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. 2012 Feb 17;2:10.3402/iee.v2i0.17093. doi: 10.3402/iee.v2i0.17093

Rodents on pig and chicken farms – a potential threat to human and animal health

Annette Backhans 1,*, Claes Fellström 1
PMCID: PMC3426328  PMID: 22957130

Abstract

Rodents can cause major problems through spreading various diseases to animals and humans. The two main species of rodents most commonly found on farms around the world are the house mouse (Mus musculus) and the brown rat (Rattus norvegicus). Both species are omnivorous and can breed year-round under favourable conditions. This review describes the occurrence of pathogens in rodents on specialist pig and chicken farms, which are usually closed units with a high level of bio-security. However, wild rodents may be difficult to exclude completely, even from these sites, and can pose a risk of introducing and spreading pathogens. This article reviews current knowledge regarding rodents as a hazard for spreading disease on farms. Most literature available regards zoonotic pathogens, while the literature regarding pathogens that cause disease in farm animals is more limited.

Keywords: rodents, infections, zoonoses, pigs, chicken


Rodents can cause major problems due to destruction and contamination of food, and also by the spread of various diseases. This review describes the occurrence of pathogens in rodents specifically on pig and chicken farms. The emphasis is on zoonotic pathogens that are indirectly transmitted to humans through contaminated food, or pathogens that cause important diseases in pigs. The order Rodentia (L. rodere, to gnaw) constitutes the most successful mammalian group, both in terms of the number of species and individuals (1). Two commensal (L. cum mensa, sharing a table) species are common inhabitants on farms worldwide: the house mouse (Mus musculus) and the brown rat syn. norwegian rat (Rattus norvegicus). Both species originated from Asia, from where they spread over the world along with the development of agriculture, which provided shelter and supplies of food. They are underground dwellers, omnivorous and can breed year-round when conditions are optimal (1, 2). The house mouse weighs 12–30 g, eats vegetables or any available food, and is active at any hour of the day. It manages well without water for a substantial time and can adapt to temperatures down to 10 °C (1). Its home range is less than 10 m2 and daily movement of an individual mouse is only a few square or cubic metres. A female can produce up to 10–14 l, each containing 3–12 puppies per year (2). The brown rat usually weighs 200–400 g and lives in territorial colonies with population densities on farms of 50–300 individuals. Compared with the house mouse, it has a rather large home range of 25–150 m in diameter, but individual rats can move 3 km away and back in one night (2), and rats are more active during night time (3).

Rodents as carriers of zoonotic disease

On farms, the risk of rodent-borne spread of pathogens to production animals is obvious due to the difficulty of excluding rodents from animal houses. Several studies have focused on rodents as possible carriers of various pathogens. Table 1 shows selected studies regarding rodents as carriers of zoonotic pathogens. Included in the table are studies published in international peer-reviewed journals, on rodents caught on pig or chicken farms and their surroundings. Results regarding rodent species other than brown rats, black rats, and house mice have been excluded.

Table 1.

Selected studies on rodents as carriers of human pathogens on pig and chicken farms

Pathogen studied Reference Rodent species Country Location Detection method Detection rate
Salmonella Enteritidis Davies and Wray (14) Mice Great Britain Broiler & layer breeder flocks Culture 29/84
Salmonella Enteritidis Lapuz, Tani et al. (106) R. rattus Japan Layer farms Culture 113/851
Salmonella Infantis 158/851
Salmonella Livingstone Meerburg, Jacobs-Reitsma et al. (11) R. norvegicus Ns Organic farms Culture 0/8
M. musculus 1/83
Salmonella spp. Pocock, Searle et al. (18) M. musculus domesticus UK Mixed farms Culture 0/341
Salmonella Enteritidis Henzler and Opitz (16) M. musculus USA Poultry farms Culture 116/715
Salmonella sp. Le Moine, Vannier et al. (107) R. norvegicus France Pig farms Culture 1/40
M. musculus 2/34
Campylobacter spp. Meerburg, Jacobs-Reitsma et al. (11) R. norvegicus ns Organic farms Culture 1/8
M. musculus 8/83
Campylobacter jejuni Le Moine, Vannier et al. (107) R. norvegicus France Pig farms Culture 16/40
M. musculus 4/34
Yersinia spp. biotype 1A Pocock, Searle et al. (18) M. musculus UK Mixed farms Culture 21/354
Yersinia (Y.) enterocolitica O:3 Aldova, Cerny et al. (24) R. rattus Czechoslovakia Pig houses Culture 16/96
Y. enterocolitica O:3 Pokorna and Aldova (108) R. rattus Czechoslovakia Pig houses Culture 5/36
Y. enterocolitica 4/O:3 Kaneko, Hamada et al. (25) R. norvegicus Japan Slaughter-house, barn, zoo Culture 2/270
R. rattus
Y. enterocolitica 4/O:3 Backhans, Fellström et al. (26) R. norvegicus Sweden Pig farm TaqMan PCR 7/56
M. musculus 2/120
Y. pseudotuberculosis Pocock, Searle et al. (18) M. musculus UK Mixed farms Culture 1/354
Y. pseudotuberculosis Kaneko, Hamada et al. (35) R. norvegicus Japan Barn Culture 8/259
R. rattus 0/11
Y. pseudotuberculosis Aldova, Cerny et al. (24) R. rattus Czechoslovakia Pig houses Culture 16/178
R. norvegicus
Y. pseudotuberculosis Backhans, Fellström et al. (26) R. norvegicus Sweden Pig farm TaqMan PCR 0/56
M. musculus 1/120
Cryptosporidium parvum Quy, Cowan et al. (65) R. norvegicus UK Farms IFAT 105/438
Cryptosporidium parvum Webster and MacDonald (66) R. norvegicus UK Rural Modified Ziehl-Nielsen 46/73
Leptospira spp. Webster, Ellis et al. (40) R. norvegicus UK Mixed farms MAT, ELISA, cultivation 37/259
Listeria spp. Webster, Ellis et al. (109) R. norvegicus UK Rural Cultivation 5/44
Trichinella spiralis Stojcevic, Zivicnjak et al. (61) R. norvegicus Croatia Pig farms ns 18/2287
Trichinella spiralis Leiby, Duffy et al. (110) R. norvegicus USA Pig farm Peptic digestion 188/443
Toxoplasma gondii Kijlstra, Meerburg et al. (50) R. rattus Netherlands Organic pig farms TaqMan PCR 4/39
M. musculus 2/31
Toxoplasma gondii Smith, Zimmerman et al. (56) R. norvegicus USA Pig farms Serology (MAT) 0/9
M. musculus 2/588
Toxoplasma gondii Webster (111) R. norvegicus UK Rural ILAT ELISA 84/235
Hantavirus Webster (111) R. norvegicus UK Rural ELISA 5/173

R, Rattus; M, Mus; ns, not specified; IFAT, indirect immunofluorescent antibody test; MAT, microscopic agglutination test; ELISA, enzyme-linked immunosorbent assay; ILAT, indirect latex agglutination test.

