Food Protection Trends - April 2011 - (Page 214)

TABLE 1. Prevalence and 95% exact binomial confidence intervals for observed ivermectin residue levels in bovine liver samples Ivermectin residue level (µg/kg) No detectable residues >0– <5 7 20 1491 1 Number of samples Prevalence Standard error Binomial exact confidence interval (95%) 227 4 1 1 1 0.97 0.017 0.004 0.004 0.004 0.011 0.008 0.004 0.004 0.004 0.940–0.988 0.005–0.043 0.000–0.024 0.000–0.024 0.000–0.024 Exceeds the MRL of 100 µg/kg times and other residue avoidance practices appear to have been observed, for the most part. All three North American countries monitor veterinary drug residues in cattle. In Canada, the MRL for ivermectin is 70 µg/kg in liver, lower than the limit established by JECFA (13) and used by Mexico. Between 2006 and 2009, the Canadian National Chemical Residue Monitoring Program (NCRMP) did not report any non-conforming ivermectin residues in either Canadian or imported cattle samples (4, 5). Between 2005 and 2007 in the United States, sampling identified non-conforming ivermectin residues in samples from various cattle production classes (in 2005: 1/302 for bulls, 1/337 for heavy calves, 1/303 for steers, and 2/298 for non-formula fed veal; in 2006: 1/173 for non-formula fed veal and in 2007: 1/316 for bulls, 3/200 for heavy calves, and 1/1046 for steers). In 2008, no non-conforming ivermectin residues in cattle were detected through sampling in the United States (29–31), although one non-conforming sample from Uruguay was detected by sampling of imported products (32). In May 2010, a recall class II (low risk) involving ivermectin residues in beef products was reported by the USDA. The recall involved cooked beef products originating from a federally inspected plant in Brazil; this plant was delisted and its beef products prohibited from entering the United States (30, 33). Economic losses resulting from products that must be destroyed when non-conformities are detected (7) as well as the loss of consumer confidence are im- portant consequences at a national level. Furthermore, non-conformances could result in the establishment of international trade barriers (6). Exporting countries have the responsibility to protect both public health and markets by complying with international requirements. Like other meat exporting countries, Mexico must be aware of this situation (28, 34) and focus on minimizing the occurrence of non-conforming residues of all regulated chemicals, including ivermectin, while using all its available resources efficiently. We do not know the underlying reason(s) for the non-conformity in the single animal detected in this study. The number of non-conformities and even of positive results was insufficient to allow the calculation of risk factors associated with ivermectin residues in this study. The likelihood of use of ivermectin in cattle depends upon the farmer’s and / or veterinarian’s perception of the likelihood of parasite infestation of the cattle, which tends to be seasonal (19). Since the use of ivermectin is expected to be different at different times of the year, the results from this study are not likely to be representative of populations slaughtered throughout the year. However, late autumn (November / December) is likely to be a season of greater use of ivermectin in cattle, as this season is considered to be a time of high occurrence of some external parasites in cattle. This suspected seasonality could be related to the nonconformance reported (7). Use of veterinary drugs in accordance with the manufacturers’ recommendations, in conjunction with good veterinary practices, should prevent occurrence of tissue residues that exceed the established MRLs (7, 34). In this study, non-conformance with respect to ivermectin residues was rare in slaughter cattle in Nuevo Leon. These results are consistent with one of the main objectives of residue monitoring programs in general, which is to verify that nonconforming residues are infrequent and consequently that the health of consumers is protected (7). However, it should be recognized that the Mexican toxic residues program and the present study include samples exclusively from federally inspected plants, which represent approximately 8% of the total number of abattoirs and a small proportion of the total annual production in Mexico (26). We strongly recommend continual assessment of the monitoring program to validate its efficacy, and efficiency as well as the inclusion of priority chemicals and further recommend future studies to identify risk factors associated with ivermectin residue. ACKNOWLEDGMENTS We thank the many SAGARPA personnel who provided information and support to this study, in particular Octavio Carranza, Jose Jacobo Lopez Camero, Aurelio Hernandez Lozada, Carlos Montalvo Tamez and Mireya Ortiz Nicoli and acknowledge the support provided by Miriam Montante, Antonio Quintanilla and all the laboratory personnel who actively contributed to this study. We also thank the abattoirs and veterinary inspectors for their participation. Funding for the study was provided by Consorcio Tecnico del Noroeste de Mexico and OCETIF, AC. 214 FOOD PROTECTION TRENDS | APRIL 2011

Table of Contents for the Digital Edition of Food Protection Trends - April 2011

Food Protection Trends - April 2011
Contents
Sustaining Members
Reflections of Your President
Commentary from the Executive Director
Prevalence of Ivermectin Residues in Cattle Slaughtered in Federally Inspected Abattoirs in Nuevo Leon, Mexico
FDA’s Domestic and Imported Cheese Compliance Program Results: January 1, 2004 —December 31, 2006
New Members
What’s Happening in Food Safety
Industry Products
Special Contributors and Sponsors
Preliminary Program
Ivan Parkin Lecture
John H. Silliker Lecture
Activities
General Information
Registration Rates
Coming Events
Advertising Index
Journal of Food Protection Table of Contents
Booklet Order Form
Membership Application
Celebrating 100 Years of IAFP: 1960s

Food Protection Trends - April 2011