Análise epidemiológica da infecção por Leptospira spp. em pequenos ruminantes no agreste e no sertão pernambucano.

Abstract

The aim of the present study was to characterize the epidemiological situation and spatial distribution of Leptospira spp. infection of small ruminants in the Agreste and Sertão regions of the state of Pernambuco (Brazil). The search for antibodies was conducted with 902 animals (476 goats and 426 sheep), which were at least a year old, on 23 separate properties. The microscopic agglutination test (MAT) was applied, using 23 pathogenic serovars of Leptospira spp. as antigens. The cutoff point used was 1:100. A standardized investigative questionnaire was used to study the risk factors. This questionnaire contained objective questions for the breeder related to the general characteristics of the property, as well as reproduction and sanitary conditions on the property. Of the 902 samples analyzed, 213 (23.6% C.I. 20.9% - 26.5%) were positive, which included 27.3% (130/476 C.I 23.4% - 31.6%) of goats and 19.5% (83/426 C.I. 15.9% - 23.6%) of sheep. The most common serovars were Autumnalis (54.1%), Icterohaemorrhagiae (15.0%) and Copenhageni (10.8%) among goats and Autumnalis (32.4%), Icterohaemorrhagiae (14.0%) and Castellonis (9.8%) among sheep. The most widespread serovar was Autumnalis in goats and Icterohaemorrhagiae in sheep. There was at least one positive animal (from one or both species) on all of the properties. In total, 87.5% (14/16) of the properties were considered to contain foci associated with goats. This figure was 92.8% (13/14) for sheep. It was possible to identify areas of a greater density of foci, which were higher risk areas, such as the Sertão for goats and three of the micro-regions studied for sheep. In terms of the risk factors, significant differences were found for the gender of goats (OR=0.40; C.I. 0.18 – 0.88) and sheep (OR=0.38; C.I. 0.14 – 0.99), the breeding system used (OR=2.03; C.I. 1.07 – 3.84), the type of herd (OR=2.28; C.I. 1.39 – 3.72), an absence of rats in food (OR=0.55; C.I. 0.34 – 0.91) and restricted surface water (OR=0.60; C.I. 0.37 – 0.99) for sheep. Many factors can affect the occurrence of leptospirosis in herds of small ruminants in the Agreste and Sertão regions of Pernambuco. Health education and employee training programs related to prevention and control methods for leptospirosis and other infectious diseases could help to reduce the number of infections and consequently, the economic losses caused by this disease.