Measurement / residue studyindependent cross-checkfull text checked★ key study I-RES-101 in-depth review
Gentamicin found in one in five Egyptian chicken samples, mostly in liver
Assessment of antibiotic residues in chicken meat.
Overview
Kamouh HM et al.. Open Vet J 2024 · PMID 38633178 · DOI 10.5455/OVJ.2024.v14.i1.40
21% of samples contained gentamicin, most often liver and gizzard; boiling removed over 90%.
Does the study support the specific claim? Partly · Methodological quality: low
Plain-language summary
Study explained simply
- What did the researchers want to find out?
How often are oxytetracycline, gentamicin and ciprofloxacin residues present in retail chicken in Egypt, and does boiling reduce them?
- How was the study done?
Cross-sectional residue survey (microbial inhibition test plus HPLC) with a boiling experiment
- How many people, animals or samples were studied?
100 samples (25 per tissue)
- What was actually found?
Positive: oxytetracycline 23%, gentamicin 21%, ciprofloxacin 17% of samples. Gentamicin by tissue: breast 16%, thigh 16%, gizzard 20%, liver 32%; mean concentrations (ng/g) 31.8, 52.5, 201.3, 243.2 (max liver 378.5). Above the MRL used: breast 1/25, thigh 2/25, gizzard 4/25, liver 5/25. Boiling 30 min reduced gentamicin by 91.8-95.2% (liver 378.5 -> 18.3 ng/g), oxytetracycline by 88.2% and ciprofloxacin by 23-31%.
- How large was the observed effect?
Positive: oxytetracycline 23%, gentamicin 21%, ciprofloxacin 17% of samples. Gentamicin by tissue: breast 16%, thigh 16%, gizzard 20%, liver 32%; mean concentrations (ng/g) 31.8, 52.5, 201.3, 243.2 (max liver 378.5). Above the MRL used: breast 1/25, thigh 2/25, gizzard 4/25, liver 5/25. Boiling 30 min reduced gentamicin by 91.8-95.2% (liver 378.5 -> 18.3 ng/g), oxytetracycline by 88.2% and ciprofloxacin by 23-31%.
- What do the results mean in everyday life?
Antibiotic traces are real in Egyptian chicken, especially in offal; cooking removes most gentamicin; the amounts are tiny compared with medical doses.
- What are the study's limitations?
Small sample from one governorate; Gentamicin MRLs taken from EU bovine/porcine values (EU 37/2010 lists gentamicin MRLs only for bovine and porcine species, I-RES-01); Inconsistent counts (21 MIT-positive vs 25 positive in Table 7 text); No dietary risk assessment
- What does it say about Elawady's specific claim?
Supports that gentamicin is used in Egyptian broilers; does not support kidney or hearing damage.
- Do the results apply to Germany and Europe?
Not applicable to EU production.
- What can explicitly not be concluded from this study?
Cannot show any health effect.
Scientific in-depth review
1. Full reference
- Authors
- Kamouh HM et al.
- Journal
- Open Vet J
- Year
- 2024
- Identifier
- PMID 38633178 DOI 10.5455/OVJ.2024.v14.i1.40
- Verification
- verified – PubMed efetch 2026-10-26; Crossref 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
No external funding; authors declare no conflict of interest (full text)
2. Research question
How often are oxytetracycline, gentamicin and ciprofloxacin residues present in retail chicken in Egypt, and does boiling reduce them?
3. Study design and population
- Study design
- Measurement / residue study – Cross-sectional residue survey (microbial inhibition test plus HPLC) with a boiling experiment
- Population
Chicken breast, thigh, gizzard and liver from slaughterhouses in Kafr El-Sheikh markets
- Country
Egypt
- Period
not stated (received Oct 2023)
- Sample size
100 samples (25 per tissue)
- Inclusion and exclusion criteria
as described in the abstract
4. Methods and endpoints
- Exposure / intervention
Antibiotic use in broilers (residues)
- Comparator
MRLs (EU 2010 values as cited by authors)
- Endpoints
Detection rates, concentrations, MRL exceedance, reduction by boiling
- Statistical methods
as reported in the abstract
5. Actual results
- Results
Positive: oxytetracycline 23%, gentamicin 21%, ciprofloxacin 17% of samples. Gentamicin by tissue: breast 16%, thigh 16%, gizzard 20%, liver 32%; mean concentrations (ng/g) 31.8, 52.5, 201.3, 243.2 (max liver 378.5). Above the MRL used: breast 1/25, thigh 2/25, gizzard 4/25, liver 5/25. Boiling 30 min reduced gentamicin by 91.8-95.2% (liver 378.5 -> 18.3 ng/g), oxytetracycline by 88.2% and ciprofloxacin by 23-31%.
- Absolute risks
Worst-case 100 g raw liver portion about 38 ug gentamicin = 3.2% of ADI (reviewer calculation)
- Authors' conclusion
Antimicrobial residues were detected in chicken meat parts retailed in Egypt; cooking can reduce them at least in part.
6. Strengths
- Confirmatory HPLC
- Tissue-specific data
- Cooking experiment
- Full text read (methods, results, funding)
7. Weaknesses
- Small sample from one governorate
- Gentamicin MRLs taken from EU bovine/porcine values (EU 37/2010 lists gentamicin MRLs only for bovine and porcine species, I-RES-01)
- Inconsistent counts (21 MIT-positive vs 25 positive in Table 7 text)
- No dietary risk assessment
8. Risk of bias
- Orienting tool
- none applicable
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Convenience sample; reporting inconsistencies.
9. Assessment of the statistical interpretation
Worst-case intake from a 100 g portion of the most contaminated raw liver = 3.2% of the JECFA ADI; 0.15% after boiling (stats/C-RES-03_gentamicin_exposure.py).
10. Relevance to the specific claim
Only located study measuring gentamicin residues in Egyptian chicken.
11. Independent contrary findings
12. Transferability to Germany and Europe
13. Overall methodological judgement
21% of samples contained gentamicin, most often liver and gizzard; boiling removed over 90%.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | some concerns |
| Precision of results | low |
| Directness | direct |
| Reproducibility | not replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | low |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
15. Linked fact checks
- 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
- 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
- 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 supporting the claim