Zoonotic bacteria

The three most commonly reported zoonoses in the EU are the foodborne enteric diseases campylobacteriosis, salmonellosis, and yersiniosis (4). Most cases of campylobacteriosis are caused by Campylobacter jejuni, followed by Campylobacter coli and Campylobacter lari. Humans become infected by consuming contaminated meat, especially poultry meat, which is commonly contaminated by C. jejuni. Pigs, in particular growing pigs, are commonly colonised by Campylobacter spp., mostly by C. coli, but also by C. jejuni (5, 6). However, results from genotyping studies indicate that isolates from pigs differ genetically from human isolates to a larger extent than poultry isolates (7). There are just a few studies on the subject of rodents as a risk of transmission of campylobacter, but one study concluded that occurrence of rodents was one of the risk factors for high Campylobacter prevalence in broiler chicken flocks (8), and a similar tendency, although not significant, was described by in another study (9). Mice experimentally infected with C. jejuni become colonised and excrete bacteria for several weeks (10). One study found that isolates from pig manure and rodents on organic pig farms differed genetically (11), but these isolates originated from different farms, so the results may simply reflect biodiversity within the species.

Non-typhoidal salmonellosis is the second most reported zoonosis, and also the most frequently reported cause of food-borne outbreaks within the EU (4). The majority of cases worldwide are caused by Salmonella serovar Enteritidis, of which the most important sources are eggs and poultry meat (4, 12). The second most common, and in North America the most common serovar, is Salmonella Typhimurium, which is usually derived from pig, poultry, or bovine meat (4). Infected pigs are usually subclinical carriers of zoonotic Salmonella, although some serovars cause disease in the pig (13). The source of infection of Salmonella to poultry or other farm animals, except for the introduction of infected animals, can be anything from a broad range of wild animals including birds and rodents, to cats, feed, and the environment. Salmonella persists for years in suitable conditions, surviving both freezing and dryness (13). Davies and Wray (14) showed that Salmonella Enteritidis could be cultured from a large proportion (19–86%) of mice on infected layer and broiler farms, and that droppings from infected mice were infective for pullets up to 2 months after inoculation. Liebana et al. (15) further emphasised mice as the most common finding in their study of vast numbers of environmental and vector samples on S. Enteritidis-contaminated farms. Henzler and Opitz (16) found that mice amplify the bioconcentration of S. Enteritidis, resulting in an isolation rate three times higher than from the environment. Mouse population density has also been shown to be an important factor for the transmission of Salmonella between chicken and mouse. In a study from Denmark, a strong correlation was indicated between Salmonella in production animals and wildlife, including rodents. However, wildlife animals tested positive only during periods when Salmonella was detected in production animals, indicating the production animals as the source of infection (17). Similarly, two other studies showed that low prevalence of Salmonella in mice on farms coincided with negative farm animals (11, 18).

Yersiniosis is the third most frequently reported zoonosis in Europe, with the majority of human cases caused by Yersinia (Y). enterocolitica bioserotype 4/O:3 (19), with occasional outbreaks especially in the northern hemisphere caused by Yersinia pseudotuberculosis (20, 21). The reservoir of human pathogenic Y. enterocolitica is the domestic pig (22). One study found Y. enterocolitica in about 8% of wild rodents in Scandinavia, but no human pathogenic biotypes (23). House mice on farms are colonised mainly by Y. enterocolitica serogroup 1A (18), but serotype O:3 has been isolated from black rats (Rattus rattus) in pig houses (24), and serotype 4/O:3 from brown rats in a slaughterhouse (25) and brown rats and house mice in pig houses, of similar genotypes as pig isolates from the same farms (26).

Yersinia pseudotuberculosis appears to circulate between animals and the environment in wild birds (27), various free-living mammals such as deer, hare, marten, and racoon dog (28) and water (29), but has also been isolated from domestic pigs (30, 31) and from wild boars (32). In Finland, recent outbreaks of Y. pseudotuberculosis were traced to carrots and iceberg lettuce stored in such a way that they were accessible to rodents and other wildlife. The same authors identified pest animals as a risk factor for high prevalence of Y. pseudotuberculosis on pig farms (20, 21, 33). Furthermore, Y. pseudotuberculosis has been found in mice, moles, and barn rats (34, 35). Identical restriction endonuclease patterns were found in isolates from rat and a patient within the same area in Japan where transmission through rodent-contaminated water was suspected (29). Rats were also strongly suspected of being the source of infection in a breeding monkey outdoor facility (36).

Leptospirosis is a zoonotic disease of worldwide distribution which causes subclinical to severe cases of icteric leptospirosis with renal failure, often called Weil's disease (37). Animals of different species, including rodents, act as maintenance hosts for different serovars of Leptospira (38). Several studies show that wild rodents are common carriers of leptospires, including feral rodents (39), rodents on farms (40), and rodent pets (41). A high proportion of sewer rats in Copenhagen were recently found to be infected with serovars Pomona, Sejroe, and Icterhaemorrhagiae (42).

In the Netherlands, black rats on pig farms were found to be carriers of methicillin-resistant Staphylococcus aureus (MRSA) of a multilocus sequence type 38 strain that has emerged as a cause of hospital-acquired infections (43).

Zoonotic parasites

The parasite Toxoplasma gondii is a coccidium that infects all warm-blooded animals which act as intermediate hosts (44), whereas definitive hosts are cats of various species (45). In humans, infection during pregnancy can cause abortion or congenital toxoplasmosis in the foetus, with subsequent central nervous system (CNS) and ocular lesions (46). The sources of infection to humans are soil exposure (47), eating undercooked meat, especially pork (44), and cleaning cat litter boxes (48), while rodents are believed to be an important source of T. gondii infection to cats (49). Rodents also seem to play a role in the transmission of T. gondii to pigs: a correlation between T. gondii seroprevalence in pigs and seropositive rodents has been shown in several studies (50, 51). Prevalence studies show somewhat different results depending on methods used. Various serological methods have been used (52, 53), but also polymerase chain reaction (PCR) applied directly on brain tissue, which generally results in higher prevalences (54, 55). Murphy et al. (81) used both PCR and serology simultaneously in mice and found a PCR detection rate of 59%, whereas the detection rate by serology was only 1.0%. Thus, low sensitivity for serological methods detecting T. gondii could be the explanation for the low prevalence of toxoplasmosis previously reported in rodents (56, 57).

