DPH: Health Alert – Alpha-gal Syndrome/Lone Star Tick Bite Now Reportable in Delaware
Delaware Public Health officials have confirmed six cases of Alpha-gal Syndrome in the First State – and AGS is now reportable in Delaware. AGS is not caused by an infection – but is an allergic condition and is associated with the bite of a lone star tick – but may be caused by other types of tick bites as well. The lone star tick is the most common species of tick in Delaware. Affected persons become allergic to the alpha-gal sugar molecule in mammalian meat and dairy products. AGS is a serious and potentially life-threatening allergic condition, with symptoms and severity varying among persons. Symptoms generally appear two to eight hours after eating foods or being exposed to other products containing alpha-gal.
Additional information from DPH:
Background
AGS is an emerging, tick bite-associated allergic condition characterized by an immunoglobulin E (IgE)-mediated hypersensitivity to galactose-alpha-1,3-galactose (alpha-gal), a sugar molecule found in most non-primate mammalian meat and products derived from these mammals. It is also known as mammalian meat allergy, alpha-gal allergy, red meat allergy, and tick bite meat allergy.
AGS is a serious and potentially life-threatening allergic condition, with symptoms and severity varying among persons. Symptoms generally appear two to eight hours after eating foods or being exposed to other products containing alpha-gal (for example, mammalian meat and dairy products). AGS is associated with the bite of the lone star tick, Amblyomma americanum, in the United States. The lone star tick is Delaware’s most abundant species of tick.
Clinical Characteristics
AGS is characterized by a delayed onset of symptoms following ingestion of mammalian meat or products made from mammals. The allergic reactions can occur two to eight hours after exposure to the allergen. The clinical spectrum of AGS is broad with symptoms ranging from hives and gastrointestinal distress to angioedema and life-threatening anaphylaxis. Delaware patients have had the following signs and symptoms:
•Abdominal pain
•Nausea
•Diarrhea
•Vomiting
•Acute episode of hypotension
•Dizziness
•Itching
•Hives
•Heartburn/indigestion
•Swelling
•Shortness of breath
•Anaphylaxis
Diagnosis
AGS is typically diagnosed by an allergy specialist or other health care provider through a detailed patient history, physical examination, and an Allergen-Specific Immunoglobulin E (IgE) test that tests for alpha-gal IgE levels.
There is no definitive IgE level that confirms AGS diagnosis. Patients can have sensitization to alpha-gal without clinical reactivity, and only a fraction of patients with alpha-gal IgE experience allergic reactions.. Even though the presence of alpha-gal IgE is an established diagnostic criterion, levels do not correlate directly with symptom severity and not all patients who test positive for alpha-gal IgE will have AGS. Unlike most other food allergies, AGS signs and symptoms have a delayed onset after ingesting the allergen/offending food types and this can make diagnosis even more difficult.
Recommendations for Prevention
Preventing tick bites is the most important method to reduce the risk of the development of AGS and other tick-borne diseases. Additional tick bites may worsen or reactivate allergic reactions to alpha-gal. Educate patients to avoid tick bites by doing the following:
•Avoid wooded or brushy areas with high grass and leaf litter.
•Stick to the center of trails.
•Treat clothing with products containing 0.5% permethrin or use EPA-registered insect repellents containing products like DEET. Always follow label instructions.
•Perform tick checks on themself, children, and pets after being outdoors.
•Shower within two hours of coming indoors and tumble dry clothes in a dryer on high heat for10 minutes to kill ticks.
•Keep pets up to date on tick preventive products.
Recommendations for Management of AGS
As with any severe allergy, patients with AGS should work with their health care providers to develop a multi-faceted approach, including a management plan which should include preventing additional tick bites, a diet without mammalian meat and mammalian meat products, and use of rescue medications such as antihistamines and epinephrine auto-injectors. It is important to note that not all patients have reactions to every ingredient containing alpha-gal. Moreover, certain types of meat, meat products, and cuts of meat contain more alpha-gal than others. People with AGS who need to avoid eating meat from mammals can continue to eat chicken, turkey, fish, and other non-mammalian meats because those meats do not contain alpha-gal.
Reporting
Report any suspected cases of AGS or patients with laboratory evidence of AGS by completing the CDC case report form and emailing it to reportdisease@delaware.gov, or by calling the Office of Infectious
Disease at 1-888-295-5156. We encourage physicians to complete and communicate the
CDC case report form with all relevant signs and symptoms and exposures to assist the DPH with their investigations.
More Information
•CDC, About Alpha-gal Syndrome: https://www.cdc.gov/alpha-gal-syndrome/about/index.html
•DPH, Alpha-gal Syndrome Frequently Asked Questions: https://dhss.delaware.gov/dph/files/AlphaGalSyndrome_FAQ_PUB_ENG_1123_.pdf
