Coronavirus in cat flea: findings and questions regarding COVID-19

Feline Infectious Peritonitis: European Advisory Board on Cat Diseases Guidelines

Feline coronavirus (FCoV) is a ubiquitous RNA virus of cats, which is transmitted faeco-orally. In these guidelines, the European Advisory Board on Cat Diseases (ABCD) presents a comprehensive review of feline infectious peritonitis (FIP). FCoV is primarily an enteric virus and most infections do not cause clinical signs, or result in only enteritis, but a small proportion of FCoV-infected cats develop FIP. The pathology in FIP comprises a perivascular phlebitis that can affect any organ. Cats under two years old are most frequently affected by FIP. Most cats present with fever, anorexia, and weight loss; many have effusions, and some have ocular and/or neurological signs. Making a diagnosis is complex and ABCD FIP Diagnostic Approach Tools are available to aid veterinarians. Sampling an effusion, when present, for cytology, biochemistry, and FCoV RNA or FCoV antigen detection is very useful diagnostically. In the absence of an effusion, fine-needle aspirates from affected organs for cytology and FCoV RNA or FCoV antigen detection are helpful. Definitive diagnosis usually requires histopathology with FCoV antigen detection. Antiviral treatments now enable recovery in many cases from this previously fatal disease; nucleoside analogues (e.g., oral GS-441524) are very effective, although they are not available in all countries.

Predictive factors for flea occurrence in red foxes (Vulpes vulpes) from semi-arid Mediterranean environments

The role of red fox as host for a wide range of parasites, particularly fleas and other arthropods causing vector-borne diseases, in combination with its capability to adapt to anthropized environments, makes this wild canid an epidemiologically remarkable species at the wildlife-domestic-human interface, especially in the present time of rise of emerging and re-emerging diseases. This study evaluated the prevalence and parasite intensity of fleas in 88 foxes from Murcia Region (Southeastern Spain) and determined the geographic distribution of areas with the highest potential risk of flea presence. Pulex irritans, Ctenocephalides felis, Spilopsyllus cuniculi and Nosopsyllus fasciatus were identified. The overall prevalence was 76.13%. This is the first time that N. fasciatus has been reported in foxes from Murcia Region. The predictive model established a certain pattern to determine the areas with the highest risk of acquiring fleas. Positive correlation of daily potential evapotranspiration (ET₀ ) in winter and the opposite effect occurring for ET₀ in summer were obtained, as well as positive correlations for mean daily temperature (T_mean ) in summer and mean precipitation (P_mean ) in winter and summer. The model was also found positively correlated in the forest habitat ecotone areas and the anthropized areas.

Art-science multidisciplinary collaborations to address the scientific challenges posed by COVID-19

The ongoing coronavirus pandemic COVID-19 constitutes a scientific and social challenge. The application of mixed-methods research with multidisciplinary collaborations increases the success of experimental design and interpretation of results to approach scientific challenges. The objective is to develop and implement protean art algorithms with interactions between artists and scientists for scientific research in areas of molecular biology, immunology, ecology and biomedicine. In this perspective, artists were invited to contribute pieces related to the pandemic, and scientists were then challenged to contribute their view and proposed research inspired by artist contribution to face COVID-19 scientific challenges. Proposed research objectives inspired by artist contributions contribute to approach COVID-19 scientific and social challenges with results that may translate into new diagnosis and control interventions. The proposed research objectives approach vaccine protective mechanisms and the development of nutritional interventions with possible impact on boosting protective response to vaccination, the impact of fuel pollutants on host immunity and virus transmission, the possible role of ectoparasite vectors in the appearance of SARS-CoV-2 variants and virus transmission, collaboration between different sectors to contribute to virus surveillance and reduce risks of contagion, characterization of the incidence of zoonotic diseases during and after the COVID-19 pandemic in relation to modifications in the interactions between humans and reservoir animal species, evaluation of the risks associated with sexual or congenital transmission of SARS-CoV-2, development of new methods for the easy and rapid detection of very low SARS-CoV-2 virus amounts in infected but asymptomatic individuals, and understanding society perceptions about the socio-ecological relationships between decoupled environments and the risks and effects of pandemics. This approach may be used to promote social participation in science through combined scientific and artistic perspectives with impact on science and society.KEY MESSAGEMixed-methods research with multidisciplinary collaborations increases the success of experimental design and interpretation of results.Implementation of protean art algorithms through interactions between artists and scientists advances scientific research.Proposed research objectives inspired by artist contributions contribute to approach COVID-19 scientific and social challenges with results that may translate into new diagnosis and control interventions.