The eight recognised species of the nematode Trichinella are all pathogenic to humans, causing intestinal and muscular disease of varying severity (58). The most important species associated with human disease is T. richinella spiralis, which is most adapted to domestic and wild pigs (58), whereas other species have wild carnivores as main and intermediate hosts. In Europe, T. richinella britova has become more widespread due to its occurrence in sylvatic carnivores, whereas T. spiralis dominates in domestic pigs and wild boars (59). In Romania, for example, trichinellosis is a serious health problem, with an annual incidence of 6.2 cases per 100,000 inhabitants between 1990 and 2007 (60). Rats can be infected by Trichinella, but their importance in spreading the disease is unclear. Leiby et al. (22) found that a population of rats scavenging on infected dead pigs remained infected during a 25-month period after the infected pigs were removed. Stojcevic et al. (61), on the other hand, detected infected rats only on pig farms with positive pigs in an area with endemic infection of T. spiralis and concluded that the cause of infection in rats is improper slaughter procedures, which result in the spread of infected pork scraps in the environment.

The parasitic gastrointestinal infections cryptosporidiosis and giardiosis are common and have worldwide distributions. For both of these infections, outbreaks can often be traced to water or to food, and the infectious dose is small (62, 63). To date, there are 19 known species of the protozoan Cryptosporidium (64), of which two, Cryptosporidium hominis and Cryptosporidium parvum, can cause diarrhoea in humans. C. hominis is restricted to humans, whereas C. parvum is zoonotic. Before the development of molecular biology methods for genotyping isolates of Cryptosporidium, wild animals including rodents were considered carriers of zoonotic Cryptosporidium (65, 66), leading to an overestimation of their zoonotic importance. More recent studies show that most of the Cryptosporidium oocysts detected in rodents belong to other species or genotypes than C. parvum, for instance mouse genotype I, which is host-adapted to rodents, and Cryptosporidium muris (67), which in rare cases has been isolated from human patients (68, 69). Giardia intestinalis (syn. duodenalis, lamblia) has been described as the most common intestinal parasite in humans and livestock (70). Similarly, with the use of molecular methods, Giardia, an intestinal flagellate, has been divided into assemblages A–G, each of which has distinct host spectra. Assemblages A and B are zoonotic genotypes, C and D are dog genotypes, E livestock, F cat, and G are rat genotypes (71). Other Giardia species that have been isolated from rodents are Giardia muris and Giardia microti, species which are not zoonotic (72).

Zoonotic virus

Hepatitis E virus (HEV) belongs to the family Hepeviridae and includes four genotypes with the ability to infect humans and other animals. Besides genotypes 1 and 2, which are restricted to humans, genotypes 3 and 4 have been detected in both humans and pigs (73). Several studies have shown that occupational pig exposure is a factor for HEV infection (74), which suggests animal-human transmission of the virus. In the search for other potential reservoir animals for hepatitis E, Kabrane-Lazizi et al., 1999 found that between 44 and 90% of rats tested positive by ELISA (75). However, sequence and phylogenetic analyses of rat HEV indicate that these constitute a completely different genotype of unknown pathogenicity to humans (76).

Rodents as carriers of animal pathogens

Only a few studies have been published on rodent transmission of specific animal pathogens in pig and chicken herds, but some of the agents discussed previously as zoonoses can also affect the health of pigs, e.g. Toxoplasma gondii, Leptospira, and Campylobacter spp. and some serovars of Salmonella.

Bacteria

The genus Brachyspira constitutes bacteria that are found in the intestines of many species of mammals and birds. Brachyspira hyodysenteriae is the aetiological agent of swine dysentery (SD) (77), a pig disease that causes severe mucohaemorrhagic diarrhoea. All age groups of pigs except for newborns can be affected (78). Brachyspira pilosicoli causes a milder colitis referred to as porcine colonic spirochaetosis (PCS) (79). Weaners and growers are affected with watery diarrhoea or porridge-like faeces, sometimes with mucus, resulting in reduced growth rate. In chicken, Brachyspira spp. colonisation, referred to as avian intestinal spirochaetosis (AIS), is associated with egg production losses and signs of disease. Intestinal spiral-shaped bacteria have been observed microscopically in both laboratory and wild-caught rodents, of which some showed the morphological characteristics of Brachyspira spp. (80). Isolates designated as Brachyspira hyodysenteriae have been detected in both wild and laboratory rodents (81, 82). Experimentally, B. hyodysenteriae has been shown to effectively spread between laboratory mice and pigs (83). Porcine genotypes of B. hyodysenteriae have been isolated from rats and mice caught in pig herds (84, 85) and porcine genotypes of B. pilosicoli in mice (84, 86).

The intracellular bacterium Lawsonia intracellularis is the cause of porcine proliferative enteropathy (PPE) (87), a very common intestinal disease with large economic impact in growing pigs (5, 88). The clinical appearance is similar to that of colonic spirochaetosis, with diarrhoea and retarded growth. L. intracellularis has been detected in a number of animal species other than the pig, i.e. hamster, deer, ostrich, ferret, horse, and rabbit (8991). Rodents have been implicated as possible reservoirs for the bacteria (92), and a recent study showed that infected rats shed large numbers of bacteria in their faeces for up to 3 weeks (93).

Virus

Encephalomyocarditis virus (EMCV) is a cardiovirus of the Picornaviridae that in growing pigs causes acute myocarditis and sudden deaths (94, 95). In sows, it causes reproductive problems with abortions and dead and weak piglets (96, 97). Outbreaks occur mainly in clusters in certain areas, which in Europe have been located in Belgium, Italy, Greece, and Cyprus (98). The epidemiology is inconclusive, but wild rodents are considered a natural reservoir for EMCV (99), from which the virus is shed in faeces (100, 101). In a few cases, EMCV has been suspected of causing disease in humans (102) and seroprevalence has been found to be high in veterinarians, farmers, abattoir workers and especially hunters (103).

Porcine respiratory syndrome (PRRS), a highly contagious syndrome with reproductive failure and pneumonia in growing pigs, has spread worldwide and often remains as an endemic infection in herds (104). Several non-porcine reservoirs for this arterivirus have been suspected, but attempts at virus isolation from rodents caught on infected pig farms have failed, and transmission experiments to laboratory rodents have shown that rodents are not susceptible to the virus (105).

Conclusions and perspectives

The literature shows that wild rodents carry pathogens that can be transmitted to production animals on farms and thereby constitute an important factor in the epidemiology of these pathogens. In general, rodents are not true reservoirs of the pathogens reviewed here, but could act as transmitters of disease within a facility or in some cases between farms. In addition, rodents on farms can be a link between wild fauna and domestic animals used for consumption, and in the case of intensively reared animals kept indoors, rodents pose a danger of introducing new infections into herds. The conclusion is that rodent control should be considered an important measure to provide good bio-security on farms. Considering that climate change can be suspected to promote rodent populations in the temperate zone, in the future the problem is likely to become more difficult to combat. The use of rodent-proof buildings will thus be important when planning new facilities for production animals.

