A snippet from the Prevent Disease link:
Emphasis is mine.

"Susan Wolver, MD, and Diane Sun, MD, from Virginia Commonwealth University in the US, and colleagues, explains why if you have been bitten by a tick, you may now develop an allergy to red meat. Their article elucidates this connection and discusses the journey of the discovery, yet stop short of emphasizing how these ticks were genetically designed. It's a new syndrome and natural consequence of the interaction of human blood and being bitten by modern ticks they say.

Delayed anaphylaxis -- a severe, life-threatening allergic reaction -- to meat has been identified initially in the southeastern United States. Patients may wake up in the middle of the night, with hives or anaphylaxis usually three to six hours after having eaten red meat for dinner. Until recently, the link between red meat ingestion and anaphylaxis had remained elusive."