Wikipedia

It was found that three cooks [on land] had prepared the meals, one of whom had infected lesions on the index and middle finger of his right hand.[2] The lesions on the cook's fingers were found to be infected with staphylococci. Tests revealed identical phage types and antibiotic resistances for all samples, indicating that the cook was the source of the contamination. ... He had bandaged the lesions but not reported them to his superior, as he considered them trivial. Also, management had not verified that he was in good health, despite being required to do so ...

... Prior to being served, the meals had been stored at room temperature in the kitchen for 6 hours, then refrigerated (albeit at an insufficient 10 °C (50 °F)) for 14½ hours and then stored in the aircraft ovens, again without refrigeration, for another 8 hours. Had the food been kept properly refrigerated from the time it was prepared until it was ready to be served, the outbreak would not have occurred.

Readers of Admiral Cloudberg will know that typically several things have to go wrong for aviation disasters to happen. In this case:

• the cook did not properly manage or report their hand injury
• the cook's supervisor did not verify that the cooks were in good health
• the meals were not properly stored