Immediate Symptoms Spark Concern (Image Credits: Pixabay)
Spain – Several foodborne outbreaks struck nursery schools across the country in 2023 and 2024, affecting children under 3 years old who consumed chicken-based meals.[1][2] Testing of the implicated foods uncovered elevated levels of biogenic amines, prompting a detailed investigation by the Scientific Committee of the Spanish Agency for Food Safety and Nutrition (AESAN). These incidents revealed potential gaps in poultry handling that could pose risks to the youngest eaters.[3]
Immediate Symptoms Spark Concern
Children experienced reactions within minutes of eating the meals. Redness appeared around the mouth, sometimes extending to the hands, accompanied by rashes, hives, and intense itching.[1] The symptoms resolved quickly without medical intervention, but their rapid onset pointed to a clear food trigger.
Investigators traced the cases to dishes like stewed chicken thighs and chicken in sauce. No unusual odors were noted during preparation, and school practices showed no obvious faults. Yet, multiple suppliers’ chicken tested positive for high biogenic amine levels in both raw and frozen forms.[2]
Understanding Biogenic Amines in Poultry
Biogenic amines form when bacteria break down amino acids in protein-rich foods such as chicken. Common types include histamine, tyramine, putrescine, and cadaverine, which signal microbial growth and reduced quality.[1] Chicken proves particularly prone due to its composition, especially if stored improperly.
Studies on fresh chicken pieces stored at refrigeration temperatures showed rising concentrations over time. For instance, thighs held at 4°C for six days reached putrescine levels of 12 to 22 mg/kg and cadaverine up to 80 mg/kg. Processed products exhibited even higher peaks, with putrescine surpassing 3,500 mg/kg in some cases.[2]
Outbreak Samples Show Elevated Levels
Laboratory analysis of foods from the incidents confirmed the presence of these compounds. Histamine ranged from under 10 mg/kg to 119 mg/kg, while tyramine hit 265 mg/kg in one breast sample.[1] Such findings exceeded typical thresholds, particularly when considering portion sizes for young children.
The table below summarizes select outbreak data for a 40-gram serving portion, highlighting contributions to acute reference doses (ARfD):
| Outbreak | Food Item | Histamine (mg/kg) | % ARfD (0-1 yr) | Tyrimine (mg/kg) | % ARfD (0-1 yr) |
|---|---|---|---|---|---|
| 1 | Stewed chicken | 22-34 | 39-118% | 58-60 | 5-6% |
| 2 | Chicken in sauce | 38 | 43% | 89 | 8% |
| 8 | Chicken breast | 119 | 133% | 265 | 25% |
These levels suggested poor initial quality or mishandling during transport and storage.[2]
Young Children Prove Most Vulnerable
Toddlers under 3 years carry heightened risks from biogenic amines. Their immature diamine oxidase (DAO) enzymes limit detoxification, and lower body weights amplify exposure from small meals.[1] AESAN adjusted ARfD values – 3.57 mg histamine and 42.86 mg tyramine for ages 0-1 – showed some samples pushing or surpassing limits.
While adults tolerate 25-50 mg histamine per meal, children demand caution at levels tenfold lower, around 2.5 mg/kg for histamine. Combined amines may worsen effects through synergy.[2]
Clear Path to Safer Poultry Handling
The AESAN committee outlined preventive steps to curb future risks. Operators must prioritize fresh, hygienically superior raw materials and maintain a strict cold chain at 0-4°C.[1]
- Limit chicken use to within five days post-slaughter.
- Implement good manipulation practices and staff training.
- Manage stocks tightly and plan menus to avoid prolonged storage.
- Monitor microbial loads and amine formation where feasible.
- Explore aids like high-pressure processing or natural antimicrobials.
These measures align with EU hygiene regulations and target the full supply chain.[2]
The outbreaks, though mild in outcome, exposed how everyday foods like chicken can harbor hidden threats when quality falters. Spanish authorities now stress proactive controls to protect nursery menus. Key takeaways include recognizing biogenic amines as quality markers and tailoring safeguards for vulnerable groups.
- High amine levels in chicken signal microbial issues – test and reject suspect batches.
- Children under 3 need stricter limits due to detoxification challenges.
- Cold chain compliance and fresh sourcing prevent most risks.
What steps should nurseries take next? Share your thoughts in the comments.
