Systematic assessment of the impact of adenovirus infection on a captive reintroduction project for red squirrels (Sciurus vulgaris).

PCR was used to amplify adenoviral DNA, and transmission electron microscopy (TEM) to detect adenovirus particles in tissue and intestinal content samples from red squirrels (Sciurus vulgaris) associated with a reintroduction study on Anglesey (North Wales), from other populations on the island and from stock held at the Welsh Mountain Zoo, 38 km to the east. Samples were collected during the routine surveillance postmortem examinations of all 60 red squirrels with carcases retrieved in a suitable condition between 2004 and 2010, including 29 captive and 31 free-living animals. Following significant clusters of mortality in captive red squirrels, adenovirus was identified retrospectively in faecal material from 12 of 13 (92 per cent) examined carcases from squirrels captive on Anglesey, and 14 of 16 (88 per cent) from the Welsh Mountain Zoo. Virus was identified in 13 of 31 (42 per cent) free-living wild animals, with evidence of both subclinical and clinically significant enteric adenoviral infections in wild squirrels. Without ancillary PCR and TEM testing, the extent of adenovirus infection in such populations would have been underestimated. Screening protocols that include examinations for adenovirus should, therefore, be part of the routine biosecurity measures protecting reintroduction or captive breeding programmes for red squirrels.

Field assessment of Trypanosoma cruzi infection and host survival in the native rodent Octodon degus.

Chagas disease is a zoonosis caused by the flagellated parasite Trypanosoma cruzi and transmitted by triatomine insects to several mammalian species acting as reservoir hosts. In the present study, we assess T. cruzi-prevalence, survivorship and T. cruzi-infection rate of the endemic rodent Octodon degus from a hyper-endemic area of Chagas disease in Chile. Parasite detection is performed by PCR assays on blood samples of individuals captured in austral summer of 2010, and on non-infected individuals recaptured in 2011 as well as on new captures. Results show a high infection level in this species (up to 70%). Infected O. degus have the same chance of surviving to the next reproductive season as uninfected individuals, irrespective of sex. We suggest that O. degus, an abundant long-lived rodent with high dispersal capability, could be considered an important native reservoir of T. cruzi in the wild transmission cycle of Chagas disease in Chile.