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  • Oravainen, Jonna; Sahlström, Leena; Lyytikäinen, Tapani (Evira, 2011)
    Afrikkalainen sikarutto on lakisääteisesti vastustettava helposti leviävä sikojen ja villisikojen virustauti, jolla on myös vakavia sosioekonomisia vaikutuksia. Akuutissa tautimuodossa eläimillä esiintyy syömättömyyttä, korkeaa kuumetta, verenpurkaumia iholla, veristä ulostetta sekä mahdollisesti ripulia. Kuolleisuus on lähes 100 % ja tauti johtaa kuolemaan 7-10 vrk tartunnan jälkeen. Tauti ei tartu ihmisiin. Tautia esiintyy sekä kesy- että villisioissa suurimmassa osassa Saharan eteläpuolista Afrikkaa ja Sardiniassa. Vuodesta 2007 lähtien tautia on esiintynyt Kaukasuksen alueella ja vuonna 2011 lähellä Suomen rajaa: Leningradin alueella ja Kuolan niemimaalla. Tässä riskiprofiilissa kartoitetaan reitit ja tapahtumasarjat, jotka voivat johtaa siihen, että afrikkalainen sikarutto tulee Suomeen ensimmäisen kerran. Näistä oleellisimmat ovat: maahantulo infektioalueella matkustaneiden ihmisten mukana, infektoituneen lihan tai lihatuotteen mukana, elävien kesysikojen ja sperman mukana, kontaminoituneiden eläinkuljetusajoneuvojen mukana, kansainvälisen liikenteen ruokajätteen mukana ja Suomeen vaeltavan infektoituneen villisian mukana. Tilatason tautisuojaus sekä tehokas ja kohdennettu tiedottaminen taudin vaaroista ovat avainasemassa, kun halutaan suojata Suomen sikaelinkeinoa afrikkalaiselta sikarutolta.
  • Perko-Mäkelä, Päivikki; Isohanni, Pauliina; Katzav, Marianne; Lund, Marianne; Hänninen, Marja-Liisa; Lyhs, Ulrike (BioMed Central, 2009)
    Background: Campylobacter is the most common cause of bacterial enteritis worldwide. Handling and eating of contaminated poultry meat has considered as one of the risk factors for human campylobacteriosis.Campylobacter contamination can occur at all stages of a poultry production cycle. The objective of this study was to determine the occurrence of Campylobacter during a complete turkey production cycle which lasts for 1,5 years of time. For detection of Campylobacter, a conventional culture method was compared with a PCR method. Campylobacter isolates from different types of samples have been identified to the species level by a multiplex PCR assay. Methods: Samples (N = 456) were regularly collected from one turkey parent flock, the hatchery, six different commercial turkey farms and from 11 different stages at the slaughterhouse. For the detection of Campylobacter, a conventional culture and a PCR method were used. Campylobacter isolates (n = 143) were identified to species level by a multiplex PCR assay. Results: No Campylobacter were detected in either the samples from the turkey parent flock or from hatchery samples using the culture method. PCR detected Campylobacter DNA in five faecal samples and one fluff and eggshell sample. Six flocks out of 12 commercial turkey flocks where found negative at the farm level but only two were negative at the slaughterhouse. Conclusion: During the brooding period Campylobacter might have contact with the birds without spreading of the contamination within the flock. Contamination of working surfaces and equipment during slaughter of a Campylobacter positive turkey flock can persist and lead to possible contamination of negative flocks even after the end of the day's cleaning and desinfection. Reduction of contamination at farm by a high level of biosecurity control and hygiene may be one of the most efficient ways to reduce the amount of contaminated poultry meat in Finland. Due to the low numbers of Campylobacter in the Finnish turkey production chain, enrichment PCR seems to be the optimal detection method here.
  • Haltia, Laura; Honkanen-Buzalski, Tuula; Spiridonova, Irina; Olkonen, Arvi; Myllys, Vesa (BioMed Central, 2006)
    Background: Mastitis prevalence, milking procedures and management practices were investigated in 25 big dairy herds supplying milk to an Estonian dairy company. The aim of the study was to provide information for the company to be used in their new udder health improvement program to be set up after the completion of this study. Methods: Quarter milk samples were collected from 3,166 cows for bacterial analysis and SCC (somatic cell counting). During the farm visit the veterinarian filled in a questionnaire about milking procedures and management practices with the help of farm managers. If the milk SCC of a cow or of a quarter exceeded 200,000/ml, the cow was defined as having mastitis. Results: The percentage of cows having inflammation in one or more quarters measured by SCC (200,000/ml) was 52.7%. Corynebacterium bovis, Staphylococcus aureus and coagulase negative staphylococci were the most common bacterial isolates. Women as farm owners, and participating in the milking, were associated with lower mastitis prevalence on the farm. Peat bedding was associated with higher mastitis prevalence. Conclusion: We demonstrated relatively high mastitis prevalence in this study. Contagious bacteria (eg. S. aureus, C. bovis, S. agalactiae and coagulase negative staphylococci) caused most of the infections. These infections are usually spread from cow to cow at milking if the milking hygiene is not good enough. The mastitis situation could be improved by improving milking procedures and hygiene.
  • Nokireki, T.; Huovilainen, A.; Lilley, T.; Kyheröinen, E.-M.; Ek-Kommonen, C.; Sihvonen, L.; Jakava-Viljanen, M. (2013)
    Background: In 1985, a bat researcher in Finland died of rabies encephalitis caused by European bat lyssavirus type 2 (EBLV-2), but an epidemiological study in 1986 did not reveal EBLV-infected bats. In 2009, an EBLV-2-positive Daubenton’s bat was detected. The EBLV-2 isolate from the human case in 1985 and the isolate from the bat in 2009 were genetically closely related. In order to assess the prevalence of EBLVs in Finnish bat populations and to gain a better understanding of the public health risk that EBLV-infected bats pose, a targeted active surveillance project was initiated. Results: Altogether, 1156 bats of seven species were examined for lyssaviruses in Finland during a 28–year period (1985–2012), 898 in active surveillance and 258 in passive surveillance, with only one positive finding of EBLV-2 in a Daubenton’s bat in 2009. In 2010–2011, saliva samples from 774 bats of seven species were analyzed for EBLV viral RNA, and sera from 423 bats were analyzed for the presence of bat lyssavirus antibodies. Antibodies were detected in Daubenton’s bats in samples collected from two locations in 2010 and from one location in 2011. All seropositive locations are in close proximity to the place where the EBLV-2 positive Daubenton’s bat was found in 2009. In active surveillance, no EBLV viral RNA was detected. Conclusions: These data suggest that EBLV-2 may circulate in Finland, even though the seroprevalence is low. Our results indicate that passive surveillance of dead or sick bats is a relevant means examine the occurrence of lyssavirus infection, but the number of bats submitted for laboratory analysis should be higher in order to obtain reliable information on the lyssavirus situation in the country.
