An ability to identify an individual's inherent susceptibility to a particular disease holds great promise for global health. Targeting of susceptible individuals ultimately leverages the impact of specific preventive measures beyond their production levels and can vastly improve the cost effectiveness of the preventive treatments themselves. We have developed a saliva-based technology that has the capacity to assess an individual's genetic-based signature oligosaccharides with relative ease. The patterns of the genetic-based oligosaccharides potentially predispose the subject to the attachment and subsequent infection by various pathogens. The model that led to development of this technology is a test that can quantify susceptibility to Dental caries, an infectious disease. This technology was developed as part of a STTR grant from NIH/NIDCR. The test can forecast in young adults, the severity of the disease to ?1 cavity and/or filling with >95% confidence. When applied to children, it is predictive and focuses on groups of teeth at risk. This paves the way to targeted preventive strategies. Expanding the potential application to other infectious diseases requires little imagination since the environment and mechanisms within the oral cavity are remarkably similar to other tissue systems that are also at risk for infections. Furthermore, saliva contains most of an individual's genetically expressed catalog of oligosaccharides, including the oligosaccharide-based blood types. We believe that saliva can provide a window into the question of why some people get very ill with an infectious disease, others only modestly so, and yet others, not at all. The proposed study of three infectious diseases known to involve an oligosaccharide-based host-pathogen interaction explores the possibility that saliva contains the appropriate oligosaccharide information. The three diseases are otitis media, gastric ulcers, and influenza Type B. These diseases share fundamental attachment and infection mechanisms with Dental caries; yet, the three diseases are also different enough to offer the opportunity to broaden the conceptual base for the core technology. The goal of this application is to provide subjects and technology that could provide a clear demonstration that saliva contains the predictors of susceptibility to infectious diseases with venues that may be remote from the oral cavity. ? ? ?