Frequency of Trichinella spiralis in blood and muscles of horses from two slaughter houses (industrial and rural) in the State of Mexico, Mexico

Abstract

THE OBJECTIVE OF THIS STUDY WAS THE EVALUATION OF THE FREQUENCY OF TRICHINELLA SPIRALIS IN HORSE MEAT THAT IS USED FOR HUMAN AND ANIMAL CONSUMPTION. A TOTAL OF 150 HORSES WERE SAMPLED, FROM TWO PRIVATE SLAUGHTERHOUSES, ONE INDUSTRIAL SLAUGHTERHOUSE WITH SOME LEVEL OF TECHNOLOGY AND THE OTHER ONE RURAL WITH LESS TECHNOLOGY. SEVENTY ANIMALS FROM THE FIRST ONE AND 80 FROM THE SECOND ONE WERE SAMPLED. AFTER THE HORSES WERE SLAUGHTERED 10 G WERE TAKEN FROM THREE MUSCLES OF EACH HORSE: GLUTEUS, MASSETER AND DIAPHRAGM OR TONGUE AS WELL AS 5 ML OF BLOOD. THE MUSCLE TISSUE WAS OBSERVED LOOKING FOR TRICHINELLA SPIRALIS LARVAE BY: A) TRICHINOSCOPY B) ARTIFICIAL DIGESTION AND C) POLYMERASE CHAIN REACTION. THIS LAST TECHNIQUE WAS USED ALSO FOR THE BLOOD ANALYSIS. FOR BOTH SLAUGHTERHOUSES, ALL MUSCLES OBSERVED BY TRICHINOSCOPY WERE NEGATIVE. BY ARTIFICIAL DIGESTION ANALYSIS, T. SPIRALIS LARVAE WERE FOUND IN THE THREE MUSCLES OF ONLY ONE HORSE OF THE 70 THAT CAME FROM THE INDUSTRIAL SLAUGHTERHOUSE, WHICH REPRESENTS A 1.42% PREVALENCE IN THIS LOT. OF THE EIGHTY HORSES OF THE RURAL SLAUGHTERHOUSE T. SPIRALIS WAS FOUND IN ONLY THE MASSETER OF ONE HORSE AND THIS REPRESENTS 1.25% POSITIVENESS. WITH THE POLYMERASE CHAIN REACTION T. SPIRALIS WAS IDENTIFIED IN THREE MUSCLES OF ONE HORSE OF THE INDUSTRIAL SLAUGHTERHOUSE AND IN BLOOD OF ANOTHER TWO HORSES WHICH GIVES A TOTAL INFECTION FREQUENCY OF 4.28%. IN THE HORSES FROM THE RURAL SLAUGHTERHOUSE, THE POLYMERASE CHAIN REACTION WAS POSITIVE IN MUSCLES OF THREE HORSES; THE TOTAL FREQUENCY OF INFECTION IN THIS LOT WAS 3.75%, TAKING INTO CONSIDERATION THAT THE RESULTS FOR BLOOD WITH THIS TECHNIQUE CAME OUT NEGATIVE. IT IS CONCLUDED THAT THE FREQUENCY OF T. SPIRALIS WAS SIMILAR TO WHAT HAS BEEN FOUND IN OTHER REPORTS, ALTHOUGH THERE WERE DIFFERENCES BETWEEN BOTH SLAUGHTERHOUSES IN RELATION TO THE PARASITIC BURDEN OF THE ANIMALS.