Conflict of interest and funding

The authors have not received any funding or benefits from industry or elsewhere to conduct this study.

References

  • 1.Hanney PW. North Vancouver: David & Charles (Holdings) Limited; 1975. Rodents, their lives and habits. [Google Scholar]
  • 2.Nowak RM. 6th ed. Baltimore, Maryland: John Hopkins University Press; 1999. Walker's mammals of the world. [Google Scholar]
  • 3.Akande O. Uppsala, Sweden: Swedish University of Agricultural Sciences; 2008. A study on wild rat behaviour and control on a pig farm; p. 53. Master thesis. [Google Scholar]
  • 4.Anon Community summary report on trends and sources of zoonoses and zoonotic agents and food-borne outbreaks in the European Union in 2008. EFSA J 2010. 8:1–368. [Google Scholar]
  • 5.Jacobson M, Hård af Segerstad C, Gunnarsson A, Fellström C, de Verdier Klingenberg K, Wallgren P, et al. Diarrhoea in the growing pig – a comparison of clinical, morphological and microbial findings between animals from good and poor performance herds. Res Vet Sci. 2003;74:163–9. doi: 10.1016/S0034-5288(02)00187-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6.Nesbakken T, Eckner K, Høidal HK, Røtterud O-J. Occurrence of Yersinia enterocolitica and Campylobacter spp. in slaughter pigs and consequences for meat inspection, slaughtering, and dressing procedures. Int J Food Microbiol. 2003;80:231–40. doi: 10.1016/s0168-1605(02)00165-4. [DOI] [PubMed] [Google Scholar]
  • 7.Denis M, Chidaine B, Laisney MJ, Kempf I, Rivoal K, Mégraud F, et al. Comparison of genetic profiles of Campylobacter strains isolated from poultry, pig and Campylobacter human infections in Brittany, France. Pathol Biol (Paris) 2009;57:23–9. doi: 10.1016/j.patbio.2008.04.007. [DOI] [PubMed] [Google Scholar]
  • 8.Berndtson E, Emanuelson U, Engvall A, Danielsson-Tham ML. A 1-year epidemiological study of campylobacters in 18 Swedish chicken farms. Prev Vet Med. 1996;26:167–85. [Google Scholar]
  • 9.Kapperud G, Skjerve E, Vik L, Hauge K, Lysaker A, Aalmen I, et al. Epidemiological investigation of risk factors for campylobacter colonization in Norwegian broiler flocks. Epidemiol Infect. 1993;111:245–55. doi: 10.1017/s0950268800056958. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Berndtson E, Danielsson-Tham ML, Engvall A. Experimental colonization of mice with Campylobacter jejuni . Vet Microbiol. 1994;41:183–8. doi: 10.1016/0378-1135(94)90147-3. [DOI] [PubMed] [Google Scholar]
  • 11.Meerburg BG, Jacobs-Reitsma WF, Wagenaar JA, Kijlstra A. Presence of Salmonella and Campylobacter spp. in wild small mammals on organic farms. Appl Environ Microbiol. 2006;72:960–2. doi: 10.1128/AEM.72.1.960-962.2006. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Ekdahl K, De Jong B, Wollin R, Andersson Y. Travel-associated non-typhoidal salmonellosis: geographical and seasonal differences and serotype distribution. Clin Microbiol Infect. 2005;11:138–44. doi: 10.1111/j.1469-0691.2004.01045.x. [DOI] [PubMed] [Google Scholar]
  • 13.Griffith RW, Schwartz KJ, Meyerholz DK. Salmonella. In: Straw BE, Zimmerman JJ, D'Allaire S, Taylor DJ, editors. Diseases of Swine. 9th ed. Ames, Iowa: Blackwell Publisher; 2006. [Google Scholar]
  • 14.Davies RH, Wray C. Mice as carriers of Salmonella enteritidis on persistently infected poultry units. Vet Rec. 1995;137:337–41. doi: 10.1136/vr.137.14.337. [DOI] [PubMed] [Google Scholar]
  • 15.Liebana E, Garcia-Migura L, Clouting C, Clifton-Hadley FA, Breslin M, Davies RH. Molecular fingerprinting evidence of the contribution of wildlife vectors in the maintenance of Salmonella Enteritidis infection in layer farms. J Appl Microbiol. 2003;94:1024–9. doi: 10.1046/j.1365-2672.2003.01924.x. [DOI] [PubMed] [Google Scholar]
  • 16.Henzler DJ, Opitz HM. The role of mice in the epizootiology of Salmonella enteritidis infection on chicken layer farms. Avian Dis. 1992;36:625–31. [PubMed] [Google Scholar]
  • 17.Skov MN, Madsen JJ, Rahbek C, Lodal J, Jespersen JB, Jørgensen JC, et al. Transmission of Salmonella between wildlife and meat-production animals in Denmark. J Appl Microbiol. 2008;105:1558–68. doi: 10.1111/j.1365-2672.2008.03914.x. [DOI] [PubMed] [Google Scholar]
  • 18.Pocock MJO, Searle JB, Betts WB, White PCL. Patterns of infection by Salmonella and Yersinia spp. in commensal house mouse (Mus musculus domesticus) populations. J Appl Microbiol. 2001;90:755–60. doi: 10.1046/j.1365-2672.2001.01303.x. [DOI] [PubMed] [Google Scholar]
  • 19.Fredriksson-Ahomaa M, Autio T, Korkeala H. Efficient subtyping of Yersinia enterocolitica bioserotype 4/O:3 with pulsed-field gel electrophoresis. Lett Appl Microbiol. 1999;29:308–12. doi: 10.1046/j.1365-2672.1999.00625.x. [DOI] [PubMed] [Google Scholar]
  • 20.Jalava K, Hakkinen M, Valkonen M, Nakari UM, Palo T, Hallanvuo S, et al. An outbreak of gastrointestinal illness and erythema nodosum from grated carrots contaminated with Yersinia pseudotuberculosis . J Infect Dis. 2006;194:1209–16. doi: 10.1086/508191. [DOI] [PubMed] [Google Scholar]
  • 21.Nuorti JP, Niskanen T, Hallanvuo S, Mikkola J, Kela E, Hatakka M, et al. A widespread outbreak of Yersinia pseudotuberculosis O:3 infection from iceberg lettuce. J Infect Dis. 2004;189:766–74. doi: 10.1086/381766. [DOI] [PubMed] [Google Scholar]
  • 22.Wauters G. Carriage of Yersinia enterocolitica serotype 3 by pigs as a source of human infection. Contrib Microbiol Immunol. 1979;5:249–52. [PubMed] [Google Scholar]
