Efficiency of Virucidal Disinfectants on Wood Surfaces in Animal Husbandry.

The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests were based on German testing guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), were inoculated with enveloped or non-enveloped viruses and then treated with one of three different disinfectants. The results revealed that intact, fine-sawn timber with a low roughness depth can be effectively inactivated. Peracetic acid proved to be the most effective disinfectant across all tests. Regardless of the pathogen and the type of wood, a concentration of 0.1% of the pure substance at a temperature of 10 °C and an exposure time of one hour can be recommended. At a temperature of -10 °C, a concentration of 0.75% is recommended. The basic chemicals formic acid and glutaraldehyde demonstrated only limited effectiveness overall. The synergistic effects of various wood components on the inactivation of viruses offer potential for further investigation. Disinfectant tests should also be conclusively verified in field trials to ensure that the results from standardised laboratory tests can be transferred to real stable conditions.

Tenacity of Animal Disease Viruses on Wood Surfaces Relevant to Animal Husbandry.

The aim of this study was to analyse the hygienic suitability of wood often used in animal husbandry. To this end, the inactivation of viruses (Enterovirus E as a surrogate for non-enveloped viruses and Newcastle disease virus as a surrogate for enveloped viruses) on germ carriers consisting of various types of wood was studied over an extended period to assess the biosafety of wood as an agricultural building material. The study was designed to assess the intrinsic biocidal activity of the wood itself, without the use of a disinfectant. The laboratory tests were based on German test guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), as well as stainless-steel carriers, were inoculated with enveloped and non-enveloped viruses and stored for up to four months, and the remaining infectivity of the viruses was continuously assessed. The results showed that intact, finely sawn timber with a low depth of roughness had an inactivating effect on the viruses up to 7.5 decadal logarithmic levels. For the non-enveloped virus, inactivation was fastest on Douglas fir wood, with the target reduction for effective inactivation (reduction by factor 4.0 log10) being achieved after two weeks, and for the enveloped virus on pine wood, it was already achieved from the day of drying. The hygienic effects of the wood carriers may be due to their hygroscopic properties and wood constituents. These effects offer potential for further investigation, including tests with other wood species rich in extractives.

Dog ecology and rabies knowledge, attitude and practice (KAP) in the Northern Communal Areas of Namibia.

In 2021, a comprehensive dog demographic questionnaire combined with a KAP survey were conducted in the northern communal areas (NCAs) of Namibia with the aim of gaining a better understanding of dog populations, owner behaviour, and knowledge, attitudes and practices (KAP) relating to rabies. The survey of 3,726 households across the eight regions of the NCAs provided insights that will inform interventions in order to improve human rabies prevention and Namibia's dog rabies control strategy. The results showed a relatively low average human/dog ratio (HDR) of 5.4:1 indicating a surprisingly high dog population of at least 272,000 dogs in the NCAs, 93% of which appear to be owned but are free-roaming. Data analysis revealed opportunities but also highlighted needs for improvements in rabies surveillance and mass dog vaccinations. Although knowledge, attitude, and practice scores towards epidemiologic and clinical aspects, human rabies prevention, and dog rabies vaccination were deemed to be acceptable, the survey nevertheless revealed deficiencies in certain aspects in some of the population. Interestingly, data seemed to indicate relatively high dog bite incidences per 100,000 people, ranging between 262 and 1,369 and a certain number of unreported human rabies cases. Despite the very high number of dogs, only 50% of dog-owning households reported having vaccinated their dogs. In order to address these issues, the planning, announcement, and implementation of mass dog vaccination campaigns needs to be adapted to achieve adequate vaccination coverage. Another focus needs to be on rabies awareness and education if Namibia is to be significantly contributing to the global goal of "Zero by 30".

SARS-CoV-2 Infection and Clinical Signs in Cats and Dogs from Confirmed Positive Households in Germany.

