The role of the home environment in the transmission of infectious diseases and the impact of use of anti microbial products for cleaning in the home have not been studied in the U.S. The purposes of this blinded clinical trial with randomized group assignment are to test the effectiveness of two home hygiene regimens in reducing transmission of infectious disease symptoms among household members and to examine the effects of use of antibacterial products for dishwashing, laundry, and personal hygiene on the microbial flora of the hands and the development of anti microbial resistance. 240 households in the Washington Heights neighborhood of northern Manhattan, recruited from neighborhood schools, churches, neighbor referrals and three local WIC program offices, will be studied. Each household will be randomized to one of two interventions: a regimen in which anti microbial-containing, commercially available products will be used for dishwashing, laundry, and personal hygiene or a non-anti microbial regimen in which parallel products, but without anti microbial ingredients, will be used. Investigators and subjects will be blinded to group assignment. Study households will be contacted by telephone weekly and by home visit monthly for 12 months. Test products will be provided free to all participant households. The primary homemaker will provide information about hygiene practices in the home and about infectious disease symptoms in each member of the household. Disease transmission in the household will be defined as two or more persons in the same household with at least one related symptom (vomiting, diarrhea, fever, runny nose, cough, conjunctivitis, skin infection). The accuracy of symptom self-reporting will be verified by physical examination by a nurse practitioner. A hand culture will be obtained from the primary homemaker at the beginning of the study and quarterly during the study to examine any effects of use of anti microbial or non-anti microbial products on the types, numbers, and resistance patterns of bacteria on the hands. Logistic regression, Liang-Zeger regression, and Chi Square analyses will be used to test differences in rates of transmission of symptoms and changes in quantity, types and resistance patterns of microbial flora of the hands.