  • 23.Kapperud G. Yersinia enterocolitica in small rodents from Norway, Sweden and Finland. Acta Patholog Microb. 1975;83B:335–42. doi: 10.1111/j.1699-0463.1975.tb00110.x. [DOI] [PubMed] [Google Scholar]
  • 24.Aldova E, Cerny J, Chmela J. Findings of yersinia in rats and sewer rats. Zentralblatt fur Bakteriologie Mikrobiologie und Hygiene-Abt. 1 Orig. A. 1977;239:208–12. [PubMed] [Google Scholar]
  • 25.Kaneko KI, Hamada S, Kasai Y, Kato E. Occurrence of Yersinia enterocolitica in house rats. Appl Environ Microbiol. 1978;36:314–8. doi: 10.1128/aem.36.2.314-318.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26.Backhans A, Fellström C, Lambertz ST. Occurrence of pathogenic Yersinia enterocolitica and Yersinia pseudotuberculosis in small wild rodents. Epidemiol Infect. 2011;139:1230–8. doi: 10.1017/S0950268810002463. [DOI] [PubMed] [Google Scholar]
  • 27.Niskanen T, Waldenström J, Fredriksson-Ahomaa M, Olsen B, Korkeala H. virF-positive Yersinia pseudotuberculosis and Yersinia enterocolitica found in migratory birds in Sweden. Appl Environ Microbiol. 2003;69:4670–5. doi: 10.1128/AEM.69.8.4670-4675.2003. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28.Fukushima H, Gomyoda M. Intestinal carriage of Yersinia pseudotuberculosis by wild birds and mammals in Japan. Appl Environ Microbiol. 1991;57:1152–5. doi: 10.1128/aem.57.4.1152-1155.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29.Fukushima H, Gomyoda M, Shiozawa K, Kaneko S, Tsubokura M. Yersinia pseudotuberculosis infection contracted through water contaminated by a wild animal. J Clin Microbiol. 1988;26:584–5. doi: 10.1128/jcm.26.3.584-585.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 30.Niskanen T, Fredriksson-Ahomaa M, Korkeala H. Yersinia pseudotuberculosis with limited genetic diversity is a common finding in tonsils of fattening pigs. J Food Prot. 2002;65:540–5. doi: 10.4315/0362-028x-65.3.540. [DOI] [PubMed] [Google Scholar]
  • 31.Shiozawa K, Hayashi M, Akiyama M, Nishina T, Nakatsugawa S, Fukushima H, et al. Virulence of Yersinia pseudotuberculosis isolated from pork and from the throats of swine. Appl Environ Microbiol. 1988;54:818–21. doi: 10.1128/aem.54.3.818-821.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 32.Fredriksson-Ahomaa M, Wacheck S, Koenig M, Stolle A, Stephan R. Prevalence of pathogenic Yersinia enterocolitica and Yersinia pseudotuberculosis in wild boars in Switzerland. Int J Food Microbiol. 2009;135:199–202. doi: 10.1016/j.ijfoodmicro.2009.08.019. [DOI] [PubMed] [Google Scholar]
  • 33.Laukkanen R, Martinez PO, Siekkinen K-M, Ranta J, Maijala R, Korkeala H. Transmission of Yersinia pseudotuberculosis in the pork production chain from farm to slaughterhouse. Appl Environ Microbiol. 2008;74:5444–50. doi: 10.1128/AEM.02664-07. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 34.Fukushima H, Gomyoda M, Kaneko S. Mice and moles inhabiting mountainous areas of Shimane Peninsula as sources of infection with Yersinia pseudotuberculosis . J Clin Microbiol. 1990;28:2448–55. doi: 10.1128/jcm.28.11.2448-2455.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 35.Kaneko KI, Hamada S, Kasai Y, Hashimoto N. Smouldering epidemic of Yersinia pseudotuberculosis in barn rats. Appl Environ Microbiol. 1979;37:1–3. doi: 10.1128/aem.37.1.1-3.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 36.Kageyama T, Ogasawara A, Fukuhara R, Narita Y, Miwa N, Kamanaka Y, et al. Yersinia pseudotuberculosis infection in breeding monkeys: detection and analysis of strain diversity by PCR. J Med Primatol. 2002;31:129–35. doi: 10.1034/j.1600-0684.2002.01034.x. [DOI] [PubMed] [Google Scholar]
  • 37.Levett PN. Leptospirosis. Clin Microbiol Rev. 2001;14:296–326. doi: 10.1128/CMR.14.2.296-326.2001. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 38.Ellis WA. Leptospirosis. In: Straw BE, Zimmerman JJ, D'Allaire S, Taylor DJ, editors. Diseases of Swine. 9th ed. Ames, Iowa, USA: Blackwell Publisher; 2006. [Google Scholar]
  • 39.Aviat F, Blanchard B, Michel V, Blanchet B, Branger C, Hars J, et al. Leptospira exposure in the human environment in France: a survey in feral rodents and in fresh water. Comp Immunol Microbiol Infect Dis. 2009;32:463–76. doi: 10.1016/j.cimid.2008.05.004. [DOI] [PubMed] [Google Scholar]
  • 40.Webster JP, Ellis WA, Macdonald DW. Prevalence of Leptospira spp. in wild brown rats (Rattus norvegicus) on UK farms. Epidemiol Infect. 1995;114:195–201. doi: 10.1017/s0950268800052043. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 41.Gaudie CM, Featherstone CA, Phillips WS, McNaught R, Rhodes PM, Errington J, et al. Human Leptospira interrogans serogroup icterohaemorrhagiae infection (Weil's disease) acquired from pet rats. Vet Rec. 2008;163:599–600. doi: 10.1136/vr.163.20.599. [DOI] [PubMed] [Google Scholar]
  • 42.Krojgaard LH, Villumsen S, Markussen MDK, Jensen JS, Leirs H, Heiberg AC. High prevalence of Leptospira spp. in sewer rats (Rattus norvegicus) Epidemiol Infect. 2009;137:1586–92. doi: 10.1017/S0950268809002647. [DOI] [PubMed] [Google Scholar]
  • 43.van de Giessen AW, van Santen-Verheuvel MG, Hengeveld PD, Bosch T, Broens EM, Reusken CBEM. Occurrence of methicillin-resistant Staphylococcus aureus in rats living on pig farms. Prev Vet Med. 2009;91:270–3. doi: 10.1016/j.prevetmed.2009.05.016. [DOI] [PubMed] [Google Scholar]
