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Original Article
Risk Assessment Program of Highly Pathogenic Avian Influenza with Deep Learning Algorithm
Hachung Yoon, Ah-Reum Jang, Chungsik Jung, Hunseok Ko, Kwang-Nyeong Lee, Eunesub Lee
Osong Public Health Res Perspect. 2020;11(4):239-244.   Published online August 31, 2020
DOI: https://doi.org/10.24171/j.phrp.2020.11.4.13
  • 2,905 View
  • 49 Download
  • 1 Citations
AbstractAbstract PDFSupplementary Material
Objectives

This study presents the development and validation of a risk assessment program of highly pathogenic avian influenza (HPAI). This program was developed by the Korean government (Animal and Plant Quarantine Agency) and a private corporation (Korea Telecom, KT), using a national database (Korean animal health integrated system, KAHIS).

Methods

Our risk assessment program was developed using the multilayer perceptron method using R Language. HPAI outbreaks on 544 poultry farms (307 with H5N6, and 237 with H5N8) that had available visit records of livestock-related vehicles amongst the 812 HPAI outbreaks that were confirmed between January 2014 and June 2017 were involved in this study.

Results

After 140,000 iterations without drop-out, a model with 3 hidden layers and 10 nodes per layer, were selected. The activation function of the model was hyperbolic tangent. Precision and recall of the test gave F1 measures of 0.41, 0.68 and 0.51, respectively, at validation. The predicted risk values were higher for the “outbreak” (average ± SD, 0.20 ± 0.31) than “non-outbreak” (0.18 ± 0.30) farms (p < 0.001).

Conclusion

The risk assessment model developed was employed during the epidemics of 2016/2017 (pilot version) and 2017/2018 (complementary version). This risk assessment model enhanced risk management activities by enabling preemptive control measures to prevent the spread of diseases.

Editorial
The Impact of Social Distancing on the Transmission of Influenza Virus, South Korea, 2020
Young June Choe, Jong-Koo Lee
Osong Public Health Res Perspect. 2020;11(3):91-92.   Published online June 1, 2020
DOI: https://doi.org/10.24171/j.phrp.2020.11.3.07
  • 4,846 View
  • 235 Download
  • 14 Citations
PDF
Original Articles
Chemical Constituents of Essential Oils Possessing Anti-Influenza A/WS/33 Virus Activity
Hwa-Jung Choi
Osong Public Health Res Perspect. 2018;9(6):348-353.   Published online December 31, 2018
DOI: https://doi.org/10.24171/j.phrp.2018.9.6.09
  • 16,688 View
  • 241 Download
  • 24 Citations
AbstractAbstract PDF
Objectives

This study was conducted to determine whether essential oils had anti-influenza A/WS/33 virus activity and whether there were specific compounds associated with this activity.

Methods

There were 63 essential oils evaluated for anti-influenza (A/WS/33 virus) activity using a cytopathic effect reduction method. The chemical composition of the anti-influenza essential oils was phytochemically analyzed by gas chromatography-mass spectrometry.

Results

The antiviral assays demonstrated that 11 of the 62 essential oils (100 μg/mL) possessed anti-influenza activity, reducing visible cytopathic effects of influenza A/WS/33 virus activity by > 30%. Furthermore, marjoram, clary sage and anise oils exhibited anti-influenza A/WS/33 virus activity of > 52.8%. However, oseltamivir (the anti-influenza A and B drug), showed cytotoxicity at the same concentration (100 μg/mL) as the essential oils. The chemical composition detected by GC–MS analysis, differed amongst the 3 most potent anti-viral essential oils (marjoram, clary sage and anise oils) except for linalool, which was detected in all 3 essential oils.

Conclusion

This study demonstrated anti-influenza activity in 11 essential oils tested, with marjoram, clary sage and anise essential oils being the most effective at reducing visible cytopathic effects of the A/WS/33 virus. All 3 oils contained linalool, suggesting that this may have anti-influenza activity. Further investigation is needed to characterize the antiviral activity of linalool against influenza A/WS/33 virus.

