scholarly journals Infectious SARS-CoV-2 is emitted in aerosols

2021 ◽  
Author(s):  
Seth A. Hawks ◽  
Aaron J. Prussin ◽  
Sarah C. Kuchinsky ◽  
Jin Pan ◽  
Linsey C. Marr ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Infectious Virus ◽  
Emission Rate ◽  
Clinical Signs ◽  
Respiratory Viruses ◽  
Post Inoculation ◽  
Viral Shedding ◽  
Contact Transmission ◽  
Respiratory Droplets ◽  
Kinetics Of

Respiratory viruses such as SARS-CoV-2 are transmitted in respiratory droplets and aerosols, which are released during talking, breathing, coughing, and sneezing. Non-contact transmission of SARS-CoV-2 has been demonstrated, suggesting transmission in aerosols. Here we demonstrate that golden Syrian hamsters emit infectious SARS-CoV-2 in aerosols, prior to and concurrent with the onset of mild clinical signs of disease. The emission rate is 25 infectious virions/hour on days 1 and 2 post-inoculation, with viral RNA levels 200-fold higher than infectious virus in aerosols. Female hamsters have delayed kinetics of viral shedding in aerosols compared to male hamsters. The majority of virus is contained within aerosols <8 microns in size. Thus, we provide direct evidence that, in hamsters, SARS-CoV-2 is an airborne virus.

scholarly journals Experimental infection of domestic dogs and cats with SARS-CoV-2: Pathogenesis, transmission, and response to reexposure in cats

2020 ◽  
Vol 117 (42) ◽  
pp. 26382-26388 ◽  
Author(s):  
Angela M. Bosco-Lauth ◽  
Airn E. Hartwig ◽  
Stephanie M. Porter ◽  
Paul W. Gordy ◽  
Mary Nehring ◽  
...  
Keyword(s):  
Antibody Response ◽  
Acute Infection ◽  
Clinical Signs ◽  
Neutralizing Antibody ◽  
Human Infection ◽  
Vaccine Strategy ◽  
Animal Reservoir ◽  
Viral Shedding ◽  
Contact Transmission ◽  
Infection Resistance

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has reached nearly every country in the world with extraordinary person-to-person transmission. The most likely original source of the virus was spillover from an animal reservoir and subsequent adaptation to humans sometime during the winter of 2019 in Wuhan Province, China. Because of its genetic similarity to SARS-CoV-1, it is probable that this novel virus has a similar host range and receptor specificity. Due to concern for human–pet transmission, we investigated the susceptibility of domestic cats and dogs to infection and potential for infected cats to transmit to naive cats. We report that cats are highly susceptible to infection, with a prolonged period of oral and nasal viral shedding that is not accompanied by clinical signs, and are capable of direct contact transmission to other cats. These studies confirm that cats are susceptible to productive SARS-CoV-2 infection, but are unlikely to develop clinical disease. Further, we document that cats developed a robust neutralizing antibody response that prevented reinfection following a second viral challenge. Conversely, we found that dogs do not shed virus following infection but do seroconvert and mount an antiviral neutralizing antibody response. There is currently no evidence that cats or dogs play a significant role in human infection; however, reverse zoonosis is possible if infected owners expose their domestic pets to the virus during acute infection. Resistance to reinfection holds promise that a vaccine strategy may protect cats and, by extension, humans.

scholarly journals Pathogenesis, transmission and response to re-exposure of SARS-CoV-2 in domestic cats

2020 ◽  
Author(s):  
Angela M. Bosco-Lauth ◽  
Airn E. Hartwig ◽  
Stephanie M. Porter ◽  
Paul W. Gordy ◽  
Mary Nehring ◽  
...  
Keyword(s):  
Antibody Response ◽  
Acute Infection ◽  
Clinical Signs ◽  
Neutralizing Antibody ◽  
Domestic Cats ◽  
Vaccine Strategy ◽  
Animal Reservoir ◽  
Viral Shedding ◽  
Contact Transmission ◽  
Infection Resistance

