Federal officials declared the salmonella outbreak linked to Foster Farms chicken products has affected more people, causing the Centers for Disease Control and Prevention in Atlanta to retract its former statement that the outbreak seemed to be ending.

CDC announced Monday that since Jan. 16, a total of 51 new cases have been reported from five states: three cases in Arizona, one case in Hawaii and Tennessee and two cases in Utah. Forty-four of the new cases were found in California.

"It raises concern that this outbreak may not be over," said Robert Tauxe, the CDC's deputy director for the division of foodborne, waterborne and environmental diseases.

A total of 481 people in 25 states and Puerto Rico have been affected by the outbreak. Patients range in age from less than 1 years old to 93 years old. The first case of illness was reported on March 1, 2013, according to Food Safety News. The most recent cases were reportedly date to Feb. 11. 

The illnesses are tied to chicken processed at three Foster Farms plants in California. Foster Farms did not recall any of its products from those plants, but health officials did mention that the company were developing safety measures for its products.

In January, Foster Farms voluntary shut down its poultry plant after health officials found the factory was infested with roaches during the four visits over the last five months: Sept. 14, Nov. 4, Dec. 28 and Jan. 7.  Health officials cited the factory for "egregious unsanitary conditions." The plant closed and reopened several times following the first volunteer shut down.

According to CDC, the strains of Salmonella Heidelberg linked to the current outbreak are resistant to several prescribed antibiotics.

"Although these antibiotics are not typically used to treat Salmonella bloodstream infections or other severe Salmonella infections, antibiotic resistance can increase the risk of hospitalization in infected individuals," CDC said.

In June 2012, Foster Farms poultry reportedly sickened 134 people in 13 states. According to reports, officials failed to inform the public about the issue at hand. Health officials mentioned there was not enough information to link the outbreak to a specific product.

In October, a second outbreak sickened 389 people in 23 states, with 40 percent of the victims being hospitalized. FSIS stated the problem was that "several of the outbreak strains were resistant to the most common drugs used to treat salmonella infections."

Salmonella is a bacteria that can cause diarrhea, cramps and fever and sometimes chills, nausea and vomiting for up to seven days. A recent Consumer Reports survey of retail chicken breasts found Salmonella on 11 percent of samples.

The company recommends customers to cook all chicken to a minimum of 165 degrees Fahrenheit.