a1 Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, UK
a2 Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK
Zoonotic visceral leishmaniasis (ZVL) caused by Leishmania infantum is an important disease of humans and dogs. Here we review aspects of the transmission and control of ZVL. Whilst there is clear evidence that ZVL is maintained by sandfly transmission, transmission may also occur by non-sandfly routes, such as congenital and sexual transmission. Dogs are the only confirmed primary reservoir of infection. Meta-analysis of dog studies confirms that infectiousness is higher in symptomatic infection; infectiousness is also higher in European than South American studies. A high prevalence of infection has been reported from an increasing number of domestic and wild mammals; updated host ranges are provided. The crab-eating fox Cerdocyon thous, opossums Didelphis spp., domestic cat Felis cattus, black rat Rattus rattus and humans can infect sandflies, but confirmation of these hosts as primary or secondary reservoirs requires further xenodiagnosis studies at the population level. Thus the putative sylvatic reservoir(s) of ZVL remains unknown. Review of intervention studies examining the effectiveness of current control methods highlights the lack of randomized controlled trials of both dog culling and residual insecticide spraying. Topical insecticides (deltamethrin-impregnated collars and pour-ons) have been shown to provide a high level of individual protection to treated dogs, but further community-level studies are needed.
(Received February 24 2009)
(Revised July 26 2009)
(Accepted July 30 2009)
(Online publication October 16 2009)
c1 Corresponding author: Institute of Integrative & Comparative Biology, University of Leeds, Leeds LS2 9JT, United Kingdom. Tel: +44-113-3432824. Fax: +44-113-3432835. Email: R.J.Quinnell@leeds.ac.uk