Cross-sectional studyindependent cross-checkabstract checked★ key study I-EGG-124 in-depth review
UAE supermarket eggs: Salmonella found only on shells of cage eggs
Occurrence, antimicrobial resistance, and whole-genome characterization of Salmonella in retail eggs in the United Arab Emirates: Evidence of a clonal dominance of serovar Braenderup.
Overview
Habib I et al.. Food Microbiol 2026 · PMID 41963064 · DOI 10.1016/j.fm.2026.105092
11.6% of cage-egg packs had Salmonella on the shell vs none of 60 cage-free packs; egg contents were clean.
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 Salmonella in retail eggs.
- How was the study done?
Retail survey with genome sequencing.
- How many people, animals or samples were studied?
380 packs.
- What was actually found?
Shell contamination only in cage-laid eggs; no contamination inside eggs.
- How large was the observed effect?
11.6% vs 0%.
- What do the results mean in everyday life?
Handle and cook eggs properly; cage eggs had more shell contamination in this survey.
- What are the study's limitations?
Few cage-free samples.
- What does it say about Elawady's specific claim?
Partly supports the cage comparison.
- Do the results apply to Germany and Europe?
Regional.
- What can explicitly not be concluded from this study?
It cannot show illness risk.
Scientific in-depth review
1. Full reference
- Authors
- Habib I et al.
- Journal
- Food Microbiol
- Year
- 2026
- Identifier
- PMID 41963064 DOI 10.1016/j.fm.2026.105092
- Verification
- verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
No competing interests declared; funding not stated in abstract.
2. Research question
How common is Salmonella in retail table eggs in the UAE, by production system?
3. Study design and population
- Study design
- Cross-sectional study – Cross-sectional retail survey with whole-genome sequencing
- Population
380 retail egg packs (4,560 eggs) from supermarkets in three UAE cities
- Country
United Arab Emirates (some packs imported from Oman)
- Period
not stated in abstract
- Sample size
380 packs (4,560 eggs)
- Inclusion and exclusion criteria
not detailed in abstract
4. Methods and endpoints
- Exposure / intervention
Cage-laid eggs (320 packs)
- Comparator
Cage-free (barn/free-range) eggs (60 packs)
- Endpoints
Salmonella on eggshells and in egg contents; serovars; resistance
- Statistical methods
Proportions with 95% CI
5. Actual results
- Results
Eggshell pools positive 37/380 (9.7%; 6.9-13.2%); egg contents 0/380. All positives from cage-laid packs: 37/320 (11.6%; 8.3-15.6%) vs 0/60 cage-free (0%; 0-6.0%). S. Braenderup ST22 dominated (13/35); S. Enteritidis 4/35; ciprofloxacin non-wild-type 25/37; multidrug resistance 4 isolates.
- Absolute risks
Eggshell contamination 11.6% (cage) vs 0% (cage-free); contents 0% (upper 95% bound about 0.8%).
- Authors' conclusion
Provides a foundational reference for Salmonella in UAE retail eggs and suggests clonal dissemination within domestic production.
6. Strengths
- Large retail sample
- Regional Arab data
- Genomic characterisation
7. Weaknesses
- Few cage-free packs (60)
- Shell, not contents, contamination
- Cage status confounded with producer
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
Cross-sectional; producer clustering.
9. Assessment of the statistical interpretation
Recalculated Fisher p = 0.0017 (stats/C-EGG-09_salmonella_housing.py); clustering by producer not accounted for, so precision is overstated.
10. Relevance to the specific claim
Regional retail evidence consistent with more Salmonella in cage-laid eggs (on shells), while contents were clean.
11. Independent contrary findings
Egyptian farm study (I-EGG-125) found the opposite pattern under high biosecurity.
12. Transferability to Germany and Europe
High regional relevance for the Arab world.
13. Overall methodological judgement
Supports the direction of the claim for shell contamination; reinforces handling and cooking advice.
| 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 | mixed |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Data from Egypt with similar design.
15. Linked fact checks
- Salmonella is far more common in caged egg production than in cage-free systems (44% vs 3.2%). – Studies supporting the claim