Epidemiología de la infección por leptospiras en el ganado vacuno de Asturias

Abstract

On a sample of 3,578 bovine sera representative of the different areas, breeds, ages and herds of the Asturian region, the investigation of antibodies against 6 leptospiral serovars (pomona, grippotyphosa, hardjo, icterohaemorrhagiae, autumnalis and poi) was carried out, obtaining a overall seroprevalence of 10.4%. The most prevalent serovars were pomona (5.6%) and grippotyphosa (2.4%), with the remaining serovars showing a prevalence of less than 1%. The distribution of serovar pomona was uniform throughout the region, that of serovar grippotyphosa showed a western trend and that of serovar hardjo was irregular, although with an important presence in the council of Aller. No significantly different seroprevalences were observed in relation to herd size and age, but they were observed with breed; The Asturian race from the valleys had a higher seroprevalence than the rest, although the geographical component could have influenced this. As a complement to the previous study, 3,537 sera were investigated corresponding to all the animals present in 207 of the herds seropositive to one of the 6 serovars studied. The seroprevalence found in the herds positive for serovar hardjo was 25.6%, while in the herds positive for the other 5 serovars the seroprevalence was lower, ranging between 10.6% and 16.5%. Finally, on 776 sera from 27 of the previous herds, a new study was carried out a year later that showed a decreasing trend in the seroprevalence of serovars pomona and gripotyphosa and a slightly increasing trend in that of serovar hardjo. Both results can be considered as evidence of the different adaptation of these serovars to cattle.