The Salmonella Heidelberg outbreak linked to Foster Farms chicken has now sickened over 500 people in 25 states and Puerto Rico, according to the Centers for Disease Control and Prevention.

NBC Health reported that the Salmonella Heidelberg outbreak has increased by 43 cases between March 1, 2013, and April 7, 2014. The new additions bring the total number of cases to 524, the CDC revealed on Wednesday. Health officials are blaming recently purchased raw poultry for the increases in cases.

Seventy-six percent of the cases have been reported in California. The new illnesses were reported in five states: Arizona (2), California (34), Michigan (1), Texas (2) and Washington (1).

The outbreak increased the number of individuals infected with seven outbreak strains of Salmonella Heidelberg. Thirty-seven percent of infected individuals have been hospitalized because the strains are resistant to antibiotics, including ampicillin, chloramphenicol, gentamicin, kanamycin, streptomycin, sulfisoxazole, and tetracycline. 

"Basically, what we're saying is the outbreak is not over," Dr. Rob Tauxe, the CDC's deputy director of foodborne, waterborne and environmental diseases, said. "As the new cases have been reported, almost all of them report eating chicken and almost all say it's Foster Farms."

Patron affected by the outbreak range in age from less than 1 year to 93 years, with a median age of 18 years; fifty-one percent are male. Only 13 percent have developed blood infections as a result of their illness and five percent develop blood infections. No deaths have been linked to the Salmonella Heidelberg outbreak.

NBC reported that despite the illness, Foster Farms has not recalled any products associated with the ongoing outbreak, stating that the company does not have the "definitive link" needed to push a recall. USDA's Food Safety and Inspection Service said it is "assessing interventions implemented at Foster Farms facilities to prevent future illnesses."

"Foster Farms is committed to leadership in food safety and producing the safest chicken on the West Coast," Foster Farms noted in a press release on Wednesday. "Since October 2013, Foster Farms has developed a multiple-hurdle approach to reduce or eliminate Salmonella at each stage of production - from screening breeder flocks before entering the Foster Farms system, to farms where the birds are raised, to the plants where the chicken is processed as a whole bird and when it is cut into parts. As a result, the company has steadily reduced the prevalence of Salmonella at the parts level toward a goal of less than 10 percent - well below the USDA-measured industry benchmark of 25 percent."

One of the largest Foster Farms plants in California was shut down several times after health officials found the factory was infested with live cockroaches during various times over the last five months.

Salmonella is a bacterium that can cause diarrhea, cramps and fever and sometimes chills, nausea and vomiting for up to seven days. To ensure food safety customers must cook poultry thoroughly at a temperature of 165 degrees Fahrenheit.