Measurement / residue studyindependent cross-checkfull text checked★ key study I-RES-08 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
Most chicken samples had antibiotic residues, often above legal limits, but estimated intake was far below harmful levels.
Does the study support the specific claim? Partly · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Measure residues.
- How was the study done?
HPLC.
- How many people, animals or samples were studied?
180 chicken samples (breast, thigh, liver) from shops in Mit Ghamr, Egypt.
- What was actually found?
Oxytetracycline in 72%, enrofloxacin in 52%, sulfadimidine in 17%; more than half of positives above legal limits; liver highest; hazard quotients at most 0.05.
- How large was the observed effect?
HQ <= 0.05.
- What do the results mean in everyday life?
Regulation problem, low direct risk.
- What are the study's limitations?
One town; no confirmatory mass-spectrometry; simple intake assumptions; gentamicin not tested.
- What does it say about Elawady's specific claim?
Partly supports residue concern; not harm.
- Do the results apply to Germany and Europe?
Low.
- What can explicitly not be concluded from this study?
Resistance effects; health harm; anything about gentamicin.
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 Science, Technology & Innovation Funding Authority (STDF) with the Egyptian Knowledge Bank (EKB); authors declare no competing interests.
2. Research question
Enrofloxacin, oxytetracycline, sulfadimidine residues in Egyptian retail chicken
3. Study design and population
- Study design
- Measurement / residue study – Cross-sectional retail residue survey (HPLC-PDA, validated per EC Decision 2002/657/EC, no LC-MS/MS confirmation) of broiler tissues with deterministic dietary risk assessment (EDI, HQ)
- Population
Broiler chicken breast, thigh and liver from different poultry shops in Mit Ghamr City, 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
Randomly collected dressed carcasses (~1.25 kg) from poultry shops; no further criteria
4. Methods and endpoints
- Exposure / intervention
Tissue type
- Comparator
MRLs (EU 2010 for enrofloxacin; Codex 2024 for oxytetracycline and sulfadimidine); JECFA/Codex ADIs (ENR 2, OTC 30, SDI 50 ug/kg bw/day)
- Endpoints
Residue prevalence and concentrations; % above MRL; EDI and HQ for schoolchildren (34 kg), women (77.1 kg) and men (79.1 kg)
- Statistical methods
Triplicate measurements; ANOVA with Tukey HSD between tissues; method validation (R2 0.9995-1; recoveries 92-99%; intra-day RSD 1.6-4.3%)
5. Actual results
- Results
Detected: enrofloxacin 51.67% (93/180), oxytetracycline 71.67% (129/180), sulfadimidine 16.67% (30/180). Of positives above MRL: 54.84% (51/93), 55.81% (72/129), 70% (21/30). 5% of each tissue type contained all three drugs; 40% of breasts and 50% of thighs and livers contained two. Mean concentrations (ug/kg) ENR/OTC/SDI: breast 90.4/317.7/573.3; 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); children highest. Gentamicin was not analysed.
- Absolute risks
not reported (HQ screening indices only)
- Authors' conclusion
HQ values indicate no significant health risk for adults or children (children relatively higher), but frequent MRL exceedances highlight the need for strict antibiotic monitoring and respect of withdrawal periods.
6. Strengths
- Three tissues including liver
- Validated HPLC-PDA method with reported recoveries and precision
- Age-group-specific exposure estimates
7. Weaknesses
- One town; shop-level sampling without documented farm origin
- No confirmatory LC-MS/MS (authors' stated limitation); PDA identification by retention time and spectrum only
- HQ based on toxicological ADIs; resistance selection and allergy not quantitatively assessed
- Intake assumptions derived from a website estimate and carcass apportioning; same daily intake assumed for children and adults
- Raw tissue; cooking effects not considered
- Gentamicin (named in C-RES-03) not tested
- Sampling period stated ambiguously ('between September and March 2025')
8. Risk of bias
- Orienting tool
- No standard tool fits (residue survey/exposure assessment); structured validity judgement
- 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
Single-reviewer structured judgement based on the full text; not formal (needs two independent reviewers).
| Domain | Judgement | Rationale |
|---|---|---|
| Sampling / representativeness | some concerns | Random shop sampling but one town and 60 samples per tissue. |
| Analytical measurement | some concerns | Validated HPLC-PDA, but no mass-spectrometric confirmation; very high liver values (e.g. OTC mean 10,625 ug/kg) would warrant confirmation. |
| Risk characterisation | some concerns | Deterministic HQ with simplified intake assumptions; no resistance-based endpoint. |
| Reporting | low | Detailed prevalence and concentration tables; funding and COI stated. |
Full-text review (25 October 2026): Added sampling period, MRL sources, method validation data, intake/body-weight assumptions, co-occurrence of residues, author-stated lack of LC-MS/MS confirmation, funding; noted gentamicin not analysed; structured validity domains (overall unchanged).
9. Assessment of the statistical interpretation
HQ far below 1 even for children despite MRL exceedances in more than half of positive samples; MRL exceedance is a regulatory/withdrawal-period signal, not a demonstration of toxic risk. Liver drives the highest concentrations but has low assumed intake (1.6 g/day).
10. Relevance to the specific claim
11. Independent contrary findings
12. Transferability to Germany and Europe
Low.
13. Overall methodological judgement
Shows widespread non-compliance with veterinary drug residue limits in retail chicken in one Egyptian town (supports residue concern in C-RES-01/02 and C-FSH-16 for Egypt), without estimated toxicological risk at the assumed intake. It does not address gentamicin or kidney/hearing harm (C-RES-03).
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | unknown |
| Consistency with the overall evidence | unknown |
| Regional transferability | low |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Representativeness.
15. Linked fact checks
- Current agricultural practices - feeding animals unnatural feed and using hormones - produce contaminated food (archive quote attributed to the episode 'The New Food Pyramid', January 2026). – Studies supporting the claim
- Everyday foods carry 'explicit toxins': residues of antibiotics, fertilisers, stimulants/growth promoters, chemicals and pesticide residues, which the body must deal with daily. – Studies supporting the claim
- Pesticide, antibiotic and hormone residues in food are a main cause of chronic health problems (implied by his theory statement and recurring remarks such as 'you are poisoned: the amount of pesticides and hormones'). – Studies supporting the claim
- Poultry farms inject chicks with gentamicin; consumers then ingest gentamicin with chicken liver, gizzards and meat, which damages kidneys and hearing. – Studies with mixed or unclear results