  • Rosengren, Heidi; Sahlström, Leena; Tammiranta, Niina (Evira, 2009)
    Bluetongue (BT) on vektorivälitteinen märehtijöiden virustauti, joka kuuluu Suomessa vastustettavien, helposti leviävien eläintautien ryhmään. Taudin oireet ovat epäspesifisiä, ja niihin kuuluvat muun muassa kuume, haavaumat suun limakalvoilla, nielemisvaikeudet, turvotukset pään alueella ja ontuminen. Bluetongue-tautia ei ole koskaan todettu Suomessa. Viime vuosina BT-tautipurkauksia on todettu aikaisempaa pohjoisempana. Suomen kannalta lähimpiä tautipurkauksia on todettu Ruotsissa ja Norjassa. Tässä riskiprofiilissa tarkastellaan BT:n maahan tuloon ja tartunnan edelleen leviämiseen liittyviä riskitekijöitä sekä tartunnan leviämisen seurauksia. Tarkastelussa on huomioitu Suomen ilmaston ja eläinpopulaation erityispiirteet. Lisäksi on selvitetty taudin mahdollisia seurauksia, sekä millä edellytyksillä tartunta voisi Suomessa jäädä endeemiseksi. Suomessa esiintyy ainakin neljä Culicoides-suvun lajia, jotka on ulkomailla yhdistetty BT-virukseen. Ilmatieteen laitoksen kymmenen viime vuoden tilastojen mukaan lämpötilat ovat olleet riittävän korkeita tarpeeksi pitkään mahdollistaakseen polttiaisen ja BT-viruksen lisääntymisen ja leviämisen koko maassa, mutta ilmastolliset olosuhteet ovat taudin kannalta suotuisimmat Ahvenanmaalla, Etelä- ja Länsi-Suomessa.
  • Perko-Mäkelä, Päivikki (Evira, 2011)
    Campylobacter, mainly Campylobacter jejuni and C. coli, are worldwide recognized as a major cause of bacterial food-borne gastroenteritis (World Health Organization 2010). Epidemiological studies have shown handling or eating of poultry to be significant risk factors for human infections. Campylobacter contamination can occur at all stages of a poultry meat production cycle. In summer 1999, every broiler flock from all three major Finnish poultry slaughterhouses was studied during a five month period. Caecal samples were taken in the slaughterhouses from five birds per flock. A total of 1 132 broiler flocks were tested and 33 (2.9%) of those were Campylobacter-positive. Thirty-one isolates were identified as C. jejuni and two isolates were C. coli. The isolates were serotyped for heat-stable antigens (HS) and genotyped by pulsed-field gel electrophoresis (PFGE). The most common serotypes found were HS 6,7, 12 and 4-complex. Using a combination of SmaI and KpnI patterns, 18 different PFGE types were identified. Thirty-five Finnish C. jejuni strains with five SmaI/SacII PFGE types selected among human and chicken isolates from 1997 and 1998 were used for comparison of their PFGE patterns, amplified fragment length polymorphism (AFLP) patterns, HaeIII ribotypes, and HS serotypes. The discriminatory power of PFGE, AFLP and ribotyping with HaeIII were shown to be at the same level for this selected set of strains, and these methods assigned the strains into the same groups. The PFGE and AFLP patterns within a genotype were highly similar, indicating genetic relatedness. An HS serotype was distributed among different genotypes, and different serotypes were identified within one genotype. From one turkey parent flock, the hatchery, six different commercial turkey farms (together 12 flocks) and from 11 stages at the slaughterhouse a total of 456 samples were collected during one and the half year. For the detection of Campylobacter both conventional culture and a PCR method were used. No Campylobacter were detected in either of the samples from the turkey parent flock or from the hatchery samples using the culture method. Instead PCR detected DNA of Campylobacter in five faecal samples from the turkey parent flock and in one fluff and an eggshell sample. Six out of 12 commercial turkey flocks were found negative at the farm level but only two of those were negative at slaughter. Campylobacter-positive samples within the flock at slaughter were detected between 0% and 94%, with evisceration and chilling water being the most critical stages for contamination. All of a total of 121 Campylobacter isolates were shown to be C. jejuni using a multiplex PCR assay. PFGE analysis of all isolates with KpnI restriction enzyme resulted in 11 PFGE types (I-XI) and flaA-SVR typing yielded nine flaA-SVR alleles. Three Campylobacter-positive turkey flocks were colonized by a limited number of Campylobacter genotypes both at the farm and slaughter level.In conclusion, in our first study in 1999 a low prevalence of Campylobacter in Finnish broiler flocks was detected and it has remained at a low level during the study period until the present. In the turkey meat production, we found that flocks which were negative at the farm became contaminated with Campylobacter at the slaughter process. These results suggest that proper and efficient cleaning and disinfection of slaughter and processing premises are needed to avoid cross-contamination. Prevention of colonization at the farm by a high level of biosecurity control and hygiene may be one of the most efficient ways to reduce the amount of Campylobacter-positive poultry meat in Finland. In Finland, with a persistent low level of Campylobacter-positive flocks, it could be speculated that the use of logistic slaughtering, according to Campylobacter status at farm, might have be advantageous in reducing Campylobacter contamination of retail poultry products. However, the significance of the domestic poultry meat for human campylobacteriosis in Finland should be evaluated.
