Epidemic of Salmonellosis in Passerine Birds in Switzerland With Spillover to Domestic Cats

Abstract

A die-off of passerine birds, mostly Eurasian siskins (Carduelis spinus), occurred in multiple areas of Switzerland between February and March 2010. Several of the dead birds were submitted for full necropsy. Bacteriological examination was carried out on multiple tissues of each bird. At gross examination, common findings were light-tan nodules, 1 to 4 mm in diameter, scattered through the esophagus/crop. Histologically, a necroulcerative transmural esophagitis/ingluvitis was observed. Bacterial cultures yielded Salmonella enterica subsp. enterica serovar Typhimurium. At the same time, 2 pet clinics reported an unusual increase of domestic cats presented with fever, anorexia, occasionally dolent abdomen, and history of presumed consumption of passerine birds. Analysis of rectal swabs revealed the presence of S. Typhimurium in all tested cats. PFGE (pulsed field electrophoresis) analysis was performed to characterize and compare the bacterial isolates, and it revealed an indistinguishable pattern between all the avian and all but 1 of the feline isolates. Cloacal swabs collected from clinically healthy migrating Eurasian siskins (during autumn 2010) did not yield S. Typhimurium. The histological and bacteriological findings were consistent with a systemic infection caused by S. Typhimurium. Isolation of the same serovar from the dead birds and ill cats, along with the overlapping results of the PFGE analysis for all the animal species, confirmed a spillover from birds to cats through predation. The sudden increase of the number of siskins over the Swiss territory and their persistency during the whole winter of 2009-2010 is considered the most likely predisposing factor for the onset of the epidemic.

Salmonella spp. in Wild Free‐Living Birds from Atlantic Forest Fragments in Southern Bahia, Brazil

“…Studies indicate that Salmonella Typhimurium is the most prevalent serovar in wild birds [10,11] with reports of outbreaks of septicemia and deaths in wild birds in the United Kingdom, Canada, Sweden, Switzerland, and Norway [12][13][14][15][16]. Wild birds affected by Salmonella spp.…”

Wildlife health investigations: needs, challenges and recommendations

“…However, despite the listed impediments, scanning surveillance retains considerable potential value. It provides an ideal setting for disease discovery, in particular of emerging diseases of wildlife, as has been the case for chronic wasting disease and bovine tuberculosis in the United States [21], for babesiosis in Alpine chamois and salmonellosis in passerine birds in Switzerland [98,99] or for avian pox in British tit species [100]. …”

“…The peak of submissions in 2006–2007 was associated with the avian influenza outbreak in Switzerland [101] and the recrudescence of cases in 2010 was partly due to an epidemic of salmonellosis in passerine birds [99]. …”

Simple and noninvasive method for assessment of digestive efficiency: Validation of fecal steatocrit in greenfinch coccidiosis model

“…Greenfinches like other passerines with similar biology regularly suffer outbreaks of digestive tract infections such as salmonellosis (Giovannini et al, 2013;Grant, Todd, & Pennycott, 2007;Lawson et al, 2010), trichomonosis (Lehikoinen, Lehikoinen, Valkama, Väisänen, & Isomursu, 2013) and coccidiosis (Hõrak et al, 2004). All these microbes inhibit the absorption of nutrients, so we expected that experiments aiming at manipulation of infection will affect fat absorption capacity, estimated on the basis of steatocrit.…”