On a global scale, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a serious threat to the health of the human population. Not only humans can be infected, but also their companion animals. The antibody status of 115 cats and 170 dogs, originating from 177 German households known to have been SARS-CoV-2 positive, was determined by enzyme-linked immunosorbent assay (ELISA), and the results were combined with information gathered from a questionnaire that was completed by the owner(s) of the animals. The true seroprevalences of SARS-CoV-2 among cats and dogs were 42.5% (95% CI 33.5-51.9) and 56.8% (95% CI 49.1-64.4), respectively. In a multivariable logistic regression accounting for data clustered in households, for cats, the number of infected humans in the household and an above-average contact intensity turned out to be significant risk factors; contact with humans outside the household was a protective factor. For dogs, on the contrary, contact outside the household was a risk factor, and reduced contact, once the human infection was known, was a significant protective factor. No significant association was found between reported clinical signs in animals and their antibody status, and no spatial clustering of positive test results was identified.

Do Seropositive Wild Boars Pose a Risk for the Spread of African Swine Fever? Analysis of Field Data from Latvia and Lithuania.

In 2020, ASF occurred in wild boars throughout Latvia and Lithuania, and more than 21,500 animals were hunted and tested for the presence of the virus genome and antibodies in the framework of routine disease surveillance. The aim of our study was to re-examine hunted wild boars that tested positive for the antibodies and negative for the virus genome in the blood (n = 244) and to see if the virus genome can still be found in the bone marrow, as an indicator of virus persistence in the animal. Via this approach, we intended to answer the question of whether seropositive animals play a role in the spread of the disease. In total, 2 seropositive animals out of 244 were found to be positive for the ASF virus genome in the bone marrow. The results indicate that seropositive animals, which theoretically could also be virus shedders, can hardly be found in the field and thus do not play an epidemiological role regarding virus perpetuation, at least not in the wild boar populations we studied.

Investigation into a Superspreading Event of the German 2020-2021 Avian Influenza Epidemic.

Between November 2020 and May 2021, Germany faced the largest highly pathogenic avian influenza (HPAI) epidemic recorded so far with 245 outbreaks in poultry and captive birds and more than 1000 diagnosed cases in wild birds. In March 2021, an HPAI outbreak of subtype H5N8 was confirmed in a holding rearing laying hens for sales. Disease introduction probably occurred via indirect contact with infected wild birds. Since the index farm sold chicken to customers including many smallholders, partly in travel trade, the primary outbreak triggered 105 known secondary outbreaks in five German federal states. An outbreak investigation was carried out with links between the involved farms retrieved from the German Animal Disease Notification System used for network analysis. In some cases, links were confirmed through sequence-based molecular analysis. Special emphasis was put on the estimation of the flock incubation period as a prerequisite of sound contact tracing. The unique circumstances of an outbreak farm with frequent direct trade contacts prior to disease suspicion enabled an assessment of the flock incubation period based on the consequences of contacts, further supported by molecular analysis and modeling of disease spread. In this case, the flock incubation period was at least 14 days.

Does having a cat in your house increase your risk of catching COVID-19?

Due to the zoonotic origin of SARS-Coronavirus 2 (SARS-CoV-2), the potential for its transmission from humans back to animals and the possibility that it might establish ongoing infection pathways in other animal species has been discussed. Cats are highly susceptible to SARS-CoV-2 and were shown experimentally to transmit the virus to other cats. Infection of cats has been widely reported. Domestic cats in COVID-19-positive households could therefore be a part of a human to animal to human transmission pathway. Here, we report the results of a qualitative risk assessment focusing on the potential of cat to human transmission in such settings. The assessment was based on evidence available by October 2021. After the introduction of SARS-CoV-2 to a household by a human, cats may become infected and infected cats may pose an additional infection risk for other members of the household. In order to assess this additional risk qualitatively, expert opinion was elicited within the framework of a modified Delphi procedure. The conclusion was that the additional risk of infection of an additional person in a household associated with keeping a domestic cat is very low to negligible, depending on the intensity of cat-to-human interactions. The separation of cats from humans suffering from SARS-CoV-2 infection should contribute to preventing further transmission.

Identification of Risk Factors for African Swine Fever: A Systematic Review.