Prevention of tick-borne diseases: challenge to recent medicine

Abstract

Ticks represent important vectors and reservoirs of pathogens, causing a number of diseases in humans and animals, and significant damage to livestock every year. Modern research into protection against ticks and tick-borne diseases focuses mainly on the feeding stage, i.e. the period when ticks take their blood meal from their hosts during which pathogens are transmitted. Physiological functions in ticks, such as food intake, saliva production, reproduction, development, and others are under control of neuropeptides and peptide hormones which may be involved in pathogen transmission that cause Lyme borreliosis or tick-borne encephalitis. According to current knowledge, ticks are not reservoirs or vectors for the spread of COVID-19 disease. The search for new vaccination methods to protect against ticks and their transmissible pathogens is a challenge for current science in view of global changes, including the increasing migration of the human population.

Highlights

• Tick-borne diseases have an increasing incidence due to climate change and increased human migration

• To date, there is no evidence of transmission of coronavirus COVID-19 by tick as a vector

• To date, there are only a few modern, effective, and actively- used vaccines against ticks or tick-borne diseases

• Neuropeptides and their receptors expressed in ticks may be potentially used for vaccine design

One Health: EAACI Position Paper on coronaviruses at the human-animal interface, with a specific focus on comparative and zoonotic aspects of SARS-CoV-2

The latest outbreak of a coronavirus disease in 2019 (COVID‐19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), evolved into a worldwide pandemic with massive effects on health, quality of life, and economy. Given the short period of time since the outbreak, there are several knowledge gaps on the comparative and zoonotic aspects of this new virus. Within the One Health concept, the current EAACI position paper dwells into the current knowledge on SARS‐CoV‐2’s receptors, symptoms, transmission routes for human and animals living in close vicinity to each other, usefulness of animal models to study this disease and management options to avoid intra‐ and interspecies transmission. Similar pandemics might appear unexpectedly and more frequently in the near future due to climate change, consumption of exotic foods and drinks, globe‐trotter travel possibilities, the growing world population, the decreasing production space, declining room for wildlife and free‐ranging animals, and the changed lifestyle including living very close to animals. Therefore, both the society and the health authorities need to be aware and well prepared for similar future situations, and research needs to focus on prevention and fast development of treatment options (medications, vaccines).

SARS-CoV-2 in animals: potential for unknown reservoir hosts and public health implications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously 2019-nCoV) is suspected of having originated in 2019 in China from a coronavirus infected bat of the genus Rhinolophus. Following the initial emergence, possibly facilitated by a mammalian bridge host, SARS-CoV-2 is currently transmitted across the globe via efficient human-to-human transmission. Results obtained from experimental studies indicate that animal species such as cats, ferrets, raccoon dogs, cynomolgus macaques, rhesus macaques, white-tailed deer, rabbits, Egyptian fruit bats, and Syrian hamsters are susceptible to SARS-CoV-2 infection, and that cat-to-cat and ferret-to-ferret transmission can take place via contact and air. However, natural infections of SARS-CoV-2 have been reported only in pet dogs and cats, tigers, lions, snow leopards, pumas, and gorillas at zoos, and farmed mink and ferrets. Even though human-to-animal spillover has been reported at several instances, SARS-CoV-2 transmission from animals-to-humans has only been reported from mink-to-humans in mink farms. Following the rapid transmission of SARS-CoV-2 within the mink population, a new mink-associated SARS-CoV-2 variant emerged that was identified in both humans and mink. The increasing reports of SARS-CoV-2 in carnivores indicate the higher susceptibility of animal species belonging to this order. The sporadic reports of SARS-CoV-2 infection in domestic and wild animal species require further investigation to determine if SARS-CoV-2 or related Betacoronaviruses can get established in kept, feral or wild animal populations, which may eventually act as viral reservoirs. This review analyzes the current evidence of SARS-CoV-2 natural infection in domestic and wild animal species and their possible implications on public health.