H5N8 Highly Pathogenic Avian Influenza in the Republic of Korea: Epidemiology During the First Wave, from January Through July 2014
Hachung Yoon, Oun-Kyong Moon, Wooseog Jeong, Jida Choi, Young-Myong Kang, Hyo-Young Ahn, Jee-Hye Kim, Dae-Sung Yoo, Young-Jin Kwon, Woo-Seok Chang, Myeong-Soo Kim, Do-Soon Kim, Yong-Sang Kim, Yi-Seok Joo
Osong Public Health Res Perspect. 2015;6(2):106-111.   Published online April 30, 2015
DOI: https://doi.org/10.1016/j.phrp.2015.01.005
  • 1,518 View
  • 24 Download
  • 11 Citations
AbstractAbstract PDF
Objectives
This study describes the outbreaks of H5N8 highly pathogenic avian influenza (HPAI) in Korea during the first wave, from January 16, 2014 through July 25, 2014. Its purpose is to provide a better understanding of the epidemiology of H5N8 HPAI.
Methods
Information on the outbreak farms and HPAI positive wild birds was provided by the Animal and Plant Quarantine Agency. The epidemiological investigation sheets for the outbreak farms were examined.
Results
During the 7-month outbreak period (January–July 2014), H5N8 HPAI was confirmed in 212 poultry farms, 38 specimens from wild birds (stools, birds found dead or captured). Ducks were the most frequently infected poultry species (159 outbreak farms, 75.0%), and poultry in 67 (31.6%) outbreak farms was asymptomatic.
Conclusion
As in the previous four H5N1 epidemics of HPAI that occurred in Korea, this epidemic of H5N8 proved to be associated with migratory birds. Poultry farms in Korea can hardly be free from the risk of HPAI introduced via migratory birds. The best way to overcome this geographical factor is to reinforce biosecurity to prevent exposure of farms, related people, and poultry to the pathogen.
Assessment of Intensive Vaccination and Antiviral Treatment in 2009 Influenza Pandemic in Korea
Chaeshin Chu, Sunmi Lee
Osong Public Health Res Perspect. 2015;6(1):47-51.   Published online February 28, 2015
DOI: https://doi.org/10.1016/j.phrp.2014.11.007
  • 1,339 View
  • 15 Download
  • 2 Citations
AbstractAbstract PDF
Objectives
We characterized and assessed public health measures, including intensive vaccination and antiviral treatment, implemented during the 2009 influenza pandemic in the Republic of Korea.
Methods
A mathematical model for the 2009 influenza pandemic is formulated. The transmission rate, the vaccination rate, the antiviral treatment rate, and the hospitalized rate are estimated using the least-squares method for the 2009 data of the incidence curves of the infected, vaccinated, treated, and hospitalized.
Results
The cumulative number of infected cases has reduced significantly following the implementation of the intensive vaccination and antiviral treatment. In particular, the intensive vaccination was the most critical factor that prevented severe outbreak.
Conclusion
We have found that the total infected proportion would increase by approximately six times under the half of vaccination rates.
Assessment of the Intensive Countermeasures in the 2009 Pandemic Influenza in Korea
Jin Hyuk Choi, Yunhwan Kim, Seoyun Choe, Sunmi Lee
Osong Public Health Res Perspect. 2014;5(2):101-107.   Published online April 30, 2014
DOI: https://doi.org/10.1016/j.phrp.2014.03.003
  • 1,421 View
  • 16 Download
AbstractAbstract PDF
Objectives
It is critical to implement effective multiple countermeasures to mitigate or retain the spread of pandemic influenza. We propose a mathematical pandemic influenza model to assess the effectiveness of multiple countermeasures implemented in 2009.
Methods
Age-specific parameters, including the transmission rate, the proportion of asymptomatic individuals, the vaccination rate, the social distancing rate, and the antiviral treatment rate are estimated using the least-square method calibrated to the incidence data.
Results
The multiple interventions (intensive vaccination, social distancing, antivrial treatment) were successfully implemented resulting in the dramatic reduction in the total number of incidence.
Conclusion
The model output is sensitive to age-specific parameters and this leads to the fact that a more elaborate age group model should be developed and extensive further studies must be followed.
Development of a Specific and Rapid Diagnostic Method for Detecting Influenza A (H1N1) pdm09 Virus Infection Using Immunochromatographic Assay
Mi Jung Ji, Byung Ki Cho, Young Shik Cho, Young Jin Choi, Donghyok Kwon, Kyeongcheol Shin, Joo-Yeon Lee, Chun Kang, Byoung Su Yoon
Osong Public Health Res Perspect. 2013;4(6):342-346.   Published online December 31, 2013
DOI: https://doi.org/10.1016/j.phrp.2013.10.006
  • 1,427 View
  • 13 Download
  • 2 Citations
AbstractAbstract PDF
Objectives
