Research Article

Babesia vesperuginis: natural and experimental infections in British bats (Microchiroptera)

R. A. Gardnera1 p1 and D. H. Molyneuxa1 c1

a1 Department of Biological Sciences, University of Salford, Salford M 5 4 WT


Babesia vesperuginis is described from blood of two species of British bat: Pipistrellus pipistrellus and Myotis myslacinus. Reticulocytes appeared significantly elevated in blood films of P. pipistrellus infected with B. vesperuginis compared with uninfected laboratory-maintained bats or apparently uninfected wild-caught bats. Infected captive bats had significantly enlarged spleens. B. vesperuginis was transmitted by inoculation of infected blood to 5 uninfected captive P. pipistrellus. The course of infection followed a pattern of a rising parasitaemia accompanied by a rise in reticulocytes, followed by a fall in parasitaemia to low (<0·1%) or undetectable levels. When sacrificed, the Babesia-infected bats had significantly lowered blood haemoglobin, significantly raised white blood cell counts and enlarged spleens compared to uninfected bats. Attempts to transmit the parasite to irradiated and athymic ‘nude’ mice by inoculation of infected blood were unsuccessful. The experimental results and observations of infected wild bats indicate the potential pathogenicity of B. vesperuginis to bats. It is likely that the vector of B. vesperuginis is Argas vespertilionis because no Ixodid ticks were found on P. pistrellus.


c1 Address for reprints: Professor D. H. Molyneux, Department of Biological Sciences, University of Salford, Salford M5 4WT.

p1 Coralab Research, Huntingdon Road Laboratories, Cambridge CB3 0DJ.