Outbreak Detection Stories

Imagine you go to your doctor’s office or an emergency room with more than just an upset stomach. Your doctor may ask for a sample of “poop,” (or in doctor terms: feces, or stool). Testing the stool sample is important for the patient, doctor, and public health officials to know if your sickness is connected to other illnesses (or a possible outbreak). Do the stool sample. It could save your life and those of others.

Foodborne diseases are preventable, yet common causes of illness, disability, and death worldwide. Find out how CDC and global partners are equipping countries with tools and training to make food safer.

In 2012, over 40 people in 20 states got sick from eating peanut butter and other peanut products contaminated with Salmonella. At the beginning of the outbreak investigations, public health investigators used DNA “fingerprints” of Salmonella bacteria obtained through PulseNet’s diagnostic testing with pulsed-field gel electrophoresis, or PFGE, to identify cases of illness that were part of this outbreak. The PFGE pattern had rarely been seen previously –typically causing only 5-8 cases of salmonellosis per year.

In 2011, cantaloupes contaminated with the bacteria Listeria monocytogenes caused the deadliest foodborne disease outbreak in the United States in nearly 90 years. Before the outbreak was detected, the Colorado health department sent samples of Listeria from patients to the Colorado public health laboratory for “DNA fingerprinting.” In record time, public health officials identified cantaloupe as the source of the outbreak (the first time a Listeria outbreak was linked to this source) and CDC sent out a national warning to protect the health of all Americans from this Listeria threat. Without PulseNet and the valuable work of many government agencies and health care professionals, as many as 62 more people would have been infected by the cantaloupe, with up to 21 percent of those victims dying.

Beginning in late December 2010, eight people in Michigan, Wisconsin, and Minnesota came down with a rare and serious illness caused by E.coli O157:H7 that was lurking in hazelnuts.

Without PulseNet’s ability to match up bacteria from sick people in many locations, this outbreak would not have been caught. PulseNet quickly identified that the type of E. coli stood out from other cases of E. coli infection that were occurring at the same time. The E. coli strain that infected these people had a common DNA pattern or “fingerprint.” After only eight cases of infection, the contaminated food was identified and potential additional illnesses were averted.