African swine fever (ASF) is an internationally-spreading viral pig disease that severely damages agricultural pork production and trade economy as well as social welfare in disease-affected regions. A comprehensive understanding of ASF risk factors is imperative for efficient disease control. As the absence of effective ASF vaccines limits disease management options, the identification and minimisation of ASF-associated risk factors is critical to preventing ASF outbreaks. Here, we compile currently known potential ASF risk factors identified through a systematic literature review. We found 154 observation-based and 1239 potential ASF risk factors, which we were able to group into the following defined risk categories: 'ASF-virus', 'Biosecurity', 'Disease control', 'Environment', 'Husbandry', 'Movement', 'Network', 'Pig', 'Society' and 'Surveillance'. Throughout the epidemiological history of ASF there have been similar risk categories, such as 'Environment'-related risk factors, predominantly reported in the literature irrespective of the ASF situation at the time. While ASF risk factor reporting has markedly increased since 2010, the majority of identified risk factors overall have referred to domestic pigs. The reporting of risk factors for ASF in wild boar mostly commenced from 2016 onwards. The compendium of ASF risk factors presented herein defines our current knowledge of ASF risk factors, and critically informs ASF-related problem solving.

Testing Different Deterrents as Candidates for Short-Term Reduction in Wild Boar Contacts-A Pilot Study.

African swine fever (ASF) is a viral infection of pigs and represents a major threat to animal health and trade. Due to the high tenacity of the causative virus in carcasses of wild boar, contacts of wild boar with infectious carcasses are regarded an important driver of the so-called habitat cycle. The latter is believed to play a major role in maintaining the present ASF situation in wild boar in Europe. Therefore, search campaigns and timely removal and disposal of carcasses are considered important disease control approaches. If timely disposal is not feasible due to logistic reasons, deterrence of wild boar may be a provisionary option. The performance of seven deterrents (physical and chemical) was tested in a forest near Greifswald, Germany. Carcasses as entities of attraction for wild boar were substituted by luring sites. It could be demonstrated in this pilot study that certain physical (LED blinkers, aluminum strips) and chemical (HAGOPUR Wildschwein-Stopp™, Hukinol™) deterrents are capable of reducing the odds of wild boar contacts to one third, but in depth testing of the aforementioned promising deterrent candidates is recommended. A choice of those deterrents identified as suitable, reasonable, and easy to apply should be carried out, when carcass search campaigns are launched in the case of an outbreak of ASF in wild boar.

Monitoring of Pseudorabies in Wild Boar of Germany-A Spatiotemporal Analysis.

To evaluate recent developments regarding the epidemiological situation of pseudorabies virus (PRV) infections in wild boar populations in Germany, nationwide serological monitoring was conducted between 2010 and 2015. During this period, a total of 108,748 sera from wild boars were tested for the presence of PRV-specific antibodies using commercial enzyme-linked immunosorbent assays. The overall PRV seroprevalence was estimated at 12.09% for Germany. A significant increase in seroprevalence was observed in recent years indicating both a further spatial spread and strong disease dynamics. For spatiotemporal analysis, data from 1985 to 2009 from previous studies were incorporated. The analysis revealed that PRV infections in wild boar were endemic in all German federal states; the affected area covers at least 48.5% of the German territory. There were marked differences in seroprevalence at district levels as well as in the relative risk (RR) of infection of wild boar throughout Germany. We identified several smaller clusters and one large region, where the RR was two to four times higher as compared to the remaining areas under investigation. Based on the present monitoring intensity and outcome, we provide recommendations with respect to future monitoring efforts concerning PRV infections in wild boar in Germany.

Ecology and epidemiology of rabies in humans, domestic animals and wildlife in Namibia, 2011-2017.

