Leptospirosis in native mixed-breed sheep slaughtered in a semiarid region of Brazil

Farías

et al. 2018

Trop Anim Health Prod

Although some studies in sheep have indicated leptospire colonization of the genital tract, further studies are needed to clarify the role of genital carriers in this species. Thus, this study aimed to evaluate the colonization of pathogenic leptospires in the genital and urinary tract of slaughtered sheep. Fifty-seven adult, female woolless sheep destined for slaughter were used. Renal (n = 57), bladder (n = 57), ovary (n = 34), uterine tube (n = 44), and uterus (n = 33) samples were collected for molecular detection of Leptospira sp. DNA, and blood samples (n = 57) for serological testing. The molecular testing was performed using polymerase chain reaction (PCR), and the serological testing was performed using microscopic serum agglutination test (MAT). Samples with amplifying DNA were subjected to genetic sequencing. In total, leptospiral DNA was found in the tissues of 44 (77.2%) sheep, whereas only nine animals were positive on both PCR and MAT; there was slight agreement between PCR and MAT techniques (k = 0.0268; p = 0.684). In 61 (54.9%) genital tract and in five (4.4%) urinary tract samples, the leptospiral DNA was detected, with significant difference (p < 0.001). The genes of one sample from the uterine tube and another from the bladder were sequenced and demonstrated 99% similarity to Leptospira interrogans. Anti-Leptospira antibodies were detected in 11 (19.3%) of the tested animals. The results reinforce the importance of the genital tract as an extra-renal site of colonization, suggesting the possibility of venereal transmission in sheep.

Section: Discussionsupporting

confidence: 57%

High frequency of genital carriers of Leptospira sp. in sheep slaughtered in the semi-arid region of northeastern Brazil

Farías

et al. 2018

Trop Anim Health Prod

“…This study found high occurrences in Icterohaemorrhagiae and Autumnalis, with 25.21% occurrences in the former and 31.09% occurrences in the latter, which is a recurrent fact in studies related to animals in the Northeast (Costa et al, 2017;Moraes et al, 2019). This is an important fact, as it brings worries to human and animal health, once leptospirosis can also occur in occupational form, and these serogroups are important to the disease cycle in humans, especially to those in contact with the animals and their fluids, such as agricultors, slaughterhouse workers and veterinarians (Dorjee et al, 2008;Adler & De La Peña Moctezuma, 2010), and it was observed the presence of the disease in both biomes, despite their differences in soil and climate, suggesting a relation between the region studied and the occurrence of these serogroups.…”

Section: Discussionsupporting

confidence: 50%

Epidemiological survey for goat leptospirosis in two distinct biomes in Northeastern Brazil

Viana

Lima

et al. 2021

RSD

Self Cite

Caprine breeding is a largely exploited activity in Brazil, with a herd of over 10 million goats concentrated mostly in the Northeast region, which contains 93.9% of the national herd. However, this region is affected by huge losses due to inappropriate management and illness occurrence, such as leptospirosis, a reproductive disease that causes economic and productive losses. Considering these previous statements, we aimed to determine the most frequent seroprevalence, serogroups and factors associated with the occurrence of leptospirosis in goats from different states and biomes of the Brazilian northeast and properly locate the disease throughout the region through the analysis of epidemiological questionnaires and geographic data. The samples were submitted to the Microscopic Agglutination Test (MAT) with a cutoff of 50. In addition, geographic data were analysed to create maps with epidemiological descriptions of the disease in the states. The total occurrence of seropositive animals was 19.93% (119/597), 18.92% (35/185) in the state of Alagoas and 20.38% (84/412) in Maranhão. The most common serogroups in these states were Autumnalis (31.09%) and Icterohaemorrhagiae (23.81%). Dividing the results, it was possible to observe a greater occurrence of the serogroup Autumnalis (42.86%) Icterohaemorrhagiae (28.57%) in the state of Alagoas, Caatinga biome, plus Autumnalis (26.19%) and Icterohaemorrhagiae (23.81%) in the state of Maranhão, Cerrado biome. It was proven that Leptospira sp. is present in both states and biomes analyzed, present in diverse areas as in vegetation and climate, warning preventive care towards the disease.

