Background and Purpose: In the development of vaccines, it is important to increase the antigen of the vaccine. We have confirmed the potential of Morus alba L., a Toll-like receptor 4 (TLR4) activator, as an adjuvant as a method for increasing the antigenicity of the vaccine. Experimental Approach: TLR4 is highly expressed on immune cells, therefore, the present study was undertaken to investigate the underlying immunological processes of Morus alba L. as an oral adjuvant in a mouse model. Mice were immunized with two types of antigen (ovalbumin (OVA) or inactivated influenza vaccine) combined with Morus alba L. Key Results: In the OVA antigen model, the co-administration of Morus alba L. significantly promoted phagocytosis in murine peritoneal macrophages. The maturation and function of dendritic cells were significantly up-regulated the expression of MHC-II, CD86, and CD80 compared to OVA alone. The titers of OVA-specific IgG, IgG subtype responses, and IgA were increased, the proliferation of T and B-cells was markedly enhanced, and the production of IL-12, IFN-, and IL-4 was better than OVA alone. In the inactivated influenza H1N1(PR8) vaccine model, the co-administration of Morus alba L. with vaccine significantly increased the IgM, IgG, and IgG subtype responses. The immunization of mice with Morus alba L. adjuvant reduced mortality in mice after a lethal challenge with influenza virus. Conclusion and Implications: Morus alba L. is a novel mucosal adjuvant for vaccination that provided safe and effective adjuvant effects and successfully induced both serum and mucosal antibody responses and cell-mediated responses.

Influenza A virus (IAV), a deadly zoonotic pathogen, occasionally cross-species transmission among humans, swine and avian. The ectodomain of matrix protein 2 (M2e) is highly conserved in IAV, and multi-copy M2e from different species are usually displayed on the surface of nanoparticles to improve immunogenicity and constitute universal IAV nanovaccines. In our previous study, three M2e were inserted into the C-terminal of Cap protein of porcine circovirus type 2 (PCV2) to form a universal nanovaccine that protects PCV2 and different subtypes of IAV. Howerer, M2e adopts at least two converted conformations, and the intermolecular linker of M2e enhances the conformational instability, which limits the recognition of B cell receptors and production of high-level antibodies. Here, we report that the permutation of the M2e affects immune effect of nanovaccines. Three M2e derived from humans, swine and avian IAV were inserted into the C-terminal of the Cap protein to form nanovaccines. Immunoprotective effects of different M2e arrangements were explored in mice. Results showed that the M2e closest to the surface of nanoparticle induced the most efficient protection against IAV derived from corresponding species. The results will help to develop more effective universal IAV and PCV2 bivalent nano-vaccines, as well as universal IAV vaccines for specific species.

Bufonid herpesvirus 1 (BfHV1) was initially described in 2018 from cases of severe dermatitis in Swiss populations of the common toad (Bufo bufo). We identified a closely related herpes virus strain in a German toad population affected by an epidemic of multifocal proliferative to ulcerative dermatitis.

Background: There is an urgent need to improve health outcomes among severe COVID-19 patients. Therefore, this study aimed to demystify efficacy and safety of tocilizumab among those patients based on the best available evidence. Methods: Nine electronic databases were searched for relevant studies by three authors in July using search terms “tocilizumab”, “COVID”, “SARS”. The last date checked was 26 August, 2020. Eligible studies were assessed through an inclusion criterion focused on cohort studies and severe COVID-19 adult patients. Any disagreement between the authors was resolved by discussions. Primary outcomes were mortality and clinical improvement, while secondary outcomes were tocilizumab-related adverse effects. Results: Tocilizumab reduced the mortality rate by 41%, 40%, 28%, and 37% in 7, 14, 21, and 28 days. There was neither statistically significant difference between the tocilizumab group and the control group in the clinical improvement (pooled risk ratio1.21 [0.89, 1.64]) nor in respiratory support change. There were no difference between the two groups in the occurrence of serious adverse events (pooled risk difference 0.00 [-0.02, 0.03]), bacteremia (pooled risk ratio 1.25 [0.80, 1.97]), elevation of liver functions (pooled risk difference -0.00 [-0.03, 0.02]) and infusion related reactions (pooled risk difference 0.01 [-0.02, 0.03]). However, the occurrence of neutropenia (pooled risk ratio 9.23 [1.06, 80.24]) and new infections (pooled risk difference 0.07 [0.00, 0.14]) were more likely in the tocilizumab group. Conclusion: Because of the reported adverse effects of tocilizumab in treating severe COVID-19 patients, the use of that biological agent should be limited to selected patients based on the best available evidence.

