–by Dr. Raymond Cloyd
We have received several inquiries regarding information pertaining to the relationship between tick bites and allergic reactions after eating meat, which doctors have called the ‘Alpha-Gal Syndrome.’ The information is correct. What happens is that the gut of a lone star tick, Amblyomma americanum (Figure 1),
Fig 1. Lone star tick female (Author–Pestworld.org)
after feeding on a mammal; such as a raccoon or mouse, becomes filled with a carbohydrate-based molecule called alpha-galactose or alpha-gal. Alpha-galactose enters the body when an infected lone star tick feeds/bites a human, which stimulates the immune system to produce antibodies that will ward-off the molecule. Consequently, if the immune system encounters alpha-galactose again, then a potentially life-threating allergic reaction may ensue. So, what is the problem? Well, many meat products including beef (Figure 2)
Fig 2. Beef tenderloin (Author–delish.com)
and pork contain alpha-galactose, and anyone having been bitten by a lone star tick, and then later on consuming meat may develop an allergic reaction. However, fish and chicken can be eaten without concern because they do not have the antigens associated with alpha-galactose. Therefore, it is important to protect yourself in order to avoid being bitten by ticks, in this case, the lone star tick, by taking the recommended precautions (e.g. use repellents, wear light-colored clothing, tuck pant legs into white socks, and inspect yourself after having returned from wooded areas) so you can continue to enjoy eating meat at home or at your favorite restaurant.