After its first description in Wuhan (China), SARS-CoV-2 the agent of coronavirus disease 2019 (COVID-19) rapidly spread worldwide. Previous studies suggested that pets could be susceptible to SARS-CoV-2. Here, we investigated the putative infection of SARS-CoV-2 in 22 cats and 11 dogs from owners previously infected or suspected of being infected by SARS-CoV-2. For each animal, rectal, nasopharyngeal swabs and serum were taken. Swabs were submitted to RT-qPCR assays targeting 2 genes of SARS-CoV-2. All dogs were tested SARS-CoV-2 negative. One cat was tested positive by RT-qPCR on rectal swab. Nasopharyngeal swabs from this animal were tested negative. This cat showed mild respiratory and digestive signs. Serological analysis confirm the presence of antibodies against the SARS-CoV-2 in the two serum samples taken 10 days apart. Genome sequence analysis revealed that the cat SARS-CoV-2 belongs to the phylogenetic clade A2a like most of the French human SARS-CoV-2. This study reports for the first time the natural infection of a cat in France (near Paris) probably through their owners. There is currently no evidence that cats can spread COVID-19 and owners should not abandon their pets or compromise their welfare.
African swine fever (ASF) has spread across many countries in Europe since the introduction into Georgia in 2007. We report here on the first cases of ASF in wild boar detected in Germany close to the border with Poland. In addition to the constant risk of ASF virus (ASFV) spread through human activities, movements of infected wild boar also represent a route of introduction. Since ASF emerged in Western Poland in November 2019, surveillance efforts, in particular examination of wild boar found dead, were intensified in the regions of Germany bordering with Poland. The first case of ASF in wild boar in Germany was therefore detected by passive surveillance and confirmed on 10th September 2020. By 24th September 2020, 32 cases were recorded. Testing of samples from tissues of carcasses in different stages of decomposition yielded cycle threshold values from 18 to 36 in the OIE-recommended PCR which were comparable between the regional and national reference laboratory. Blood swabs yielded reliable results, indicating that the method is suitable also under outbreak conditions. Phylogenetic analysis of the ASFV whole-genome sequence generated from material of the first carcass detected in Germany, revealed that it groups with ASFV genotype II including all sequences from Eastern Europe, Asia and Belgium. However, some genetic markers including a 14 bp tandem repeat duplication in the O174L gene were confirmed that have so far been detected only in sequences from Poland (including Western Poland). Epidemiological investigations that include estimated postmortem intervals of wild boar carcasses of infected animals suggest that ASFV had been introduced into Germany in the first half of July 2020 or even earlier.
Tracing and isolation of close contacts is used to control outbreaks of coronavirus disease 2019 (COVID-19) in China. However, risk factors associated with occurrence of COVID-19 among close contacts have not been well described. 106 household contacts were included in this study, of whom 19 were developed into COVID-19 cases and the secondary attack rate was 17.9%. Multivariable analysis showed increasing risk of occurrence of COVID-19 among household contacts associated with female of index patients (Adjusted Hazard Ratio [aHR] = 5.61, 95%CI = 1.51-20.83), critical disease of index patients ([aHR] = 7.58, 95%CI = 1.66-34.66), effective contact duration with index patients >2 days ([aHR] = 4.21, 95%CI = 1.29-13.73), and effective contact duration >11 days ([aHR] = 17.88, 95%CI = 3.26-98.01).The sex and disease severity of index COVID-19 patients, and longer effective contact duration with COVID-19 confirmed cases could help epidemiologists to identify potential COVID-19 case among household contacts at an early stage.
Previous research has identified a relationship between climate and occurrence of SARS-CoV and MERS-CoV cases, information that can be used to reduce the risk of infection. Using COVID-19 notification and postcode data from New South Wales, Australia during the exponential phase of the epidemic in 2020, we used time-series analysis to investigate the relationship between 749 cases of locally-acquired COVID-19 and daily rainfall, 9am and 3pm temperature, and 9am and 3pm relative humidity. Lower 9am relative humidity (but not rainfall or temperature) was associated with increased case occurrence; a reduction in relative humidity of 1% was predicted to be associated with an increase of COVID-19 cases by 6.11%. During periods of low relative humidity, the public health system should anticipate an increased number of COVID-19 cases.
