Prevalence of antimicrobial residues in table eggs in Trinidad

The prevalence of antimicrobial residues in pooled table eggs from layer farms, shopping malls, and supermarkets in Trinidad was determined. A total of 23 layer farms and 14 shopping malls were sampled twice, I month apart, whereas 102 supermarkets were each sampled once. For each farm, 25 eggs were randomly collected and pooled to constitute a composite sample, whereas six eggs from each farm source available at sale outlets were randomly sampled from malls and supermarkets to constitute a composite sample. Questionnaires were administered at the farms to determine the occurrence of risk factors for contamination of antimicrobial residues in eggs and at sale outlets to determine storage conditions. The Charm 11 test was used to qualitatively detect antimicrobial residues (beta-lactams, macrolides, sulfonamides, and tetracyclines). Of 46 composite eggs tested from farms, 3 (6.5%) were contaminated with residues compared with 5 (16.1%) of 31 and 16 (15.0%) of 107 mall and supermarket eggs, respectively, but the difference was not statistically significant (P > 0.05). The residues detected were as follows: sulfonamides, 12 (6.5%) of 184; macrolides, 7 (3.8%) of 184; tetracycline, 5 (2.7%) of 184; and P-lactam, 0 (0.0%) of 184. The difference was statistically significant (P < 0.05). The use of medicated feeds on farm, claim of adherence to the antimicrobial withdrawal period, and temperature of egg storage did not significantly (P > 0.05) affect the prevalence of residues in eggs. It was concluded that the presence of antimicrobial residues, particularly sulfonamides, in table eggs could be of public health significance to the consumer.