The Centers for Disease Control and Prevention released the updated numbers on Wednesday. The agency reported in January that the outbreak appeared to be over. It has been going on since March 2013.
The CDC noted an uptick in illnesses in February.
The outbreak led to a public health alert from the U.S. Department of Agriculture for raw chicken packaged at three Foster Farms facilities in California.
Though no one has died, the CDC says the outbreak strains have been resistant to several commonly prescribed antibiotics.
Foster Farms says it has implemented a salmonella control program that has reduced the prevalence of salmonella in its products.