1. Food produced at company A\ue2\u20ac\u2122s factory gets contaminated and is distributed to grocery stores nationwide.2. John buys the food and uses his store loyalty card when he checks out.3. A few days after eating the food, John gets diarrhea, fever and stomach cramps.4. John goes to his doctor, who collects a stool sample to test for germs.5. The clinical lab finds the Salmonella germ and sends a sample of it to the state public health lab for further testing.6. The state public health lab identifies the DNA fingerprint of the Salmonella germ from John and enters the results into the PulseNet database.7. CDC\ue2\u20ac\u2122s PulseNet finds people in other states who got sick from Salmonella with the same DNA fingerprint.8A. CDC cont...