Whooping cough makes resurgence: "Pertussis, the highly contagious disease also known as whooping cough, has become a growing problem in adolescents in recent years despite its history as primarily a disease of infants and young children, federal data show. 'Even though the highest rate of pertussis is still among children under 6 months of age, the highest proportion of cases is now among adolescents,' said Dr. Amanda Cohn, an epidemic intelligence service officer for the Atlanta-based U.S. Centers for Disease Control and Prevention (CDC). Dr. Cohn is one of the authors of a report titled 'Pertussis -- United States, 2001-2003,' published in the CDC's Morbidity and Mortality Weekly Report that was released last week. The study showed that reported cases of pertussis increased from a historic low of 1,010 in 1976 to 11,647 cases in 2003. 'A large increase in reported cases has occurred among adolescents' as vaccinations they received as young children have lost effectiveness, the authors wrote."