“…When seropositive reactions were grouped per state, the Autumnalis serogroup predominated in Alagoas, Ceará, and Sergipe. This serogroup was also the most frequently observed in the Northeast in general, which may suggest the possibility of sheep being the reservoirs for this serogroup in the Caatinga biome, since it has been frequently reported in various studies performed in the Northeast region of Brazil [3,6,23], and was also isolated from sheep in the state of Rio Grande do Sul [28]. This implies that ovine have an important role in the epidemiology of leptospirosis, acting as a host for infection of other animals.…”

Section: Discussionmentioning

confidence: 60%

Spatial Distribution of Serologically Reactive Sheep to Leptospira spp. in the Northeast Region of Brazil

Viana

Calado

et al. 2021

Acta Scientiae. Vet.

Self Cite

Background: Considering the importance of leptospirosis in sheep farming and public health and the significance of identifying which serogroups circulate in sheep within each region, the objective of this study was to determine the seroprevalence and spatial distribution of the most frequent serogroups causing infection by Leptospira sp. in ovine herds in the Northeast region of Brazil.Materials, Methods & Results: Blood samples were collected from 4197 sheep from 229 herds in 7 Northeastern States. Sera were analyzed via microscopic agglutination test (MAT). The frequency of seroreactive sheep for Leptospira sp. was 14.06%. The states of Alagoas, Ceará, Paraíba, Piauí, Rio Grande do Norte, and Sergipe, located in the Caatinga biome, had the highest frequencies of serologically reactive sheep, and Maranhão, in the Cerrado biome, had the lowest frequency. The most frequent serogroups were Autumnalis (19.49%), Australis (15.76%) and Serjoe (14.41%). In the states of Ceará, Paraíba, Rio Grande do Norte, and Sergipe, 100% of their municipalities had at least one seroreactive animal. The highest frequencies of seropositive animals were found in the municipalities of União (50%), Passagem (49.06%), Canindé (48.89%), Igaci (28.95%), Gararu (31.2%), Pirapemas (17.5%), and Angicos (16%) located in the states of Piauí, Paraíba, Ceará, Alagoas, Sergipe, Maranhão and Rio Grande do Norte, respectively.Discussion: The animal-level prevalence (14.06%) obtained in the present study is significant, especially considering the rustic nature of the species and the adverse conditions of the region for the infectious agent. In semi-arid conditions, it has been suggested that perhaps sheep do not seroconvert detectable titers on MAT with a cut-off point of 1:100. It is important to highlight that theovine population in the Northeast region of Brazil is composed of mixed animals, which have been considered more resistant to infection by Leptospira spp. Also, environmental factors hostile to the survival of the infectious agent in the studied region should be taken into consideration, since they may have influenced the seropositive animal-level prevalence. A noteworthy variation was observed in agglutinin titers, which ranged from 100 to 1,600, where 80.2% of the positive samples had titers ≤ 200. It is important to highlight that more elevated titers (≥ 400) were obtained in all seven states, which may suggest an acute infection caused by a non-adapted serovar, indicating that preventive and control measures focused on possible infection sources for sheep should be adopted. Although some states showed the same serogroups as the most frequent, a variety of serogroups was observed in municipalities, which may indicate different sources of infection, whether interspecies, intraspecies, or via alternative routes of transmission in semi-arid conditions, such as venereal. This indicates that even though sheep are more resistant to infection, they become exposed due to the environment or management conditions. As such, identification, isolation, and treatment of the affected animals are alternative measures recommended for prevention and control of leptospirosis in sheep in the semi-arid region. It is evident that despite the lack of rain observed in the last decade in the Northeast region of Brazil, which prevented the formation of favorable environments for the presence of Leptospira, the infectious agent remains among the sheep, as well as other production and wild animals in the region. Some factors may be contributing to this scenario, such as the fact that sheep farming in the region is characterized mainly by subsistence systems, where veterinary assistance and adequate sanitary management are absent, thus increasing the possibility of contact with Leptospira.Keywords: small ruminants, semi-arid, zoonosis.