Testing may be performed to evaluate water following a sewage backflow that may contain a wide variety of pathogenic organisms including Salmonella, Shigella, enteric viruses, Giardia, Cyptosporidium, and multicellular parasites. Sewage may also contain blood-borne pathogens such as HIV and the virus that causes hepatitis. Testing may also be performed to verify the effectiveness of remediation procedures.
Other testing may be performed to evaluate bacteria organisms that indicate overcrowding of an occupied space, insufficient ventilation for the occupancy load, the presence of past water damage, and/or a lack of maintenance either in the HVAC system or in the building as a whole or both. Some species are consistent with contamination of indoor environments accompanied by other microbial contaminants and/or the ability to produce hypersensitivity pneumonitis in exposed individuals or opportunistic pathogenicity potential. Results may indicate a healthy environment or an indication that further investigation should be performed. Most bacteria are generally considered environmental. Their sources may be outdoors, indoor dust, water damage, or any combination.
The presence of some common environmental bacteria, such as Actinomycetes (especially the thermophiles) in indoor environments is of concern because of their ability to produce hypersensitivity pneumonitis in exposed individuals, as well as their opportunistic pathogenicity potential. The presence of high levels of actinomycetes indoors requires immediate further investigation.
Following sewage events in structures, bacteria pathogens in sewage (including gram-negative organisms Salmonella, Escherichia coli, and Shigella) represent risk to the occupants, especially those that contact the water. Following extraction of the water and drying of the structure, the cell walls of the bacteria (endotoxins), which are prone to become airborne, can produce toxic effects.
Some healthy people host human-associated bacteria, such as Staphylococcus aureus, that is pathogenic and may be communicated to people with compromised immune systems (e.g. “Staph infection”).
When to test for bacteria: