“We run some 200,000 tests a year on samples of food and determine whether the food is safe,” said Esteban. “About 100,000 of those samples are tested for e-coli, salmonella or listeria.”
When the laboratory tests uncover contamination, Esteban is often part of a government team that pours over the information and makes the decision to halt shipments of food from production plants or removes the contaminated food from the store shelves.
The Centers for Disease Control and Prevention (CDC) estimates that each year roughly one in six Americans or 48 million people gets sick, 128,000 are hospitalized and 3,000 die of foodborne diseases each year.
Esteban said the ability of the scientists to detect food contamination has greatly improved over the years.
Where it used to take weeks to analyze a food sample, he said it now can be done in a matter of hours. In addition, scientists are now capable of extracting far more information from individual food samples than in the past.
“Before we took one food sample for each separate pathogen, but now we can test for multiple pathogens from the same sample,” Esteban said.
Esteban said scientists also can produce a DNA fingerprint of bacteria found in individuals who have become ill, and match that with the DNA of the bacteria found in the food source, allowing for a precise determination of the cause of an outbreak and a quicker response to save lives.
In addition to managing 250 people at three USDA laboratories and keeping his pulse on the daily activities, Esteban said he meets with consumers groups, industry representatives, research scientists and regulators to explain changes in sampling and testing methods and revised standards. He said one of his biggest challenges is explaining what the USDA is doing and why it is taking particular actions to the different audiences so they understand the rationale, have the information that they need and can assess the impact.
Before Esteban held his current position, he was the scientific advisor for laboratory services for USDA’s food inspection service. Earlier, he served as the director of agency’s testing laboratory in Alameda, Calif., and did extensive work at the CDC as an epidemiologist and food safety officer.
As head of the USDA’s California laboratory, Esteban played a critical role investigating whether the dangerous chemical melamine, which had been imported from China and used in animal feed, had entered the U.S. food chain. Esteban said he and his team worked day and night, tested numerous food samples from around the country and in the end found no threat to human health.