• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.101-107
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• 2011

This study aimed to determine dose-response (DR) curve of avian influenza (AI) virus to predict the probability of illness or adverse health effects that may result from exposure to a pathogenic microorganism in a quantitative microbial risk assessment. To determine the parametric DR relationship of several strains of AI virus, 7 feeding trial data sets challenging humans (5 sets) and chickens (2 sets) for strains of H3N2 (4 sets), H5N1 (2 sets) and H1N1 (1 set) from the published literatures. Except for one data set (study with intra-tracheal inoculation for data set no. 6), all were obtained from the studies with intranasal inoculation. The data were analyzed using three types of DR model as the basis of heterogeneity in infectivity of AI strains in humans and chickens: exponential, beta-binomial and beta-Poisson. We fitted to the data using maximum likelihood estimation to get the parameter estimates of each model. The alpha and beta values of the beta-Poisson DR model ranged 0.06-0.19 and 1.7-48.8, respectively for H3N2 strain. Corresponding values for H5N1 ranged 0.464-0.563 and 97.3-99.4, respectively. For H1N1 the parameter values were 0.103 and 12.7, respectively. Using the exponential model, r (infectivity parameter) ranged from $1.6{\times}10^{-8}$ to $1.2{\times}10^{-5}$ for H3N2 and from $7.5{\times}10^{-3}$ to $4.0{\times}10^{-2}$ for H5N1, while the value was $1.6{\times}10^{-8}$ for H1N1. The beta-Poisson DR model provided the best fit to five of 7 data sets tested, and the estimated parameter values in betabinomial model were very close to those of beta-Poisson. Our study indicated that beta-binomial or beta-Poisson model could be the choice for DR modeling of AI, even though DR relationship varied depending on the virus strains studied, as indicated in prior studies. Further DR modeling should be conducted to quantify the differences among AI virus strains.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.173-181
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• 2011

Purpose : 2009 Pandemic influenza A (H1N1) virus was identified in March 2009 and subsequently caused worldwide outbreaks. We described the clinical and epidemiological characteristics of H1N1 influenza infection. Methods : We used retrospective medical chart reviews to collect data on the visiting patients from a single institute. H1N1 infection was confirmed in specimens with the use of a RT-PCR (real time reverse transcriptase polymerase chain reaction assay). Result : 6,836 patients had H1N1 RT-PCR test, and 2,781 were confirmed with H1N1 virus infection. 158 patients (5.7%) had hospital treatment and inpatients were significantly younger (5.4${\pm}$3.3 years) than outpatients (7.5${\pm}$3.9 years) among H1N1 virus confirmed patients. Oxygen, steroid, immunoglobulin, ventilator treatment was provided in a substantial proportion among pneumonia patients accompanying wheezy respiration. In addition more intensive care was needed in patients accompanying segmental, lobar, interstitial, mixed pneumonia and lung effusion (27.2%) than patients with bronchopneumonia (7.3%) among H1N1 virus infection confirmed patients. Seventy-one infants had oseltamivir treatment out of 83 infants under 1 year, and no significant side effects and complications were identified. Conclusion : In 2009 pandemic influenza A (H1N1), hospital treatment was needed in younger patients. Early intensive care was needed in pneumonia patients accompanying wheezy respiration, and patients accompanying segmental, lobar, interstitial, mixed pneumonia and lung effusion.

• Journal of Sensor Science and Technology
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• v.23 no.4
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• pp.278-283
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• 2014

In this study, we propose an immunosensor using zinc oxide nanorods (NRs) inside PDMS channel for detecting the influenza A virus subtype H7N9. ZnO with high isoelectric point (IEP, ~9.5) makes it suitable for immobilizing proteins with low IEP. In this proposed H7N9 immunosensor structure ZnO NRs were grown on the PDMS channel inner surface to immobilize H7N9 capture antibody. A sandwich enzyme-linked immunosorbent assay (ELISA) method with was used 3,3',5,5' tetramethylbenzidine (TMB) for detecting H7N9 influenza virus. The immunosensor was evaluated by amperometry at various H7N9 influenza antigen concentrations (1 pg/ml - 1 ng/ml). The redox peak voltage and current were measured by amperometry with ZnO NWs and without ZnO NWs inside PDMS channel. The measurement results of the H7N9 immunosensor showed that oxidation peak current of TMB at 0.25 V logarithmically increased from 2.3 to 3.8 uA as the H7N9 influenza antigen concentration changed from 1 pg/ml to 1 ng/ml. And then we demonstrated that ZnO NRs inside PDMS channel can improve the sensitivity of immunosensor to compare non-ZnO NRs inside PDMS channel.