  • Rikula, Ulla (Evira, 2008)
    Canine distemper (CD) is one of the longest-known infectious diseases of dogs and is still prevalent in many parts of the world. Vaccination combined with biosecurity measures is the most productive way to prevent and control infectious diseases. The beneficial effects of vaccination are realized not only on the individual but also on the population level, the latter in the form of herd immunity (HI). Control of CD among dogs relies heavily on vaccination, while in fur farms and zoos with several species or large numbers of CD-susceptible animals in close contact, biosecurity measures in some cases offer the only available means for CD control. Modified live CD virus vaccines have been successfully used to control CD among farmed mink, and since no licensed vaccines for other species kept for fur exist, mink CD vaccines have also been used for foxes and raccoon dogs in CD emergency situations. CD vaccines for dogs (Canis familiaris) and mink (Mustela vison) were studied in experimental settings for their ability to induce virus-neutralising (VN) antibodies in target species. Mink vaccines were also assessed in silver foxes (Vulpes vulpes), blue foxes (Alopex lagopus) and raccoon dogs (Nyctereutes procyonoides). Purpose-bred beagle dogs were vaccinated twice with one of three CD vaccines: Candur® SHP, Canlan®-3 or Dohyvac® DA2P, and the levels of VN antibodies were determined at the time of vaccination and one month after the second vaccination. Fur animals were vaccinated once with Distemink®, Distem®-R-TC or vaccine 3 (which was not licensed in Finland) and the levels of VN antibodies were determined at vaccination and 2-4 times 1-4 months afterwards. Significant differences among vaccine groups were found both in the proportion of animals with measurable levels of VN antibodies and in the mean titres of antibodies. The levels of VN antibodies were also determined from a large field sample (n = 4 627) of vaccinated dogs. In addition to the three CD vaccines in the seroconversion study above, additional two vaccines, Duramune®-4 and Nobivac® DHP, had been used in the field. Each dog with a known vaccination history, date of birth, sex and breed was sampled once. Based on the overall geometric mean titre of the dogs vaccinated with a single vaccine brand, vaccines were divided into high-take (Candur®, Nobivac® and Duramune®) and low-take (Dohyvac® and Canlan®) groups. The vaccine groups differed significantly among dogs less than two years of age both in the proportion of dogs with detectable VN antibodies and in the mean titres. Both the number of vaccinations and age were associated with the titre and vaccine usage. To control for possible confounding factors, the comparison of titres among vaccine usage groups was adjusted by classifying them according to the number of vaccinations (one to four) and the age group (less than one, one to two, or over two years old). The same division into low- and high-take vaccines was observed, irrespective of the number of vaccinations the dogs had received. The observations of this seroprevalence study regarding Candur® , Canlan® and Dohyvac® were consistent with the results of the seroconversion study. CD was reintroduced into Finland in 1990 after 16 years of absence. The disease remained at a low endemic level in 1990-1994, reached epidemic proportions in 1994-1995 and disappeared during 1995. The epidemic also involved vaccinated dogs. Among the virologically-confirmed cases the proportion of Dohyvac®-vaccinated dogs was higher than expected from the market shares on the assumption that all the vaccines had an equal take. As a result of this observation, Dohyvac® was withdrawn from and Nobivac® and Duramune® introduced to the market during 1995. A drastic redistribution of the market shares between the low-take and high-take vaccines took place, and this coincided with the decline and dying out of the outbreak. The observed occurrence pattern of CD from 1990-1996 was largely attributed to the changes in the level of HI, although the possible contribution of other factors, such as developments in the dog demographics, was also recognized. It was concluded that an HI above 75% is needed to keep CD in check, i.e., only sporadic cases of CD, at most, can occur. With the currently used vaccines an HI of 80% corresponds to a vaccine coverage of some 94%. It was concluded that the development of vaccine-induced immunity is a multifactorial process depending on the properties of the vaccine, on the individual variation, age, species and other factors influencing the immunocompetence of the host. On the individual level the prevention of clinical signs is sufficient, but on the population level, halting the circulation of the virus is crucial for the definitive control of CD. The ultimate test and criterion for a vaccine is its contribution to herd immunity. Heterogeneity in the dog population contributes to the occurrence of CD.
  • Rikula, Ulla (Evira, 2008)
    Canine distemper (CD) is one of the longest-known infectious diseases of dogs and is still prevalent in many parts of the world. Vaccination combined with biosecurity measures is the most productive way to prevent and control infectious diseases. The beneficial effects of vaccination are realized not only on the individual but also on the population level, the latter in the form of herd immunity (HI). Control of CD among dogs relies heavily on vaccination, while in fur farms and zoos with several species or large numbers of CD-susceptible animals in close contact, biosecurity measures in some cases offer the only available means for CD control. Modified live CD virus vaccines have been successfully used to control CD among farmed mink, and since no licensed vaccines for other species kept for fur exist, mink CD vaccines have also been used for foxes and raccoon dogs in CD emergency situations. CD vaccines for dogs (Canis familiaris) and mink (Mustela vison) were studied in experimental settings for their ability to induce virus-neutralising (VN) antibodies in target species. Mink vaccines were also assessed in silver foxes (Vulpes vulpes), blue foxes (Alopex lagopus) and raccoon dogs (Nyctereutes procyonoides). Purpose-bred beagle dogs were vaccinated twice with one of three CD vaccines: Candur® SHP, Canlan®-3 or Dohyvac® DA2P, and the levels of VN antibodies were determined at the time of vaccination and one month after the second vaccination. Fur animals were vaccinated once with Distemink®, Distem®-R-TC or vaccine 3 (which was not licensed in Finland) and the levels of VN antibodies were determined at vaccination and 2-4 times 1-4 months afterwards. Significant differences among vaccine groups were found both in the proportion of animals with measurable levels of VN antibodies and in the mean titres of antibodies. The levels of VN antibodies were also determined from a large field sample (n = 4 627) of vaccinated dogs. In addition to the three CD vaccines in the seroconversion study above, additional two vaccines, Duramune®-4 and Nobivac® DHP, had been used in the field. Each dog with a known vaccination history, date of birth, sex and breed was sampled once. Based on the overall geometric mean titre of the dogs vaccinated with a single vaccine brand, vaccines were divided into high-take (Candur®, Nobivac® and Duramune®) and low-take (Dohyvac® and Canlan®) groups. The vaccine groups differed significantly among dogs less than two years of age both in the proportion of dogs with detectable VN antibodies and in the mean titres. Both the number of vaccinations and age were associated with the titre and vaccine usage. To control for possible confounding factors, the comparison 8 of titres among vaccine usage groups was adjusted by classifying them according to the number of vaccinations (one to four) and the age group (less than one, one to two, or over two years old). The same division into low- and high-take vaccines was observed, irrespective of the number of vaccinations the dogs had received. The observations of this seroprevalence study regarding Candur® , Canlan® and Dohyvac® were consistent with the results of the seroconversion study. CD was reintroduced into Finland in 1990 after 16 years of absence. The disease remained at a low endemic level in 1990-1994, reached epidemic proportions in 1994-1995 and disappeared during 1995. The epidemic also involved vaccinated dogs. Among the virologically-confirmed cases the proportion of Dohyvac®-vaccinated dogs was higher than expected from the market shares on the assumption that all the vaccines had an equal take. As a result of this observation, Dohyvac® was withdrawn from and Nobivac® and Duramune® introduced to the market during 1995. A drastic redistribution of the market shares between the low-take and high-take vaccines took place, and this coincided with the decline and dying out of the outbreak. The observed occurrence pattern of CD from 1990-1996 was largely attributed to the changes in the level of HI, although the possible contribution of other factors, such as developments in the dog demographics, was also recognized. It was concluded that an HI above 75% is needed to keep CD in check, i.e., only sporadic cases of CD, at most, can occur. With the currently used vaccines an HI of 80% corresponds to a vaccine coverage of some 94%. It was concluded that the development of vaccine-induced immunity is a multifactorial process depending on the properties of the vaccine, on the individual variation, age, species and other factors influencing the immunocompetence of the host. On the individual level the prevention of clinical signs is sufficient, but on the population level, halting the circulation of the virus is crucial for the definitive control of CD. The ultimate test and criterion for a vaccine is its contribution to herd immunity. Heterogeneity in the dog population contributes to the occurrence of CD.