AbstractThe pandemic caused by SARS-CoV-2 has reached nearly every country in the world with extraordinary person-to-person transmission. The most likely original source of the virus was spillover from an animal reservoir and subsequent adaptation to humans sometime during the winter of 2019 in Wuhan Province, China. Because of its genetic similarity to SARS-CoV-1, it is likely that this novel virus has a similar host range and receptor specificity. Due to concern for human-pet transmission, we investigated the susceptibility of domestic cats and dogs to infection and potential for infected cats to transmit to naïve cats. We report that cats are highly susceptible to subclinical infection, with a prolonged period of oral and nasal viral shedding that is not accompanied by clinical signs, and are capable of direct contact transmission to other cats. These studies confirm that cats are susceptible to productive SARS-CoV-2 infection, but are unlikely to develop clinical disease. Further, we document that cats develop a robust neutralizing antibody response that prevented re-infection to a second viral challenge. Conversely, we found that dogs do not shed virus following infection, but do mount an anti-viral neutralizing antibody response. There is currently no evidence that cats or dogs play a significant role in human exposure; however, reverse zoonosis is possible if infected owners expose their domestic pets during acute infection. Resistance to re-exposure holds promise that a vaccine strategy may protect cats, and by extension humans, to disease susceptibility.

scholarly journals Genetic and antigenic characteristics of H4 subtype avian influenza viruses in Korea and their pathogenicity in quails, domestic ducks and mice

2013 ◽  
Vol 94 (1) ◽  
pp. 30-39 ◽  
Author(s):  
Hyun-Mi Kang ◽  
Jun-Gu Choi ◽  
Kwang-Il Kim ◽  
Ha-Young Park ◽  
Choi-Kyu Park ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Clinical Signs ◽  
Significant Loss ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Post Inoculation ◽  
Avian Influenza Viruses ◽  
Domestic Ducks ◽  
Viral Shedding ◽  
Nationwide Surveillance

In Korea, a nationwide surveillance programme was implemented in 2003 to identify highly pathogenic avian influenza viruses (AIVs). AIVs belonging to one of the most common haemagglutinin subtypes, H4, were isolated from two domestic ducks and 52 wild birds between 2004 and 2010. These H4 AIVs could be further classified into three neuraminidase subtypes: H4N6 (94.4 %), H4N2 (3.7 %) and H4N3 (1.9 %). Phylogenetic analysis revealed that the H4 AIVs had a variety of genetic constellations, with at least nine different genotypes represented. The pathogenicity of these H4 viruses was assessed in quails, domestic ducks and mice. None of the H4 AIVs induced clinical signs in quails or domestic ducks. Viral shedding in quails was relatively high, and virus was recovered up to 5–7 days post-inoculation (p.i.) in oropharyngeal swabs, but the viruses replicated poorly in domestic ducks. Quails may act as an intermediate host in which AIVs are amplified and transmitted to other species. In mice, all of the AIVs were recovered efficiently at relatively high titres from the lungs up to 7 days p.i., demonstrating the potential for AIVs to infect mice directly without prior adaptation. None of the AIVs induced clinical signs nor was any lethal to infected mice. However, there was significant loss of body weight in mice infected with viruses of duck origin. It is suggested that the active surveillance of influenza viruses needs to be enhanced in domestic poultry as well as in wild birds, and that it should include assessment of pathogenicity in animal models.

scholarly journals The Influence of Cyclosporin Immunosuppression on the Efficacy of Famciclovir or Valaciclovir Chemotherapy Studied in a Murine Herpes Simplex Virus Type 1 Infection Model

1997 ◽  
Vol 8 (4) ◽  
pp. 317-326 ◽  
Author(s):  
AM Thackray ◽  
HJ Field
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Infectious Virus ◽  
Clinical Signs ◽  
Infection Model ◽  
Post Inoculation ◽  
Simplex Virus

