A salmonella outbreak linked to egg shells has triggered a recall of 13 brands of eggs throughout the US. Iowa based company Wright County Eggs issued the recall August 13 after illnesses were confirmed in Minnesota, Colorado, and California. The possibly tainted eggs are date-stamped between May 16 and August 13, and many states have reported increases in the cases of salmonella enteritidis since May. The illness can cause fever, cramps, diarrhea, and more serious consequences in people with compromised immune systems. The US Food and Drug Administration is conducting an investigation into the Iowa firm.