Spatial distribution of equine seroreagent to Leptospira spp. in Northeastern Brazil

Abstract

Considering the importance of leptospirosis in both equine husbandry and public health, as well as the relevance of knowledge of current serogroup and the small number of studies addressing this disease in equines in Northeastern Brazil, the present study performed a serological survey of Leptospira spp. in a serum bank of 1,267 equines originating from 177 municipalities, located in four states in Northeastern Brazil: Ceará, Rio Grande do Norte, Paraíba and Pernambuco. The microscopic agglutination test (MAT) was used for diagnosis of leptospirosis using 24 serovars as antigens. The frequency of reagent equines was 29.7% (376/1,267), and 68.9% (122/177) of municipalities had at least one positive reaction. The serogroups reagent were Australis (37.2%), Icterohaemorrhagiae (29.3%), Tarassovi (9.6%), Sejroe (5.8%), Pomona (5.3%), Grippotyphosa (4.5%), Pyrogenes (2.4%), Bataviae (1.9%), Ballum and Hebdomadis (1.3%), Mini (0.5%), Celledoni, Shermani, and Javanica (0.3% each). There were significant statistical differences regarding sex and age, with a higher frequency in females (P= 0.014), and in animals ≥ 6 years (P=0.001). We concluded that seropositivity to Leptospira spp. is high in equines in Northeastern Brazil, with a predominance of serologic reactions to the Australis serogroup in the border areas between the states, and the Icterohaemorrhagiae serogroup in coastal areas or their vicinity. The high degree of seropositivity found points to the need to implement prophylactic strategies, both intraspecies infection prophylaxis and rodent control. We also recommended avoiding animal crowding and separating animals according to sex and age group during handling.

Seroprevalence of Leptospira spp. in horses from Rio Grande do Norte, Brazil

“…It also corroborates a serological survey on donkeys slaughtered in Pernambuco, destined for meat exportation for human consumption (Morais et al 2019c). It was the main serogroup in the Central Potiguar mesoregion and the second most diagnosed in East and West Potiguar (Morais et al 2019a). Such expressive numbers of prevalence for this variant warn to the management and hygiene practices in the studied mesoregions.…”

“…The Rio Grande do Norte (n=252) had the highest seropositive rate. In this study, most of the samples from the State (82% of 252) were from West Potiguar, which had a rate (26%; 53/206) well below this survey (96.5%), as well as from East Potiguar (56%, 13/26), despite the lower number of samples (Morais et al 2019a). Since the climatic conditions are the same in both regions, this difference may be related to the type of samples studied (random/convenience X sent to a diagnostic laboratory) and the sanitary management to which these animals were submitted.…”

“…Such expressive numbers of prevalence for this variant warn to the management and hygiene practices in the studied mesoregions. This predominance positively correlates with rodents, precarious or deficient cleaning conditions, and inadequate food storage (Siqueira 2012, Alves et al 2016, Morais et al 2019a. Infection of the equine species by this serovar leads to high production of antibodies, and a greater possibility of clinical manifestations (Chiareli et al 2008), a situation that was not observed in any animal in this study at the time of sampling.…”

Seroepidemiology of leptospirosis and molecular characterization of the first Leptospira strain isolated from Fernando de Noronha archipelago, Brazil

“…Horses had the highest seroprevalence found and presented the highest titers mostly against Icterohaemorrhagiae. Although serological surveys in Brazil have confirmed infection caused by serogroup Australis, including horses from Northeast region (Morais et al, 2019), Icterohaemorrhagiae infection has been consistently demonstrated in numerous other studies, currently categorizing this serogroup as the most prevalent among horses in Brazil (Pinto et al, 2017).…”

Seroepidemiological investigation of animal leptospirosis and molecular characterization of the first Leptospira strain isolated from Fernando de Noronha archipelago, Brazil

“…Horses had the highest seroprevalence found and presented the highest titres mostly against Icterohaemorrhagiae. Although serological surveys in Brazil have confirmed infection caused by serogroup Australis, including horses from Northeast region (Morais et al., 2019), Icterohaemorrhagiae infection has been consistently demonstrated in numerous other studies, currently categorizing this serogroup as the most prevalent among horses in Brazil (Pinto et al., 2017).…”