  • 44.Tenter AM, Heckeroth AR, Weiss LM. Toxoplasma gondii: from animals to humans. Int J Parasitol. 2000;30:1217–58. doi: 10.1016/s0020-7519(00)00124-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 45.Dubey JP, Miller NL, Frenkel JK. Toxoplasma gondii life cycle in cats. J Am Vet Med Assoc. 1970;157:1767–70. [PubMed] [Google Scholar]
  • 46.Jones J, Lopez A, Wilson M. Congenital toxoplasmosis. Am Fam Physician. 2003;67:2131–2138+2145. [PubMed] [Google Scholar]
  • 47.Birgisdóttir A, Asbjörnsdottir H, Cook E, Gislason D, Jansson C, Olafsson I, et al. Seroprevalence of Toxoplasma gondii in Sweden, Estonia and Iceland. Scand J Infect Dis. 2006;38:625–31. doi: 10.1080/00365540600606556. [DOI] [PubMed] [Google Scholar]
  • 48.Kapperud G, Jenum PA, Stray-Pedersen B, Melby KK, Eskild A, Eng J. Risk factors for Toxoplasma gondii infection in pregnancy. Am J Epidemiol. 1996;144:405–12. doi: 10.1093/oxfordjournals.aje.a008942. [DOI] [PubMed] [Google Scholar]
  • 49.Dabritz HA, Miller MA, Gardner IA, Packham AE, Atwill ER, Conrad PA. Risk factors for Toxoplasma gondii infection in wild rodents from central coastal California and a review of T. gondii prevalence in rodents. J Parasitol. 2008;94:675–83. doi: 10.1645/GE-1342.1. [DOI] [PubMed] [Google Scholar]
  • 50.Kijlstra A, Meerburg B, Cornelissen J, De Craeye S, Vereijken P, Jongert E. The role of rodents and shrews in the transmission of Toxoplasma gondii to pigs. Vet Parasitol. 2008;156:183–90. doi: 10.1016/j.vetpar.2008.05.030. [DOI] [PubMed] [Google Scholar]
  • 51.Weigel RM, Dubey JP, Siegel AM, Kitron UD, Mannelli A, Mitchell MA, et al. Risk factors for transmission of Toxoplasma gondii on swine farms in Illinois. J Parasitol. 1995;81:736–41. [PubMed] [Google Scholar]
  • 52.Dubey JP, Bhaiyat MI, Macpherson CNL, de Allie C, Chikweto A, Kwok OCH, et al. Prevalence of Toxoplasma gondii in rats (Rattus norvegicus) in Grenada, West Indies. J Parasitol. 2006;92:1107–8. doi: 10.1645/GE-902R.1. [DOI] [PubMed] [Google Scholar]
  • 53.Frenkel JK, Hassanein KM, Hassanein RS, Brown E, Thulliez P, Quintero-Nunez R. Transmission of Toxoplasma gondii in Panama City, Panama: a five-year prospective cohort study of children, cats, rodents, birds, and soil. Am J Trop Med Hyg. 1995;53:458–68. doi: 10.4269/ajtmh.1995.53.458. [DOI] [PubMed] [Google Scholar]
  • 54.Marshall PA, Hughes JM, Williams RH, Smith JE, Murphy RG, Hide G. Detection of high levels of congenital transmission of Toxoplasma gondii in natural urban populations of Mus domesticus . Parasitology. 2004;128:39–42. doi: 10.1017/s0031182003004189. [DOI] [PubMed] [Google Scholar]
  • 55.Murphy RG, Williams RH, Hughes JM, Hide G, Ford NJ, Oldbury DJ. The urban house mouse (Mus domesticus) as a reservoir of infection for the human parasite Toxoplasma gondii: an unrecognised public health issue? Int J Environ Health Res. 2008;18:177–85. doi: 10.1080/09603120701540856. [DOI] [PubMed] [Google Scholar]
  • 56.Smith KE, Zimmerman JJ, Patton S, Beran GW, Hill HT. The epidemiology of toxoplasmosis on Iowa swine farms with an emphasis on the roles of free-living mammals. Vet Parasitol. 1992;42:199–211. doi: 10.1016/0304-4017(92)90062-e. [DOI] [PubMed] [Google Scholar]
  • 57.Dubey JP, Thulliez P, Powell EC. Toxoplasma gondii in Iowa sows: comparison of antibody titers to isolation of T. gondii by bioassays in mice and cats. J Parasitol. 1995;81:48–53. [PubMed] [Google Scholar]
  • 58.Gottstein B, Pozio E, Nockler K. Epidemiology, diagnosis, treatment, and control of trichinellosis. Clin Microbiol Rev. 2009;22:127–45. doi: 10.1128/CMR.00026-08. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 59.Pozio E, Rinaldi L, Marucci G, Musella V, Galati F, Cringoli G, et al. Hosts and habitats of Trichinella spiralis and Trichinella britovi in Europe. Int J Parasitol. 2009;39:71–9. doi: 10.1016/j.ijpara.2008.06.006. [DOI] [PubMed] [Google Scholar]
  • 60.Neghina R, Neghina A, Marincu I, Roxana M, Iacobiciu I. Epidemiology and epizootology of trichinellosis in Romania 1868–2007. Vector-Borne Zoonotic Dis. 2010;10:6. doi: 10.1089/vbz.2009.0084. [DOI] [PubMed] [Google Scholar]
  • 61.Stojcevic D, Zivicnjak T, Marinculic A, Marucci G, Andelko G, Brstilo M, et al. The epidemiological investigation of Trichinella infection in brown rats (Rattus norvegicus) and domestic pigs in Croatia suggests that rats are not a reservoir at the farm level. J Parasitol. 2004;90:666–70. doi: 10.1645/GE-158R. [DOI] [PubMed] [Google Scholar]
  • 62.Plutzer J, Ongerth J, Karanis P. Giardia taxonomy, phylogeny and epidemiology: facts and open questions. Int J Hyg Environ Health. 2010;213:321–33. doi: 10.1016/j.ijheh.2010.06.005. [DOI] [PubMed] [Google Scholar]
  • 63.Smith HV, Cacciò SM, Tait A, McLauchlin J, Thompson RCA. Tools for investigating the environmental transmission of Cryptosporidium and Giardia infections in humans. Trends Parasitol. 2006;22:160–7. doi: 10.1016/j.pt.2006.02.009. [DOI] [PubMed] [Google Scholar]
  • 64.Fayer R. Taxonomy and species delimitation in Cryptosporidium . Exp Parasitol. 2010;124:90–7. doi: 10.1016/j.exppara.2009.03.005. [DOI] [PubMed] [Google Scholar]
  • 65.Quy RJ, Cowan DP, Haynes PJ, Sturdee AP, Chalmers RM, Bodley-Tickell AT, et al. The Norway rat as a reservoir host of Cryptosporidium parvum . J Wildl Dis. 1999;35:660–70. doi: 10.7589/0090-3558-35.4.660. [DOI] [PubMed] [Google Scholar]
