By SARA ARTHURS
The salmonella outbreak in pre-cut melons that sickened a Hancock County woman has made national headlines, but solving smaller-scale mysteries like this is routine work for epidemiologists.
Epidemiologists are public health professionals who investigate patterns and causes of disease and injury in humans.
Chad Masters, epidemiologist with Hancock Public Health, said a local investigation typically starts with a report from a lab, usually Blanchard Valley Hospital.
But not all diseases are “reportable.” Influenza, for example, is reportable to Hancock Public Health in certain circumstances, such as a hospitalization or the death of a child. But not every case of someone sick with the flu is reported.
Masters said his office follows up with the laboratory, as well as the health care provider who ordered the lab work. Epidemiologists might initially ask questions such as whether the victim works in food service, or if the sick person is a child, if they attend day care.
Investigators might seek information on what animals the victim had come into contact with, or where they might have come across contaminated water.
Masters said the team then communicates with the state through a secure database. He monitors it daily, regardless of whether an outbreak is happening.
Salmonella is always reportable. Most salmonella cases in the U.S. come from food, the CDC says. Individuals can also get it from handling turtles and snakes, or from not cooking poultry thoroughly. So, a similar investigation might lead to a pet store, Masters said.
In the case of salmonella, state health officials actually conduct the initial interview, and they did so in the case of the local woman, Masters said. The interview takes about 30 to 45 minutes.
This was then followed by a 14-page questionnaire that looks at specific types of produce. This led to the realization that consuming pre-cut melon was something the sick people had in common.
Masters said salmonella is spread through fecal contamination of some kind, which could mean water that had somehow been contaminated got into contact with the produce, or that there was cross-contamination at the processing plant.
He said some of the cases in this outbreak occurred in April, but most were between May 9 and May 17. Sometimes it isn’t until a month or two later that all the pieces of the puzzle are put together.
Technology plays a major role, Masters said. The state has a disease reporting system, and the CDC has a national system. This allows the agencies to see links between cases, and to search the database for information.
“That really does help out a great deal,” Masters said.
He said there’s also a “good working network” of epidemiologists in Ohio, including northwestern Ohio. So if there was some sort of outbreak affecting several Ohio counties, Masters and his counterparts elsewhere would be in contact.
In fact, he said epidemiologists in Lucas County and in southern Michigan regularly cross the state line to collaborate on solving puzzles, “which is really what it’s about.”
Masters has been in his current position full-time since 2010. Hancock County had previously contracted with Seneca County for an epidemiologist. He said the work is rewarding and involves “a lot of investigative work.”
He said many people aren’t aware of the testing that’s done, such as the CDC genetically matching to determine if it’s the same strain.
It’s “extremely important” to make sure that you get it right, if you’re asking a company to recall what might be millions of pounds of some type of food, he said.
People who purchased pre-cut melon from one of the stores involved in the recall should take it back to the store or throw it away, said Hancock Public Health Commissioner Karim Baroudi.
Masters said while it’s important to be aware of this outbreak, it’s also important to go about your life and recognize that the U.S. food system is generally safe. You don’t have to avoid eating melon forever, just as you don’t need to stop buying romaine lettuce, which was linked not long ago to an outbreak of a different bacteria, E. coli.
People can also prevent disease through good food-handling practices. This includes hand washing, and not chopping a salad, say, on a cutting board that just housed raw chicken.
“We learn from the outbreaks” and see gaps that might be addressed in the future, Baroudi said.