Lehmärokko- ja Borna-virusinfektioiden osoittaminen, epidemiologia ja isäntäkirjo

Several orthopoxviruses (OPV) and Borna disease virus (BDV) are enveloped, zoonotic viruses with a wide geographical distribution. OPV antibodies cross-react, and former smallpox vaccination has therefore protected human populations from another OPV infection, rodent-borne cowpox virus (CPXV). Cowpox in humans and cats usually manifests as a mild, self-limiting dermatitis and constitutional symptoms, but it can be severe and even life-threatening in the immunocompromised. Classical Borna disease is a progressive meningoencephalomyelitis in horses and sheep known in central Europe for centuries. Nowadays the virus or its close relative infects humans and also several other species in central Europe and elsewhere, but the existence of human Borna disease with its suspected neuropsychiatric symptoms is controversial. The epidemiology of BDV is largely unknown, and the present situation is even more intriguing following the recent detection of several-million-year-old, endogenized BDV genes in primate and various other vertebrate genomes. The aims of this study were to elucidate the importance of CPXV and BDV in Finland and in possible host species, and particularly to 1) establish relevant methods for the detection of CPXV and other OPVs as well as BDV in Finland, 2) determine whether CPXV and BDV exist in Finland, 3) discover how common OPV immunity is in different age groups in Finland, 4) characterize possible disease cases and clarify their epidemiological context, 5) establish the hosts and possible reservoir species of these viruses and their geographical distribution in wild rodents, and 6) elucidate the infection kinetics of BDV in the bank vole. An indirect immunofluorescence assay and avidity measurement were established for the detection, timing and verification of OPV or BDV antibodies in thousands of blood samples from humans, horses, ruminants, lynxes, gallinaceous birds, dogs, cats and rodents. The mostly vaccine-derived OPV seroprevalence was found to decrease gradually according to the year of birth of the sampled human subjects from 100% to 10% in those born after 1977. On the other hand, OPV antibodies indicating natural contact with CPXV or other OPVs were commonly found in domestic and wild animals: the horse, cow, lynx, dog, cat and, with a prevalence occasionally even as high as 92%, in wild rodents, including some previously undetected species and new regions. Antibodies to BDV were detected in humans, horses, a dog, cats, and for the first time in wild rodents, such as bank voles (Myodes glareolus). Because of the controversy within the human Borna disease field, extra verification methods were established for BDV antibody findings: recombinant nucleocapsid and phosphoproteins were produced in Escherichia coli and in a baculovirus system, and peptide arrays were additionally applied. With these verification assays, Finnish human, equine, feline and rodent BDV infections were confirmed. Taken together, wide host spectra were evident for both OPV and BDV infections based on the antibody findings, and OPV infections were found to be geographically broadly distributed. PCR amplification methods were utilised for hundreds of blood and tissue samples. The methods included conventional, nested and real-time PCRs with or without the reverse transcription step and detecting four or two genes of OPVs and BDV, respectively. OPV DNA could be amplified from two human patients and three bank voles, whereas no BDV RNA was detected in naturally infected individuals. Based on the phylogenetic analyses, the Finnish OPV sequences were closely related although not identical to a Russian CPXV isolate, and clearly different from other CPXV strains. Moreover, the Finnish sequences only equalled each other, but the short amplicons obtained from German rodents were identical to monkeypox virus, in addition to German CPXV variants. This reflects the close relationship of all OPVs. In summary, RNA of the Finnish BDV variant could not be detected with the available PCR methods, but OPV DNA infrequently could. The OPV species infecting the patients of this study was proven to be CPXV, which is most probably also responsible for the rodent infections. Multiple cell lines and some newborn rodents were utilised in the isolation of CPXV and BDV from patient and wildlife samples. CPXV could be isolated from a child with severe, generalised cowpox. BDV isolation attempts from rodents were unsuccessful in this study. However, in parallel studies, a transient BDV infection of cells inoculated with equine brain material was detected, and BDV antigens discovered in archival animal brains using established immunohistology. Thus, based on several independent methods, both CPXV and BDV (or a closely related agent) were shown to be present in