel respiratory viruses, enterovirus D68 and bocavirus, and compares the clinical course of infection with these viruses to established respiratory viruses.

These manuscripts add to the existing literature of pediatric respiratory viruses. Their findings fill the knowledge gap about spectrum of disease associated with well recognized respiratory viruses in older children, who have not traditionally been included in prior studies, and provide valuable information about two emerging respiratory pathogens. This research may identify priority target groups for prevention and treatment strategies and could inform the development of new vaccines and treatments.