Proposed classifications of immunogenomic editing by cancers and pathogens

Several evolutionary mechanisms exist between a lethal disease agent, such as a cancer or a pathogen, and the immune system of a surviving subpopulation of hosts. Immunogenomic editing is herein defined as the evolution of a lethal disease agent genome or the surviving carrier or host subpopulation immune system genomes. One type of immunogenomic editing called immunoediting has already been identified for cancer genomes. The effects of two other types of immunogenomic editing have been observed for pathogens and humans. However, these types of editing are only a few types of a much broader immunogenomic editing process, and some of the other types of immunogenomic editing have not been explicitly recognized. Immunogenomic editing can include seven types, and several types of immunogenomic editing have applications including analysis of subpopulation responses to cancers and pathogens. Applications would also include facilitating analysis of substantial subpopulation vulnerability differences to lethal pathogen epidemics. The need for quicker analysis of the actual transmission chains and the immunogenomic mechanisms for the faster spread of dangerously virulent pathogens can be expected to increase, since modern transportation technology can spread new pathogens very rapidly around the world.

SARS-CoV-2 infection in domestic and feral cats: current evidence and implications

Current evidence indicates that cats play a limited role in COVID-19 epidemiology, and pets are probably dead-end hosts of SARS-CoV-2 and pose negligible risks of transmission to humans. Still, one health concept is to be adopted widely as a component of mitigation strategies to tackle the ongoing pandemic. Therefore, in terms of the magnitude of infection and potential to transmit SARS-CoV-2 to humans, our surveillance efforts should mainly focus on mustelids (especially minks, ferrets, and others) for early detection and control of infection. This will ensure that SARS-CoV-2 will not get established in the wild animal population of these susceptible species. We agree with Dr. Passarella Teixeira on the possibility of domestic and feral cats acting as an urban reservoir, subsequently transmitting the virus to human beings. However, it is less likely that such a phenomenon will be reported even if it has occurred due to the efficient and extensive human-to-human transmission of SARS-CoV-2.

Proteomics-Based Insights Into the SARS-CoV-2-Mediated COVID-19 Pandemic: A Review of the First Year of Research

In late 2019, a virus subsequently named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in China and led to a worldwide pandemic of the disease termed coronavirus disease 2019. The global health threat posed by this pandemic led to an extremely rapid and robust mobilization of the scientific and medical communities as evidenced by the publication of more than 10,000 peer-reviewed articles and thousands of preprints in the first year of the pandemic alone. With the publication of the initial genome sequence of SARS-CoV-2, the proteomics community immediately joined this effort publishing, to date, more than 100 peer-reviewed proteomics studies and submitting many more preprints to preprint servers. In this review, we focus on peer-reviewed articles published on the proteome, glycoproteome, and glycome of SARS-CoV-2. At a basic level, proteomic studies provide valuable information on quantitative aspects of viral infection course; information on the identities, sites, and microheterogeneity of post-translational modifications; and, information on protein-protein interactions. At a biological systems level, these studies elucidate host cell and tissue responses, characterize antibodies and other immune system factors in infection, suggest biomarkers that may be useful for diagnosis and disease-course monitoring, and help in the development or repurposing of potential therapeutics. Here, we summarize results from selected early studies to provide a perspective on the current rapidly evolving literature.

