Staphylococcal contamination of intact, hard-boiled eggs resulted in the food poisoning of an estimated 300 children out of 850 who had participated in an Easter egg hunt. Enterotoxigenic staphylococci that were isolated from the Easter eggs matched that obtained from an infected cook who prepared the eggs three to five days before the hunt and which he left unrefrigerated. Experimental studies demonstrated that heated eggs can absorb 2 mL of contaminated cool water through intact eggshells. When water was inoculated with pathogenic staphylococci at even low contamination levels, rapid growth and enterotoxin production within cooked eggs could be easily duplicated. This is the first large outbreak of its type; safeguards can and should be employed to prevent future ones.
Merrill GA, Werner SB, Bryant RG, Fredson D, Kelly K. Staphylococcal Food Poisoning Associated With an Easter Egg Hunt. JAMA. 1984;252(8):1019-1022. doi:10.1001/jama.1984.03350080021020