Rabies is a fatal zoonotic disease that causes a heavy burden on societies. Namibia, a country in southern Africa, is aiming at controlling the disease in its main reservoir, the domestic dog. To facilitate the implementation comprehensive information on the ecology and epidemiology of the disease and surveillance is of utmost importance. The study presented assesses the baseline data for both human and animal rabies surveillance in Namibia in recent times and establishes correlations with ecological and socio-economic data in order to provide an up-to-date picture on the epidemiology of rabies in Namibia. For instance, it was important to identify the main drivers in the epidemiology, and whether the control strategy by mass vaccination of dogs is undermined by cycles of rabies in wildlife. Rabies in humans was reported mainly from the Northern Communal Areas (NCAs), with a total of 113 cases from 2011 to 2017, representing an incidence of between 1.0 and 2.4 annual human rabies deaths per 100,000 inhabitants. Kavango, the region with the highest human rabies incidence was also the region with the lowest animal rabies surveillance intensity. Generally, the vast majority (77%) of dog samples originated from communal farm land, followed by urban areas (17%), while only a small fraction (3%) was submitted from freehold farm areas. In contrast, kudu and eland submissions were almost exclusively from freehold farmland (76%) and urban areas (19%), whereas the submission of cattle samples was evenly distributed among freehold farms (46%) and communal farm land (46%). The likelihood of sample submission decreased exponentially with distance to one of the two laboratories. Overall, 67% (N = 1,907) of all samples submitted tested rabies-positive, with the highest positivity rate observed in kudus (89%) and jackals (87%). The transmission cycle of rabies in dogs appears restricted to the northern communal areas of Namibia, whilst rabies in wildlife species is predominately reported from farmland in central Namibia, mostly affecting kudu (Tragelaphus strepsiceros) and livestock with a likely reservoir in wildlife canids such as jackals or bat-eared foxes. The analysis confirms the presence of two independent transmission cycles in Namibia with little geographic overlap, thus allowing for a sustainable control of rabies in dogs in the NCAs.

[Modeling of the financial reserves required by the livestock disease compensation fund of Lower Saxony for rebates in the course of disease outbreaks incorporating spatial restriction zones]. / Modellierung der für Kompensationen im Zusammenhang mit Tierseuchenausbrüchen erforderlichen finanziellen Rücklagen der Niedersächsischen Tierseuchenkasse unter Berücksichtigung räumlicher Restriktionszonen.

One of the tasks of the livestock disease compensation funds of the federal states in Germany is the financial compensation of livestock holders for livestock losses and costs incurred for disease control measures due to certain diseases. Usually, one half of these services are financed through financial reserves built up with the contributions paid by the owners of the respective animal species. The other half is covered by the federal state itself. But there is hardly any reference to how to calculate aforementioned financial reserves. Basically, following an approach presented recently regarding estimations concerning the compensation fund of the federal state of Saxony-Anhalt, in a stochastic modeling of the required reserves concerning the fund of Lower Saxony the anticipated costs within the spatial restriction zones allocated to outbreaks were incorporated for the first time. The overall costs (including the federal state's stakes), the share of the comnensation fund (required reserves) and the the partial costs for a total of 25 categories and subcategories and subcategories of livestock species making up the latter were estimated. It became evident that overall costs/the share of the fund were particularly determined among the diseases by foot-and-mouth disease and among the cost factors by the costs incurred for the compensation of livestock value within the areas surrounding the outbreaks in which all susceptible animals are killed (culling zone). The 80th, 90 and 95th percentile of the established probability distribution of the overall costs referred to a financial volume of about 312, 409 and 540 million euro, while the respective percentiles of the probability distribution of the required reserves of the compensation fund amounted to 175, 225 and 296 million euro.

[Estimation of the financial reserves required by livestock disease compensation funds for rebates in the course of disease outbreaks using the example of Saxony-Anhalt (Germany)]. / Abschätzung der für Kompensationen im Zusammenhang mit Tierseuchenausbrüchen erforderlichen finanziellen Rücklagen einer Tierseuchenkasse am Beispiel Sachsen-Anhalts.