Abstract Background Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe cutaneous adverse drug reaction associated with human herpesvirus reactivation. However, the risk factors for viral reactivation and their impact on outcomes remain unclear.We aimed to explore the impact of viral reactivation on DRESS outcomes and potential risk factors for reactivation. Methods This was a retrospective cohort study in an academic medical center. Cases were validated in-hospital cases of DRESS from 2009 to 2017. Results Overall, 100 patients fulfilled the case criteria. Ninety-three patients had at least one viral marker tested. HHV6, EBV and CMV reactivation occurred in 24 out of 85 cases (28%), 15 out of 87 (17%) cases, and 18 out of 89 (20%) cases respectively. Viral reactivation cases were associated with higher 1-year mortality, dialysis initiation, recurrent flares of disease, and longer hospital stay (all p<0.05). Risk of inpatient mortality (OR, 5.8; 95% CI, 1.7-20.7; p<0.01) and 1-year mortality (OR, 10.0, 95% CI, 2.9-34.9; p<0.01) increased with multiple viral reactivations. Viral reactivation was independent of demographics, comorbidities, treatment or causative drug. Conclusion Human herpesviridae viral reactivation in DRESS, particularly multiple viral reactivations, is associated with poorer clinical outcomes.

Background: Laboratory abnormalities associated with disease severity and mortality in patients with coronavirus disease 2019 (COVID-19) have been reported in many observational studies. However, there are significant heterogeneities in patient characteristics and research methodologies in these studies. Objectives: We aimed to provide an updated synthesis of the association between laboratory abnormalities and COVID-19 prognosis. Methods: We conducted an electronic search of PubMed, Scopus, Ovid, Willey, Web of Science, and the China National Knowledge Infrastructure (CNKI) for studies reporting hematological, coagulation, inflammatory, and immunological results during hospital admission of COVID-19 patients with different severities and outcomes. Results: A total of 64 studies were included in the current meta-analysis, with 8 hematological, 3 coagulation, 5 inflammatory, and 23 immunological variables reported. Of them, white blood cell (WBC) and neutrophil counts, D-dimer level, procalcitonin (PCT), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), ferretin, serum amyloid A (SAA), interleukins (ILs)–2R, IL-6, and IL-10 were significantly increased in severely ill patients and non-survivors. Meanwhile, non-severely ill patients and survivors presented significantly higher counts of eosinophils, lymphocytes, and CD4+ and CD8+ T cells. Conclusions: The current meta-analysis provides a comprehensive and updated synthesis of the association between admission laboratory abnormalities with severity and mortality of COVID-19. Our results highlight that increases in the levels of PCT, ESR, CRP, ferretin, SAA, IL-2R, IL-6, and IL-10 were associated with disease deterioration, whereas elevated eosinophils, lymphocytes, and T-cell subsets might serve as indicators of favorable outcomes.

Infection with African swine fever virus (ASFV) causes a highly lethal hemorrhagic disease in domestic and Eurasian wild pigs. Thus, it is a major threat to pig populations worldwide and a cause of substantial economic losses. Recently, less virulent ASFV strains emerged naturally, which showed higher experimental virulence in wild boar than in domestic pigs. The reason for this difference in disease progression and outcome is unclear but likely involves different immunological responses. Unfortunately, besides the importance of CD8α+ lymphocytes, little is known about the immune responses against ASFV in suids. Against this background, we used a multicolor flow cytometry platform to investigate the T-cell responses in wild boar and domestic pigs after infection with the moderately virulent ASFV strain “Estonia2014” in two independent trials. CD4–/CD8α+ and CD4+/CD8α+ αβ T-cell frequencies increased in both subspecies in various tissues, but CD8α+ γδ T cells differentiated and responded in wild boar only. Proliferation in CD8α+ T cells was found 10 days post infectionem only. Frequencies of T-bet+ T cells increased in wild boar but not in domestic pigs. Of note, we found a considerable loss of perforin expression in cytotoxic T cells, 5 and 7 dpi. Both subspecies established a regulatory T-cell response 10 dpi. In domestic pigs, we show increasing levels of ICOS+ and CD8α+ invariant Natural Killer T cells. These disparities in T-cell responses might explain some of the differences in disease progression in wild boar and domestic pigs and should pave the way for future studies.

