Treponemal infections in hares in The Netherlands

Abstract

Treponemal infections in wild European brown hares (Lepus europaeus) from The Netherlands were diagnosed by means of serological tests for human syphilis and histological demonstration of spirochetes by the Bosma-Steiner silver impregnation method in histological sections of skin lesions. The treponeme should probably be classified as "Treponema paraluisleporis."

High syphilis seropositivity in European brown hares ( Lepus europaeus ), Lower Saxony, Germany

“…The high number of seropositive animals demonstrates widespread treponematosis in wild EBHs in Lower Saxony, Germany. This concurs with previous studies on T. paraluisleporidarum infection in EBHs in Serbia (Jakšić, 1957), Hungary (Horvath, Kemenes, & Molnar, 1979), the Netherlands (Lumeij, 2011; Lumeij et al, 1994), Sweden (Mörner, 1999), Italy (Verin et al, 2012), Austria and Germany (Posautz et al, 2014), and the Czech Republic (Nováková et al, 2019), where seroprevalence ranged between 1% and 64% ( n = 8; 37.8 ± 21.4 [mean ± SD ]). Yet, the significantly higher rate of adult EBHs with antibodies against T. paraluisleporidarum in the current study in Lower Saxony argues for a horizontal (sexual) transmission mode, which is also reported for human‐ ( T. pallidum ) and rabbit‐syphilis ( TP eC; Froberg, Fitzgerald, Hamilton, Hamilton, & Zarabi, 1993; Small & Newman, 1972).…”

“…European brown hares are rarely reported with clinical lesions such as skin ulcerations and crusting of the anogenital and facial region (Lumeij, de Koning, Bosma, van der Sluis, & Schellekens, 1994). However, similar to what is seen in human syphilis, infection elicits a pronounced serological response in its lagomorph host (Baker‐Zander & Lukehart, 1984).…”

High syphilis seropositivity in European brown hares, Lower Saxony, Germany

“…The latter argues for a sexual transmission mode, as reported for human and rabbit syphilis [10]. Clinical manifestations have been described to occur in about 1% of the infected wild EBHs [4] and were not seen in any of the examined hares in this study. This is likely attributed to the low number of animals that were prospectively sampled (19) and which were clinically examined.…”

“…We used serological tests to demonstrate the presence of antibodies against TP eL. EBHs are rarely reported with clinical lesions such as skin ulcerations and crusting of the anogenital and facial region [4]. However, similar to what is seen in human syphilis, infection elicits a pronounced serological response in its lagomorph host [5].…”

Syphilis in European brown hares (Lepus Europaeus)

“…The Bosma-Steiner silver staining method as used in the present study is considered an important improvement for the detection of Treponema spp in lagomorphs since the digestion of mucoid substances by amylase treatment and use of short time high concentration silver impregnation results in better visualization of spirochetes in formalin-fixed tissue sections. An alternative method to make a diagnosis is by performing serology as specified previously (7).…”