With certain restrictions, the federal states of Germany are obligated to financially compensate livestock owners for animal losses due to livestock diseases. If livestock disease compensation funds demand contributions from livestock owners for certain species in order to pay compensations, the federal states have to pay only one half of the rebate. The remaining 50% has to be financed through reserves of the respective compensation fund built up with the contributions. But there is no reference on how to calculate such financial reserves. Therefore, for the livestock disease compensation fund of Saxony-Anhalt (Germany), an attempt was made to estimate the required reserves.To this end, expert opinions concerning the expected number of affected holdings in potential outbreaks of different diseases were collected. In a conservative approach, assuming these diseases occur in parallel within a single year, overall costs as well as individual costs for altogether 25 categories and subcategories of livestock species were stochastically modeled.The 99.9th percentile of the resulting frequency distribution of the overall costs referred to a financial volume of about 23 million euro. Thus, financial reserves of 11,5 million euro were recommended to the livestock disease compensation fund.

[Occurrence and geographical distribution of antibodies to hepatitis E virus in wild boars of Saxony-Anhalt, Germany (2011)]. / Vorkommen und geografische Verbreitung von Antikörpern gegen Hepatitis E-virus beim Wildschwein in Sachsen-Anhalt (2011).

Hepatitis E Virus (HEV) may cause acute hepatitis in humans. In industrialised countries, acute hepatitis E generally occurs only sporadically. However, in recent years an increase in the number of reported cases has been observed. Concerning autochthonous, non-travel-associated cases, a zoonotic transmission, particularly from the animal reservoirs of domestic pig and wild boar, and via undercooked meat is assumed. Meanwhile, HEV has been detected in domestic pig holdings as well as in wild boars in many regions of the world, including Europe and Germany. The samples from wild boars in the German investigations usually originated from different sub-regions with relatively small sample sizes per region--with no samples stemming from the territory of the federal state of Saxony-Anhalt. Therefore, in 2011 330 blood samples from wild boars were examined serologically for antibodies to HEV, genotype 3, in Saxony-Anhalt. An average seroprevalence of 33% and a non-homogeneous spatial distribution of positive samples with statistically significant clusters in the southwest and east of the state territory were found.

Spatio-temporal analysis of the progression of Aujeszky's disease virus infection in wild boar of Saxony-Anhalt, Germany.

Aujeszky's disease (AD, pseudorabies) is a notifiable disease caused by Suid herpesvirus 1 (SuHV-1), also named pseudorabies virus (PrV). The study aimed at determining the occurrence and spatio-temporal trend of specific antibodies to AD virus (ADV) among wild boar of Saxony-Anhalt, a landlocked federal state situated in the western part of eastern Germany. To this end, a total of 7,209 blood samples were collected and tested from 2000 to 2011. An average seroprevalence of 6.8% was found for the entire observation period, whilst seroprevalence increased significantly between time periods January 2000-March 2009 (n = 3,605; prevalence = 4.5%) and March 2009-December 2011 (n = 3,604; prevalence = 9.1%). Spatial analysis revealed an extremely heterogenous distribution of seropositive samples with cluster formation [relative risk (RR) up to 41, P = 0.001] in the east. A comparison of spatial clusters between the aforementioned time intervals showed an expansion of the disease in the north to north-westerly direction. A test for spatial shift involving the entire territory of Saxony-Anhalt detected a spread of ADV infection in the latter direction (P = 0.079) at the average speed of 3.3 km/year. Detailed study of the distribution and spread of the disease among wild boar, including assessment of the speed of spatial spread, has not been done in the region before. Saxony-Anhalt has been officially recognised as being free of AD in domestic pigs since 1996. Despite increasing ADV seroprevalences in the wild boar population of Saxony-Anhalt and other federal states in the east of Germany, no spill-over to domestic pigs have been reported. The currently implemented monitoring will be continued in conjunction with surveillance of classical swine fever (CSF) to further trace ADV infections in the wild boar population of Saxony-Anhalt.

[Spatiotemporal analysis of the infection of the Red Fox (Vulpes vulpes L.) with Echinococcus multilocularis in Saxony-Anhalt]. / Raum-Zeit-Analyse der Infektion des Rotfuchses (Vulpes vulpes L.) mit Echinococcus multilocularis in Sachsen-Anhalt.