Porcine circovirus type 3 (PCV-3) had posed a potential threat to the swine industry since its discovery in the United States in 2015. The Shanxi province had a wide range of large-scale pig farms in China, but the transmission of PCV-3 was unclear. To further investigate the epidemic profile and genetic diversity of the virus, the lung samples (491) from 19 different pig slaughterhouse in 11 cities covering the whole of the Shanxi province of China were evaluated by PCR. The results indicated that the PCV-3 positive rate at the slaughterhouse level and at the individual level was 100% (19/19) and 86.76% (426/491), respectively. The PCR-positive samples were further sequenced, and eight new PCV3 isolates were identified. The complete genomes of the eight virus isolates showed 97.45%–99.90% nucleotide identity with other PCV-3 isolates available in NCBI. Phylogenetic analysis based on the complete genome and capsid gene divided the PCV-3 strains into two main groups and several subclusters. The eight identified PCV-3 strains could be divided into the same clades, according to amino acid mutations A24/V and R27/K of Cap proteins. The results could provide new insight into the prevalence and genetic variation of PCV-3 in the Shanxi province of China, as well as the possibility of transmission from this center. It also reminded me that the molecular epidemiology of this new circovirus was urgent.

Peste des Petits Ruminants (PPR) is a highly contagious viral disease that mainly affects goats and sheep in Asia, Africa and the Middle East. The PPR virus (PPRV) can be classified into four genetically distinct lineages (I, II, III, and IV). All have been historically present in Africa, except the Asian lineage IV that has been spreading across the globe and Africa for the last decades. Previous studies have identified the presence of the lineage IV in Nigeria since 2010. In this study, samples were taken from 268 small ruminants with PPR symptoms across Nigeria in 2017-2018 to provide an update on the distribution and genetic diversity of the lineage IV in the country. Sequence from a portion of the PPRV nucleoprotein (N) gene could be obtained from 72 samples, and all but one belonged to lineage IV. Phylogenetic analysis identified at least 5 lineage IV sub-clusters in Nigeria, re-grouping samples across multiple regions. Our results suggest an extensive endemic circulation of PPRV lineage IV across Nigeria and across borders with neighbouring countries, highlighting the difficulty of the control of this disease in the region.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV) and 2019 novel coronavirus (2019-nCoV) pose a serious threat to human health. To determine the genetic relationships between the two clades and the genetic mechanism of origin of 2019-nCoV, we compared the whole genomic sequences of SARS-CoV and 2019-nCoV and dissected their phylogenetic histories. Surprisingly, we found that the two clades have frequently exchanged genetic material through homologous recombination in recent decades. Nearly 2/3 of the genetic material of CoVZC45 comes from 2019-nCoV lineage, while the other 1/3 descends from SARS-CoV clade. In particular, the 2019-nCoV lineage might have acquired its receptor-binding domain from the SARS-CoV clade, enabling 2019-nCoV to bind to human angiotensin-converting enzyme 2 receptor and helping it to spread rapidly in humans. Our findings suggest the role of a virus of the SARS-CoV clade in causing COVID-19 and warn of the possible emergence of more mosaic CoVs capable of causing severe epidemics.

