In 2016, novel H5N6 highly pathogenic avian influenza virus emerged in Korea. During the outbreak, the virus caused the largest culling, especially in brown chicken lines. We determined the pathogenicity and transmissibility of the virus in 2 white chicken lines of the specific pathogen-free chickens, broilers and brown chicken line of Korean native chicken (KNC). A KNC had a longer virus shedding period and longer mean death time than others. Our study showed that this characteristic in the KNC might have contributed to a farm-to-farm transmission of the brown chicken farms.
Agriculture ; Animals ; Chickens ; Influenza in Birds ; Korea ; Virulence ; Virus Shedding

Viral shedding lasted 31 and 19 days from symptom onset in two patients with east respiratory syndrome coronavirus (MERS-CoV) pneumonia, respectively. Environmental real-time RT-PCR was weakly positive for bed guardrail and monitors. Even after cleaning the monitors with 70% alcohol-based disinfectant, RT-PCR was still weakly positive, and converted to negative only after wiping with diluted sodium chlorite. Further studies are required to clarify the appropriate methods to clean environments during and after treatment of patients with MERS-CoV infection.
Coronavirus Infections* ; Coronavirus* ; Humans ; Middle East* ; Pneumonia ; Sodium ; Virus Shedding*

Quail has been proposed to be an intermediate host of influenza A viruses. However, information on the susceptibility and pathogenicity of pandemic H1N1 2009 (pH1N1) and swine influenza viruses in quails is limited. In this study, the pathogenicity, virus shedding, and transmission characteristics of pH1N1, swine H1N1 (swH1N1), and avian H3N2 (dkH3N2) influenza viruses in quails was examined. Three groups of 15 quails were inoculated with each virus and evaluated for clinical signs, virus shedding and transmission, pathological changes, and serological responses. None of the 75 inoculated (n = 45), contact exposed (n = 15), or negative control (n = 15) quails developed any clinical signs. In contrast to the low virus shedding titers observed from the swH1N1-inoculated quails, birds inoculated with dkH3N2 and pH1N1 shed relatively high titers of virus predominantly from the respiratory tract until 5 and 7 DPI, respectively, that were rarely transmitted to the contact quails. Gross and histopathological lesions were observed in the respiratory and intestinal tracts of quail inoculated with either pH1N1 or dkH3N2, indicating that these viruses were more pathogenic than swH1N1. Sero-conversions were detected 7 DPI in two out of five pH1N1-inoculated quails, three out of five quails inoculated with swH1N1, and four out of five swH1N1-infected contact birds. Taken together, this study demonstrated that quails were more susceptible to infection with pH1N1 and dkH3N2 than swH1N1.
Birds ; Influenza A virus ; Influenza, Human ; Orthomyxoviridae ; Pandemics ; Quail ; Respiratory System ; Swine ; Virus Shedding ; Viruses

BACKGROUND: We compared vaccinia virus shedding from the vaccine inoculation site (vaccination lesion) and two sites of a dressing covering the vaccination site; the outer surface of the semipermeable dressing (outer surface) and the inner surface of the semipermeable dressing, that is, the surface of a folded gauze under the semipermeable membrane (gauze surface) MATERIAL AND METHODS: Subjects were recruited from the volunteers who participated in a clinical trial of the efficacy of a 1:10 dilution of Lancy-Vaxina? (Berna Biotech, Switzerland), and were seen every 2-3 days (days 6, 8, 10, 13, and 15 after smallpox vaccination) for scheduled dressing changes. Swab specimens were obtained from the vaccination lesion, the outer surface, and the gauze surface. Quantitative viral culture assays for these specimens were done. RESULTS: Vaccinia virus was recovered from 126 (81%) of the 156 vaccination lesion samples collected from the 40 participants. A high virus titer was recovered from the vaccination lesion (geometric mean titer (log10)=3.91 on day 8). Of the 39 swab samples obtained from the gauze surface of the gauze, 16 (41%) were positive for virus. An intermediate titer was recovered from the gauze surface (geometric mean titer (log10)=0.91 on day 8). Of the 133 swab samples obtained from the outer surface, only one (0.8%) was positive for vaccinia. No virus was recovered from the outer surface on day 8. CONCLUSION: Our findings suggest that the addition of a semipermeable dressing to the folded gauze further reduces viral shedding and therefore increases protection.
Bandages* ; Membranes ; Smallpox* ; Vaccination* ; Vaccinia virus* ; Vaccinia* ; Viral Load ; Virus Shedding ; Volunteers