  • Jakava-Viljanen, Miia (Evira, 2007)
    Pigs coexist with diverse and dense commensal microbiota in their gastrointestinal tract (GIT). Lactobacilli, identified as common members of porcine intestinal microbiota, have been considered to be an important group of bacteria in maintaining the stability of GIT, in preventing intestinal infections and generally, in supporting intestinal health. Because several species of lactobacilli have GRAS (generally regarded as safe) status and some of them have an ability to interact with intestinal epithelial cells, thus promoting host-bacterial interactions, their possible applications as mucosal vaccine vector and/or probiotics have aroused interest. Selection criteria for lactobacilli to be used as vaccine vector or probiotic include the abilities to adhere to the intestinal epithelium cells and colonize the lumen of the GI tract. The adherence to host tissues, which enables the organism to overcome local defences such as mucociliary function and peristaltis, is usually mediated by specialized proteins called adhesins. These adhesins are responsible for recognizing and binding to specific receptor structures of the host cells. Bacterial adhesins are often found in hair-like appendages called pili or fimbriae that extend outward from bacterial surface. Alternatively, they can be directly associated with the microbial cell surface. Surface layer proteins (Slps) of lactobacilli have been shown to confer tissue adherence. In this study, S-layer positive lactobacilli from the intestine and faeces of pigs were isolated and their ability to adhere to pig and human intestinal cells as well as to extracellular matrix (ECM) components, collagen, laminin and fibronectin were studied. The adherence of S-layer carrying lactobacilli varied from strong to moderate for human and porcine small intestine enterocytes and for the components of ECM and basal membranes (BM). Removal of the intact Slps reduced the adhesion of some strains to fibronectin and laminin, whereas, the adhesiveness to laminin increased with some strains. Besides the putative binding properties of Slps, a very large number of surface layer protein subunits present in an S-layer make the use of the S-layer structure a very 7 interesting alternative to surface display antigens. Therefore, the aim of this study was to characterize the S-layer proteins. Two new surface layer proteins (SlpB and SlpD), with potential to be tested as antigen carriers, were characterized, and three S-layer protein (slpB, slpC and slpD) genes were isolated, sequenced, and studied for their expression in Lactobacillus brevis neotype strain ATCC 14869. Under different growth conditions, L. brevis strain was found to form two colony types, smooth (S) and rough (R), and to express the S-proteins differently by mechanism not involving DNA rearrangements. The adhesion studies indicate that L. brevis adheres to human and pig intestinal epithelial cells but it is not currently known whether the binding is mediated by the surface proteins in this L. brevis strain of human origin. To identify the S-layer positive lactobacilli strains used in this study, a polyphasic taxonomic approach was applied. The methods used included 16S rRNA gene sequence analysis, numerical analysis of 16 and 23 rRNA gene ribotypes and DNA-DNA reassociation. In addition, all strains were included in a multilocus sequence analysis (MLSA) study for species identification using housekeeping genes encoding the phenylalanyl-tRNA synthase alpha subunit (pheS) and RNA polymerase alpha subunit (rpoA). These results indicated that six out of eight porcine lactobacilli strains from Finland and the related L. sobrius strains, originating from porcine intestine from elsewhere, constitute a single species, L. amylovorus, and that the name L. sobrius should be considered as a later synonym of L. amylovorus. In the final part of this study, the adhesin FedF of Eschrichia coli F18 fimbriae was characterized. The work aims at developing lactobacilli as a live mucosal vaccine vector for pigs against diseases caused by F18+ E. coli. The F18 fimbriae carrying E. coli strains colonize the microvilli of porcine small intestinal epithelial cells and cause post-weaning diarrhoea (PWD) and edema disease (ED) in pigs. It has been shown that oral immunization of weaned piglets with adhesins can induce a protective mucosal immune response. Naked FedF appeared to be very unstable but in our study it could be produced as a fusion protein with maltose binding protein (MBP). Specific adhesion to isolated porcine intestinal epithelial cells was demonstrated with MBP-FedF fusions as well as the ability of anti-MBP-FedF antibodies to prevent binding of E. coli F18 to porcine epithelial cells.