The aim of this study was to develop an immunochromatographic assay (ICA) for the detection of influenza A (H1N1) pdm09 virus infection. Materials and methods Several monoclonal antibodies against influenza A (H1N1) pdm09 virus were generated and an ICA (pdm09-ICA) was developed for the rapid and specific detection of influenza A (H1N1) pdm09 virus infection. The specificity and sensitivity of the developed assay were compared with that of hemagglutination assay and real-time reverse-transcription polymerase chain reaction (rRT-PCR).
Results
The detection limit was estimated to be 1/2 (8) hemagglutinating unit; the sensitivity and specificity rates of pdm09-ICA were 75.86% (110/145) and 100% (43/43), respectively, compared with rRT-PCR. The cross-reactivity for 20 influenza viruses, including seasonal H1N1 viruses, was found to be negative except for the H1N1 virus (A/Swine/Korea/GC0503/2005).
Conclusion
These results indicate that the proposed method can be easily used for rapid and specific detection of the pdm09 infection. The assay developed in this study would be a useful tool for distinguishing the pdm09 infection from seasonal influenza A and B infections.
Generation and Characterization of Recombinant Influenza A(H1N1) Viruses Resistant to Neuraminidase Inhibitors
WooYoung Choi, Jin-Young Shin, Hwan-Eui Jeong, Mi-Jin Jeong, Su-Jin Kim, Joo-Yeon Lee, Chun Kang
Osong Public Health Res Perspect. 2013;4(6):323-328.   Published online December 31, 2013
DOI: https://doi.org/10.1016/j.phrp.2013.10.005
  • 1,416 View
  • 15 Download
  • 6 Citations
AbstractAbstract PDF
Objectives
To examine the effect of neuraminidase (NA) mutations on the NA inhibitor (NAI) resistance phenotype, the recombinant influenza A/Chungbuk/4448/2008(H1N1) virus isolated in South Korea during the 2008–2009 season was generated by reverse genetics.
Methods
Site-directed mutagenesis was introduced on the NA gene of A/Chungbuk/4448/2008(H1N1) virus, and a total of 23 single, double, and triple mutants were generated. Resistance phenotype of these recombinant viruses was determined by NA-inhibition (NAI) assays based on a fluorometric method using two NAIs (oseltamivir and zanamivir).
Results
NA-inhibition assays showed that all the single and double mutants containing the Y275 except the single Y275-E119V mutant conferred important levels of resistance to oseltamivir, whereas all the single, double, and triple mutants containing the E119V mutation were associated with the resistance to zanamivir.
Conclusion
Considering the effect of mutations in NA gene on the resistance to NAIs, it is important to monitor the possible emergence and dissemination of multidrug-resistant variants in the human population due to amino acid changes at NA gene as well as to develop novel NAIs.
Brief Report
Public Health Crisis Preparedness and Response in Korea
Hye-Young Lee, Mi-Na Oh, Yong-Shik Park, Chaeshin Chu, Tae-Jong Son
Osong Public Health Res Perspect. 2013;4(5):278-284.   Published online October 31, 2013
DOI: https://doi.org/10.1016/j.phrp.2013.09.008
  • 1,511 View
  • 17 Download
  • 20 Citations
AbstractAbstract PDF
Since the 2006 Pandemic Influenza Preparedness and Response Plan according to the World Health Organization’s recommendation, the Republic of Korea has prepared and periodically evaluated the plan to respond to various public health crises including pandemic influenza. Korea has stockpiled 13,000,000 doses of antiviral drugs covering 26% of the Korean population and runs 519 isolated beds in 16 medical institutions. The division of public health crisis response in Korea Centers for Disease Control and Prevention are in charge of responding to public health crises caused by emerging infectious diseases including severe acute respiratory syndrome, avian influenza human infection, and pandemic influenza. Its job description includes preparing for emerging infectious diseases, securing medical resources during a crisis, activating the emergency response during the crisis, and fortification of capabilities of public health personnel. It could evolve into a comprehensive national agency to deal with public health crisis based on the experience of previous national emerging infectious diseases.
Original Article
Evaluation of the Effectiveness of Pandemic Influenza A(H1N1) 2009 Vaccine Based on an Outbreak Investigation During the 2010–2011 Season in Korean Military Camps
Kyo-Hyun Kim, Yoon Gu Choi, Hyun-Bae Yoon, Jung-Woo Lee, Hyun-Wook Kim, Chaeshin Chu, Young-Joon Park
Osong Public Health Res Perspect. 2013;4(4):209-214.   Published online August 31, 2013
DOI: https://doi.org/10.1016/j.phrp.2013.07.002
  • 1,449 View
  • 15 Download
  • 2 Citations
AbstractAbstract PDF
Objectives
