Measurement / residue studyindependent cross-checkfull text checked★ key study I-CHK-12 in-depth review

Antibiotic residues in Egyptian chicken

Health risk assessment of enrofloxacin, oxytetracycline, and sulfadimidine residues in broiler chicken carcasses marketed in Mit Ghamr, Egypt.

Overview

Noah SM et al.. Sci Rep 2026 · PMID 42527435 · DOI 10.1038/s41598-026-63227-2

Many chicken samples had antibiotic residues above legal limits, especially in liver, but estimated health risk was low.

Does the study support the specific claim? Partly · Methodological quality: moderate

Original publication

Plain-language summary

Study explained simply

What did the researchers want to find out?: Antibiotic residues in chicken tissues and consumer risk
How was the study done?: Cross-sectional residue survey (HPLC) with risk assessment
How many people, animals or samples were studied?: 180 samples (60 breast, 60 thigh, 60 liver); Chicken tissues from poultry shops
What was actually found?: Detected: enrofloxacin 51.67%, oxytetracycline 71.67%, sulfadimidine 16.67%; of positives, 54.84%, 55.81% and 70% exceeded MRLs. Liver had highest levels (e.g., oxytetracycline mean 10,625 ug/kg). EDI 0.012-0.590 ug/kg bw/day; HQ 0.0002-0.050, indicating no significant health risk.
How large was the observed effect?: Descriptive; HQ
What do the results mean in everyday life?: Withdrawal periods are not always respected in some Egyptian supply chains.
What are the study's limitations?: One city; unclear shop selection; no confirmatory LC-MS/MS; risk estimate uses average levels and intakes only; eggs not studied.
What does it say about Elawady's specific claim?: Supports residue concern in Egypt; not toxicity.
Do the results apply to Germany and Europe?: Low (Egypt).
What can explicitly not be concluded from this study?: Cannot generalise nationwide.

Scientific in-depth review

1. Full reference

Authors: Noah SM et al.
Journal: Sci Rep
Year: 2026
Identifier: PMID 42527435 DOI 10.1038/s41598-026-63227-2
Verification: verified – PubMed efetch 2026-10-25
Retracted: no
Corrections: none
Extent checked: full text
Conflicts of interest and funding: Open-access funding by the Egyptian Science, Technology & Innovation Funding Authority (STDF) with the Egyptian Knowledge Bank; authors declare no competing interests.

2. Research question

Antibiotic residues in chicken tissues and consumer risk

3. Study design and population

Study design: Measurement / residue study – Cross-sectional residue survey (HPLC) with risk assessment
Population: Broiler carcass tissues (breast, thigh, liver; carcass ~1.25 kg) purchased from poultry shops in Mit Ghamr City, Dakahlia, Egypt
Country: Egypt (Mit Ghamr)
Period: September to March 2025 (as stated)
Sample size: 180 samples (60 breast, 60 thigh, 60 liver)
Inclusion and exclusion criteria: Samples 'randomly collected' from different poultry shops in one city; number of shops and selection procedure not reported.

4. Methods and endpoints

Exposure / intervention: Antibiotic residues
Comparator: MRLs
Endpoints: Detection; MRL exceedance; EDI; HQ
Statistical methods: HPLC-PDA validated per Commission Decision 2002/657/EC (LOD 5.45, 9 and 1.6 ug/kg; recoveries 92-99%); triplicate measurements; one-way ANOVA with Tukey HSD between tissues; deterministic EDI = mean concentration x consumption / body weight (chicken 65.2 g/day; breast 23.4 g/day, thigh 20.8 g/day, liver 1.6 g/day; BW 34 kg children, 77.1 kg women, 79.1 kg men); HQ = EDI/JECFA ADI (ENR 2, OTC 30, SDI 50 ug/kg bw/day).

