Iowa Department of Public Health Medical Director Patricia Quinlisk announced today that an Iowa woman contracted listeriosis by eating cantaloupe from a Colorado farm at the center of a widespread outbreak.

IDPH officials did not reveal the name of the person who contracted listeriosis, but said the patient was a pregnant woman in northwest Iowa. She survived the bacterial infection that has killed at least 18 people across the country and sickened dozens more, but she miscarried the pregnancy. Rod Boshart reported that the woman had purchased a cantaloupe in Iowa that came from Jensen Farms.

“While Jensen Farms has issued a voluntary recall of its Rocky Ford-brand cantaloupes, and the recalled items should be off store shelves, more illness may be reported because it can take up to two months for a person to develop listeriosis after eating contaminated food,” said IDPH Medical Director, Dr. Patricia Quinlisk. […]

Healthy adults and children occasionally get infected with Listeria, but rarely become seriously ill, Quinlisk noted. Pregnant women, however, are about 20 times more likely than other healthy adults to get listeriosis. Older adults, newborns and adults with weakened immune systems are also in a high risk group, she noted.

The most important way to avoid listeriosis and other food borne illnesses associated with fruits and vegetables is to make sure you thoroughly wash them, even if the item has a skin or rind, Quinlisk advised. Any bacteria on the outside of the fruit or vegetable can be pulled to the inside when the knife slices through. For melon safety in particular, follow these steps:

Individuals and food preparers should wash their hands with warm water and soap for at least 20 seconds before and after handling any whole melon, such as cantaloupe, watermelon, or honeydew.

Scrub the surface of melons, such as cantaloupes, with a clean produce brush or dish cloth and dry them with a clean cloth or paper towel before cutting.

The U.S. Centers for Disease Control had previously reported Listeria illnesses from contaminated cantaloupe in the following states: Alabama, Arkansas, California, Colorado, Idaho, Illinois, Indiana, Kansas, Maryland, Missouri, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, Texas, Virginia, West Virginia, Wisconsin, and Wyoming.

Jensen Farms of Holly, Colo. recalled its cantaloupes Sept. 14 after the farm’s melons were traced to the Listeria illnesses. The farm says it shipped cantaloupes to 28 states, though the FDA has said it may be more. Illnesses have been discovered in states that were not on the shipping list and company officials have said the product is often resold, so it’s hard to track.

FDA Commissioner Margaret Hamburg said Tuesday that the agency is still investigating the cause of the outbreak. Officials have said they are looking at the farm’s water supply and possible animal intrusions among other things in trying to figure out how the cantaloupes got contaminated. Listeria bacteria grow in moist, muddy conditions and are often carried by animals.