A death that occurred in 2024 has now been confirmed as caused by alpha-gal syndrome (AGS) transmitted by the lone-star tick, following months of investigation. The man’s death had been a mystery because the autopsy showed no indication of a heart attack or other life-threatening illness, but a blood test taken this year showed evidence of an allergic reaction at a level 200 times higher than believed survivable. Further testing showed antibodies to alpha-gal in the man’s blood, which triggers the release of histamines, causing an allergic reaction to consumption of all mammalian meats and products (i.e., red meats including beef, pork, lamb, venison, goat, and rabbit).
As discussed in a TAG public health article in August, the lone-star tick (Amblyomma americanum) is widely spread in much of the Northeast, South, and Midwest US. A bite from an infected tick can cause symptoms ranging from hives, sneezing, stomach pain/nausea, vomiting, diarrhea, and shortness of breath to life-threatening anaphylaxis, which may occur in up to 50% of cases.
Because AGS is still relatively rare, with little awareness among medical professionals, diagnosis is difficult, requiring a blood test, allergy prick test, or physician-controlled oral food challenge. Additionally, symptoms do not occur immediately, as they do with most allergies, but may take two to six hours to develop.
As a potentially life-threatening allergic condition, it is critical to seek emergency medical care if AGS is suspected. For more information, see TAG’s Infectious Disease Fact Sheet on AGS.
Public Health News:
- To date in 2025, in Cambodia, 17 human cases of H5N1 bird flu have been reported; 6 deaths have occurred, according to the Ministry of Health. The most recent death was a man from Phnom Penh. Close contacts are being examined to determine if any illness spread has occurred and antiviral drugs have been distributed.
- A case of H5N5 influenza has been reported in Washington State in an older person with underlying health conditions who kept chickens at his home. This is the first report of illness in a human linked to this subtype although cases in wild birds and domesticated poultry have been detected. Surveillance is continuing to determine if there are additional cases.
- England is experiencing an unusually early influenza season with hospitalization rates at near peak levels in early November 2025. Most affected are young adults and school children. The Influenza A (H3N2) predominant strain has evolved this season with 7 genetic changes that may make it evade some of the protections that people have built up.
- Ethiopia has confirmed its first-ever Marburg virus outbreak, with nine cases. Typically, this virus has a near 50% mortality rate and there is no vaccine or targeted treatment. Health officials are working to contain it quickly. Marburg originates in the bites from fruit bats and is spread through contact with bodily fluids.
- As of November 14, 2025, more than 2,000 cases of acute GI illness have been reported in Brazil, linked to E. coli contaminated well water that affected the municipal water supply. Deficiencies in chlorination were found.
- The first human death from alpha-gal syndrome (AGS) linked to anaphylaxis after red meat consumption has been reported in a man who died in 2024 in New Jersey.