Finland. Bank voles could be productively infected with BDV. This experimental infection did not result in notable pathological findings or symptoms, despite the intense spread of the virus in the central and peripheral nervous system. Infected voles commonly excreted the virus in urine and faeces, which emphasises their possible role as a BDV reservoir. Moreover, BDV RNA was regularly reverse transcribed into DNA in bank voles, which was detected by amplifying DNA by PCR without reverse transcription, and verified with nuclease treatments. This finding indicates that BDV genes could be endogenized during an acute infection. Although further transmission studies are needed, this experimental infection demonstrated that the bank vole can function as a potential BDV reservoir. In summary, multiple methods were established and applied in large panels to detect two zoonoses novel to Finland: cowpox virus and Borna disease virus. Moreover, new information was obtained on their geographical distribution, host spectrum, epidemiology and infection kinetics.Lehmärokkovirus (Cowpox virus, CPXV), joka kuuluu ortopoxviruksiin (OPV), ja Borna-virus (Borna disease virus, BDV) ovat zoonoottisia, laajalle levinneitä viruksia. Aiemmat isorokkorokotukset ovat ristireaktion avulla suojanneet ihmisväestöä jyrsijävälitteiseltä CPXV:ltä. CPXV:n aiheuttama lehmärokko ilmenee ihmisellä ja kissalla yleisoireisena, mutta hyvänlaatuisena ihotulehduksena, joskin se voi immuunipuutteisille yksilöille olla hengenvaarallinen. Klassinen Bornan tauti taas on aivojen, aivokalvojen ja selkäytimen tulehdus, joka on tunnettu hevosissa ja lampaissa Keski-Euroopassa vuosisatojen ajan. Nykyään BDV tai sen lähisukulainen infektoi muitakin lajeja, esimerkiksi ihmisiä, Keski-Euroopan ulkopuolellakin, mutta varsinaisen ihmisen Bornan taudin olemassaolo sen oletettuine hermostollis-mielenterveydellisine oireineen on kiistanalainen. BDV:n kaltaisten geenien on vastikään havaittu asettuneen pysyvästi muun muassa kädellisten perimään. Tämän tutkimuksen tavoitteina oli selventää CPXV:n ja BDV:n merkitystä Suomessa sekä tunnistaa niiden mahdollisia isäntälajeja. OPV- ja BDV-vasta-aineiden osoittamiseksi tuhansista ihmisten ja eläinten verinäytteistä pystytettiin immunofluoresenssimenetelmä vasta-aineiden sitoutumislujuuden määrityksineen. Lähinnä isorokkorokotteista aiheutuneiden OPV-vasta-aineiden esiintyvyyden havaittiin alenevan syntymävuoden mukaan 100 %:sta 10 %:in. Luonnolliseen CPXV-tartuntaan viittaavat OPV-vasta-aineet olivat tavallisia koti- ja villieläimissä: hevosessa, naudassa, ilveksessä, koirassa, kissassa ja villijyrsijöissä. Jyrsijöissä tartuntoja havaittiin myös aiemmin tuntemattomissa OPV-isäntälajeissa sekä uusilla esiintymisalueilla. BDV-vasta-aineitakin todettiin useassa lajissa. Bornan taudin kiistanalaisuuksien vuoksi sovellettiin immunofluoresenssin lisäksi yhdistelmä-DNA-teknologia- ja peptidipohjaisia varmistusmenetelmiä. Niillä vahvistettiin ihmisen, hevosen, kissan, ja ensimmäistä kertaa villijyrsijöiden (muun muassa metsämyyrän) BDV-infektiot Suomessa. Satojen veri- ja kudosnäytteiden tutkimisessa hyödynnettiin monipuolisia geenimonistusmenetelmiä, joilla osoitettiin OPV- ja BDV-geenejä. OPV-DNA:ta monistui ihmispotilaista ja metsämyyristä, mutta BDV-RNA:ta ei löydetty luonnollisesti infektoituneista yksilöistä. Suomalaiset OPV-DNA-löydökset olivat emäsjärjestykseltään samanlaisia keskenään ja läheistä sukua Venäjältä eristetyn CPXV:n kanssa eroten muista CPXV-kannoista. Saksalaisista myyristä monistuneet DNA-pätkät taas olivat samanlaisia saksalaisten CPXV-varianttien lisäksi apinarokkoviruksen kanssa, mikä kuvastaa OPV:ten lähisukulaisuutta. Potilaita infektoiva OPV varmistui CPXV:ksi, joka todennäköisimmin on aiheuttanut myös havaitut jyrsijäinfektiot. CPXV:tä ja BDV:tä yritettiin eristää potilaiden ja villieläinten näytteistä solulinjojen ja jyrsijöiden avulla. CPXV saatiin eristettyä lapsesta, joka kärsi yleistyneestä lehmärokosta. BDV-eristysyritykset villijyrsijöistä olivat tässä tutkimuksessa tuloksettomia. Kuitenkin rinnakkaisissa tutkimuksissa havaittiin sekä ohimenevä BDV-infektio hevospotilaan aivokudoksella tartutetuissa soluissa että BDV-proteiinia eläinpotilasarkiston aivonäytteistä immunovärjäysen avulla. Useaan riippumattomaan menetelmään pohjautuen voitiin siis osoittaa sekä CPXV:n että BDV:n (tai lähisukulaisen) esiintyvän Suomessa. Kokeellisessa infektiossa BDV levisi laajalle metsämyyrän hermostossa aiheuttamatta merkittävä patologisia muutoksia tai oireita. Moni myyrä eritti virusta virtsassaan ja/tai ulosteissaan. Tämän lisäksi BDV-RNA käänteiskopioitui usein DNA:ksi metsämyyrissä, mikä viittaa siihen, että BDV-geenit voisivat asettua genomiin akuutin infektion aikana. Vaikkakin tarttumistutkimukset ovat vielä tarpeen, koe kokonaisuudessaan osoitti, että metsämyyrät voivat toimia mahdollisena BDV-säilymönä