African swine fever virus (ASFV) can survive in soy-based products for 30 days with T ½ ranging from 9.6-12.9 days in soybean meals and soy oil cake. As the US imports soy-based products from several ASFV-positive countries, knowledge of the type and quantity of these specific imports, and their ports of entry (POE), is necessary information to manage risk. Using the data from the International Trade Commission Harmonized Tariff Schedule website in conjunction with pivot tables, we analyzed imports across air, land, and sea POE of soy-based products from 43 ASFV-positive countries to the US during 2018 and 2019. In 2018, 104,366 metric tons (MT) of soy-based products, specifically conventional and organic soybean meal, soybeans, soy oil cake and soy oil were imported from these countries into the US via seaports only. The two largest suppliers were China (52.7 %, 55,034 MT) and the Ukraine (42.9%, 44,775 MT). In 2019, 73,331 MT entered the US and 54.7% (40,143 MT) came from the Ukraine and 8.4% (6,182 MT) from China. Regarding POE, 80.9% to 83.2% of soy-based imports from China entered the US at the seaports of San Francisco, CA and Seattle, WA, while 89.4% to 100% entered from the Ukraine via the seaports of New Orleans, LA and Charlotte, NC. Analysis of five-year trends (2015 to 2019) of the volume of soy imports from China indicated reduction over time (with a noticeably sharp decrease between 2018 and 2019), and seaport utilization was consistent. In contrast, volume remained high for Ukrainian soy imports, and seaport utilization was inconsistent. Overall, this exercise introduced a new approach to collect objective data on an important risk factor, providing researchers, government officials, and industry stakeholders a means to objectively identify and quantify potential channels of foreign animal disease entry into the US.

Myxomatosis is an emergent disease in Iberian hare, having been considered a rabbit disease for decades. Genome sequencing of the strains obtained from affected Iberian hares showed to be distinct from the classical strains that circulated in rabbits since the virus introduction in Europe, in 1952. The main genomic difference concerns the presence of an additional 2.8Kb region disrupting the M009L gene and adding a set of genes with homology to the MYXV genes M060R, M061, M064 and M065R originated in poxviruses. After the emergence of this recombinant virus (MYXV-Tol or ha-MYXV), in the summer of 2019, the recombinant MYXV was not detected in rabbit surveys suggesting apparent species segregation with the MYXV classic strains persistently circulating in rabbits. Recently, a group of six unvaccinated European rabbits (Oryctolagus cuniculus cuniculus) from a backyard rabbitry in the South Portugal, developed signs of myxomatosis (anorexia, dyspnoea, oedema of eyelids, head, ears, external genitals and anus, and skin myxomas in the base of the ears), five of them dying within 24-48 hours of symptoms onset. Molecular analysis revealed that only the recombinant myxoma virus was present. This is the first documented report of a recombinant myxoma virus (ha-MYXV)  in farm rabbits associated with high mortality, which aggravates the concern for the future of the Iberian hare and wild rabbits and the safety of the rabbit industry against which the existing vaccines may not be fully protective.

Tembusu virus (TMUV) is a positive-sense RNA virus that is associated with severe reduction in egg production and even death in ducks. TMUV infection shows high incidence and is a threat to the global duck industry. However, the possible origin, genotype, and codon usage bias of TMUV are not very clear. Here, we addressed these questions by analyzing the available genomic sequences from China. The results showed that the ancestor of avian TMUV was most likely a mosquito TMUV. Moreover, three TMUV clades were identified by three different phylogenetic analysis methods. The TMUV genome exhibits a stronger mutation pressure than natural selection pressure. TMUV has the potential to cause an infection outbreak among humans, thereby posing a major threat to public health. Our findings provide important insights that reveal the ongoing TMUV spread in China and can aid in future prevention and control.

Lumpy Skin Disease virus (LSDV) is involved in the genus Capripoxvirus(CaPV) of the family Poxviridae. Sheep and goat pox (SGP) vaccine is used heterologously against Lumpy Skin Disease(LSD) in Turkey. In the presented study, it was investigated the propagation of SGP vaccine virus that attenuated in primary lamb kidney cell, in bovine origin MDBK cells and evaluated the immunity of vaccine against LSD in cattle with comparison to the commercial SGP vaccine (Penpox-M) are used in the field. 2 cattle were vaccinated with 10 doses of SGP vaccine produced in MDBK. In efficacy study, 3 cattle were vaccinated with SGP vaccine produced in MDBK, 3 cattle vaccinated with Penpox-M. 2 cattle were not vaccinated as control animal. After vaccination on the day 31, all animals were challenged with virulent Pendik strain and blood samples were taken periodically. Logarithmic differences of the challenge titres between vaccinated and non-vaccinated were calculated. In safety study, clinical sign wasn’t observed in animals vaccinated with 10 doses. It was determined that difference between the animals vaccinated with vaccine produced in MDBK cell and unvaccinated was less than log 2.5 and the viremia occurred in vaccinated animals. The titre difference was higher than log 2.5 in animals vaccinated with the Penpox-M, and viremia didn’t occur. In conclusion, this study revealed that SGP vaccine virus was propagated in MDBK cells and it is safe to administered in cattle but it didn’t provide fully protection, Penpox-M provided protection against LSD.

