Importance of Outbreak Investigations
Outbreak investigations help us learn more about the causes of outbreaks. Officials can learn what germs are causing waterborne illness, what types of water are involved, and what groups of people become ill. This knowledge can be used to control an outbreak and prevent additional illnesses. The lessons learned from these investigations are routinely used to develop recommendations on how to prevent similar outbreaks from happening in the future.
Determining the type of water causing an illness may seem straightforward, but it is more complicated than you might think. People rarely know whether contaminated water made them ill, and it can be difficult or impossible to figure out. Many of the germs that are spread by water can also be spread in other ways, including by eating contaminated food or by contact with an ill person or animal. People come in contact with water often each day, making it even harder to know which exposure might have made a person sick. Finally, it can take several days or even weeks to become ill after being exposed to a germ, making it difficult to pinpoint the place and time of exposure. Without an outbreak investigation, it can be difficult or impossible to link illnesses to water.
When a group of people become ill at the same time, an investigation that collects information on timing and location of exposures and illnesses (known as an epidemiologic investigation) can help determine where and when the outbreak started and what caused it. An outbreak investigation can sometimes identify a direct link between the illnesses and contaminated water and might identify the type of water, systems, or settings involved. This information is difficult to gather outside of an outbreak (such as with individual infections).