Several brands of soft cheeses have been recalled by a California company in the wake of a Listeria outbreak that has sickened at least 24 people in 9 states and killed one, the Centers for Disease Control reported.
The CDC is working with state health officials to investigate the outbreak, which first arose on August 8, 2010. Of the 24 individuals that were sickened, 21 had to be hospitalized and 1 death was reported in Ohio. Five of the patients were female, and one of them lost her fetus. It’s possible, however, that there are more cases that haven’t been reported yet. 
Dr. Robet Tauxe, deputy director of the CDC Division of Foodborne, Waterborne and Environmental Diseases, says that 1 more case likely exists for every case that investigators know of.
Federal authorities detained goat cheese, feta, and string cheese and stuffed chicken products this week as part of the investigation. The soft cheese is believed to be the source of the contamination. 
In August, the CDC noticed an uptick in a rare DNA fingerprint of listeria in the agency’s national database of the DNA fingerprints of bacterial strains from people sickened by food-borne illness. The database helps federal health officials identify possible outbreaks.
Using whole genome sequencing technology, the CDC was able to identify 4 DNA fingerprints that were closely genetically-related and potentially connected to listeria infections that were reported 5 years ago.
Cases of listeria have so far been reported in California, Colorado, Illinois, Massachusetts, Michigan, New York, Ohio, Tennessee, and Washington. Investigators aren’t certain that soft cheeses are to blame for the outbreak, but the majority of infected individuals said they had eaten soft cheese just before falling ill. Four of the 7 individuals reported a specific brand of cheese that they ate, all of which were distributed by Karoun Dairies. None of those products tested positive for listeria, but the company has since issued a voluntary recall and has halted production of certain cheeses. 
The affected cheeses were sold under the brand names Karoun, Arz, Gopi, Queso Del Valle, Central Valley Creamery, and Yanni. The products are vacuum-packed and sold in jars or pails.
Listeria can be difficult to eliminate because the bacteria can live for years in cracks and crevices. The Listeria bacteria cause an illness called listeriosis that leads to fever, muscle aches, and gastrointestinal problems. In severe cases, it can cause meningitis, which three of the outbreak’s youngest victims have been diagnosed with.
Pregnant women, newborns, elderly people and individuals with a weakened immune system are the most at risk for serious illness.
 USA Today