Milloin on hyvä muistaa lemmikkivälitteisen zoonoosin mahdollisuus?

Vertaisarvioitu.Peer reviewe

Studying the virome in psychiatric disease

An overlooked aspect of current microbiome studies is the role of viruses in human health. Compared to bacterial studies, laboratory and analytical methods to study the entirety of viral communities in clinical samples are rudimentary and need further refinement. In order to address this need, we developed Virobiome-Seq, a sequence capture method and an accompanying bioinformatics analysis pipeline, that identifies viral reads in human samples. Virobiome-Seq is able to enrich for and detect multiple types of viruses in human samples, including novel subtypes that diverge at the sequence level. In addition, Virobiome-Seq is able to detect RNA transcripts from DNA viruses and may provide a sensitive method for detecting viral activity in vivo. Since Virobiome-Seq also yields the viral sequence, it makes it possible to investigate associations between viral genotype and psychiatric illness. In this proof of concept study, we detected HIV1, Torque Teno, Pegi, Herpes and Papilloma virus sequences in Peripheral Blood Mononuclear Cells, plasma and stool samples collected from individuals with psychiatric disorders. We also detected the presence of numerous novel circular RNA viruses but were unable to determine whether these viruses originate from the sample or represent contaminants. Despite this challenge, we demonstrate that our knowledge of viral diversity is incomplete and opportunities for novel virus discovery exist. Virobiome-Seq will enable a more sophisticated analysis of the virome and has the potential of uncovering complex interactions between viral activity and psychiatric disease. (c) 2021 Elsevier B.V. All rights reserved.Peer reviewe

Infection prevention and control practices of ambulatory veterinarians : A questionnaire study in Finland