  • Jakava-Viljanen, Miia (Evira, 2007)
    The intestinal commensal microbiota of pigs comprises hundreds of different types of microorganisms (Stewart, 1997; Inoue et al., 2005). The members of the genus Lactobacillus are important residents of the gastrointestinal (GI) microbiota and have been subjects of increasing interest due to their possible role in the maintenance of GI health. Because of these putative health promoting properties, Lactobacillus species are widely used as probiotics (Ouwehand et al., 2002). One important criterion proposed for a probiotic bacterium is its ability to adhere and colonize host tissues, which enables multiplication and survival of the bacterium in the host and may prevent the colonization of pathogenic bacteria via competitive exlusion (CE). The F18 fimbriae-expressing (F18+) E. coli cause post-weaning diarrhoea (PWD) and edema disease (ED) in newly weaned piglets. The key virulence factors in diarrhoea are enterotoxins and fimbrial adhesins (Berberov et al., 2004; Zhang et al., 2006). Protection against these diseases can be established by preventing the fimbrial adhesion of these bacteria to the enterocytes of the porcine intestine. The FedF protein of F18 fimbriae was recognised as the adhesin and antibodies against FedF were found to inhibit the adhesion of F18+ E. coli to porcine enterocytes (Smeds et al., 2001; Smeds et al., 2003). However, oral immunisation with purified F18 fimbriae did not result in protection against ED by a challenge infection with F18+ verotoxigenic E. coli (VTEC) (Verdonck et al., 2007) and there are no commercial vaccines available against infections caused by F18 fimbriae-carrying E. coli strains. Like many other bacteria, several species of Lactobacillus have a surface (S-) layer as the outermost component of the cell (reviewed in Åvall-Jääskeläinen and Palva, 2005). The function of Lactobacillus S-layers characterized so far is involved in mediating adhesion to different host tissues. In addition to surface layer proteins (Slps) adhesive properties, the very large number of S-layer subunits present on the cell surface has prompted research aiming at the use of S-layers as a vehicle for the delivery of biologically active compounds, such as drug molecules, antibodies, enzymes and vaccine antigens (Sleytr et al., 2007). 13 The accurate species identification of bacteria is of fundamental importance in the development of new mucosal vaccine vectors or probiotics. Species of Lactobacillus form the most numerous genus in the heterogeneous group of lactic acid bacteria (LAB). The genus contains about one hundred described species, which are subdivided by 16S rRNA analysis, DNA-DNA hybridization and other phylogenetic methods, into eight major groups. The 16S rRNA gene is a reliable phylogenetic marker but is not an effective identification tool as it does not allow discrimination among closely related species. A multilocus sequence analysis (MLSA), on the contrary, effectively offers a high resolution and yields a robust identification system. MLSA compares the primary DNA sequences from multiple conserved protein coding loci for assessing the diversity and relation of different isolates across related taxa. The combined use of the phenylalanyl-tRNA synthase alpha subunit (pheS) and RNA polymerase alpha subunit (rpoA) gene sequences offers a reliable identification system for nearly all Lactobacillus species (Naser, 2006).
  • Ariel, Ellen; Holopainen, Riikka; Olesen, Niels Jörgen; Tapiovaara, Hannele (Springer, 2010)
    Two iridovirus isolates recovered from cod (Gadus morhua) and turbot (Psetta maxima) in Denmark were examined in parallel with a panel of other ranaviruses including frog virus 3 (FV3), the reference strain for the genus Ranavirus. The isolates were assessed according to their reactivity in immunofluoresent antibody tests (IFAT) using both homologous and heterologous antisera and their amplification in PCR using primers targeting five genomic regions. The corresponding PCR fragments were sequenced, and the sequences obtained were used in phylogenetic analysis. In addition, the pathogenicity to rainbow trout under experimental challenge conditions was investigated. The viruses were serologically and genetically closely related to highly pathogenic ranaviruses such as European catfish iridovirus (ECV), European sheatfish iridovirus (ESV) and epizootic haematopoietic necrosis virus (EHNV). The challenge trials indicate that rainbow trout fry cultured at 15 C are not target species for the virus isolates in the present panel. We suggest that the two isolates belong in the genus Ranavirus and propose the name Ranavirus maxima (Rmax) for the turbot isolate.
  • Nuotio, Lasse Olavi (Evira, 2006)
    The monitoring and control of infectious animal diseases, limiting or prevention of their spread and efforts towards their eventual eradication are central tasks of the veterinary civil service. In addition to the cost-effectiveness of prophylaxis over disease and treatment, the animal welfare aspect is also involved. The purpose of this work is to review, describe and assess the available control measures against selected viral infections or diseases of domestic ruminants. The selected infections or diseases are bovine viral diarrhoea / mucosal disease (BVD), infectious bovine rhinotracheitis / infectious pustular vulvovaginitis (IBR), enzootic bovine leukosis (EBL) and maedi–visna (MV) of sheep. Each is recognized as a signifi cant disease of domestic animals. Decisive control and eradication measures are necessarily based on the biological, veterinary and diagnostic characteristics of the affl ictions, as well as on their epidemiology in terms of the intrinsic determinants of the hosts, host–agent relationships and sources and transmission of the infection, and occurrence of these infections or diseases. This information is compiled and presented in the fi rst part of the thesis with special reference to available or possible control and eradication measures. These measures and programmes against the four affl ictions employed in major cattle and sheep producing countries in individuals and herds and on national and international levels are outlined and assessed briefl y. In the descriptive part of the thesis the domestic and EU legislation that forms the offi cial framework for disease control and eradication are outlined. The development in the situation concerning these four infections or diseases is described from the early records to date. The fi rst recorded entries of the occurrence of BVD and EBL in Finland date back to the 1960s, those of IBR to the beginning of the 1970s and of MV to the beginning of the 1980s. Large-scale surveillance and health monitoring among dairy, suckler-cow and beef herds and sheep fl ocks, starting during the fi rst half of the 1990s, enabled the estimation of actual prevalences of these infections and diseases. A common feature of the occurrence of these infections or diseases is that none has had a prevalence of more than an estimated few percent before 1990, and a maximum of 1% since then. This has formed a very favourable starting point for the nation-wide control and eradication measures. The voluntary control programmes or schemes, as well as the offi cial control and eradication measures are described. The successful eradication of IBR and EBL in 1994 and 1996, respectively, and the signifi cant reduction in the occurrences of BVD and MV from 1990 to date, are reported in detail. The effi cacies of the offi cial control and eradication measures and of the actions of the voluntary control programmes or schemes are analyzed further, making use of a heuristic formulation for the infection reproduction number (R), i.e. the number of secondary cases produced by one infective animal. The infl uence of the measures is resolved into the three components of R: the probability of transmission, frequency of infectious contacts and length of the infectious period, and the impact of the measures on each component is graded on a three-step scale. 9 The conclusion is drawn that the offi cial measures complemented by voluntary actions for control and eradication have for the most part been adequate. The signifi cance of fi nancial compensation from the state for the costs incurred in the control of notifi able diseases is noted. In the case of BVD the decisive measures for fi nal eradication have only been available since 2004 and their impact will be seen in the next few years. The role of continued surveillance and health moni toring for both overseeing the situation with BVD and MV, and maintaining an IBR and EBLfree status is emphasized.
