Serosurvey of anti-Neospora caninum antibodies in wild boars (Sus scrofa), hunting dogs and hunters of Brazil.

The protozoan Neospora caninum is an important cause of abortion in cattle worldwide, with domestic dogs serving as the definitive hosts. Although hunting activities have been indicated as a potential risk factor for N. caninum infection in dogs, no serological evidence has so far been reported in hunting dogs, wild boars (Sus scrofa), and hunters. A total of 98 wild boars, 168 hunting dogs, and 15 hunters from three Brazilian regions were sampled and tested for anti-N. caninum antibodies by indirect immunofluorescence antibody test, resulting in 15/168 (9%) seropositive hunting dogs, and 0/98 wild boars, and 0/15 hunters seropositive. The absence of N. caninum antibodies in wild boars may suggest low exposure to oocysts shed by hunting dogs and wild canids in three different Brazilian regions. Finally, the absence of hunter seropositivity supports the current lack of evidence that N. caninum is a zoonotic parasite.