Diagnosis, epidemiology and Program of Control of Paratuberculosis in bovine herds of Argentina

PAOLICCHI F, MORSELLA C; VERNA A, SPATH E, MARTINIS D, ZUMARRAGA M; GIOFFRE A, CATALDI A, ROMANO M.

Bilbao, Spain

Congreso; 7th International Colloquium on Paratuberculosis; 2002

Since 1985 activities of diagnosis and investigation in Paratuberculosis in ruminants through serological, bacterialogical and immunopathological methods are carried out in our Bacteriology Laboratory from INTA - FCA UNMdP, Province of Buenos Aires, Argentina. Between 1992 and 2002 the serological technique used has been the absorbed indirect ELlSA test with a sensibility of 66% and a specificity of 98%, adjusted by ROC - MedCale Program. A total of 68.335 sera (bovine: 61.525; cervine: 6.670, and ovine: 140) has been processed, while a total of 9.123 samples from reports of 4 year old or older cattle of the Provinces of Buenos Aires (BA:n=3.160), La Pampa (LP:n=716), Corrientes (C:n=761), La Rioja (LR:n=101), Neuquén (N:n=74), and Río Negro (RN:n=385) has been studied. Apparent seroprevalences were adjusted to obtain the real seroprevalence which was in BA: 26.5% (meat) and 56% (milk), LP: 2.4%, C: 1%, LR: 0,2%, N: 0%, RN: 7%. Since 1985 feces (F), organs (OR), or milk (M) samples have been processed. A total of 136 strains of Mycobacterium avium subsp. paratuberculosis was isolated from F (n=100:66 meat cattle (mc), 28dairy cattle (dc), 6 deer (de)) OR (n=34: 12 mc, 3 dc, 19 de) and M (n=2 dc). Of all the strains isolated and typified by PCR to confirm IS900 insertion sequence, 61 strains have been typified by RFLP in 4 different patterns designated "A" (75%), "B" (10%), "C" (6.1 %), and "E" (13%), and were compared with isolations from Europe. The more prevalent pattern in Argentina has been identical to the least frequent in Europe, R9(C17), while the other patterns were not found in Europe. Deer only have pattern "A". These results demonstrate the important prevalence of Paratuberculosis in Argentina and the relevance of identifying diseased herds to organize its control and eradication.