There are several routes of African swine fever (ASF) introduction into a country. Among the possible routes of entry, quarantine policies determine the possibility of introduction by legal import of live pigs and pig products. This study aimed at assessing the probability of ASF introduction through legal import of live pigs and pig products during the high risk period (HRP) using a quantitative stochastic approach during 2009-2018. The result indicates that the mean annual probability of ASF introduction by legal import of live pig was 1.58×10-7 (1.52~1.67×10-7 95% CI). The mean annual probability by legal import of pig products was 1.59×10-10 (1.55~1.64×10-10 95% CI), of which Poland assumed 87.9% of the mean annual risk. The current import quarantine policy of Korean government may be enough to block the release of the virus via legal import of live pigs and pig products, and it should be continually enforced. This result can help to elucidate source of infection and minimize the catastrophic consequences of the potential ASF reintroduction into South Korea by designing risk mitigation strategies such as risk-based selection of routes to be assessed and prevented and decreased exposure possibility by increased control of food waste and swill feeding practices.
Tilapia lake virus (TiLV) is an emerging virus that is rapidly spreading across the world. Over the past 6 years (2014–2020), TiLV outbreaks had been reported in at least 16 countries, spanning three continents, including Asia, Africa, and America. Despite its enormous economic impact, its origin, evolution, and epidemiology are still largely poorly characterised. Here, we report eight TiLV whole genome sequences from Thailand sampled between 2014–2019. Together with publicly available sequences from various regions of the world, we estimated the origin of TiLV to be between 2003–2009, 5–10 years before the first report of the virus in Israel in 2014. Our analyses consistently showed that TiLV started to spread in 2000s, and reached its peak in 2014–2016, matching well with the timing of its first report. From 2016 onwards, the TiLV population declined steadily. This could be a result of herd immunity building up in the fish population, and / or a reflection of a better awareness of the virus coupled with a better and more cautious protocol of Tilapia importation. Despite the fact that we included all publicly available sequences, our analyses revealed long unsampled histories of TiLVs in many countries, especially towards its basal diversification. This result highlights the lack and the need for systematic surveillance of TiLV in fish.
The current COVID-19 global pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) of probable bat origin, has highlighted the ongoing need for a One Health response to emerging zoonotic disease events, which are significantly increasing over time. Understanding the human-animal interface and its relevance to disease transmission remains a critical control point for many emerging zoonoses. Determination of the susceptibility of various animal species to infection with SARS-CoV-2 and the role of animals in the epidemiology of the disease will be critical to informing appropriate human and veterinary public health responses to this pandemic. A scoping literature review was conducted to collect, evaluate and present the available research evidence regarding SARS-CoV-2 infections in animals. Experimental studies have successfully demonstrated SARS-CoV-2 infection and transmission in cats, ferrets, hamsters, bats and non-human primates under experimental settings. Dogs appear to have limited susceptibility to SARS-CoV-2, while other domestic species including pigs and poultry do not appear susceptible. Naturally occurring SARS-CoV-2 infections in animals appear uncommon, with 14 pets, 8 captive big cats and an unreported number of farmed mink testing positive to date. Infections typically appear asymptomatic in dogs, while clinical signs of respiratory and/or gastrointestinal disease tend to be mild to moderate in felines, and severe to fatal in mink. Most animal cases have been infected by close contact with COVID-19 patients. In domestic settings, viral transmission is self-limiting, however in high density animal environments there can be sustained between-animal transmission. To date, two potential cases of animal-to-human transmission are being investigated, on infected mink farms. Given the millions of COVID-19 cases worldwide and ongoing potential for further zoonotic and anthroponotic viral transmission, further research and surveillance activities are needed to definitively determine the role of animals in community transmission of SARS-CoV-2.
The aim of the present study was to evaluate the duration of protective immunity against Porcine epidemic diarrheoa virus (PEDV). To that, a two phases study was performed. In the first phase, 75 four-week-old pigs (group A) were orally inoculated (0 days post-inoculation; dpi) with a European PEDV G1b strain and 14 were kept as controls (group B). The second phase started five month later (154 dpi), when animals in group A were homologous challenged and animals in group B were challenged for first time. Clinical signs, viral shedding and immune responses were evaluated after each inoculation, including the determination of antibodies (ELISA and viral neutralisation test, IgA and IgG ELISPOTs using peripheral blood mononuclear cells and lymph node cells) and the frequency of interferon-gamma (IFN-γ) secreting cells. During the first phase, loose stools/liquid faeces were observed in all group A animals. Faecal shedding of PEDV occurred mostly during the first 14 days but, in some animals, persisted until 42 dpi. All inoculated animals seroconverted for specific-PEDV IgG and IgA, and for neutralizing antibodies (NA). At 154 dpi, 77% of pigs were still positive for NA. After that, the homologous challenge resulted in a booster for IgG, IgA, NA, as well as specific-PEDV IgG, IgA and IFN-γ secreting cells. In spite of that, PEDV was detected in faeces of all pigs from group A, indicating that the immune response did not prevent reinfection although the duration of the viral shedding and the total load of virus shed was significantly lower for previously challenged pigs (p<0.05). Taken together, the results indicated that, potentially, maintenance of PEDV infection within an endemic farm may occur by transmission to and from previously infected animals and also indicates that sterilising immunity is shorter than the productive life of pigs.