• Korean Journal of Veterinary Service
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• v.42 no.3
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• pp.135-144
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• 2019

Low pathogenic avian influenza (LPAI; H9N2) and Newcastle disease (ND) are economically important poultry diseases in Korea. In this study, we investigated pathological features and virus distribution in the lymphoid tissues of chicks experimentally infected with H9N2 and/or ND virus. Six-weeks-old SPF chickens were divided into 4 groups, Control (C), H9N2 (E1), NDV (E2), and H9N2+NDV (E3). E1 group was challenged with 0.1 ml A/Kr/Ck/01310/01 (H9N2) $10^{5.6}$ $EID_{50}$ intranasally, E2 group was challenged with 0.5 ml KJW (NDV) $10^{5.0}{\sim}10^{6.0}$ $ELD_{50}$ intramuscularly, and E3 group was challenged with H9N2, followed 7 days later by NDV. In histopathological examination, E1 group showed depletion and necrosis in bursa of Fabricius, thymus, cecal tonsil, and spleen, whereas E2 and E3 groups were noted severe lymphocyte depletion and necrosis with destruction of lymphoid organs structures. In TUNEL assay, apoptotic bodies were detected in lymphoid organs of all experimental groups, which was most severe in E3 group. H9N2 and ND viruses were predominantly detected in cecal tonsil of E1, E2, and E3 groups by PCR and immunohistochemistry (ICH). In conclusion, co-infection of H9N2 with NDV caused severe pathologic lesions and apoptosis in lymphoid tissues compared to single infections.

• Journal of Life Science
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• v.9 no.3
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• pp.289-292
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• 1999

This study was performed to monitor the circulation of various influenza virus strains since influenza is one of the commonest respiratory disease in man, its causative virus has been the subjects of extensive research. The authors investigated the epidemics of influenza in Pusan in 1998. Influenza viruses have been isolated from patients with respiratory disease whose ages range from 1 to 68. Virus isolation from female was higher than male. The isolation of virus was mostly concentrated in December in 1998. The isolated virus showed strong cytopathic effect on MDCK cells and identified as influenza A/Sydney/05/97-like(H3N2) and influenza A/Beijing/262/95-like(H1N1). A negative staining of electron micrograph showed 130 nm with H1N1 in diameter, respectively.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.345-350
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• 2010

Various extracts from 30 medicinal plants were evaluated for their antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) and cytotoxicity in MDCK cell culture. The plant material (30 g) was extracted with methanol (300 mL) at room temperature for 24 h, after which the methanolic extracts were filtered, evaporated, and subsequently lyophilized. Evaluation of the potential antiviral activity was conducted by a viral replication inhibition test. Among these medicinal plants, Tussilago farfara, Brassica juncea, Prunus armeniaca, Astragalus membranaceus, Patrinia villosa, and Citrus unshiu showed marked antiviral activity against influenza virus A/H1N1 at concentrations ranging from 0.15625 mg/mL to 1.25 mg/mL, 0.3125 mg/mL to 10 mg/mL, 5 mg/mL to 10 mg/mL, 0.625 mg/mL to 10 mg/mL, 0.625 mg/mL to 10 mg/mL, and 0.3125 mg/mL to 5 mg/mL, respectively. The extracts of Tussilago farfara showed cytotoxicity at concentrations greater than 2.5 mg/mL, whereas the other five main extracts showed no cytotoxicity at concentrations of 10 mg/mL. Taken together, the present results indicated that methanolic extracts of the six main plants might be useful for the treatment of influenza virus H1N1.