  • Nuotio, Lasse (2006)
    The monitoring and control of infectious animal diseases, limiting or prevention of their spread and efforts towards their eventual eradication are central tasks of the veterinary civil service. In addition to the cost-effectiveness of prophylaxis over disease and treatment, the animal welfare aspect is also involved. The purpose of this work is to review, describe and assess the available control measures against selected viral infections or diseases of domestic ruminants. The selected infections or diseases are bovine viral diarrhoea / mucosal disease (BVD), infectious bovine rhinotracheitis / infectious pustular vulvovaginitis (IBR), enzootic bovine leukosis (EBL) and maedi–visna (MV) of sheep. Each is recognized as a signifi cant disease of domestic animals. Decisive control and eradication measures are necessarily based on the biological, veterinary and diagnostic characteristics of the affl ictions, as well as on their epidemiology in terms of the intrinsic determinants of the hosts, host–agent relationships and sources and transmission of the infection, and occurrence of these infections or diseases. This information is compiled and presented in the fi rst part of the thesis with special reference to available or possible control and eradication measures. These measures and programmes against the four affl ictions employed in major cattle and sheep producing countries in individuals and herds and on national and international levels are outlined and assessed briefl y. In the descriptive part of the thesis the domestic and EU legislation that forms the offi cial framework for disease control and eradication are outlined. The development in the situation concerning these four infections or diseases is described from the early records to date. The fi rst recorded entries of the occurrence of BVD and EBL in Finland date back to the 1960s, those of IBR to the beginning of the 1970s and of MV to the beginning of the 1980s. Large-scale surveillance and health monitoring among dairy, suckler-cow and beef herds and sheep fl ocks, starting during the fi rst half of the 1990s, enabled the estimation of actual prevalences of these infections and diseases. A common feature of the occurrence of these infections or diseases is that none has had a prevalence of more than an estimated few percent before 1990, and a maximum of 1% since then. This has formed a very favourable starting point for the nation-wide control and eradication measures. The voluntary control programmes or schemes, as well as the offi cial control and eradication measures are described. The successful eradication of IBR and EBL in 1994 and 1996, respectively, and the signifi cant reduction in the occurrences of BVD and MV from 1990 to date, are reported in detail. The effi cacies of the offi cial control and eradication measures and of the actions of the voluntary control programmes or schemes are analyzed further, making use of a heuristic formulation for the infection reproduction number (R), i.e. the number of secondary cases produced by one infective animal. The infl uence of the measures is resolved into the three components of R: the probability of transmission, frequency of infectious contacts and length of the infectious period, and the impact of the measures on each component is graded on a three-step scale. The conclusion is drawn that the offi cial measures complemented by voluntary actions for control and eradication have for the most part been adequate. The signifi cance of fi nancial compensation from the state for the costs incurred in the control of notifi able diseases is noted. In the case of BVD the decisive measures for fi nal eradication have only been available since 2004 and their impact will be seen in the next few years. The role of continued surveillance and health moni toring for both overseeing the situation with BVD and MV, and maintaining an IBR and EBLfree status is emphasized.
  • Kangas, Susanna; Lyytikäinen, Tapani; Peltola, Jukka; Ranta, Jukka; Maijala, Riitta (BioMed Central, 2007)
  • Viljamaa-Dirks, Satu (Evira, 2008)
    Rapu on ollut jo kauan osa pohjoismaista kulttuuriperinnettä. Yli sata vuotta sitten Manner-Euroopasta levinnyt tuhoisa raputauti, rapurutto, hävitti kuitenkin suuren osan tuottavista jokirapukannoista. Monet rapuruton esiintymiseen ja diagnostiikkaan liittyvät kysymykset ovat vielä ratkaisematta vuosikymmeniä kestäneestä tutkimustyöstä huolimatta. Raputautien diagnoosimenetelmiä ja käynnissä olevia tutkimushankkeita käsiteltiin Kuopiossa järjestetyssä tapaamisessa, johon kutsuttiin edustajat pohjoismaisista raputauteja tutkivista laboratorioista. Kokous järjestettiin Elintarviketurvallisuusvirasto Eviran Kuopion yksikössä. Tutkijoita Suomesta, Ruotsista, Norjasta, Virosta ja Latviasta oli paikalla, samoin kuin OIE- rapuruton referenssilaboratorion asiantuntija Englannista. Tapaamisen ensimmäisenä päivänä käsiteltiin eri maiden rapukantoja, raputautitilannetta ja tautien tunnistusmenetelmiä. Toisena päivänä keskusteltiin tarkemmin eri diagnoosimenetelmistä sekä raputauteihin kohdistuvasta tutkimuksesta. Tapaaminen järjestettiin Pohjoismaiden Ministerineuvoston tuella.
