Hepatitis E and Lymphocytic Leukemia in Man, Italy

nonpregnant or dry dairy cows that had been held in the same pasture, distant from the main farm structures, during October 15–November 15, 2011; during the stamping out process, a second dairy cow from this group had a positive test result by ELISA. Hunting of wild boar (Sus scrofa) had been organized during September–December 2011 in the adjacent forest, and wild boar offal was discarded in a corner of the pasture, with no biosecurity precautions. A recent study confirmed the high prevalence of B. suis biovar 2 infection in wild boars in this province (2). These findings suggest that these animals were naturally infected with B. suis biovar 2; because of the period between infection and testing, the results indicate that antibodies can be detected in cattle by ELISA performed on milk or serum >16 weeks after infection. Blood samples were taken from the farmer, his wife, and their 2 children, all of whom regularly consumed raw milk. No clinical signs or symptoms suggestive of brucellosis were reported, and slow agglutination test results for all family members were negative (titer <160), which suggests they had no exposure to B. suis biovar 2 (3). A total of 111 cattle carcasses, including that of the second seropositive cow, were sampled at the abattoir, and all other samples were negative for Brucella spp. Our findings indicate that preventive measures against the spread of pathogens such as Brucella spp. must be implemented by hunters (i.e., awareness campaigns, biosecurity education, and responsible hunting practices). In addition, biochemical typing of Brucella spp. is necessary to trace the source of infections (4,5), and epidemiologic inquiry of positive test result(s) should be conducted to identify or exclude bovine brucellosis and to investigate possible B. suis biovar 2 infections. Our bacteriologic results (absence of isolation of B. suis biovar 2 from all samples collected at the abattoir) suggest that stamping out is not necessary because B. suis biovar 2 is not likely to be transmitted between cattle because they are spillover hosts, not preferential hosts for B. suis biovar 2, and are thus not likely to sustain the infection. Finally, from a veterinary public health perspective, B. suis biovar 2 has a low residual pathogenicity in humans (5,6).