The Centers for Disease Control and Prevention defines emerging infections as those whose incidence in humans has increased in the past two decades or threaten to increase in the near future. In 2004, the National Institutes of Allergy and Infectious Diseases (NIAID) listed more than 100 emerging infections. The Yale School of Public Health (YSPH) has taken a leadership role in research, teaching, surveillance, and control of a number of emerging infectious diseases ever since the concept was first introduced in the late 1990’s. These infections include anaplasmosis, babesiosis, Borrelia miyamotoi infection, Leptospirosis, Lyme disease, West Nile virus infection, trypanosomiasis, multidrug-resistant tuberculosis, Powassan virus infection, and Zika virus. Most of these infections are globally distributed. The YSPH also collaborates with the Connecticut Department of Public Health on important surveillance, teaching, research, and control efforts through the Connecticut Emerging Infections Disease Program. This program, funded by the Centers for Disease Control and Prevention has ongoing projects related to influenza, food-borne illness, hospital-associated infections including Clostridium difficile and their community interface, tick-borne diseases, and human papillomavirus. Finally, the YSPH has close collaborative ties with the Connecticut Agricultural Experiment Station that carries out research, teaching, surveillance, and control programs for both mosquito-borne and tick-borne diseases in Connecticut.