In December 2010, there was an outbreak of acute febrile respiratory disease in many Korean military camps that were not geographically related. A laboratory analysis confirmed a number of these cases to be infected by the pandemic influenza A(H1N1) 2009 (H1N1pdm09) virus. Because mass vaccination against H1N1pdm09 was implemented at the infected military camps eleven months ago, the outbreak areas in which both vaccinated and nonvaccinated individuals were well mixed, gave us an opportunity to evaluate the effectiveness of H1N1pdm09 vaccine through a retrospective cohort study design.
Methods
A self-administered questionnaire was distributed to the three military camps in which the outbreak occurred for case detection, determination of vaccination status, and characterization of other risk factors. The overall response rate was 86.8% (395/455). Case was defined as fever (≥38 °C) with cough or sore throat, influenza-like illness (ILI), and vaccination status verified by vaccination registry. Crude vaccine effectiveness (VE) was calculated as “1 − attack rate in vaccinated individuals/attack rate in nonvaccinated individuals”, and adjusted VE was calculated as “1 – odds ratio” using logistic regression adjusted for potential confounding factor. A number of ILI definitions were used to test the robustness of the result.
Results
The attack rate of ILI was 12.8% in register-verified vaccinated individuals and 24.0% in nonvaccinated individuals. The crude VE was thus calculated to be 46.8% [95% confidence interval (CI): 14.5–66.9]. The adjusted VE rate was 46.8% (95% CI: –9.4 to 74.1). Various combinations of ILI symptoms also showed similar VE rates.
Conclusion
We evaluated the effectiveness of H1N1pdm09 vaccine in the 2010–2011 season in an outbreak setting. Although the result was not sensitive to any analytical method used and ILI case definition, the magnitude of effectiveness was lower than estimated in the 2009–2010 season.
Articleses
Sensitivity Analysis of the Parameters of Korea’s Pandemic Influenza Preparedness Plan
Chaeshin Chu, Junehawk Lee, Dong Hoon Choi, Seung-Ki Youn, Jong-Koo Lee
Osong Public Health Res Perspect. 2011;2(3):210-215.   Published online December 31, 2011
DOI: https://doi.org/10.1016/j.phrp.2011.11.048
  • 1,499 View
  • 16 Download
  • 10 Citations
AbstractAbstract PDF
Objectives
Our aim was to evaluate Korea’s Pandemic Influenza Preparedness Plan.
Methods
We conducted a sensitivity analysis on the expected number of outpatients and hospital bed occupancy, with 1,000,000 parameter combinations, in a situation of pandemic influenza, using the mathematical simulation program InfluSim.
Results
Given the available resources in Korea, antiviral treatment and social distancing must be combined to reduce the number of outpatients and hospitalizations sufficiently; any single intervention is not enough. The antiviral stockpile of 4–6% is sufficient for the expected eligible number of cases to be treated. However, the eligible number assumed (30% for severe cases and 26% for extremely severe cases) is very low compared to the corresponding number in European countries, where up to 90% of the population are assumed to be eligible for antiviral treatment.
Conclusions
A combination of antiviral treatment and social distancing can mitigate a pandemic, but will only bring it under control for the most optimistic parameter combinations.
The Emergence of Oseltamivir-Resistant Seasonal Influenza A (H1N1) Virus in Korea During the 2008-2009 Season
Woo-Young Choi, Inseok Yang, Sujin Kim, Namjoo Lee, Meehwa Kwon, Joo-Yeon Lee, Chun Kang
Osong Public Health Res Perspect. 2011;2(3):178-185.   Published online December 31, 2011
DOI: https://doi.org/10.1016/j.phrp.2011.11.042
  • 1,406 View
  • 13 Download
  • 10 Citations
AbstractAbstract PDF
Objectives
To monitor antiviral drug resistance among seasonal influenza viruses isolated in Korea during the 2008-2009 influenza season, we examined influenza isolates collected through Korea Influenza Surveillance Scheme for antiviral drug susceptibility.
Methods
For genetic analysis of antiviral drug resistance, the matrix (M2) and neuraminidase (NA) genes of each isolate were amplified by reverse transcription-polymerase chain reaction and followed by nucleotide sequencing. For phylogenetic analyses, the sequences of hemagglutinin (HA) and NA genes of each isolate were aligned using multiple alignment program. For phenotypic analysis of antiviral drug resistance, drug susceptibilities against M2 inhibitor (amantadine) and NA inhibitors (oseltavimir and zanamivir) were determined by virus yield reduction assay and fluorometric NA inhibition assay, respectively.
Results