Aujeszky’s disease in cattle is caused by Suid herpes virus 1. The natural infection has been reported worldwide in bovine species and it is connected to direct and indirect contact with infected suids, which represent the main reservoir of the disease. Here is reported the first documented outbreak of Aujeszky’s disease in cattle in Sicily (Italy). Severe itching and nonspecific neurological symptoms were the main reported clinical signs. No characteristic gross and histological features were reported rather than cutaneous lesions caused by excessive pruritus and hyperaemia, haemorrhages and inflammation in the central nervous system. Diagnosis was confirmed by real time PCR and immunohistochemistry on the nervous tissue. The route of infection remained unknown, but serological data observed in pigs living in close cohabitation with cattle revealed a circulation of a wild strain of the virus in the area. This study contributes to a better knowledge of this disease in an aberrant host and suggests the need of increase the prophylaxis control plans in specific breeding contexts.

Porcine epidemic diarrhea virus (PEDV), a coronavirus pathogen of the pig intestinal tract, can cause fatal watery diarrhea in piglets, thereby leading huge economic losses to swine industry around the world. The pathogenesis of PEDV has been intensively studied, however, the viral proteins of PEDV and the host factors in target cells, as well as their interactions, which underly the molecular mechanisms of viral infection, remains to be illustrated and summarized. PEDV has multiple important structural and functional proteins which play various roles in the process of virus infection. Among them, the S and N proteins play vital roles in biological processes related to PEDV survival via interacting with the host cell proteins. Vice versa, a number of host factors including receptors are required for the infection of PEDV per the interactions with the viral proteins, thereby affecting the reproduction and contributing to the life cycle of PEDV. In this review, we intend to provide an update understanding of the PEDV viral proteins and host factors and illustrate the interactions between them. Additionally, the effects of cellular factors or events or signaling pathways on PEDV infection are also discussed. Thus, these comprehensive and creative insights should facilitate to guide the future research, control and prevention of PEDV infection.

Bovine viral diarrhea virus (BVDV) is a major cause of economic loss in the cattle industry, worldwide. Infection results in reduce productive performance, growth retardation, reduced milk production, and increased susceptibility to other diseases leading to early culling of animals. There are two main measures used to control the spread of BVDV: the elimination of persistently infected (PI) animals and vaccination. Currently, modified live or inactivated vaccines are used in BVDV vaccination programs, but there are safety risks or insufficient protection, respectively, with these vaccines. Here we report the development and efficacy of the first targeted subunit vaccine against BVDV. The core of the vaccine is a fusion of the BVDV structural protein, E2, to a single-chain antibody, APCH, together termed, APCH-E2. The APCH antibody targets the E2 antigen to the major histocompatibility type II molecule (MHC-II) present on antigen-presenting cells. Industrial production of the vaccine is carried out using the baculovirus expression vector system (BEVS) using single-use manufacturing technologies. This new subunit vaccine induces strong BVDV-specific neutralizing antibodies in guinea pigs and cattle. Importantly, in cattle with low levels of natural BVDV-specific neutralizing antibodies, the vaccine induced strong neutralizing antibody levels to above the protective threshold, as determined by a competition ELISA. The APCH-E2 vaccine induced a rapid and sustained neutralizing antibody response compared to a conventional vaccine in cattle. The development of this subunit targeted vaccine provides cattle and dairy producers with an inexpensive, easily administered, safe, and efficacious BVDV vaccine.