BACKGROUND: We compared vaccinia virus shedding from the vaccine inoculation site (vaccination lesion) and two sites of a dressing covering the vaccination site; the outer surface of the semipermeable dressing (outer surface) and the inner surface of the semipermeable dressing, that is, the surface of a folded gauze under the semipermeable membrane (gauze surface) MATERIAL AND METHODS: Subjects were recruited from the volunteers who participated in a clinical trial of the efficacy of a 1:10 dilution of Lancy-Vaxina? (Berna Biotech, Switzerland), and were seen every 2-3 days (days 6, 8, 10, 13, and 15 after smallpox vaccination) for scheduled dressing changes. Swab specimens were obtained from the vaccination lesion, the outer surface, and the gauze surface. Quantitative viral culture assays for these specimens were done. RESULTS: Vaccinia virus was recovered from 126 (81%) of the 156 vaccination lesion samples collected from the 40 participants. A high virus titer was recovered from the vaccination lesion (geometric mean titer (log10)=3.91 on day 8). Of the 39 swab samples obtained from the gauze surface of the gauze, 16 (41%) were positive for virus. An intermediate titer was recovered from the gauze surface (geometric mean titer (log10)=0.91 on day 8). Of the 133 swab samples obtained from the outer surface, only one (0.8%) was positive for vaccinia. No virus was recovered from the outer surface on day 8. CONCLUSION: Our findings suggest that the addition of a semipermeable dressing to the folded gauze further reduces viral shedding and therefore increases protection.
Bandages* ; Membranes ; Smallpox* ; Vaccination* ; Vaccinia virus* ; Vaccinia* ; Viral Load ; Virus Shedding ; Volunteers

To prevent the spread of influenza among infants and adolescents attending kindergartens and schools, proper quarantining of those who are ill is necessary. In this study, the rapid antigen test (RAT) was performed in patients to investigate the factors affecting the duration of virus shedding. The study included pediatric patients who were diagnosed with influenza by RAT at Daedong Hospital between November 2016 and April 2019. We identified the influenza subtype, age, gender, fever duration, oseltamivir medications, and time gap between fever subsided and RAT examination through chart review. A total of 330 patients were examined at discharge. The average age for RAT positive and negative patients was 6.32 ± 4.26 years and 8.47 ± 4.54 years, respectively. The average duration of fever for the RAT positive patients was 3.84 ± 1.09 days, and for those who were RAT negative was 4.191 ± 1.39. The average number of doses oseltamivir for RAT positive and negative patients was 7.68 ± 1.57 and 8.72 ± 1.37, respectively. The RAT was performed 24 to 48 hours after fever subsided (TG 24–48H group). At this time, 60 patients were positive and the rate of positive expression was 55.56%. Of the TG 48–72H group, 36 patients (26.09%) were positive. Of the TG 72–96H group, 18 patients (21.43%) were positive. Age, fever duration, number of doses oseltamivir and time gap after fever subsided were the factors that influenced the duration of influenza virus shedding. These factors should be considered during the quarantining influenza patients.
Adolescent ; Animals ; Child ; Fever ; Humans ; Infant ; Influenza, Human ; Orthomyxoviridae ; Oseltamivir ; Pediatrics ; Rats ; Virus Shedding

BACKGROUND: We investigated factors associated with prolonged viral clearance of SARS-CoV-2 among non-severe adult patients in Osaka, Japan. A total of 706 laboratory-confirmed COVID-19 patients were enrolled in this longitudinal observational study between 29 January 2020 and 31 May 2020, across 62 hospitals and three non-hospital recuperation facilities. METHODS: Logistic regression analysis was performed to investigate the factors associated with prolonged (29 days: upper 25% in duration) viral clearance of SARS-CoV-2. Linear regression analysis was conducted to assess these factors 14 days after symptom onset. RESULTS: The median duration of viral clearance was 22 days from symptom onset. After adjustment for sex, age, symptoms, comorbidity, and location of recuperation, comorbidities were associated with prolonged duration: (OR, 1.77 [95% CI, 1.11-2.82]) for one, (OR, 2.47 [95% CI, 1.32-4.61]) for two or more comorbidities. Viral clearance 14 days after symptom onset was 3 days longer for one comorbidity and 4 days longer for two or more comorbidities compared to clearance when there was no comorbidity. CONCLUSION The presence of comorbidity was a robust factor associated with a longer duration of viral clearance, extending by 3 to 4 days compared to patients with no comorbidity.
Adult ; COVID-19 ; Humans ; Japan/epidemiology* ; RNA, Viral ; SARS-CoV-2 ; Virus Shedding

