Blue Bell officials say they are still finding Listeria bacteria in their facilities, but that their enhanced cleaning procedures are working.

"Because Listeria is commonly found in the natural environment, no manufacturer can ever assume it can be entirely eradicated," the company says in a written statement on their website. Blue Bell says none of its products shipped since their August relaunch have contained the food-borne bacteria, but adds that "no manufacturer can ever assume [Listeria] can be eradicated."

Blue Bell recalled all of its ice cream and other frozen dairy products in April 2015 after three people in Kansas died and 10 people across four states were hospitalized in connection with the Brenham-based creamery's Listeria outbreak. Shortly after the recall, the Centers for Disease Control revealed Listeria had also been linked back to cases as far back as 2010.

Released yesterday, the company defends its current sanitation practices and its "seek and destroy" goals to eradicate Listeria from processing plants:

We have worked closely with our expert team of microbiologists to develop an enhanced, robust testing system specifically designed for each facility to identify any possible presence of Listeria in the production environment, including extensive environmental testing and testing every single batch of ice cream we make before it is sold to customers. We are pleased that our enhanced environmental and product testing procedures are working. We have identified locations where suspected Listeria species may be present in our facility, and we continue to extensively clean and sanitize those areas and make additional enhancements to the facility and our procedures based on the environmental test results. To confirm that our robust environmental program is effective, and that our “seek and destroy” goals are being achieved, we expect to periodically find microbiological indications in our facilities. Since our plants reopened, we have tested and will continue to test every batch of ice cream produced, and no products produced have tested positive for Listeria.

According to the CDC, the bacteria is difficult to control, particularly for food processing facilities, because it thrives at low temperatures that would kill other food-borne bacteria and can hide "unnoticed" on appliances and equipment.