It's like a zombie film in reverse; an outbreak of ticks is succeeding where environmental statistics, health warnings and pictures of cute animals have failed – turning hardened meat eaters vegetarian.
Known as the Lone Star tick (Amblyomma americanum), the tick caries a variety of diseases, such as Rocky Mountain Spotted Fever, although it is not a carrier of Lyme Disease, by far the best known tick-borne infection.
However, the tick's most interesting feature is the capacity to make people allergic to meat. The ticks carry alpha-gal (Galactose-alpha-1,3-galactose), which may sound like a superhero, but is actually a type of sugar found in non-primate mammals.
Under normal conditions the stomach digests alpha-gal without negative effects. Alpha-gal in the bloodstream is a different matter. The immune system creates antibodies against it. The next time the body encounters alpha-gal it responds as though the sugar really was a superhero and the antibodies were the villain's minions. This can occur whether the alpha-gal is now in the bloodstream or the digestive system.
The intensity of the reaction varies, but in severe cases includes an inability to breathe and a feeling of being on fire every time the person eats meat.
The association was first made when an infestation of a different species of tick produced similar symptoms in Australia seven years ago. Warnings were sounded in February, but this summer has really seen the number of cases take off. The tick is spreading across the United States and has become particularly common on Long Island, bringing increasing numbers of people within range of its ravenous bite. Allergist Dr Erin McGintee reports seeing 200 cases from the island in the last three years.
Those with the allergy can still eat fish or chicken, but some dairy products can also stimulate a reaction – or even vegetable products cooked in beef fat. While allergists are unsure whether the allergy will wear off with time, those who have been hospitalized and need to carry EpiPens in case they ingest a small quantity of meat products may not be too keen to test if they have recovered, particularly since reactions often get worse each time a person is exposed.
McGintee warns that the reaction can take up to eight hours after eating meat, making it hard to identify the trigger.