Background: Veterinarians face the risk of contracting zoonotic pathogens. Infection prevention and control (IPC) guidelines stress the importance of proper hand hygiene and personal protective equipment (PPE) to prevent transmission of these pathogens. Objectives: We aimed to assess how ambulatory livestock and equine veterinarians follow IPC guidelines, when working on farms and in stables. Methods: We studied hygiene practices of livestock and equine ambulatory veterinarians (n = 129) in Finland. A web-based questionnaire was used to obtain demographic information and information regarding hand-hygiene facilities and practices, use and cleaning of PPE and cleaning of medical equipment. Results: According to 66.9% of the respondents, hand-washing facilities were often adequate on livestock farms, but only 21.4% reported that this was the case in stables (p <.001). While 75.0% reported washing their hands or using hand sanitizer always before moving on to the next farm, only 42.5% reported doing this before moving on to the next stables (p <.001). Universal protective coat or coverall use was more common in livestock practice than in equine practice (91.6% vs. 27.7%, p <.001). Stethoscope cleaning was reported to happen less frequently than once a week by 30.0% of the respondents. Conclusions: Finnish veterinarians' self-reported IPC adherence was far from uniform. IPC was more commonly followed in ambulatory livestock practice perhaps facilitated by better hand-washing facilities on farms than in stables. The study suggests that education of veterinarians is still needed and that hand-washing facilities need to be improved even in a high-income country.Peer reviewe

Toxoplasma gondii seroprevalence in veterinarians in Finland : Older age, living in the countryside, tasting beef during cooking and not doing small animal practice associated with seropositivity

Practising veterinary medicine has an inherent risk of exposure to zoonotic agents, including the protozoan parasite Toxoplasma gondii. We screened sera of veterinarians authorized to work in Finland for the presence of specific immunoglobulin G antibodies against T. gondii with an enzyme-linked fluorescent assay, and evaluated potential risk factors for T. gondii seropositivity from extensive questionnaire data with almost 1,300 quantitative variables. We used a causal diagram approach to address the complexity of the life cycle of the parasite and its numerous possible transmission routes, and built a multivariable binomial logistic regression model to identify risk factors that are particularly relevant for veterinarians. The samples and questionnaire data were collected in 2009. Altogether, 294 veterinarians, almost 15% of the Finnish veterinary profession, were included in the study. The median age was 39 years, and the majority, 86%, were women. Altogether, 43 (14.6%; 95% confidence interval: 10.9-19.0) of the 294 veterinarians tested seropositive for T. gondii. According to the final model, veterinarians who were at least 40 years old had 2.4 times higher odds to be seropositive than younger veterinarians; veterinarians who lived in the countryside had 4.0 times higher odds to be seropositive than veterinarians who lived in towns; female veterinarians who tasted beef during cooking had 2.6 times higher odds to be seropositive than male veterinarians who did not taste beef during cooking; and veterinarians who did not do small animal practice had 2.3 times higher odds to be seropositive than those who did. The results illustrate the numerous transmission routes of T. gondii.Peer reviewe

Metagenomic Evaluation of Bacteria from Voles

Voles (Arvicolinae, Rodentia) are known carriers of zoonotic bacteria such as Bartonella spp. and Francisella tularensis. However, apart from F. tularensis, the bacterial microbiome of voles has not previously been determined in Finland and rarely elsewhere. Therefore, we studied liver samples from 61 voles using 16S ribosomal RNA gene PCR analysis, followed by Sanger sequencing. Twenty-three of these samples were also studied with tag-encoded pyrosequencing. The samples originated from 21 field voles (Microtus agrestis), 37 tundra voles (Microtus oeconomus), and 3 bank voles (Myodes glareolus). With the more conventional 16S rDNA PCR analysis, 90 (33%) of the recovered 269 sequence types could be identified to genus level, including Bartonella, Francisella, Mycoplasma, Anaplasma, and Acinetobacter in 31, 15, 9, 9, and 9 sequences, respectively. Seventy-five (28%) matched best with sequences of uncultured bacteria, of which 40/75 could be classified to the order Clostridiales and, more specifically, to families Lachnospiraceae and Ruminococcaceae. Pyrosequencing from 23 samples revealed comparable and similar results: clinically relevant bacterial families such as Mycoplasmataceae, Bartonellaceae, Anaplasmataceae, and Francisellaceae were recognized. These analyses revealed significant bacterial diversity in vole livers, consisting of distinct and constant sequence patterns reflecting bacteria found in the intestinal gut, but including some known zoonotic pathogens as well. The molecular bacterial sequence types determined with the two different techniques shared major similarities and verified remarkable congruency between the methods.Peer reviewe