Porcine circovirus 4 (PCV4), a novel and unclassified member of the genus Circovirus, was first reported in China in 2019. Aimed at providing more evidence about the active circulation of PCV4, this study screened 335 pooled internal organs and detected the virus (i) at the rates of 3.28%, (ii) from both clinical healthy and clinical sick pigs of various age groups, and (iii) in six out of nice provinces of Korea. The complete genomic sequence of a Korean PCV4 strain (E115) was 1,770 nucleotides in length and had 98.5% to 98.9% identity to three PCV4 strains available at GenBank up to date. Utilizing a set of bioinformatic programs, it was revealed that the Korean PCV4 strain contained several genomic features of (i) a palindrome stem-loop structure with conserved nonanucleotide, (ii) packed overlapping ORFs oriented in different directions, and (iii) two intergenic regions in between genes encoding putative replication- associated protein (Rep) and capsid (Cap) proteins. This study also predicted the presence of essential elements known so far for the replication of circoviruses, for example, the origin of DNA replication, endonuclease and helicase domains of Rep, the nuclear localization signal on the putative Cap protein. Finally, based on the phylogeny inferred from sequences of the putative Rep protein, it was suggested that PCV4 belong to genus Circovirus of family Circoviridae and losely related to three previous known porcine circoviruses of PCV1, PCV2 and PCV3.
An 11 years-old male mixed-breed cat, with exclusively indoor life, presented 3 cough episodes after the owners tested positive by RT-PCR for SARS-CoV-2. The house is inhabited by 5 people (3 adults and 2 children), and 2 of the adults have shown mild symptoms associated with throat discomfort. The cat was vaccinated, had no history of any previous disease, and tested negative for Feline Coronavirus (FeCoV), Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV). Rectal sample collected from the cat was positive for SARS-CoV-2 by RT-PCR. Viral genome sequences recovered from human and cat samples showed an average 99.4% sequence identity. This is the first report of genome sequences of SARS-CoV-2 recovered from a cat and its owner in Latin America.
The occurrence of mycobacterial infections in different hosts and their implication as obligate or opportunistic pathogens remain mainly unclear. In addition to the well-known pathogenic members of the Mycobacterium tuberculosis - complex (MTBC), over 180 nontuberculous mycobacteria (NTM) species have been described. Although the large majority of the NTM are assumed to be non-pathogenic to most individuals, an increasing trend in NTM infections has been observed over the last decades. The reasons of such augmentation are probably more than one: improved laboratory diagnostics, an increasing number of immunocompromised patients and individuals with lung damage are some of the possible aspects. Mandibular lymph nodes of 176 hunted wild boars from the pre-Alpine region of Canton Ticino, Switzerland, were collected. Following gross inspection, each lymph node was subjected to culture and to an IS6110 based real-time PCR specific for MTBC members. Histology was performed of a selection of lymph nodes presenting gross visible lesions. Moreover, accuracy of matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry species identification was compared with sequence analysis of a combination of housekeeping genes. Mycobacteria of the MTBC were detected in five out of 176 wild boars (2.8%; CI95% 1.2 - 6.5) and were all confirmed to be Mycobacterium microti by molecular methods. In addition, based on the examined lymph nodes, NTM were detected in 57.4% (CI95% 50.0 – 64.5) of the wild boars originating from the study area. The 111 isolates belonged to 24 known species and three potentially undescribed Mycobacterium species. M. avium subsp. hominissuis thereby predominated (22.5%) and was found in lymph nodes with and without macroscopic changes. Overall, the present findings show that, with the exception of undescribed Mycobacterium species where identification was not possible (3.6%; 4/111), MALDI-TOF had a high concordance rate (90.1%; 100/111 isolates) to the sequence based reference method.
