Epidemiologic and Pathologic Aspects of Salmonella Typhimurium Infection in Passerine Birds in Norway

Abstract

Septicemic salmonellosis caused by Salmonella Typhimurium 4, 12: i:1, 2 was diagnosed in 94 (64.8%) of 145 small passerines comprising nine species, examined in Norway during 1999-2000. The birds were found dead at private feeding places throughout the country. The bullfinch (Pyrrhula pyrrhula), Eurasian siskin (Carduelis spinus), common redpoll (Carduelis flammea), and Eurasian greenfinch (Carduelis chloris) were the most frequently affected species. Pathologic findings in 94 carcasses included poor body condition (84%), enlarged spleen (73%), and necrosis of crop/esophagus (78%), liver (53%), spleen (46%), proventriculus (13%), and intestine (5.3%). Histologically, necrosis consisted of debris, fibrin, inflammatory cells, and aggregates of Gram-negative bacteria and occasionally giant cells. Based on information from questionnaires sick and dead birds were observed at feeding places from December to June, with a distinct peak during February and March. The duration of recorded outbreaks varied from less than 1 wk to 4 mo. In a separate study, 1,990 apparently healthy passerines caught at feeding places established for bird-ringing purposes were surveyed for cloacal carriage of Salmonella spp. Forty (2.0%) of the birds examined, representing sampling sites both in southern and northern parts of the country, harbored S. Typhimurium 4, 12: i:1, 2 in their intestines. The carrier species largely reflected the species most often suffering from fatal infection.

MASS MORTALITY OF EURASIAN TREE SPARROWS (PASSER MONTANUS) FROMSALMONELLATYPHIMURIUM DT40 IN JAPAN, WINTER 2008–09

“…This supports previous reports that prevalence of Salmonella infection among wild birds at feeding sites is high (Refsum et al 2003;Lawson et al 2010). The same strain of S. Typhimurium was detected in droppings excreted by a healthy sparrow visiting a bird table during the field survey, indicating the existence of asymptomatic carriers, which are considered a major source of fatal infections (Daoust et al 2000;Pennycott et al 2006).…”

“…Sparrows with salmonellosis were typically emaciated, consistent with previous reports describing infected birds as having poor body condition (Daoust et al 2000;Refsum et al 2003;Lawson et al 2010). Many birds had enteritis, often with hemorrhage.…”

“…Infection mortality may be explained by tree sparrow-specific factors such as a particular susceptibility to infection and the synanthropic behavior associated with bird feeding, resulting in greater exposure to Salmonella (Refsum et al 2003), as well as to narrow DT40 host-range adaptation (Rabsch et al 2002;Hughes et al 2008).…”

“…enterica serovar Typhimurium (S. Typhimurium) (Le Minor and Popoff 1987) have been documented since at least the mid20th century, with an early report in Great Britain 1956-66 (Wilson and Macdonald 1967). Recently, salmonellosis has caused widespread mortality in passerines in countries including North America (Daoust et al 2000;Hall and Saito 2008), Sweden (Tauni and Ö sterlund 2000), New Zealand (Alley et al 2002), Norway (Refsum et al 2003), Great Britain (Pennycott et al 2006), and Japan (Une et al 2008). Salmonellosis is considered an emerging infectious disease of wild birds because its prevalence appears to have increased over the past 40 yr (Tizard 2004), particularly in association with bird feeding (Lawson et al 2010).…”

Septicemic Salmonellosis Caused by Salmonella Hessarek in Wintering and Migrating Song Thrushes (Turdus Philomelos) in Spain

“…Salmonellosis outbreaks regularly cause mortality in wild birds in several areas of the world (Daoust et al, 2000;Refsum et al, 2003;Hall and Saito, 2008;Pennycott et al, 2010). These outbreaks mainly affect birds of the order Passeriformes and are commonly caused by Salmonella enterica subsp.…”