Veterinarians as a Risk Group for Zoonoses : Exposure, Knowledge and Protective Practices in Finland

Publisher Copyright: © 2021 The AuthorsBackground: Veterinarians may encounter a variety of zoonotic pathogens in their work. Methods: We conducted two cross-sectional questionnaire studies among veterinarians in Finland. Participants were recruited during two Annual Veterinary Congresses. In 2009, 306 veterinarians participated in an extensive questionnaire study, and in 2016, 262 veterinarians participated in a more focused study that included two same questions. Results: In 2009, the majority (90.9%) of the participating veterinarians reported having been occupationally exposed to zoonotic pathogens. Zoonotic infections (15.0%), needle stick incidents (78.8%), bites (85.0%), as well as infected skin lesions (24.2%) were reported. In 2009, 8.2% of the participants fully agreed with the statement “I have good knowledge of zoonoses and their prevention”; in 2016, the proportion was 10.3%. The reported use of protective practices and personal protective equipment in connection with specific veterinary procedures indicated that there was room for improvement, particularly in protection from pathogens that are transmissible via inhalation and mucous membranes. Conclusion: The results confirm that veterinarians are commonly occupationally exposed to zoonotic pathogens. Education should aim to improve and maintain the knowledge of zoonoses and their prevention. Use of protective practices should be advocated.Peer reviewe

Contamination by Norovirus and Adenovirus on Environmental Surfaces and in Hands of Conscripts in Two Finnish Garrisons

This study investigated the presence of norovirus and adenovirus, especially enteric adenovirus, on the environmental surfaces (n = 481) and military conscripts' hands (n = 109) in two Finnish garrisons (A and B) in 2013 and 2014. A questionnaire study was conducted to reveal possible correlations between viral findings on the conscripts' hands and their acute gastroenteritis symptoms. In addition to the swab samples, 14 fecal samples were obtained for viral analysis. In total, norovirus was present in 9.0 % of the surface swabs in 2013, whereas enteric adenovirus was present in 0.0 % and non-enteric adenovirus in 9.4 %. In the same year, 2.6 % of the hand swabs contained norovirus, 2.6 % enteric adenovirus, and 40.3 % non-enteric adenovirus. Norovirus GI.6 was continually detected on the surfaces of garrison A, and identical virus was detected in some of the fecal samples. In garrison B, two slightly different norovirus GII.4 strains were present on the surfaces. The questionnaires revealed no recent acute gastroenteritis cases in garrison A, but in garrison B, where the norovirus-positive hand swabs were collected, 30.6 % of the conscripts reported of recent symptoms. In 2014, norovirus was rarely detected, but adenovirus was again frequently present, both on the surfaces and hands. Taken together, our results suggest that gastroenteritis outbreaks occurred in 2013, but not in 2014. Due to the low number of hand swabs positive for enteric viruses, no conclusions about associations between viral findings and gastroenteritis symptoms could be drawn. This study increased our understanding of the possible transmission of viruses via contaminated environment and hands.Peer reviewe

Global Distribution of Human Protoparvoviruses

Development of next-generation sequencing and metagenomics has revolutionized detection of novel viruses. Among these viruses are 3 human protoparvoviruses: bufavirus, tusavirus, and cutavirus. These viruses have been detected in feces of children with diarrhea. In addition, cutavirus has been detected in skin biopsy specimens of cutaneous T-cell lymphoma patients in France and in 1 melanoma patient in Denmark. We studied seroprevalences of IgG against bufavirus, tusavirus, and cutavirus in various populations (n = 840), and found a striking geographic difference in prevalence of bufavirus IgG. Although prevalence was low in adult populations in Finland (1.9%) and the United States (3.6%), bufavirus IgG was highly prevalent in populations in Iraq (84.8%), Iran (56.1%), and Kenya (72.3%). Conversely, cutavirus IgG showed evenly low prevalences (0%-5.6%) in all cohorts, and tusavirus IgG was not detected. These results provide new insights on the global distribution and endemic areas of protoparvoviruses.Peer reviewe

Experimental Infection of Voles with Francisella tularensis Indicates Their Amplification Role in Tularemia Outbreaks

Peer reviewe