Seroprevalence and predominant serogroups of Leptospira sp. in serological tests of ruminants in northeastern Brazil

Abstract

The objective of this study was to determine the seroprevalence of leptospirosis and the predominant serogroups in serological tests of ruminants performed at the Transmissible Diseases Laboratory of the Federal University of Campina Grande, Patos, Paraíba, northeastern Brazil, between 2010 and 2017. This research included the records of serological tests for leptospirosis from 5594 animals, including 1527 cattle, 1761 goats, 2170 sheep, and 136 buffaloes from four Brazilian states (Paraíba, Pernambuco, Maranhão, and Rio Grande do Norte). Of the 5594 serum samples, 662 were serologically positive, corresponding to a frequency of 11.8%. Serjoe (30.6%), Autumnalis (13.6%), and Icterohaemorrhagiae (11.3%) were the most frequent subgroups among all species. The individual frequencies in cattle, goats, sheep, and buffaloes were 20% (306/1527), 8.3% (147/1761), 7.9% (171/2170), and 27.9% (38/136), respectively, with titers ranging from 1:100 to 1:3200. The most frequent serogroups according to animal species were as follows: Serjoe predominated in cattle (62%), followed by Icterohaemorrhagiae (12.5%) and Tarassovi (6.6%); Autumnalis was the most frequent in goats and sheep (29.4% and 26.9%, respectively), followed by Seramanga (12.5%) in goats and Icterohaemmorrhagiae (13.5%) in sheep; and Australis predominated in buffaloes (39.5%), followed by Pomona (31.6%) and Canicola (21.1%). Leptospira sp. infection, determined by serology, is widespread in ruminants (cattle, goats, sheep, and buffaloes) in northeastern Brazil, suggesting the existence of alternative transmission routes that are less dependent on environmental factors. Identification of the most frequent serogroups highlights the need to improve sanitary conditions, and implement efficient and targeted control measures directed at the primary infection sources.

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

“…It is important to remember that in this period, the northeast region of Brazil suffered from a long drought season, and this climatic condition can lower the rates of the disease due to its characteristic of humid area occurrence and the transmissibility characteristics of leptospirosis can influenced by climatic characteristics, as suggested by Costa et al (2016); however, leptospirosis continued to affect both biomes despite the adverse situation because leptospirosis can be influenced by many factors, such as the region, which has varied levels of temperature, humidity, topography, precipitation, and the reservoirs involved, wild (foxes, possums, rodents) and/or domestic animals (Alves et al, 2000), in addition to the possible existence of alternative routes of transmission that are less dependent on environmental factors (Pimenta et al, 2019).…”

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

“…The presence of mixed herds with cattle in the studied properties should be taken into consideration since this type of management, under semi-arid conditions, favors the preservation and dissemination of Leptospira, as mentioned by [27]. The possibility of sheep harboring this serogroup should also be considered [20,26]. As such, it is possible to suggest that bovines are acting as a source of infection for sheeps, transmitting Leptospira via direct or indirect contact, since bovines are considered adapted hosts for this serogroup [19,20,27].…”

Cross-sectional survey for canine leptospirosis in an Atlantic Rainforest area of the semiarid of Paraíba state, Northeastern Brazil

“…The Autumnalis serogroup was the second most prevalent, and although it is considered uncommon in dogs, in recent years there has been an increase in seropositivity reports (Lemos et al 2010, Castro et al 2011, 2015. It is worth mentioning that among domestic species, this serogroup is more frequently reported as predominant in sheep (Alves et al 2004, Higino et al 2010, Barbante et al 2014) and goat (Araújo Neto et al 2010, Pimenta et al 2019. Therefore, it is likely that sheep and goat may be acting as reservoirs for this serogroup, thus contaminating the environment and other species, including dogs.…”

“…Serogroups Pomona, Grippotyphosa and Serjoe were also detected in the presente survey. Pomona is commonly found in pigs, being adapted to this species (Miraglia et al 2015), wild animals tend to be reservoirs of the Grippotyphosa serogroup (Allen et al 2014, Pedersen et al 2018 and cattle are often associated with the Serjoe (Pimenta et al 2019). Therefore, it is possible that other animal species act as important reservoirs in the epidemiological cycle of leptospirosis in the region.…”