  • 66.Webster JP, MacDonald DW. Cryptosporidiosis reservoir in wild brown rats (Rattus norvegicus) in the UK. Epidemiol Infect. 1995;115:207–9. doi: 10.1017/s0950268800058271. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 67.Lv C, Zhang L, Wang R, Jian F, Zhang S, Ning C, et al. Cryptosporidium spp. in wild, laboratory, and pet rodents in China: prevalence and molecular characterization. Appl Environ Microbiol. 2009;75:7692–9. doi: 10.1128/AEM.01386-09. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 68.Gatei W, Ashford RW, Beeching NJ, Kang'ethe Kamwati S, Greensill J, Anthony Hart C. Cryptosporidium muris infection in an HIV-infected adult, Kenya. Emerg Infect Dis. 2002;8:204–6. doi: 10.3201/eid0802.010256. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 69.Palmer CJ, Xiao L, Terashima A, Guerra H, Gotuzzo E, Saldías G, et al. Cryptosporidium muris, a rodent pathogen, recovered from a human in Perú. Emerg Infect Dis. 2003;9:1174–6. doi: 10.3201/eid0909.030047. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 70.Adam RD. Biology of Giardia lamblia . Clin Microbiol Rev. 2001;14:447–75. doi: 10.1128/CMR.14.3.447-475.2001. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 71.Thompson RCA. The zoonotic significance and molecular epidemiology of Giardia and giardiasis. Vet Parasitol. 2004;126:15–35. doi: 10.1016/j.vetpar.2004.09.008. [DOI] [PubMed] [Google Scholar]
  • 72.Lebbad M, Mattsson JG, Christensson B, Ljungström B, Backhans A, Andersson JO, et al. From mouse to moose: multilocus genotyping of Giardia isolates from various animal species. Vet Parasitol. 2010;168:231–9. doi: 10.1016/j.vetpar.2009.11.003. [DOI] [PubMed] [Google Scholar]
  • 73.Meng XJ. Hepatitis E virus: animal reservoirs and zoonotic risk. Vet Microbiol. 2010;140:256–65. doi: 10.1016/j.vetmic.2009.03.017. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 74.Drobeniuc J, Favorov MO, Shapiro CN, Bell BP, Mast EE, Dadu A, et al. Hepatitis E virus antibody prevalence among persons who work with swine. J Infect Dis. 2001;184:1594–7. doi: 10.1086/324566. [DOI] [PubMed] [Google Scholar]
  • 75.Kabrane-Lazizi Y, Fine JB, Elm J, Glass GE, Higa H, Diwan A, et al. Evidence for widespread infection of wild rats with hepatitis E virus in the United States. Am J Trop Med. 1999;61:331–5. doi: 10.4269/ajtmh.1999.61.331. [DOI] [PubMed] [Google Scholar]
  • 76.Johne R, Heckel G, Plenge-Bönig A, Kindler E, Maresch C, Reetz J, et al. Novel hepatitis E virus genotype in Norway rats, Germany. Emerg Infect Dis. 2010;16:1452–5. doi: 10.3201/eid1609.100444. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 77.Taylor DJ, Alexander TJ. The production of dysentery in swine by feeding cultures containing a spirochaete. Br Vet J. 1971;127:58–61. doi: 10.1016/s0007-1935(17)37282-2. [DOI] [PubMed] [Google Scholar]
  • 78.Hampson DJ, Fellström C, Thomson J. Swine dysentery. In: Straw BE, Zimmerman JJ, D'Allaire S, Taylor DJ, editors. Diseases of Swine. 9th ed. Ames, Iowa, USA: Blackwell Publisher; 2006. [Google Scholar]
  • 79.Girard C, Lemarchand T, Higgins R. Porcine colonic spirochetosis: a retrospective study of eleven cases. Can Vet J. 1995;36:291–4. [PMC free article] [PubMed] [Google Scholar]
  • 80.Lee A, Phillips M. Isolation and cultivation of spirochetes and other spiral-shaped bacteria associated with the cecal mucosa of rats and mice. Appl Environ Microbiol. 1978;35:610–3. doi: 10.1128/aem.35.3.610-613.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 81.Joens LA, Kinyon JM. Isolation of Treponema hyodysenteriae from wild rodents. J Clin Microbiol. 1982;15:994–97. doi: 10.1128/jcm.15.6.994-997.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 82.Backhans A, Johansson KE, Fellström C. Phenotypic and molecular characterization of Brachyspira spp. isolated from wild rodents. Env Microbiol Rep. 2010;2:720–7. doi: 10.1111/j.1758-2229.2010.00165.x. [DOI] [PubMed] [Google Scholar]
  • 83.Joens LA. Experimental transmission of Treponema hyodysenteriae from mice to pigs. Am J Vet Res. 1980;41:1225–6. [PubMed] [Google Scholar]
  • 84.Fellström C, Landén A, Karlsson M, Gunnarsson A, Holmgren N. Mice as a reservoir of Brachyspira hyodysenteriae in repeated outbreaks of swine dysentery in a Swedish fattening herd. Proceedings: 18th International Pig Veterinary Society Congress. 2004;1:280. [Google Scholar]
  • 85.Trott DJ, Atyeo RF, Lee JI, Swayne DA, Stoutenburg JW, Hampson DJ. Genetic relatedness amongst intestinal spirochaetes isolated from rats and birds. Lett Appl Microbiol. 1996;23:431–6. doi: 10.1111/j.1472-765x.1996.tb01352.x. [DOI] [PubMed] [Google Scholar]
  • 86.Backhans A, Jansson DS, Aspán A, Fellström C. Typing of Brachyspira spp. from rodents, pigs and chickens on Swedish farms. Vet Microbiol. 2011;153:156–62. doi: 10.1016/j.vetmic.2011.03.023. [DOI] [PubMed] [Google Scholar]
  • 87.McOrist S, Gebhart CJ, Boid R, Barns SM. Characterization of Lawsonia intracellularis gen. nov., sp. nov., the obligately intracellular bacterium of porcine proliferative enteropathy. Int J Syst Bacteriol. 1995;45:820–5. doi: 10.1099/00207713-45-4-820. [DOI] [PubMed] [Google Scholar]
  • 88.McOrist S, Jasni S, Mackie RA, MacIntyre N, Neef N, Lawson GHK. Reproduction of porcine proliferative enteropathy with pure cultures of Ileal symbiont intracellularis. Infect Immun. 1993;61:4286–92. doi: 10.1128/iai.61.10.4286-4292.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 89.Cooper DM, Swanson DL, Gebhart CJ. Diagnosis of proliferative enteritis in frozen and formalin-fixed, paraffin-embedded tissues from a hamster, horse, deer and ostrich using a Lawsonia intracellularis-specific multiplex PCR assay. Vet Microbiol. 1997;54:47–62. doi: 10.1016/s0378-1135(96)01264-3. [DOI] [PubMed] [Google Scholar]
