Promoting the Vegetarian Lifestyle

Lone Star Tick

Lone Star Tick
Photo: CDC

The lone star tick, Amblyomma americanum is associated with deer populations in the Southeastern US. By the middle of the 20th century, deer populations had been hunted almost to extinction in some areas. Subsequent efforts to protect the deer population by restrictions on hunting were completely successful to the point where deer can be pests of suburban landscapes. Populations of ticks associated with deer, including the Lone Star Tick, Amblyomma americanum have expanded as the deer population expanded. Diseases associated with ticks that feed on humans in addition to deer have also expanded.

When ticks and other arthropods feed on blood, they inject saliva into the feeding site. Saliva contains proteins that can trigger a response from the immune system. It is the immune response that creates the red area around a bite.  The antibodies produced by individuals vary, causing individual response to vary.   It is now confirmed that some individuals respond to bites of  the Lone Star Tick by elevating antibodies that cross react to factors present in red meat.  Tick bite victims who have eaten red meat all their adult life suddenly find that it triggers an allergic response, some experiencing  anaphylaxis.  These individuals have no choice but to avoid red meat.

The link between tick bites and red meat allergy was found by Commins & colleagues* who were interested in allergic reactions to an antibody treatment for cancer. Patients with allergic reaction were concentrated primarily in the Southeast US. The allergen, galactose-a-1,3-galactose (alpha-gal), had been identified and patients with reaction to the cancer treatment had elevated levels of antibody to alpha-gal.  In the process of investigating reactions to cancer therapy, their research uncovered a correlation between elevated antibody levels and allergy to red meat.

People who had eaten red meat for years without issue, were reporting severe reactions to the consumption of red meat. Some agent had caused their immune system to develop high levels of antibody that cross reacted with red meat. Commins & colleagues unsuccessfully investigated several pathogens and parasites in an effort to identify the mystery agent.  Their success in identifying the Lone Star Tick as the causative agent was aided by patients who reported tick bites shortly before the onset of allergy symptoms. Commins & colleagues tracked serum samples of patients before and after reported tick bites and found that the antibodies were orders of magnitude higher after the tick bite.  Additional research has solidified the evidence that Lone Star Tick is the culprit.

Tick bites are associated with a number of diseases that are best avoided.   Those spending time in tick infested areas should use precautions such as protective clothing and appropriate repellents.  Ticks often rest before feeding.  Use timely “tick checks” to remove ticks from the skin before they commence feeding.

Commins & colleagues. May 2011.  The relevance of tick bites to the production of IgE antibodies to the mammalian oligosaccharide galactose-α-1,3-galactose. Journal of Allergy and Clinical Immunology. 127: 1286–1293.

About jjneal

Jonathan Neal is an Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
This entry was posted in Biomaterials, by jjneal, Environment, Health. Bookmark the permalink.

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