Swine can act as asymptomatic carriers of some Leptospira serovars. In this study, 1194 sera from 61 farms located in five different Regions of North-West Italy were collected from slaughtered healthy pigs. Presence of antibody against four Leptospira serovars was evaluated. Overall, 52.5% of analysed farms presented at least one positive animal and 34.4% presented at least one positive swine with titre ⩾1:400. A percentage of 16.6% sera was positive and 5.9% samples presented a positive titre ⩾1:400. Tuscany and Lombardy showed the highest percentage of positive farms (64.3% and 54.6%, respectively) and sera (28.5% and 13.3%, respectively), probably due to environmental conditions and potential risk factors, which promote maintenance and spreading of Leptospira in these areas. The main represented serogroups were Australis (21.3% positive farms, 8.2% positive sera) and Pomona (18.0% positive farms, 8.1% positive sera). In swine, these serogroups are the most detected worldwide; however, our results seem to highlight a reemerging of serogroup Pomona in pigs in investigated areas. A low percentage of sera (0.6%) scored positive to Canicola, leaving an open question on the role of pigs in the epidemiology of this serovar. Higher antibody titres were detected for serogroups Australis and Pomona. Swine leptospirosis is probably underestimated in Italy and could represent a potential risk for animal and human health.

The aims of this study were to determine the annual incidence of infection with Leptospira interrogans serovar Pomona and/or Leptospira borgpetersenii serovar Hardjo and its association with influenza-like illness (ILI) in meat workers in New Zealand. Sera were collected twice, 50–61 weeks apart, from 592 workers at eight abattoirs slaughtering sheep (n = 4), cattle (n = 2) and deer (n = 2), and tested by the microscopic agglutination test for Hardjo and Pomona. Forty-nine (8·3%) participants either seroconverted or had at least a twofold increased serological titre against either serovar. The worker infection risk was higher in sheep abattoirs (11·9%) than in abattoirs processing deer (0%) or cattle (1·2%) (P < 0·01). The annualized risk of mild (ILI) or severe clinical disease attributable to the two Leptospira serovars was 2·7%. This study has demonstrated that meat workers are at substantial risk of infection and clinical disease, suggesting further investigation of infection sources and preventive measures are warranted.