Background: As of March 31, 2020, about 82,545 COVID-19-infected patients in China have been confirmed. Several observational studies have reported clinical characteristics of pneumonia caused by COVID-19 in China. But there are doubts about the clinical significance of differences reported in the different studies. The objective of this paper is to meta-analyze all available data from observational studies in China to enable an objective reappraisal of the clinical characteristics. Methods: PubMed, CNKI, EMBASE, and Cochrane Library were searched. Observational studies were included if they reported information on clinical characteristics of COVID-19-infected pneumonia. Statistical heterogeneity was assessed using the I2 test, with a value ≥ 50% indicating a substantial level of heterogeneity. Results: Pooled results exhibited that the proportion of male (58%) was higher in patients with COVID-19-infected pneumonia. Fever (89%), cough (74%), fatigue (44%), and shortness of breath (31%) were the common clinical manifestations. Cardiovascular disease (8%), endocrine system disease (9%), and digestive system disease (5%) were the common comorbidities. Moreover, hypertension (29%), endocrine system disease (16%), and cardiovascular disease (8%) were the most common comorbidities in severe patients. Acute cardiac injury (5%), ARDS (11%), shock (3%), and AKI (2%) were the common complications. Conclusions: Men may be more susceptible to COVID-19. The people with hypertension and endocrine system disease are more likely to develop severe pneumonia. The most common symptoms are fever and cough. The heart and kidneys may be also important organs for the COVID-19 to attack in addition to the lungs. Most patients have bilateral imaging abnormalities.

Rabies is a viral disease that causes severe neurological manifestations both in humans and mammals. Although inactivated and/or attenuated vaccines have been developed and widely used around the world, there are still concerns with regard to their safety, efficacy, and costs. As demand has grown for a new rabies vaccine, we have developed a new vesicular stomatitis viruses (VSVs) based rabies vaccine that replaces glycoproteins with rabies virus (RABV) glycoprotein (GP), or so-called VSV/RABV-GP. The generation of VSV/RABV-GP was evaluated with GP-specific antibodies and reduced transduction with GP-specific neutralizing antibodies. Mice immunized with VSV/RABV-GP produced higher levels of both IgM and IgG antibodies compared to inactivated RABV. The secretion profiles of IgG1 and IgG2a production suggested that VSV/RAVB-GP induces the T helper cell type-2 immune bias. In addition, VSV/RAVB-GP immunization produced a neutralizing antibody of 103.37 IU/mL. Our results confirm that VSV/RABV-GP could be a new potential vaccination platform for RABV.

2019-nCoV and SARS-CoV seriously threatened human health. In order to know the genetic relations of the two dangerous clades and genetic mechanism of origin of 2019-nCoV, we compared whole genomic sequences of SARS-CoV and 2019-nCoV clades, and dissected phylogenetic histories of them. To our surprise, we found that the two clades may frequently exchange their genetic materials through homologous recombination in recent decades, resulting in 2019-nCoV and its sister branch represented by CoVZC45. Particularly the 2019-nCoV lineage might thereby acquire the receptor-binding domain from the SARS-CoV clade, enabling it to make use of angiotensin-converting enzyme 2 as well and thus spread rapidly in humans. Our findings suggest the accomplice role of a virus of SARS-CoV clade in COVID-19 and warn of the possible emergence of more mosaic CoVs capable of launching severe epidemic.

We describe results from a panel study in which pigs from a 17-sow African swine fever (ASF) positive herd in Thái Bình province, Vietnam were followed over time to record the date of onset of ASF signs and the date of death from ASF. Our objectives were to: (1) fit a susceptible-exposed-infectious-removed disease model to the data with transmission coefficients estimated using Approximate Bayesian Computation; and (2) provide commentary on how a model of this type might be used to provide decision support for disease control authorities For the outbreak in this herd the median of the average latent period was 10 days (95% HPD [highest posterior density interval]: 2 to 19 days) and the median of the average duration of infectiousness was 3 days (95% HPD: 2 to 4 days). The estimated median for the transmission coefficient was 3.3 (95% HPD: 0.4 to 8.9) infectious contacts per ASF-infectious pig per day. The estimated median for the basic reproductive number, R0, was 10 (95% HPD: 1.1 to 30). Our estimates of the basic reproductive number R0 were greater than estimates of R0 for ASF reported previously. The results presented in this study may be used to estimate the number of pigs expected to be showing clinical signs at a given number of days following an estimated incursion date. This will allow sample size calculations, with or without adjustment to account for less than perfect sensitivity of clinical examination, to be used to determine the appropriate number of pigs to examine to detect at least one with disease. A second use of the results of this study would be to inform the equation-based within-herd spread components of stochastic agent based and hybrid simulation models of ASF.