Mice with or without immunosuppression by cyclosporin (Cy) were inoculated with herpes simplex virus type 1 in the ear pinna. Without immunosuppression, 20% of the mice died; clinical signs resolved in survivors and infectious virus was cleared by 7 to 10 days post-inoculation (p.i.). With Cy, mortality was 50%, clinical signs increased and infectious virus persisted. Mice were treated with either valaciclovir (VACV) or famciclovir (FCV) from days 1–5 or 5–10 p.i. and both compounds moderated the disease, but only FCV led to rapid restoration of body weight and complete protection from mortality. Resolution of clinical signs was more marked with immunosuppression. On cessation of VACV therapy, infectious virus recurred on individual days. Without immunosuppression, recurrence was detected in neural tissues only, but with Cy, infectious virus also recurred in skin. No recurrences of infectious virus were observed in any FCV-treated mice.

scholarly journals The immune response does not prevent homologous Porcine epidemic diarrhoea virus reinfection five months after the initial challenge.

2021 ◽  
Author(s):  
Ivan Díaz ◽  
Joan Pujols ◽  
Esmeralda Cano ◽  
Marti Cortey ◽  
Núria Navarro ◽  
...  
Keyword(s):  
Immune Response ◽  
Clinical Signs ◽  
Second Phase ◽  
Post Inoculation ◽  
Viral Shedding ◽  
Porcine Epidemic Diarrhoea Virus ◽  
Diarrhoea Virus ◽  
Group A ◽  
Ifn Γ ◽  
Group B

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.

scholarly journals Comparison of the Pathogenicity of Two Different Branches of Senecavirus a Strain in China

Pathogens ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 39 ◽  
Author(s):  
Huawei Zhang ◽  
Pin Chen ◽  
Genxi Hao ◽  
Wenqiang Liu ◽  
Huanchun Chen ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Nasal Swab ◽  
Clinical Signs ◽  
Particle Morphology ◽  
Post Inoculation ◽  
Finishing Pigs ◽  
Plaque Size ◽  
Viral Shedding ◽  
Different Strains ◽  
Vesicular Disease

Senecavirus A (SVA), an emerging infectious disease, is associated with the porcine idiopathic vesicular disease. Here, the pathogenesis of different strains of SVA was investigated in growing-finishing pigs. We aimed to evaluate the replication characteristics, virus particle morphology, clinical signs, and vesicular lesions in comparison with two different strains of SVA. The animals were infected with SVA HB-CH-2016 or CH/AH-02/2017 by intranasal routes (3 mL, 109TCID50/mL) and monitored daily for 14 days post-inoculation (dpi) for clinical signs and vesicular lesions. Viremia or viral shedding was detected in the blood, fecal swab, and nasal swab samples. Results showed no distinct differences in plaque size, replication ability, and characteristic virions between SVA HB-CH-2016 and CH/AH-02/2017 strains. Animal experimental results showed that both SVA CH/AH-02/2017 and SVA HB-CH-2016 could infect pigs. However, an obvious difference in the pathogenicity and dynamics of infection was observed between SVA HB-CH-2016 and CH/AH-02/2017 strains. The pathogenesis of SVA CH/AH-02/2017 was similar to that of published results of USA strains, whereas the SVA HB-CH-2016 strain had low pathogenicity to pigs. Clinical signs and vesicular lesions were observed in SVA CH/AH-02/2017-infected pigs. Additionally, the different branches of SVA should be capable of inducing broad cross-reactive neutralizing antibodies, which play an important role in clearing the SVA virus. This study of animal models for SVA infection will be beneficial to develop vaccines and antivirals.

scholarly journals Comparison of SARS-CoV-2 infections among 3 species of non-human primates

2020 ◽  
Author(s):  
Shuaiyao Lu ◽  
Yuan Zhao ◽  
Wenhai Yu ◽  
Yun Yang ◽  
Jiahong Gao ◽  
...  
Keyword(s):  
Histopathological Examination ◽  
Clinical Signs ◽  
Post Inoculation ◽  
New World Monkeys ◽  
Viral Genomes ◽  
Viral Shedding ◽  
Nasal Swabs ◽  
Gross Lesions ◽  
Upper Respiratory ◽  
Human Primate