A Newcastle disease virus (NDV) isolate designated IBS002 was isolated from a commercial broiler farm in Malaysia. The virus was characterised as a virulent strain based on the multiple basic amino acid motif of the fusion (F) cleavage site 112RRRKGF117 and length of the C-terminus extension of the hemagglutinin-neuraminidase (HN) gene. Furthermore, IBS002 was classified as a velogenic NDV with mean death time (MDT) of 51.2 h and intracerebral pathogenicity index (ICPI) of 1.76. A genetic distance analysis based on the full-length F and HN genes showed that both velogenic viruses used in this study, genotype VII NDV isolate IBS002 and genotype VIII NDV isolate AF2240-I, had high genetic variations with genotype II LaSota vaccine. In this study, the protection efficacy of the recombinant genotype VII NDV inactivated vaccine was also evaluated when added to an existing commercial vaccination program against challenge with velogenic NDV IBS002 and NDV AF2240-I in commercial broilers. The results indicated that both LaSota and recombinant genotype VII vaccines offered full protection against challenge with AF2240-I. However, the LaSota vaccine only conferred partial protection against IBS002. In addition, significantly reduced viral shedding was observed in the recombinant genotype VII-vaccinated chickens compared to LaSota-vaccinated chickens.
Amino Acids, Basic ; Animals ; Chickens* ; Genetic Variation ; Genotype* ; Malaysia ; Newcastle disease virus* ; Newcastle Disease* ; Vaccination ; Vaccines* ; Virulence ; Virus Shedding

PURPOSE: The first aim of this study was to develop a novel inactivated porcine epidemic diarrhea virus (PEDV) vaccine using the recently isolated Korean PEDV QIAP1401 strain and to evaluate its protective efficacy in growing pigs. The second was to determine the optimum adjuvant formulation of the inactivated PEDV vaccine that induces protection against viral challenge. MATERIALS AND METHODS: To generate high titers of infectious PEDV, the QIAP1401 isolate was passaged in Vero cells. The experimental vaccines were prepared from a binary ethyleneimine-inactivated QIAP1401 strain passaged sequentially 70 times (QIAP1401-p70), formulated with four commercial adjuvants, and administered twice intramuscularly to growing pigs. Challenge studies using a virulent homologous strain of PEDV QIAP1401-p11, which was passaged 11 times after isolation, were performed to assess protection against disease progression and viral shedding during the 15-day observation period. The vaccine-induced antibody responses were measured in serum samples collected at predetermined time points by indirect enzyme-linked immunosorbent assay and virus neutralization test. RESULTS: The QIAP1401-p70 strain had 42 amino acid (aa) mutations, including a 25 aa deletion, and was selected as the inactivated PEDV vaccine candidate. Although none of the pigs that received the experimental vaccines were completely protected against subsequent viral challenge, they exhibited a significantly higher immune response than did non-vaccinated control pigs. Among the vaccine groups, the highest antibody responses were observed in the pigs that received an oil-based multiphasic water/oil/water (W/O/W) emulsion adjuvanted vaccine, which delayed the onset of clinical symptoms and viral shedding. CONCLUSION: A novel inactivated PEDV vaccine formulated with a W/O/W emulsion adjuvant was both immunogenic and protective against viral challenge.
Antibody Formation ; Disease Progression ; Enzyme-Linked Immunosorbent Assay ; Neutralization Tests ; Porcine epidemic diarrhea virus ; Swine ; Vaccines ; Vero Cells ; Virus Shedding

Foot-and-mouth disease (FMD) is an acute epidemic that spreads rapidly among cattle and pigs. In 2014, in Korea, despite enforced vaccination, the type O Southeast Asia (SEA) topotype viruses (Mya-98 lineage) infected mainly cattle and pigs simultaneously, thereby causing enormous damage. If a vaccine that is completely protective against this FMD virus is developed and used, it can become a very important preventive measure in Asia, which is where this type of virus mainly circulates. The SEA topotype has been steadily evolving and transforming into new variations since it became epidemic in Asia. Therefore, it became necessary to develop a new vaccine that could provide protection against the FMD virus strain that was responsible for the 2014–2015 outbreak in Korea. This study aimed to develop a vaccine that would provide complete protection against the SEA topotype FMD virus to control sporadic FMD outbreaks, which occur despite the enforcement of vaccination, and to completely prevent virus shedding, thereby preventing the virus from spreading. The vaccine candidate virus developed in this study showed low pathogenicity and can be distinguished from the wild-type FMD virus strain. The developed vaccine was able to protect mice from SEA and Middle East–South Asia topotype virus strains and induced high titers of antibodies against both virus strains in pigs, thereby confirming the sufficiency of its protective function. In particular, the results of the SEA topotype virus challenge test in pigs revealed that perfect immunity was created in the vaccinated pigs, without virus shedding and viremia.
Animals ; Antibodies ; Asia ; Asia, Southeastern ; Cattle ; Disease Outbreaks ; Foot-and-Mouth Disease ; Korea ; Mice ; Swine ; Vaccination ; Viremia ; Virulence ; Virus Shedding