RESUMEN
A 12-month abattoir survey was conducted between January 1999 and January 2000, to determine the prevalence of faecal carriage of verocytotoxin-producing Escherichia coli O157 (VTEC O157) in cattle and sheep slaughtered for human consumption in Great Britain. Samples of rectum containing faeces were collected from 3939 cattle and 4171 sheep at 118 abattoirs, in numbers proportional to the throughput of the premises. The annual prevalence of faecal carriage of VTEC O157 was 4.7 per cent (95 per cent confidence interval 4.1 to 5.4) for cattle and 1.7 per cent (1.3 to 2.1) for sheep, values which were statistically significantly different from each other (P < 0.001). The organisms were recovered from both cattle and sheep slaughtered throughout the year and at abattoirs in all regions of the country, but the highest prevalence was in the summer. The most frequency recovered VTEC O157 isolates were phage types 2, 8 and 21/28 in cattle and 4 and 32 in sheep, the five most frequently isolated phage types associated with illness in people in Great Britain during the same period.
Asunto(s)
Mataderos , Bovinos , Infecciones por Escherichia coli/transmisión , Escherichia coli O157/aislamiento & purificación , Contaminación de Alimentos , Ovinos , Toxinas Shiga/biosíntesis , Animales , Recolección de Datos , Inglaterra , Heces/microbiología , Humanos , Prevalencia , Recto/microbiología , Estaciones del AñoRESUMEN
Sera from 538 Yemeni goats and 690 Yemeni sheep were screened for brucellosis by the Rose Bengal Plate Test (RBPT) and reactors confirmed by the complement fixation test (CFT) and the serum agglutination test (SAT). The prevalence among goats was 0.4% and among sheep 0.6%. The prevalence among 183 imported goats and sheep was 4.4%. The sensitivity and specificity of three serological tests available for the diagnosis of brucellosis -CFT, RBPT and SAT - were compared using ovine sera obtained throughout an outbreak of abortion due to Brucella melitensis. The RBPT and the SAT were relatively insensitive compared with the CFT (71 and 44% respectively) and the RBPT was as specific as the SAT when suspicious sera were included. The results suggests that the SAT adds little information when used with other tests and the RBPT has limited applications as a screening test for ovine brucellosis.