5. Actual results

Results: Detection: enrofloxacin 51.67% (93/180), oxytetracycline 71.67% (129/180), sulfadimidine 16.67% (30/180); MRL exceedance among positives 54.84% (51/93), 55.81% (72/129), 70% (21/30). 5% of each tissue contained all three drugs; 40% of breasts and 50% of thighs and livers contained two. Mean concentrations (ug/kg): breast ENR 90.4, OTC 317.7, SDI 573.3; thigh 161.5, 964.1, 47; liver 1707.3, 10,625, 3848.1. EDI 0.012-0.590 ug/kg bw/day; HQ 0.0006-0.050 (schoolchildren), 0.0003-0.022 (women), 0.0002-0.021 (men); all far below 1.
Absolute risks: Hazard quotients 0.0002-0.050 (well below 1) at mean concentrations and average consumption; no high-consumer or worst-case scenario reported.
Authors' conclusion: No significant health risk, but strict monitoring and withdrawal periods needed.

6. Strengths

Validated HPLC method with reported LOD/LOQ, recovery and precision
Three tissues including liver
Age-group-specific Egyptian intake and body-weight assumptions

7. Weaknesses

One city; number of shops and sampling procedure unclear; small n per tissue (60)
HPLC-PDA without confirmatory LC-MS/MS (acknowledged by authors)
HQ based on mean concentrations and average consumption; no high-percentile consumers or chronic aggregate exposure
HQ addresses toxicological ADI only; resistance selection and allergy not quantified
Ambiguous sampling period ('September to March 2025')

8. Risk of bias

Orienting tool: none (exposure measurement and risk assessment; no standard RoB tool applies)
Type of assessment: structured assessment based on the full text by a single reviewer (no formal double review)
Full formal assessment: no
Overall risk of bias: some concerns
Rationale: Unchanged (some_concerns). Single-reviewer structured judgement; a formal assessment would need two independent reviewers.

8. Risk of bias
Domain	Judgement	Rationale
Sampling/selection	high	Single city, unspecified number of shops and selection; 60 samples per tissue.
Measurement	some concerns	Validated HPLC-PDA but no confirmatory mass spectrometry.
Risk model	some concerns	Mean-based deterministic EDI/HQ; no uncertainty or high-consumer scenarios.
Reporting	some concerns	Ambiguous period and some unclear statements (e.g. '180 samples of each').

Full-text review (25 October 2026): Added sampling period, method validation (LODs, recoveries), intake/body-weight assumptions, tissue-specific means, multi-residue co-occurrence, HQ by age group, STDF funding and author-stated limitation (no LC-MS/MS). Numbers confirmed; bias unchanged.

9. Assessment of the statistical interpretation

High prevalence and frequent MRL exceedance indicate poor compliance with withdrawal periods locally, but estimated chronic intakes are 1-2 orders of magnitude below ADIs even for children. Exceeding an MRL is a regulatory compliance signal, not by itself evidence of harm.

10. Relevance to the specific claim

C-CHK-05, C-EGG-10, C-CHK-12 (Egypt).

11. Independent contrary findings

Low HQ.

12. Transferability to Germany and Europe

Low (Egypt).

13. Overall methodological judgement

Shows a real residue-compliance problem in retail chicken in one Egyptian city (especially liver) with low estimated toxicological risk; it supports concern about antibiotic misuse in Egyptian poultry but not claims of direct poisoning, and it does not study eggs.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	moderate
Directness	direct
Reproducibility	partly replicated
Consistency with the overall evidence	unknown
Regional transferability	low
Adequacy of the interpretation (by the archive)	not applicable

14. Open questions

National representative residue monitoring in Egypt; eggs; LC-MS/MS confirmation; contribution to antimicrobial resistance.

15. Linked fact checks

Commercial eggs carry antibiotic residues that harm health. – Studies with mixed or unclear results
Industrial chicken is raised with routine antibiotics, and antibiotic-resistant bacteria (e.g., ESBL E. coli, MRSA, resistant Campylobacter, mcr-1) spread from poultry to humans via the food chain. – Studies with mixed or unclear results
All poultry (chicken, duck, goose, turkey, chicken liver/gizzards) is forbidden because these are domesticated, ground-feeding birds that do not fly, whereas pigeon and quail are allowed; all eggs including quail and pigeon eggs are forbidden. – Studies contradicting or limiting the claim