Sewage backups not only present unpleasant odor problems, they may cause property damage and present unhealthy living conditions. Untreated sewage contains disease-causing organisms such as bacteria, viruses and parasites. Contact with contaminated water can cause skin infections and rashes, and if ingested accidentally via improperly cleaned hands or food preparation surfaces, these contaminants can cause nausea, abdominal pain, vomiting and diarrhea. Respiratory infections and allergic reactions may also result from inhaling associated airborne microorganisms.