A total of 2757 Red Foxes from 952 locations were examined parasitologically for Echinococcus multilocularis between the years 1998 and 2007 at the State Office of Consumer Protection Saxony-Anhalt. This examination was carried out in parallel to rabies monitoring. A period-prevalence of 17.4% of infection was found. Employing different cluster tests spatial as well as spatiotemporal clusters were detected. Spatial clusters remained largely stable throughout the complete time interval and were situated in the Southwest of the state. Spatiotemporal clusters comprised the time intervals 2004-2007 and 2005-2007, respectively. It could be demonstrated that prevalence also increased significantly in the state's overall area for the time interval 2005-2007 as compared to the interval 1998-2004. The effect of this situation and development on the risk of humans to contract Alveolar Echinococcosis in Saxony-Anhalt is discussed.

[Echinococcus multilocularis in red foxes in Saxony-Anhalt: identification of areas of increased risk of infestation and association of the infestation probability with the average annual maximum temperature]. / Echinococcus multilocularis bei Rot- füchsen in Sachsen-Anhalt: Identifizierung von Gebieten mit erhöhtem Infestations- risiko und Assoziation der Infestations- wahrscheinlichkeit mit der durchschnitt- lichen Jahresmaximaltemperatur.

Between 1998 and 2004 1341 Red Foxes from 611 locations were examined parasitologically for Echinococcus multilocularis at the State Office of Consumer Protection Saxony-Anhalt. Examination was carried out in parallel to rabies monitoring. A period-prevalence of 9.2% of infestation was found. Employing a Scan Statistic a large area in the southwest of the federal state and two smaller areas of increased risk with respect to infestation with Echinococcus multilocularis were identified. The hypothesis of a negative association of the probability of infestation with the average annual maximum temperature of the location where the foxes were shot was supported by logistic regression analysis. A decreased probability of inactivation of Echinococcus multilocularis-oncospheres through heat and desiccation in areas of lower average annual maximum temperature seems to be likely.Thus, the infection pressure increases with reduced temperatures.

Seroprevalence of antibodies to Salmonella spp in semidomesticated reindeer in Norway, determined by enzyme-linked immunosorbent assay.

An indirect ELISA was developed as a possible tool to detect the seroprevalence of antibodies to Salmonella spp in semidomesticated reindeer. To cover a broad spectrum of serogroups a lipopolysaccharide mix of S. typhimurium and S. choleraesuis was used as antigen in this pilot study. Sera from 31 culture-negative reindeer with no clinical or historical evidence of salmonellosis were used as negative serum control. After immunisation with an inactivated S. typhimurium vaccine, pooled sera from 6 reindeer were used as positive serum control as no serum from naturally infected animals was available. A seroprevalence of 0.6% in 2000 clinically healthy, slaughter-reindeer from Norway was determined by using this ELISA. No more information on Salmonella in reindeer in Norway is known to the authors. This is the first ELISA established for indirect detection of Salmonella in reindeer.

[Evaluation of the performance to date of the BHV-1 eradication campaign in Saxony-Anhalt (Germany)]. / Evaluierung des bisherigen Verlaufs des BHV-1 Tilgungsverfahrens in Sachsen-Anhalt.

The present article is attempting to evaluate the to date performance of the BHV-1 eradication campaign currently run in Saxony-Anhalt. Special emphasis is put on the modelling of missing data and an optimum performance--for comparison with the observed progress of eradication. The eradication campaign turned out to have performed almost optimally so far, but problems might arise in its final phase due to insular management deficiencies and violation of laws, as well. Possible sanctions are mentioned.

Serosurvey for antibodies against Salmonella species in free-ranging moose (Alces alces) from Norway.

An indirect ELISA was developed as a tool for surveillance of antibodies against Salmonella sp. in free-ranging moose (Alces alces) in Norway. Serum samples from 303 clinically healthy moose sampled between 1993-2000 were examined. Anti-Salmonella antibodies were detected in samples from 6 individuals (1.98%). This is the first evidence of Salmonella-seropositive free-ranging moose. Possible sources and transmission routes of Salmonella comprising environment, wildlife and man are discussed.