Standardization of methodologies for detecting helminth eggs in fresh produce enteral formulations intended for patients with special dietary needs

Aim: Enteral nutrition (EN) improves patient health. However, the use of fresh produce may increase the risk of parasitic contamination. Recovery of parasites from enteral formulations is challenging and no studies have yet addressed this issue. The primary goal of this study was to standardize methodologies for detecting helminth eggs in different enteral formulations prepared with fresh produce, aiming to establish a reproducible protocol for food safety assessments. Methods: Two homemade enteral preparations (HEP) with mixed raw fresh fruits or vegetables were produced and artificially contaminated with two doses of Ascaris suum eggs (1 = 207 and 2 = 76 eggs). HEP 1 contained cabbage, orange juice, lettuce, watercress, and filtered water, while HEP 2 consisted of strawberries and filtered water. To estimate the egg recovery rate, four protocols per preparation/dose were analyzed in triplicate (48 trials total). The following variables were evaluated: homogenization (manual or using a magnetic stirrer) and dispersion solution (1 M glycine, pH 5.5 or 0.1% Alconox®). All protocols shared the following steps: sedimentation, centrifugation, and total sediment analysis. Results: The highest recovery efficiency for HEP 1 was achieved with Protocol 2 (glycine + magnetic stirrer), with averages of 66% (Dose 1) and 55% (Dose 2). For HEP 2, Protocol 4 (Alconox® + magnetic stirrer) performed best, yielding 66% (Dose 1) and 52% (Dose 2). Viable eggs of Toxocara sp., and hookworm were naturally detected in HEP 1 and 2, respectively. Conclusions: This is the first study to standardize and measure the detection sensitivity of a methodology for detecting parasites in enteral formulations. Since most patients receiving these types of food require intensive care, strict quality control is essential, including evaluation of the parasitological quality of EN to avoid exacerbating their already compromised health.