As you may remember from my previous article, reports were received from the Eastern Cape of people avoiding red meat because of alleged allergic reactions.
Red meat allergy can either be an allergy to different types of meat protein (pork, beef, goat or mutton), or it can be an allergy to a carbohydrate found in red meat, called Galactose-alpha-1,3-galactose or, Alpha-gal. These sugars/carbohydrates are protein linked and allergies to them have been identified in other parts of the world.
Ticks have been identified as a possible transmitter of Alpha-gal, so we included Ali Halajian, a veterinarian doctor from Limpopo university in our team to collect ticks and to identify various species.
Other parasites like worms and scabies are also possible ‘transmitters’ of the allergy and it was decided to do skin scrapings and to test all participants’ blood for Ascaris.
Symptoms of Alpha-gal allergy include urticaria (a very itchy rash with hives), stomach cramping, diarrhoea and, to a lesser extent, difficulty in breathing, typically several hours after the ingestion of meat of mammalian origin. In fact, alpha-gal allergy is often dubbed “midnight anaphylaxis,” as typically symptoms occur in the middle of the night several hours after a meat-based evening meal.
The Red Cross Children’s Hospital allergy study team spent just over six weeks in the rural Eastern Cape carrying out this Alpha-gal study. The first few days were spent setting up a field laboratory in the front room of a rented house, and visiting the various clinics to remind them of our appointments and plans.
Once we started seeing participants we were overwhelmed with the amount of people not eating red meat due to their perception of being allergic. A questionnaire was completed with a research team member. This questionnaire asked about demographics of the participants, clinical symptoms, when they first had a reaction, the nature of that reaction, type of red meat eaten as well as a history of exposure to tick bites, scabies and parasite infection. Blood was taken from all participants and was analyzed for Alpha Gal, Beef, Pork, and Mutton. We also tested for parasites (Ascaris) and did a Total IgE. Those with a positive Alpha Gal were taken into Zithulele Hospital for a food challenge and those with a negative blood result were given meat to eat under supervision in the clinic as a way of instilling confidence that they were not allergic and so could resume eating meat.
Difficulties in the study included getting patients from far reaching areas to come to the hospital for food challenges, and very often we would be out before sunrise picking up patients and driving them home after sunset. Participants were observed for eight hours after ingesting the meat and all reactions were treated and recorded. Another challenge was getting those participants whose blood tests were negative, or those who had passed the food challenge, to feel safe about eating meat again. Some participants had not eaten meat for many years and one particular woman who had severe reactions during the food challenge had not eaten meat for 40 years! Follow-up care for allergic participants also needed some consideration and all patients who we found to be allergic were given action plans with emergency phone numbers and instructions on what to do in the case of accidental ingestion. Hospital staff and clinics in the area were also informed of our findings.
The overall results of the study are as follows:
- 150 participants were assessed
- 84 participants were diagnosed with alpha-gal allergy
- 82 of those we diagnosed by a positive oral food challenge (OFC) and two of them because they had a very high alpha-gal blood result and recent severe symptoms after eating meat.
We would like to thank the team; Prof. Mike Levin, Dr. Tshegofatso Mabelane, Dr. Maresa Botha, Lerato Ntsukunyane, Heidi Facey-Thomas, Ali Halajian and his student Michael, Wisdom Basera and Jo Ramjith.
We would also like to give special thanks and appreciation to ThermoFisher and in particular Anton Jansen, JC Stoltz and Jacqueline Lillabet for their time and support during our entire stay in the Eastern Cape. As well as to all of those who facilitated our study while we were in the Transkei, and of course to those who volunteered to participate.