  • Tuomisto, Pirkko (Evira, 2009)
    The drive for risk-based food safety management, systems and control has spread world-wide in recent decades. Since the term is still internationally undefined, its use and implementation vary, producing different realizations. In this Ph.D. thesis, microbiological risk assessment (MRA) was investigated as a basis for risk-based food safety management, which was defined as ‘food safety management based on risk assessment in order to achieve an appropriate level of protection (ALOP)’. Governments are responsible for commissioning MRAs and also for setting food safety targets up to a certain point, but the practical management measures that need to be in place in order to achieve the targets are to be addressed by the operators. On the plant level, food safety is usually managed through regulation, quality assurance systems and a hazard analysis and critical control point (HACCP) programme with its prerequisites. In Finland, food safety management on the food plant level is implemented through an HACCP-like regulated system termed an ownchecking (OC) programme. A quantitative microbiological risk assessment (QMRA) was conducted on salmonella in the beef production chain according to the official standards of the Codex Alimentarius Commission (Codex Alimentarius), and utilized in determining the food safety metrics for beef production. The Finnish Salmonella Control Programme (FSCP) and the main official interventions due to it were examined in the light of risk-based food safety management. The targets set for beef processing plants by the government were converted into quantitative limits, and the results of salmonella monitoring included in the FSCP were examined by the QMRA. The goal of the FSCP was declared in 1994 to ‘maintain the present salmonella situation’, which was considered to refer to the salmonella incidence in humans at that time, and also the de facto ALOP. The requirement for a maximum salmonella prevalence of 1% at defined stages of the beef production chain was embodied in the FSCP. This statement was considered to convey performance objectives (PO) for the aforementioned stages. According to the QMRA, the de facto ALOP was achieved in the referred year 1999, and even the true prevalence levels in the FSCP were estimated to be clearly under the set PO limits with 95% credibility. However, the PO limits were set too high for the de facto ALOP to be maintained in practice. If the salmonella prevalence reached the PO limit of 1% or values near it, the public health risk would increase and overrun the de facto ALOP. The QMRA produced in this work has for the first time provided the possibility to quantitatively asses the relationships between targets set in the FSCP and their impact on public health. At present, imports of beef and beef-derived foods may impose on Finnish consumers a significantly greater exposure than domestic products. If their salmonella prevalence or their share of the foods consumed in Finland increase, the number of human cases could rapidly rise. The models for the QMRA were mainly Bayesian hierarchical models using Markov chain Monte Carlo (MCMC) techniques, which was found to be a flexible and appropriate method for this type of complex modelling. The resulting distributions were also regarded as an advantage compared to the results from models developed with the deterministic approach, because the presentation of results included the extent of the uncertainty, and also in this manner better illustrated the actual operational environment. Based on an inquiry, the personnel in food processing plants had a positive attitude towards food safety management systems, but the knowledge, training and involvement of those employees directly operating on the site with these systems were discovered to be deficient. Therefore, a generic semi-quantitative hygiene risk assessment model, Hygram®, was developed for small and medium-sized food enterprises to offer assistance in understanding, training, and, first of all, detecting the critical steps of the processes, and thereby to contribute to the development of their own-checking systems towards risk-based food safety management. Hygram® was not considered a risk-based tool as such, but whenever the critical limits of the process have been defined as equal to a risk assessment, Hygram® can be used as a risk-based management tool. It can also serve as a tool for systematic hazard analysis and CCP detection when establishing a food safety management system. To conclude, the development of risk-based food safety management is a process in which risk assessment is an essential tool. Scientific, technical, psychological and resource-bound barriers need to be overcome in order to put risk-based management systems into practice. This study showed that QMRA can be valuable in national risk management decision making, although few QMRAs are currently available. Appropriate tools for practical risk management decision making on the industrial level, such as Hygram®, need to be further developed.
  • Tuominen, Pirkko (Evira, 2008)
    The drive for risk-based food safety management, systems and control has spread world-wide in recent decades. Since the term is still internationally undefined, its use and implementation vary, producing different realizations. In this Ph.D. thesis, microbiological risk assessment (MRA) was investigated as a basis for risk-based food safety management, which was defined as ‘food safety management based on risk assessment in order to achieve an appropriate level of protection (ALOP)’. Governments are responsible for commissioning MRAs and also for setting food safety targets up to a certain point, but the practical management measures that need to be in place in order to achieve the targets are to be addressed by the operators. On the plant level, food safety is usually managed through regulation, quality assurance systems and a hazard analysis and critical control point (HACCP) programme with its prerequisites. In Finland, food safety management on the food plant level is implemented through an HACCP-like regulated system termed an ownchecking (OC) programme. A quantitative microbiological risk assessment (QMRA) was conducted on salmonella in the beef production chain according to the official standards of the Codex Alimentarius Commission (Codex Alimentarius), and utilized in determining the food safety metrics for beef production. The Finnish Salmonella Control Programme (FSCP) and the main official interventions due to it were examined in the light of risk-based food safety management. The targets set for beef processing plants by the government were converted into quantitative limits, and the results of salmonella monitoring included in the FSCP were examined by the QMRA. The goal of the FSCP was declared in 1994 to ‘maintain the present salmonella situation’, which was considered to refer to the salmonella incidence in humans at that time, and also the de facto ALOP. The requirement for a maximum salmonella prevalence of 1% at defined stages of the beef production chain was embodied in the FSCP. This statement was considered to convey performance objectives (PO) for the aforementioned stages. According to the QMRA, the de facto ALOP was achieved in the referred year 1999, and even the true prevalence levels in the FSCP were estimated to be clearly under the set PO limits with 95% credibility. However, the PO limits were set too high for the de facto ALOP to be maintained in practice. If the salmonella prevalence reached the PO limit of 1% or values near it, the public health risk would increase and overrun the de facto ALOP. The QMRA produced in this work has for the first time provided the possibility to quantitatively asses the relationships between targets set in the FSCP and their impact on public health. At present, imports of beef and beef-derived foods may impose on Finnish consumers a significantly greater exposure than domestic products. If their salmonella prevalence or their share of the foods consumed in Finland increase, the number of human cases could rapidly rise. The models for the QMRA were mainly Bayesian hierarchical models using Markov chain Monte Carlo (MCMC) techniques, which was found to be a flexible and appropriate method for this type of complex modelling. The resulting distributions were also regarded as an advantage compared to the results from models developed with the deterministic approach, because the presentation of results included the extent of the uncertainty, and also in this manner better illustrated the actual operational environment. Based on an inquiry, the personnel in food processing plants had a positive attitude towards food safety management systems, but the knowledge, training and involvement of those employees directly operating on the site with these systems were discovered to be deficient. Therefore, a generic semi-quantitative hygiene risk assessment model, Hygram®, was developed for small and medium-sized food enterprises to offer assistance in understanding, training, and, first of all, detecting the critical steps of the processes, and thereby to contribute to the development of their own-checking systems towards risk-based food safety management. Hygram® was not considered a risk-based tool as such, but whenever the critical limits of the process have been defined as equal to a risk assessment, Hygram® can be used as a risk-based management tool. It can also serve as a tool for systematic hazard analysis and CCP detection when establishing a food safety management system. To conclude, the development of risk-based food safety management is a process in which risk assessment is an essential tool. Scientific, technical, psychological and resource-bound barriers need to be overcome in order to put risk-based management systems into practice. This study showed that QMRA can be valuable in national risk management decision making, although few QMRAs are currently available. Appropriate tools for practical risk management decision making on the industrial level, such as Hygram®, need to be further developed.