Porcine epidemic diarrhea virus (PEDV) causes acute and devastating intestinal disease in suckling piglets, resulting in a huge loss in the worldwide swine industry. Although several researches have reported that PEDV could cause viremia, the mechanism of how PEDV spread in the blood has been still unclear. Here, we showed PEDV could cause typical diarrhea in newborn piglets through hijacking red blood cells (RBCs). Firstly, PEDV could bind and internalize into neonatal RBCs through CD71 and clathrin-mediated endocytosis, and maintain its viability for 12 h. Subsequently, PEDV-loaded RBCs could transfer the virus to CD3+ T cells by formatting conjugation structure. PEDV could continue to hitchhike CD3+ T cells to reach intestine mucosa and cause infection. Moreover, after autotransfusion with PEDV-loaded RBCs, PEDV could infect and colonize intestinal epithelial cells, causing typical diarrhea symptoms in newborn piglets. Unintentionally, PEDV-loaded RBCs were found in nasal capillary after intranasal spraying with PEDV. Since oxygen partial pressure (pO2) and temperature of nasal cavity are different from other tissues, we further determined the higher pO2 was a promoting factor for PEDV binding RBCs. Therefore, the nasal capillary was speculated to be the entry for PEDV binding RBCs. Collectively, our studies illustrated the mechanism that PEDV could cause intestine infection through hijacking RBCs, further providing a novel insight into the role of RBCs in coronavirus pathogenesis as potential cells for viral transmission.

In this report we reported the sero-prevalence of West Nile virus among the resident and migratory wild birds from different locations of Bangladesh. 48 birds (48/888, 5.4%, CI 0.04-0.07) were found sero-positive for WNV antibody.