Evolution, Ecology, and Zoonotic Transmission of Betacoronaviruses: A Review

Coronavirus infections have been a part of the animal kingdom for millennia. The difference emerging in the twenty-first century is that a greater number of novel coronaviruses are being discovered primarily due to more advanced technology and that a greater number can be transmitted to humans, either directly or via an intermediate host. This has a range of effects from annual infections that are mild to full-blown pandemics. This review compares the zoonotic potential and relationship between MERS, SARS-CoV, and SARS-CoV-2. The role of bats as possible host species and possible intermediate hosts including pangolins, civets, mink, birds, and other mammals are discussed with reference to mutations of the viral genome affecting zoonosis. Ecological, social, cultural, and environmental factors that may play a role in zoonotic transmission are considered with reference to SARS-CoV, MERS, and SARS-CoV-2 and possible future zoonotic events.

Mechanical transmission of SARS-CoV-2 by house flies

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a recently emerged coronavirus that is the causative agent of the coronavirus disease 2019 (COVID-19) pandemic. COVID-19 in humans is characterized by a wide range of symptoms that range from asymptomatic to mild or severe illness including death. SARS-CoV-2 is highly contagious and is transmitted via the oral–nasal route through droplets and aerosols, or through contact with contaminated fomites. House flies are known to transmit bacterial, parasitic and viral diseases to humans and animals as mechanical vectors. Previous studies have shown that house flies can mechanically transmit coronaviruses, such as turkey coronavirus; however, the house fly’s role in SARS-CoV-2 transmission has not yet been explored. The goal of this work was to investigate the potential of house flies to mechanically transmit SARS-CoV-2. For this purpose, it was determined whether house flies can acquire SARS-CoV-2, harbor live virus and mechanically transmit the virus to naive substrates and surfaces.

Methods

Two independent studies were performed to address the study objectives. In the first study, house flies were tested for infectivity after exposure to SARS-CoV-2-spiked medium or milk. In the second study, environmental samples were tested for infectivity after contact with SARS-CoV-2-exposed flies. During both studies, samples were collected at various time points post-exposure and evaluated by SARS-CoV-2-specific RT-qPCR and virus isolation.

Results

All flies exposed to SARS-CoV-2-spiked media or milk substrates were positive for viral RNA at 4 h and 24 h post-exposure. Infectious virus was isolated only from the flies exposed to virus-spiked milk but not from those exposed to virus-spiked medium. Moreover, viral RNA was detected in environmental samples after contact with SARS-CoV-2 exposed flies, although no infectious virus was recovered from these samples.

Conclusions

Under laboratory conditions, house flies acquired and harbored infectious SARS-CoV-2 for up to 24 h post-exposure. In addition, house flies were able to mechanically transmit SARS-CoV-2 genomic RNA to the surrounding environment up to 24 h post-exposure. Further studies are warranted to determine if house fly transmission occurs naturally and the potential public health implications of such events.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04703-8.

Arthropod Ectoparasites Have Potential to Bind SARS-CoV-2 via ACE

Coronavirus-like organisms have been previously identified in Arthropod ectoparasites (such as ticks and unfed cat flea). Yet, the question regarding the possible role of these arthropods as SARS-CoV-2 passive/biological transmission vectors is still poorly explored. In this study, we performed in silico structural and binding energy calculations to assess the risks associated with possible ectoparasite transmission. We found sufficient similarity between ectoparasite ACE and human ACE2 protein sequences to build good quality 3D-models of the SARS-CoV-2 Spike:ACE complex to assess the impacts of ectoparasite mutations on complex stability. For several species (e.g., water flea, deer tick, body louse), our analyses showed no significant destabilisation of the SARS-CoV-2 Spike:ACE complex, suggesting these species would bind the viral Spike protein. Our structural analyses also provide structural rationale for interactions between the viral Spike and the ectoparasite ACE proteins. Although we do not have experimental evidence of infection in these ectoparasites, the predicted stability of the complex suggests this is possible, raising concerns of a possible role in passive transmission of the virus to their human hosts.