In the largest salmonella scare in years, more than 32 million one-dozen cartons (as of press time) have been recalled, and this figure is likely to grow. The Centers for Disease Control and Prevention (CDC) is working with state health departments and the Food and Drug Administration to investigate the illnesses.

Since May, the rash of salmonella outbreaks in eggs appears to be ongoing, according to Atlanta-based CDC. The problem has been pegged to in-shell eggs from Wright County Egg in Galt, Iowa. The recall covers eggs packed from May 16 and Aug. 13 and were distributed around the country, packaged under the names Lucerne, Albertson, Mountain Dairy, Ralph’s, Boomsma’s, Sunshine, Hillandale, Trafficanda, Farm Fresh, Shoreland, Lund, Dutch Farms and Kemp.

A second producer, Hillandale Farms of New Hampton, Iowa, also is recalling some 170 million eggs, bringing the total from the two producers to about a half-billion eggs. The recalled eggs were reportedly sold in Arkansas, California, Iowa, Illinois, Indiana, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, Texas and Wisconsin.

Much of the investigation was originally centered on restaurants in California, Colorado and Minnesota where reports of illness have occurred, but many states have reported increases since May. The form of salmonella in question can be passed from chickens that appear healthy, and grows inside eggs and on the shell, the CDC reports.