  • 90.Duhamel GE, Klein EC, Elder RO, Gebhart CJ. Subclinical proliferative enteropathy in sentinel rabbits associated with Lawsonia intracellularis . Vet Pathol. 1998;35:300–3. doi: 10.1177/030098589803500410. [DOI] [PubMed] [Google Scholar]
  • 91.Frank N, Fishman CE, Gebhart CJ, Levy M. Lawsonia intracellularis proliferative enteropathy in a weanling foal. Equine Vet J. 1998;30:549–52. doi: 10.1111/j.2042-3306.1998.tb04533.x. [DOI] [PubMed] [Google Scholar]
  • 92.Friedman M, Bednář V, Klimeš J, Smola J, Mrlík V, Literák I. Lawsonia intracellularis in rodents from pig farms with the occurrence of porcine proliferative enteropathy. Lett Appl Microbiol. 2008;47:117–21. doi: 10.1111/j.1472-765X.2008.02394.x. [DOI] [PubMed] [Google Scholar]
  • 93.Collins AM, Fell S, Pearson H, Toribio JA. Colonisation and shedding of Lawsonia intracellularis in experimentally inoculated rodents and in wild rodents on pig farms. Vet Microbiol. 2011;150:384–8. doi: 10.1016/j.vetmic.2011.01.020. [DOI] [PubMed] [Google Scholar]
  • 94.Murnane TG, Craighead JE, Mondragon H, Shelokov A. Fatal disease of swine due to encephalomyocarditis virus. Science. 1960;131:498–9. doi: 10.1126/science.131.3399.498. [DOI] [PubMed] [Google Scholar]
  • 95.Koenen F, Vanderhallen H, Castryck F, Miry C. Epidemiologic, pathogenic and molecular analysis of recent encephalomyocarditis outbreaks in Belgium. J Vet Med B. 1999;46:217–31. [PubMed] [Google Scholar]
  • 96.Koenen F, De Clercq K, Lefebvre J, Strobbe R. Reproductive failure in sows following experimental infection with a Belgian EMCV isolate. Vet Microbiol. 1994;39:111–6. doi: 10.1016/0378-1135(94)90091-4. [DOI] [PubMed] [Google Scholar]
  • 97.Dea SA, Bilodeau R, Martineau GP. Isolation of encephalomyocarditis virus among stillborn and post-weaning pigs in Quebec. Arch Virol. 1991;117:121–8. doi: 10.1007/BF01310497. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 98.Maurice H, Nielen M, Brocchi E, Nowotny N, Kassimi LB, Billinis C, et al. The occurrence of encephalomyocarditis virus (EMCV) in European pigs from 1990 to 2001. Epidemiol Infect. 2005;133:547–57. doi: 10.1017/s0950268804003668. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 99.Spyrou V, Maurice H, Billinis C, Papanastassopoulou M, Psalla D, Nielen M, et al. Transmission and pathogenicity of encephalomyocarditis virus (EMCV) among rats. Vet Res. 2004;35:113–22. doi: 10.1051/vetres:2003044. [DOI] [PubMed] [Google Scholar]
  • 100.Psalla D, Psychas V, Spyrou V, Billinis C, Papaioannou N, Vlemmas I. Pathogenesis of experimental encephalomyocarditis: a histopathological, immunohistochemical and virological study in rats. J Comp Pathol. 2006;134:30–9. doi: 10.1016/j.jcpa.2005.06.008. [DOI] [PubMed] [Google Scholar]
  • 101.Spyrou V, Maurice H, Billinis C, Papanastassopoulou M, Psalla D, Nielen M, et al. Transmission and pathogenicity of encephalomyocarditis virus (EMCV) among rats. Vet Res. 2004;35:113–22. doi: 10.1051/vetres:2003044. [DOI] [PubMed] [Google Scholar]
  • 102.Oberste M, Gotuzzo E, Blair P, Nix W, Ksiazek T, Comer J, et al. Human febrile illness caused by encephalomyocarditis virus infection, Peru. Emerg Infect Dis. 2009;15:6. doi: 10.3201/eid1504.081428. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 103.Deutz A, Fuchs K, Schuller W, Nowotny N, Auer H, Aspöck H, et al. Seroepidemiological studies of zoonotic infections in hunters in southeastern Austria-prevalences, risk factors, and preventive methods. Berl Munch Tierarztl Wochenschr. 2003;116:306–11. [PubMed] [Google Scholar]
  • 104.Zimmerman J, Benfield DA, Murtaugh MP, Osorio F, Stevenson GW, Torremorell M. Porcine reproductive and respiratory syndrome virus (porcine arterivirus) In: Straw BE, Zimmerman JJ, D'Allaire S, Taylor DJ, editors. Diseases of Swine. 9th ed. Ames, Iowa, USA: Blackwell Publishing; 2006. [Google Scholar]
  • 105.Hooper CC, Van Alstine WG, Stevenson GW, Kanitz CL. Mice and rats (laboratory and feral) are not a reservoir for PRRS virus. J Vet Diagn Invest. 1994;6:13–15. doi: 10.1177/104063879400600103. [DOI] [PubMed] [Google Scholar]
  • 106.Lapuz R, Tani H, Sasai K, Shirota K, Katoh H, Baba E. The role of roof rats (Rattus rattus) in the spread of Salmonella Enteritidis and S. Infantis contamination in layer farms in eastern Japan. Epidemiol Infect. 2008;136:1235–43. doi: 10.1017/S095026880700948X. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 107.Le Moine V, Vannier P, Jestin A. Microbiological studies of wild rodents in farms as carriers of pig infectious agents. Prev Vet Med. 1987;4:399–408. [Google Scholar]
  • 108.Pokorna V, Aldova E. Finding of Yersinia enterocolitica in Rattus rattus . J Hyg Epidemiol Microbiol Immunol. 1977;21:104–5. [PubMed] [Google Scholar]
  • 109.Webster JP, Macdonald DW. Parasites of wild brown rats (Rattus norvegicus) on UK farms. Parasitology. 1995;111:247–55. doi: 10.1017/s0031182000081804. [DOI] [PubMed] [Google Scholar]
  • 110.Leiby DA, Duffy CH, Murrell KD, Schad GA. Trichinella spiralis in an agricultural ecosystem: transmission in the rat population. J Parasitol. 1990;76:360–4. [PubMed] [Google Scholar]
  • 111.Webster JP. Prevalence and transmission of Toxoplasma gondii in wild brown rats, Rattus norvegicus . Parasitology. 1994;108:407–11. doi: 10.1017/s0031182000075958. [DOI] [PubMed] [Google Scholar]

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