In developing countries, estimates of the prevalence and diversity of Leptospira infections in livestock, an important but neglected zoonotic pathogen and cause of livestock productivity loss, are lacking. In Madagascar, abattoir sampling of cattle and pigs demonstrated a prevalence of infection of 20% in cattle and 5% in pigs by real-time PCR. In cattle, amplification and sequencing of the Leptospira-specific lfb1 gene revealed novel genotypes, mixed infections of two or more Leptospira species and evidence for potential transmission between small mammals and cattle. Sequencing of the secY gene demonstrated genetic similarities between Leptospira detected in Madagascar and, as yet, uncultured Leptospira strains identified in Tanzania, Reunion and Brazil. Detection of Leptospira DNA in the same animal was more likely in urine samples or pooled samples from four kidney lobes relative to samples collected from a single kidney lobe, suggesting an effect of sampling method on detection. In pigs, no molecular typing of positive samples was possible. Further research into the epidemiology of livestock leptospirosis in developing countries is needed to inform efforts to reduce human infections and to improve livestock productivity.
Bibliographical noteAcknowledgements. We thank the staff of the Plague Central Laboratory, Institut Pasteur de Madagascar, for technical assistance, especially Fehivola Andriamiarimanana, as well as staff from the abattoirs for their assistance during sampling.
Financial support. This work was supported the Wellcome Trust (Senior Fellowship no. 095171 to S.T., Veterinary Training Fellowship no. 096400/Z/11/Z to K.A., Institutional Strategic Support Fund to the University of Aberdeen no. 2014815/Z/16/Z), the Biotechnology and Biological Sciences Research Council (no. BB/M010996/1), the University of Aberdeen Environment and Food Security theme and Institut Pasteur Madagascar.