  • Hallikainen, Anja; Rautala, Taneli; Karlström, Ulla; Kostamo, Pirkko; Koivisto, Pertti; Pohjanvirta, Raimo; Hietaniemi, Veli; Rajakangas, Liisa; Tuomaala, Vesa; Kankaanpää, Harri; Verta, Matti; Kostiainen, Eila; Kurttio, Päivi; Turtiainen, Tuukka; Kiviranta, Hannu; Komulainen, Hannu; Rantakokko, Panu; Viluksela, Matti; Niemi, Esko; Nuotio, Kirsti; Siivinen, Kalevi (Evira, 2009)
    Elintarvikkeiden ja talousveden kemialliset vaarat kuvataan nyt uusitussa muodossa. Raportissa käsitellään 40 vierasainetta tai –ryhmää, ja saadaan samalla kertaa kuva koko ongelmakentästä. Kaikki raporttiin valitut kemialliset yhdisteet ovat olleet viime vuosina mukana elintarvikkeiden ja/tai talousveden riskinhallintaa käsittelevissä valmisteluissa tai toimenpiteissä sekä kansallisella että EU-tasolla. Kemiallisista vaaroista oli suurimmasta osasta runsaasti tietoa saatavilla: esiintyminen elintarvikkeissa, tutkimukset ja saantilaskelmat, terveydelliset haittavaikutukset ja valvontaan liittyvät tarpeet ja lopuksi kattavat kirjallisuuskatsaukset. Yhteensä 21 suomalaista kutsuttua vierasaineasiantuntijaa on ollut mukana eri sektoritutkimuslaitoksista tämän raportin sisällön kirjoittamis- ja tarkistamistyössä. Lisäksi suuri joukko muita asiantuntijoita on kommentoinut raporttia. Asiantuntijat ovat eri hallinnonaloilta, ja osa aiheistakin ja niihin liittyvistä vierasaineista, kuten talousveden vierasaineet, kuuluvat hallinnollisesti muihin kuin maa- ja metsätalousministeriön alaisiin asiantuntijalaitoksiin. Tämä raportti on tehty mahdollisimman laajalle käyttäjäkunnalle ottaen huomioon viranomaiset sekä kuluttajat ja opetus- ja tutkimuslaitokset. Raportti on tehty helppokäyttöiseksi ja mahdollisimman selkeäksi ja lyhytsanaiseksi monine taulukkoineen ja kuvineen. Tarkoitus on, että siitä löytyy helposti eri vierasaineiden ominaisuuksia, joita voi tarvittaessa vertailla. Siitä voi etsiä uusimmat tutkimustulokset ja kansainväliset riskinarvioinnit sekä löytää vierasaineiden pitoisuustietoja etenkin kotimaisista elintarvikkeista. Arvioituja vierasainesaantimääriä voi verrata vierasaineille asetettuihin siedettäviin enimmäissaantimääriin tai vaikkapa verrata näitä turvallisuutta kuvaavia suureita eri vierasaineiden kesken. Valvontaviranomaiset voivat löytää lisäksi nopeasti tietoa lainsäädännöstä ja suositelluista valvontatoimenpiteistä. Valvontaan ja muuhun riskinhallintaan liittyvät ehdotukset ovat syntyneet yhteistyössä valvonnasta vastaavien Eviran asiantuntijoiden kanssa.
  • Hallanvuo, Saija; Johansson, Tuula (Evira, 2010)
    Opas sisältää perustietoa Suomen kannalta merkittävistä elintarvikkeisiin liittyvistä taudinaiheuttajista: bakteereista, viruksista, loisista ja prioneista. Oppaassa on kuvattu aiheuttajakohtaisesti terveydellisiä haittavaikutuksia, esiintymistä ihmisissä, eläimissä, elintarvikkeissa ja ympäristössä, raportoituja epidemioita Suomesta ja ulkomailta, ruokamyrkytykseen johtaneita tekijöitä ja valvontaa. Valvontaa tarkastellaan elintarvikkeen koko elinkaaren ajalta ja pyritään osoittamaan ne "pellolta pöytään" -ketjun riskikohdat, joissa saastuminen ja mikrobien lisääntyminen yleensä tapahtuu. Valvontatoimenpiteisiin ryhdyttäessä on kuitenkin aina tarkistettava ajantasainen lainsäädäntö. Opas on päivitetty versio EVI-EELA julkaisusta 1/2003 (Opas elintarvikkeiden ja talousveden mikrobiologista vaaroista).
  • Schulman, Kitty; Sahlström, Leena; Heikkilä, Jaakko (Evira, 2014)
    Ur djursjukdomsfaro- och smittsskyddssynvinkel är utegångskravet för ekologisk kalkon den största skillnaden mellan ekologisk och konventionell kalkonuppfödning. Smittspärrar mellan omgivningen och produktionsutrymmena kan inte tillämpas lika heltäckande utomhus som i konventionella produktionsanläggningar. Utegående kalkoner kan därför i högre grad utsättas för smittämnen från vildfåglar och gnagare samt för markburna smittämnen. Smittor påverkar kalkonernas hälsa och kan också spridas till konsumenterna via kalkonkött. Uppfödning av ängskalkoner erbjuder en mellanform mellan ekologisk och konventionell uppfödning. Smittrisker förknippade med utomhusvistelse gäller även ängskalkoner. Djursjukdomsriskerna vid betesgång kan begränsas genom kontrollåtgärder såsom skadedjursbekämpning, betesrotation och vaccination mot rödsjuka. Smittskyddet medför naturligtvis extra kostnader för producenten men dess andel av de totala rörliga kostnaderna för ekologisk produktion är ändå förhållandevis liten. Andra smittskyddsrisker inom ekologisk kalkonuppfödning är förknippade med djurstallar, utfodring och djurmaterial. Utomhusvistelse för också med sig många positiva effekter, bland annat ökad motion, lägre beläggningsgrad och bättre luftkvalitet. Med god planering och genom att tillämpa smittskyddsåtgärder kan smittriskerna minskas.