A seroepidemiological survey for paragonimosis among boar-hunting dogs in central and southern Kyushu, Japan

A seroepidemiological survey for paragonimosis among boar-hunting dogs was conducted throughout central and southern Kyushu, Japan. Among a total of 224 sera collected from boar-hunting dogs kept by 38 owners, 147 (65.6%) were positive for IgG antibodies against Paragonimus westermani antigen by ELISA. In the 147 seropositive dogs, 83 (56.5%) dogs demonstrated high antibody titers (OD > 0.700), which appeared to indicate active infection. There were no obvious differences noted in age, sex and the genetic background of the dogs. The seroprevalence was dependent on the feeding manner of the owners and was extremely variable (0–100%). The majority (34/38) of owners fed their dogs uncooked boar meat and/or allowed them free-access to the residues of hunted boars after dissection, resulting in dogs with seropositive results. The dogs that were never fed wild boar meat were entirely seronegative. These results clearly demonstrate that boar-hunting dogs play an important role as a definitive Paragonimus host and that wild boars serve as a reservoir host for the maintenance of the Paragonimus life-cycle, presumably P. westermani, in the mountainous areas of central and southern Kyushu, Japan.