• Journal of Animal Science and Technology
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• v.65 no.4
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• pp.838-855
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• 2023

The highly pathogenic avian influenza (HPAI) virus triggers infectious diseases, resulting in pulmonary damage and high mortality in domestic poultry worldwide. This study aimed to analyze miRNA expression profiles after infection with the HPAI H5N1 virus in resistant and susceptible lines of Ri chickens.For this purpose, resistant and susceptible lines of Vietnamese Ri chicken were used based on the A/G allele of Mx and BF2 genes. These genes are responsible for innate antiviral activity and were selected to determine differentially expressed (DE) miRNAs in HPAI-infected chicken lines using small RNA sequencing. A total of 44 miRNAs were DE after 3 days of infection with the H5N1 virus. Computational program analysis indicated the candidate target genes for DE miRNAs to possess significant functions related to cytokines, chemokines, MAPK signaling pathway, ErBb signaling pathway, and Wnt signaling pathway. Several DE miRNA-mRNA matches were suggested to play crucial roles in mediating immune functions against viral evasion. These results revealed the potential regulatory roles of miRNAs in the immune response of the two Ri chicken lines against HPAI H5N1 virus infection in the lungs.

• Journal of Veterinary Science
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• v.21 no.4
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• pp.56.1-56.13
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• 2020

Background: The live bird market (LBM) plays an important role in the dynamic evolution of the avian influenza H5N1 virus. Objectives: The main objective of this study was to monitor the genetic diversity of the H5N1 viruses in LBMs in Indonesia. Methods: Therefore, the disease surveillance was conducted in the area of Banten, West Java, Central Java, East Java, and Jakarta Province, Indonesia from 2014 to 2019. Subsequently, the genetic characterization of the H5N1 viruses was performed by sequencing all 8 segments of the viral genome. Results: As a result, the H5N1 viruses were detected in most of LBMs in both bird' cloacal and environmental samples, in which about 35% of all samples were positive for influenza A and, subsequently, about 52% of these samples were positive for H5 subtyping. Based on the genetic analyses of 14 viruses isolated from LBMs, genetic diversities of the H5N1 viruses were identified including clades 2.1.3 and 2.3.2 as typical predominant groups as well as reassortant viruses between these 2 clades. Conclusions: As a consequence, zoonotic transmission to humans in the market could be occurred from the exposure of infected birds and/or contaminated environments. Moreover, new virus variants could emerge from the LBM environment. Therefore, improving pandemic preparedness raised great concerns related to the zoonotic aspect of new influenza variants because of its high adaptivity and efficiency for human infection.

• Biomolecules & Therapeutics
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• v.22 no.2
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• pp.93-99
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• 2014

The interaction between viral HA (hemagglutinin) and oligosaccharide of the host plays an important role in the infection and transmission of avian and human flu viruses. Until now, this interaction has been classified by sialyl(${\alpha}2-3$) or sialyl(${\alpha}2-6$) linkage specificity of oligosaccharide moieties for avian or human virus, respectively. In the case of H5N1 and newly mutated flu viruses, classification based on the linkage type does not correlate with human infection and human-to-human transmission of these viruses. It is newly suggested that flu infection and transmission to humans require high affinity binding to the extended conformation with long length sialyl(${\alpha}2-6$)galactose containing oligosaccharides. On the other hand, the avian flu virus requires folded conformation with sialyl(${\alpha}2-3$) or short length sialyl(${\alpha}2-6$) containing trisaccharides. This suggests a potential future direction for the development of new species-specific antiviral drugs to prevent and treat pandemic flu.

• Korean Journal of Veterinary Service
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• v.38 no.1
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• pp.61-64
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• 2015

Highly pathogenic avian influenza (HPAI) occurred in the breeder duck farms in Jeonbuk of in Korea on January to February 2014. Clinically, the most ducks showed various signs from depression, dropped egg production and feed consumption to even, death. The most commonly gross changes were hepatomegaly, splenomegaly, petechial and ecchymotic hemorrhage on the liver surface, a white stripe on the cardiac muscle, multifocal hemorrhagic foci in pancreas, and severely hemorrhagic embryos. The most significant signs of H5N8 virus was supposed to specific on ducks. The viral antigen was mainly detected in the endothelium of blood vessels of various organs and tissues, peripheral nerves, and neuronal cells. Based on the above results, we identified that HPAI H5N8 induced systemic infection in the adult breeder ducks.