To the Editor: The spread of the coronavirus disease-2019 (COVID-19) remains a worsening global health crisis. Although many studies have reported risk factors for severe COVID-19, asthma characterization in COVID-19 is still controversial, with different early reports from China and recent reports from the Europe and United States.1 Prolonged viral shedding is not only a risk factor for poor outcome of COVID-19, but also clues to host immune response against the virus. However, there is limited data on this except for results from relative small group studies.2 In this study, 2 200 adult patients hospitalized for COVID-19 in Daegu were evaluated for prevalence of asthma and clinical outcomes with COVID-19 according to asthma. In addition, the risk factors for delayed viral clearance were evaluated.The prevalence of asthma in patients with COVID-19 was 3.2% which was not different from its prevalence in the Korea National Health and Nutrition Examination Survey (KNHANES) (Figure 1A and Table S1). By age group, the prevalence of asthma showed a similar U-shaped pattern as the general prevalence pattern in Korea. However, the prevalence of asthma in the 19–29-year age group (2.1%) was lower than that of KNHANES (Figure 1B).Table S2 compares the characteristics between the asthma group and the non-asthma group. Older age, overweight, and comorbidity of chronic obstructive pulmonary disease, and initial symptoms of dyspnea and nausea/vomiting were more common in the asthma group. Compared with the non-asthma group, the asthma group had a greater risk of death (13.6%vs. 6.4%, P = 0.02) and a greater need for high-flow oxygen therapy (18.2% vs . 10.5%, P = 0.048) (Figure 1C and Table S3). The higher mortality rate in asthma patients compared with non-asthmatic patients was particularly noticeable in female and overweight patients. Older patients (> 65 years) with asthma tended to have a higher mortality rate than those without asthma (Figure 1D). After adjusting for potential confounders, asthma had no significant association with clinical outcomes of COVID-19 (Figure 1E and Table S4). Meanwhile, older age, male gender, and comorbid diseases including overweight, diabetes, chronic kidney disease, cancer, autoimmune disease, dementia, and other psychological disorder were significant risk factors for mortality (Tables S5 and S6).Asthma is considered to have a lower risk of death than other well-known risk factors.3, 4 However, asthma is a heterogeneous disease and is often associated with atopic and eosinophilic asthma in younger patients. Meanwhile, obese asthma and elderly asthma are known to have common neutrophilic phenotypes.5, 6 The recent results of higher expression of COVID-19 receptors in respiratory specimens with neutrophilic asthma phenotype compared with the eosinophilic asthma phenotype.7 Considering prevalence and clinical outcome results, it is possible that neutrophilic asthma is a risk factor for infection and poor prognosis of COVID-19 rather than eosinophilic asthma.When delayed viral clearance was divided into two groups based on 30 days, 906 patients were included in the non-delayed viral clearance group and 415 patients in the delayed viral clearance group. After adjusting for potential confounders, delayed viral clearance was not significantly associated with asthma (Figure 1E and Table S4). However, older age >65 years (Odds ratio (OR) 2.002, 95% Confidence interval (CI) 1.292–3.101; P = 0.002), comorbid diseases including dementia (OR 3.123, 95% CI 1.833–5.321; P<0.001), and other psychological disorder (OR 2.084, 95% CI 1.178–3.687; P = 0.012), initial symptom of skin rash (OR 15.943, 95% CI 1.613–157.535; P = 0.018), and initial laboratory abnormalities including hemoglobin <10 g/dL (OR 2.156, 95% CI 1.161–4.003; P = 0.015) and C-reactive protein (CRP) ≥1.0 mg/dL (OR 1.588, 95% CI 1.061–2.377; P = 0.025) were significant risk factors for delayed viral clearance. On the other hand, male sex (OR 0.752, 95% CI 0.567–0.997; P = 0.047), hypertension (OR 0.704, 95% CI 0.519–0.953; P = 0.023), and initial symptom of headache (OR 0.673, 95% CI 0.485–0.932; P = 0.017) were significant protective factors for delayed viral clearance (Figure 2A and Table S7). In particular, when limited to the mild COVID-19 group classified as no activity limitations in the outcome parameters, older age, dementia, initial symptoms of skin rash and headache, and initial hemoglobin <10 g/dL showed significant differences (Figure 2B, Table S8).Several factors related to the nervous system were identified as important risk factors for delayed viral clearance. Previous studies have shown that the coronavirus can initially invade the peripheral nerves and enter the central nervous system through a synapse path.8 It is hypothesized that the ability of the immune system to find and remove viruses that have penetrated the nervous system is important for virus clearance. Male sex, hypertension and elevated CRP did not show a significant difference when analyzed only mild patients, and these may be indicators associated with severity rather than a direct effect on viral clearance.Anti-inflammatory drugs such as hydroxychloroquine and systemic steroid were shown to be risk factors for mortality and delayed viral clearance (Table S6 and S8). These medications were used more often when the hospitalization period was extended or when showing poor prognosis factors. Notwithstanding these, our results suggest that anti-inflammatory drugs need to be used with proper consideration of appropriate indications.On May 9, 2020, there were 6,859 patients with PCR-confirmed COVID-19 in Daegu. This data excluded asymptomatic or minimal symptomatic patients who did not require hospitalization. However, our study covered almost all hospitalized patients diagnosed with COVID-19 in Daegu from February to May ,therefore, selection bias is minimized.9 In Korea, most hospitals decided to terminate the quarantine by repeating PCR every week. In addition, the Korea Centers for Disease Control & Prevention (KCDC) thoroughly managed the criteria for quarantine termination and PCR results. Through this, in our study, we were able to perform a large-scale study to confirm the risk factors for delayed viral clearance.In summary, despite the positivity of differences depending on phenotypes, the prevalence of asthma was not significantly different in patients with COVID-19, and asthma did not affect the outcomes of COVID-19. Age, dementia, and initial presentations of headache, skin rash, and anemia were independently associated with viral clearance.