This section focuses on issues in infectious disease that are commonly encountered in pediatric office practice. Paul McCarthy discusses recent literature regarding the evaluation and management of acute fevers without apparent source on clinical examination in infants and children and the evaluation of children with prolonged fevers of unknown origin. Jean Klig reviews recent literature about lower respiratory tract infection in children. Eugene Shapiro discusses recent developments in the literature concerning several infectious diseases commonly facing practitioners in the office. Michael Baron reviews recent literature about gastroenteritis and diarrhea of infancy and early childhood.