Antibodies to West Nile virus in feral swine from Florida, Georgia, and Texas, USA.

West Nile virus (WNV) exposure has not yet been reported in feral swine (Sus scrofa) despite the broad geographic range and population density of this species. The objectives of this study were to determine the prevalence of antibodies to WNV in feral pigs, and to evaluate serologic diagnostics as applied to this species. Feral pig serum from three states was evaluated for antibodies to WNV. The overall WNV seroprevalence rate for 222 samples collected in 2001-2004 was 22.5%. Seroprevalence rates in Florida, Georgia, and Texas were 17.2%, 26.3%, and 20.5%, respectively. The results of this study demonstrate that feral pigs could represent useful mammalian sentinels of WNV.

Detection of Babesia and Anaplasma species in rabbits from Texas and Georgia, USA.

Rabbits have been shown to harbor a suite of zoonotic organisms, including a Babesia species, Borrelia burgdorferi, and Anaplasma phagocytophilum. In this study, we conducted a molecular survey for various tick-borne pathogens in three species of rabbits from Texas and Georgia. Of 18 black-tailed jackrabbits (Lepus californicus) tested from Texas, six (28%) were polymerase chain reaction (PCR) positive for Babesia, and nucleotide sequencing revealed two distinct species or strains. Two jackrabbits were infected with a Babesia species or strain (Babesia sp. A) that was nearly identical (99.9%) to a piroplasm previously detected in humans from Washington state, and the remaining four jackrabbits were infected with a Babesia species (Babesia sp. B) that was most similar (99.7%) to a Babesia species detected in cottontail rabbits from Massachusetts and humans from Kentucky and Missouri. Eleven (61%) black-tailed jackrabbits were positive for A. bovis, and one was positive for A. phagocytophilum. Two of four desert cottontails (Sylvilagus audubonii) from Texas were positive for the Babesia sp. B, and one desert cottontail each was positive for A. bovis and A. phagocytophilum. One of these desert cottontails was coinfected with the Babesia sp. B and A. phagocytophilum, and five jackrabbits were coinfected with Babesia species and A. bovis. Of 19 eastern cottontails (S. floridanus) from Georgia, only one (5.3%) was positive for A. phagocytophilum, and three (15.8%) were positive for A. bovis. No rabbits from Texas or Georgia were positive for Borrelia species. The only tick species detected on the Texas and Georgia rabbits was the rabbit tick, Haemaphysalis leporispalustris. These data extend the geographic and host range of these pathogens, and because both the Babesia species and A. phagocytophilum are potential zoonotic pathogens, it is important to be aware that these organisms are enzootic in parts of the southern United States.