In Korea, the resistant influenza viruses against oseltamivir were first detected in sealsonal influenza A(H1N1) viruses on Week 48 of 2008. Since then, the number of oseltamivir-resistant A(H1N1) viruses was continuously increased and had reached the highest peak on Week 52 of 2008. 533 (99.8%) of 534 A(H1N1) viruses were resistant to oseltamivir and all of them harbored the H275Y mutation in the NA gene during the 2008-2009 season. The oseltamivir resistance identified by sequencing was confirmed by NA inhibition assay. Genetic analysis based on HA gene of the resistant A(H1N1) viruses revealed that the viruses were identified as A/Brisbane/10/2007-like strain which was vaccine strain for the 2008-2009 season.
Conclusions
The oseltamivir-resistant A(H1N1) viruses were first emerged in Europe in November 2007 and then circulated globally. One year later, the oseltamivir-resistant A(H1N1) viruses were first detected in Korea in November 2008 and continued circulating until the Week 7 of 2009 during the 2008-2009 season. Considering the pandemic preparedness, it should be continued to monitor the emergence and the characterization of antiviral drug resistant influenza viruses.
Original Articles
Modeling for Estimating Influenza Patients from ILI Surveillance Data in Korea
Joo-Sun Lee, Sun-Hee Park, Jin-Woong Moon, Jacob Lee, Yong Gyu Park, Yong Kyun Roh
Osong Public Health Res Perspect. 2011;2(2):89-93.   Published online June 30, 2011
DOI: https://doi.org/10.1016/j.phrp.2011.08.001
  • 1,555 View
  • 17 Download
  • 7 Citations
AbstractAbstract PDF
Objective Prediction of influenza incidence among outpatients from an influenza surveillance system is important for public influenza strategy.
Methods
We developed two influenza prediction models through influenza surveillance data of the Korea Centers for Disease Control and Prevention (each year, each province and metropolitan city; total reported patients with influenza-like illness stratified by age) for 6 years from 2005 to 2010 and disease-specific data (influenza code J09-J11, monthly number of influenza patients, total number of outpatients and hospital visits) from the Health Insurance Review and Assessment service.
Results
Incidence of influenza in each area, year, and month was estimated from our prediction models, which were validated by simulation processes. For example, in November 2009, Seoul and Joenbuk, the final number of influenza patients calculated by prediction models A and B underestimated actual reported cases by 64 and 833 patients, respectively, in Seoul and 6 and 9 patients, respectively, in Joenbuk. R-square demonstrated that prediction model A was more suitable than model B for estimating the number of influenza patients.
Conclusion
Our prediction models from the influenza surveillance system could estimate the nationwide incidence of influenza. This prediction will provide important basic data for national quarantine activities and distributing medical resources in future pandemics.
Pathogenesis and Chronologic Localization of the Human Influenza A (H1N1) Virus in Cotton Rats
Donghyok Kwon, Kyeongcheol Shin, Jin-Young Shin, Joo-Yeon Lee, Yooncheol Ha, Nam-Joo Lee, Hee-Bok Oh, Chanhee Chae, Chun Kang
Osong Public Health Res Perspect. 2011;2(1):15-22.   Published online June 30, 2011
DOI: https://doi.org/10.1016/j.phrp.2011.04.005
  • 1,425 View
  • 22 Download
  • 7 Citations
AbstractAbstract PDF
Objectives
We aimed to evaluate the pathogenesis and chronologic localization of human influenza A (H1N1) virus in experimentally infected cotton rats.
Methods
The animals were intranasally inoculated with 107 plaque-forming units of A/Solomon Islands/3/2006 (H1N1) influenza virus and evaluated for pathogenicity for a period of 28 days. Virus replication kinetics and pathological properties were assessed chronologically. Acute antiviral responses were evaluated by mean of real-time polymerase chain reaction.
Results
Cotton rats infected with A/Solomon Islands/3/2006 virus lost weight until 6 days post-inoculation (DPI) and showed decreased activity until 3 DPI. At necropsy, focal areas of redness and consolidation of lungs were evident at 1, 2, and 3 DPI. Lung histopathology showed moderate to severe interstitial pneumonia, alveolitis and bronchiolitis. Influenza A specific viral protein was detected in bronchiolar epithelial cells, alveolar septa and pneumocytes. Influenza viruses were recovered from the lungs during the early period of infection and the titer peaked at 1 DPI. Viral proteins were detected from 4 hours to 6 hours DPI. These trends correlate with the up-regulation of mRNA expression of the IFN-α, Mx1, and Mx2 genes that play critical roles in the anti-influenza response at the early stage of infection.
Conclusion
Our results provide evidence that supports the use of cotton rats for the study of influenza virus pathogenesis and the immune response.

PHRP : Osong Public Health and Research Perspectives