The exact origin of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and source of introduction into humans has not been established yet, though it might be originated from animals. Therefore, we conducted a literature review to understand the putative reservoirs, transmission dynamics, and susceptibility patterns of SARS-CoV-2 in animals. Rhinolophu s bats are presumed to be natural progenitors of SARS-CoV-2 related viruses. Initially pangolin was thought to be the source of spillover to human, but they might get infected from human or other animal species. So, the virus spillover pathways to humans remain unknown. Human-to-animal transmission has been testified in pet, farmed, zoo and free-ranging wild animals. Infected animals can transmit the virus to other animals in natural settings like, mink-to-mink, and mink-to-cat transmission. Animal-to-human transmission is not a persistent pathway, while mink-to-human transmission continues to be illuminated. Multiple companion and captive wild animals were infected by emerging alpha variant of concern (B.1.1.7 lineage) whereas Asiatic lions were infected by delta variant, (B.1.617.2). To date, multiple animal species- cat, ferrets, non-human primates, hamsters, and bats, showed high susceptibility to SARS-CoV-2 in experimental condition, while swine, poultry, cattle showed no susceptibility. The founding of SARS-CoV-2 in wild animal reservoirs can confronts the control of the virus in humans and might carry a risk to the welfare and conservation of wildlife as well. We suggest vaccinating pet, and captive animals to stop spillover and spillback events. We recommend sustainable one health surveillance at animal-human-environmental interface to detect and prevent future epidemics and pandemics by Disease X.
This study aimed to compare the infection dynamics of three genotype II African swine fever viruses (ASFV) circulating in Europe. Eighteen domestic pigs divided into three groups were infected intramuscularly or by direct contact with two haemadsorbent ASFVs (HAD) from Poland (Pol16/DP/ OUT21) and Estonia (Est16/WB/Viru8), and with the Latvian non-HAD ASFV (Lv17/WB/Rie1). Parameters such as symptoms, pathogenicity, and distribution of the virus in tissues, humoral immune response, and dissemination of the virus by blood, oropharyngeal and rectal routes were investigated. The Polish ASFV caused a case of rapidly developing fatal acute disease, while the Estonian ASFV caused acute to subacute infections in the presence of surviving animals. In contrast, animals infected with the ASFV from Latvia developed a more subtle, mild, or even subclinical disease. Oral excretion was sporadic or even absent in the attenuated group, whereas in animals that developed an acute or subacute form of ASF, oral excretion began at the same time as in the blood, or even 3 days earlier, and persisted up to 22 days. Regardless of virulence, blood was the main route of transmission of ASFV and infectious virus was isolated from persistently infected animals for at least 19 days in the attenuated group and up to 44 days in the group of moderate virulence. Rectal excretion was limited to the acute phase of infection. In terms of diagnostics, the ASFV genome was detected in contact pigs from oropharyngeal samples earlier than in blood, independently of virulence and, together with blood, both samples could cover a longer range to detect ASFV infection. The results presented here provide quantitative data on the spread and excretion of ASFV strains of different virulence among domestic pigs that can help to better focus surveillance activities and thus increase the ability to detect ASF introductions earlier.
African swine fever (ASF) is emerging in Vietnam and poses a continuing severe threat to the swine industry. A histopathological study of clinical samples collected during the August to September 2019 outbreak of ASF was performed to determine the characteristic lesions. We analyzed samples from eight ASFV-infected farms. Histopathological results revealed the characteristic lesions of the acute to the subacute clinical form of ASF. Immunohistochemical results showed ASFV viral antigen distribution in mononuclear cells/macrophage in various organs, hepatocytes, and renal tubular epithelium. Molecular analysis of partial capsid protein 72 gene revealed that ASFV strain from the eight separate outbreaks belonged to genotype II.
The hypothesis that feed ingredients could serve as vehicles for the transport and transmission of viral pathogens was first validated under laboratory conditions. To bridge the gap from the laboratory to the field, this current project tested whether three significant viruses of swine could survive in feed ingredients during long-distance commercial transport across the continental US. One-metric ton totes of soybean meal (organic and conventional) and complete feed were spiked with a 10 mL mixture of PRRSV 174, PEDV, and SVA and transported for 23 days in a commercial semi-trailer truck, crossing 29 states, and 10,183 km. Samples were tested for the presence of viral RNA by PCR, and for viable virus in soy-based samples by swine bioassay and in complete feed samples by natural feeding. Viable PRRSV, PEDV, and SVA were detected in both soy products and viable PEDV and SVA in complete feed. These results provide the first evidence that viral pathogens of pigs can survive in representative volumes of feed and feed ingredients during long-distance commercial transport across the continental US.