AbstractCOVID-19, caused by SARS-CoV-2 infection, has recently been announced as a pandemic all over the world. Plenty of diagnostic, preventive and therapeutic knowledges have been enriched from clinical studies since December 2019. However, animal models, particularly non-human primate models, are urgently needed for critical questions that could not be answered in clinical patients, evaluations of anti-viral drugs and vaccines. In this study, two families of non-human primates, Old world monkeys (12 Macaca mulatta, 6 Macaca fascicularis) and New world monkeys (6 Callithrix jacchus), were experimentally inoculated with SARS-CoV-2. Clinical signs were recorded. Samples were collected for analysis of viral shedding, viremia and histopathological examination. Increased body temperature was observed in 100% (12/12) M. mulatta, 33.3% (2/6) M. fascicularis and none (0/6) of C. jacchus post inoculation of SARS-CoV-2. All of M. mulatta and M. fascicularis showed chest radiographic abnormality. Viral genomes were detected in nasal swabs, throat swabs, anal swabs and blood from all 3 species of monkeys. Viral shedding from upper respiratory samples reached the peak between day 6 and day 8 post inoculation. From necropsied M. mulatta and M. fascicularis, the tissues showing virus positive were mainly lung, weasand, bronchus and spleen. No viral genome was seen in any of tissues from 2 necropsied C. jacchus. Severe gross lesions and histopathological changes were observed in lung, heart and stomach of SARS-CoV-2 infected animals. In summary, we have established a NHP model for COVID-19, which could be used to evaluate drugs and vaccines, and investigate viral pathogenesis. M. mulatta is the most susceptible to SARS-CoV-2 infection, followed by M. fascicularis and C. jacchus.One Sentence SummaryM. mulatta is the most susceptible to SARS-CoV-2 infection as compared to M. fascicularis and C. jacchus.

Pathogenicity and immune response against porcine circovirus type 3 infection in caesarean-derived, colostrum-deprived pigs

2020 ◽  
Author(s):  
Gun Temeeyasen ◽  
Shay Lierman ◽  
Bailey L. Arruda ◽  
Rodger Main ◽  
Fabio Vannucci ◽  
...  
Keyword(s):  
Cellular Response ◽  
Clinical Signs ◽  
Humoral Response ◽  
T Cell Response ◽  
Porcine Circovirus ◽  
Histological Evaluation ◽  
Tissue Homogenate ◽  
Post Inoculation ◽  
Viral Shedding

Recently, a novel PCV species (PCV3) has been detected in cases associated with sow mortality, lesions consistent with porcine dermatitis and nephropathy syndrome, reproductive failure and multisystemic inflammation. The pathogenesis and clinical significance of PCV3 is still unclear. In this study, we investigated the immunopathogenesis of PCV3 in CD/CD pigs. Four treatment groups, PCV3 (n=6), PCV3-KLH (n=6), control (n=3) and control-KLH (n=3), were included with PCV3-positive tissue homogenate (gc=3.38×1012 ml−1 and gc=1.04×1011 ml−1), confirmed by quantitative PCR (qPCR) and next-generation sequencing. Clinical signs, viremia, viral shedding, systemic cytokines, humoral (IgG) and T-cellular response were evaluated for 42 days. At necropsy, tissues were collected for histological evaluation and PCV3 detection by qPCR and in situ hybridization. No significant clinical signs were observed through the study. Viremia was detected in both PCV3-inoculated groups from 3 days post-inoculation (p.i.) until the end of the study. Nasal shedding was detected from 3 to 28 days p.i. and faecal shedding was transient. PCV3 induced an early (7 days p.i.) and sustained (42 days p.i.) IgG response. No significant T-cell response was observed. Histological evaluation demonstrated lesions consistent with multisystemic inflammation and perivasculitis. All tissues evaluated were positive by qPCR and virus replication was confirmed by positive in situ hybridization. This study demonstrated the potential role of PCV3 in subclinical infection, producing a mild, multisystemic inflammatory response, prolonged viremia detectable for 42 days p.i., presence of IgG humoral response and viral shedding in nasal secretions. More research is required to understand and elucidate potential co-factors necessary in the manifestation and severity of clinical disease.

