 This screening study is designed to evaluate patients with suspected or identified recurrent or unusual infections and their family members for clinical and in vitro correlates of exposure and susceptibility. It will allow for up to 2 visits to obtain blood, urine, saliva, stool, skin biopsy, or wound drainage from such patients or their family members for research studies related to understanding the nature of the infection as well as the genetic and biochemical bases of these diseases. Patients determined by initial evaluation to be of interest for additional study or treatment will be asked to provide consent for enrollment into an appropriate NIH follow-up study. The present study will enroll up to 1500 patients and family members over the next 15 years. 