In order to analyze the prevalence of cat viral diseases in China, including feline parvovirus (FPV), feline calicivirus (FCV), feline herpesvirus-1 (FHV-1), feline leukemia virus (FeLV), feline immunodeficiency virus (FIV) and feline infectious peritonitis virus (FIPV), a total of 1,326 samples of cats from 16 cities were investigated from 2016 to 2019. Collectively, 1,060 (79.9%) cats were tested positive for at least one virus in nucleotide detection, the positive rates of cat exposure to FeLV, FPV, FHV-1, FCV, FIV and FIPV were 59.6%, 19.2%, 16.3%, 14.2%, 1.5% and 0.5%, respectively. The prevalence of FHV-1 and FPV were dominant in winter and spring. Cats from north China showed a higher positive rate of viral infection than that of cats from south China. The virus infection is not highly correlated with age, except that FPV is prone to occur within the age of 12 months. In the serological survey, the seroprevalences of 267 vaccinated cats to FPV, FCV, FHV-1 were 83.9%, 58.3% and 44.0%, respectively. Meanwhile, the seroprevalences of 39 unvaccinated cats to FPV, FCV, FHV-1 were 76.9% (30/39), 82.4% (28/34) and 58.6% (17/29), respectively. This study demonstrated that a high prevalence of the six viral diseases in China, and the insufficient serological potency of FCV and FHV reminds the urgency for more effective vaccines.
Since 2007, African swine fever virus (ASFV) has spread to countries in Europe, Asia and Oceania, and has caused devastating impacts on pigs and the pork industry. Transmission can be direct or indirect, and epidemiologic scenarios have been described in which spread occurs between free-living and domestic pigs. The purpose of this scoping review was to identify primary research in which authors made statements to support ASFV transmission between free-living and domestic pigs and assess the circumstances in which transmission events occurred. A search was conducted in five bibliographic databases and the grey literature. Two reviewers (from a team of ten) independently screened each record and charted data (demographics of the pig populations, their husbandry [domestic pigs] and habitat [free-living pigs], the spatial and temporal distribution of ASF, the occurrence or burden of ASF in the populations, and whether ticks were present in the geographic range of the pig populations). Data synthesis included statistics and a narrative summary. From 1,349 records screened, data were charted from 46 individual studies published from 1985 to 2020. Outbreak investigations revealed that whilst poor biosecurity of domestic pig operations was often reported, direct contact resulting in transmission between free-living and domestic pigs was rarely reported. Studies in which quantitative associations were made generally found that spread within populations was more important than spread between populations, although this was not always the case, particularly when domestic pigs were free-ranging. We conclude that there is limited evidence that transmission of ASFV between free-living and domestic pigs is an important feature of ASF epidemiology, especially in the current ASF epidemic in Europe and the Russian Federation. If ASFV elimination cannot be achieved in free-living pigs, compartmentalisation of free-living and domestic pig populations via biosecurity strategies could be used to support trade of domestic pigs.
Following the increase in wild boar population recorded in urban and peri-urban areas through Europe, the present survey aimed to assess the occurrence of zoonotic tick-borne bacteria in animals and their ticks collected from southern Italy, in order to evaluate the potential risk of infection for animals and humans. From October to December 2019, a total of 176 ticks collected from 93 wild boars and their spleen samples were molecularly screened for Borrelia burgdorferi sensu lato complex, Coxiella burnetii and spotted fever group (SFG) Rickettsia species. Overall, all the wild boars were infested by ticks (mean intensity, 1.9) with Dermacentor marginatus and Ixodes ricinus being identified in 99.4% and 0.6%, respectively. Out of 93 wild boars, 17 (18.3%) were infested by ticks positive to spotted fever group (SFG) Rickettsia species. Rickettsia slovaca and Rickettsia raoultii were identified in 16 (9%) and 1 (0.6%) D. marginatus, respectively, whereas a single I. ricinus (0.6%) was infected by R. slovaca. A single wild boar (1.1%) scored positive to R. slovaca. All ticks and wild boars scored negative to C. burnetii and B. burgdorferi s.l. complex. Data herein obtained suggest wild boars are involved in the dissemination of D. marginatus, especially in peri-urban settlements of the study area. An integrated management approach is advocated for wild boar population control and preventing the potential risk of tick-borne bacteria in animals and humans.