scholarly journals Animal Coronavirus Diseases: Parallels with COVID-19 in Humans

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1507
Author(s):  
Chao-Nan Lin ◽  
Kuan Rong Chan ◽  
Eng Eong Ooi ◽  
Ming-Tang Chiou ◽  
Minh Hoang ◽  
...  
Keyword(s):  
Genome Organization ◽  
Clinical Signs ◽  
Feline Infectious Peritonitis ◽  
Viral Shedding ◽  
Related Disease ◽  
The Past ◽  
Treatment And Prevention ◽  
Historical Archives ◽  
Huge Impact ◽  
Novel Coronavirus

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus in humans, has expanded globally over the past year. COVID-19 remains an important subject of intensive research owing to its huge impact on economic and public health globally. Based on historical archives, the first coronavirus-related disease recorded was possibly animal-related, a case of feline infectious peritonitis described as early as 1912. Despite over a century of documented coronaviruses in animals, the global animal industry still suffers from outbreaks. Knowledge and experience handling animal coronaviruses provide a valuable tool to complement our understanding of the ongoing COVID-19 pandemic. In this review, we present an overview of coronaviruses, clinical signs, COVID-19 in animals, genome organization and recombination, immunopathogenesis, transmission, viral shedding, diagnosis, treatment, and prevention. By drawing parallels between COVID-19 in animals and humans, we provide perspectives on the pathophysiological mechanisms by which coronaviruses cause diseases in both animals and humans, providing a critical basis for the development of effective vaccines and therapeutics against these deadly viruses.

scholarly journals Experimental Inoculation of Young Calves with SARS-CoV-2

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 441
Author(s):  
Shollie Falkenberg ◽  
Alexandra Buckley ◽  
Melissa Laverack ◽  
Mathias Martins ◽  
Mitchell V. Palmer ◽  
...  
Keyword(s):  
Nasal Swab ◽  
Species Conservation ◽  
Post Inoculation ◽  
Tissue Samples ◽  
Tracheobronchial Lymph Node ◽  
Viral Shedding ◽  
Liver And Kidney ◽  
Acid Load ◽  
Blood And Urine Samples ◽  
Receptor Distribution

The host range of SARS-CoV-2 and the susceptibility of animal species to the virus are topics of great interest to the international scientific community. The angiotensin I converting enzyme 2 (ACE2) protein is the major receptor for the virus, and sequence and structural analysis of the protein has been performed to determine its cross-species conservation. Based on these analyses, cattle have been implicated as a potential susceptible species to SARS-CoV-2 and have been reported to have increased ACE2 receptor distribution in the liver and kidney, and lower levels in the lungs. The goal of the current study was to determine the susceptibility of cattle to SARS-CoV-2 utilizing inoculation routes that facilitated exposure to tissues with increased ACE2 receptor distribution. For this, colostrum-deprived calves approximately 6 weeks of age were inoculated via the intratracheal or intravenous routes. Nasal and rectal swab samples, as well as blood and urine samples, were collected over the course of the study to evaluate viral shedding, viremia, and seroconversion. Pyrexia was used as the primary criteria for euthanasia and tissue samples were collected during necropsy. Importantly, SARS-CoV-2 RNA was detected in only two nasal swab samples collected on days 3 and 10 post-inoculation (pi) in two calves; one calf in the intratracheal group and the other calf in the intravenous group, respectively. Additionally, the calf in the intratracheal group that was positive on the nasal swab on day 3 pi also had a positive tracheobronchial lymph node on day 9 pi. Viral nucleic acid load on these samples, based on PCR cycle threshold values, were low and infectious virus was not recovered from the samples. These results suggest that there was no productive replication of SARS-CoV-2 in calves following intratracheal and intravenous inoculation.

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