I found a peanut in my pap!

In today’s headlines: 

While having breakfast at home, a man had to be rushed to hospital due to severely swollen lips and blocked airways.

Mr. Naidoo was hospitalized and treated for an acute allergic reaction. During an interview with Mrs. Naidoo, we learned that he had been eating muesli and yoghurt, his normal breakfast meal, when the emergency situation occurred. According to Mrs. Naidoo, her husband has an acute peanut allergy, but is very thorough in checking food labels to make sure that he does not eat anything that could possibly lead to a lethal reaction. Further investigation led us to FACTS, who gave us some helpful information and insight into how the food industry could avoid these situations.

Newspaper: “Dr Steinman, please tell us what you suspect caused Mr. Naidoo’s allergic reaction, and how this came to be?”

Dr Steinman: “Well, it seems that Mr. Naidoo had an allergic reaction to something he ate – which, considering the patient’s medical history, was most probably peanut. Reactions like these, worst-case scenario, can sometimes lead to anaphylaxis – a severe life-threatening reaction – and death.”

Newspaper: “According to Mrs. Naidoo, this was a peanut- and tree-nut-free muesli; and her husband is allergic to peanuts, but nothing else. The manufacturer of the muesli was contacted for comment, and explained that the product was tested for peanut and that the testing laboratory had found no traces of peanut present in the product. As the director of an allergen-testing laboratory, Dr Steinman, can you perhaps explain how this could be possible? Surely if no peanut was found via testing, then there should be no peanut in the product?”

Dr Steinman: “There are multiple reasons that could possibly provide an answer. These could include the sample size tested, the preparation of a completely homogenous test sample, meticulous execution of Standard Operating Procedures, data interpretation, the number of samples tested, and single versus duplicate testing, to name but a few. It is possible that a whole peanut or a large piece of peanut might have been present in the product that was not detected during testing. This can happen when allergen cross-contamination is present in the product or sample in ‘particulate’ form, and is ‘missed’ because of an inadequate test sample. A common way to reduce the risk of this and to increase accuracy is to do multiple tests per sample.”

Newspaper: “Please tell us more about the presence of ‘particulates’.”

Dr Steinman: “As people react differently to allergens (some are more sensitive than others), allergens need to be considered in a different way. The concentration of the particular protein consumed by the allergic individual needs to be considered. For example, one peanut could be present in a product, but may have been ground to a fine powder and distributed evenly throughout the product, yielding a low ppm concentration of the allergen. But if that same peanut or particulate is ingested whole by the individual, there is an intake of a high ppm concentration of the allergen.”

Newspaper: “How can performing multiple tests on a sample reduce the risk of not detecting the presence of an allergen present in particulate form?”

Dr Steinman: “When doing allergen testing, duplicate results conforming to each other increase confidence in the result. Inconsistencies often indicate the presence of particulates. When performing only a single test, the risk of not detecting particulates is higher, as there is no other result with which to compare it.”

We want to thank Dr Steinman for providing us with a little more information on the topic. Who would have thought that the difference between duplicate and single testing might sometimes also mean the difference between life and death?

In a nutshell, duplicate (sometimes triplicate) testing has many advantages, including:

1. Result verification 
   Comparable results increase confidence in the test method, analysis and obtained data.
2. Adding to the confidence that the test run has produced good data 
   Comparable results do not always indicate accuracy; therefore, it is very important to include reference materials with known concentrations to validate testing methods.
3. Assessing a laboratory’s repeatability 
   It is essential to show that a laboratory can produce similar results for a test that is repeated on different days of the week.
4. Assessing inter-laboratory variation
   It is important to determine the inter-laboratory variation between different analysts working within a laboratory to ensure consistent data is produced.