Quantitative studies have demonstrated an increased number of positive samples collected from environmental surfaces if swabs were pre-moistened (https://pubmed.ncbi.nlm.nih.gov/20392914/ ). Only pre-moistened swabs were evaluated by AOAC and validated by NEMIS. Wet area sampling with dry swabs should be re-validated at the factory site. Dry swabbing is allowed in rare cases within the ISO 18593 sampling guideline.
