scholarly journals Dynamics of inter-farm transmission of highly pathogenic avian influenza H5N6 integrating vehicle movements and phylogenetic information

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dae-Sung Yoo ◽  
Byung chul Chun ◽  
Younjung Kim ◽  
Kwang-Nyeong Lee ◽  
Oun-Kyoung Moon

AbstractHighly pathogenic avian influenza (HPAI) in poultry holdings commonly spreads through animal trade, and poultry production and health-associated vehicle (PPHaV) movement. To effectively control the spread of disease, it is essential that the contact structure via those movements among farms is thoroughly explored. However, few attempts have been made to scrutinize PPHaV movement compared to poultry trade. Therefore, our study aimed to elucidate the role of PPHaV movement on HPAI transmission. We performed network analysis using PPHaV movement data based on a global positioning system, with phylogenetic information of the isolates during the 2016–2017 HPAI H5N6 epidemic in the Republic of Korea. Moreover, the contribution of PPHaV movement to the spread of HPAI was estimated by Bayesian modeling. The network analysis revealed that there was the relationship between phylogenetic clusters and the contact network via PPHaV movement. Furthermore, the similarity of farm poultry species and the shared integrators between inter-linked infected premises (IPs) were associated with ties within the same phylogenetic clusters. Additionally, PPHaV movement among phylogenetically clustered IPs was estimated to contribute to approximately 30% of HPAI H5N6 infections in IPs on average. This study provides insight into how HPAI spread via PPHaV movement and scientific basis for control strategies.

2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Dae-sung Yoo ◽  
Chun Byung Chul

Abstract Background Highly pathogenic avian influenza (HPAI), a zoonotic infectious disease, has been considered a severe threat to public health. The fundamental prevention and control strategy against HPAI includes minimizing the outbreaks of poultry holdings where the virus primarily spreads through animal trade and poultry production associated vehicle movement (PPVM). However, very few attempts have been made to elucidate the association between PPVM and HPAI transmission compared to studies on poultry trade. Therefore, our study aimed to elucidate the role of PPVM on HPAI transmission. Methods We performed network analysis using PPVM data based on a global positioning system (GPS), with phylogenetic information of the HPAI virus for reliable estimation. Moreover, the contribution of PPVM to HPAI infection was estimated by Bayesian inference. Results The network analysis revealed that the connection via PPVM between the same genetic group of infected premises (IPs) was more prevalent than that of different genotype IPs. Moreover, the similarity of farm poultry species and the overlapped integrators between inter-linked IPs was associated with potential transmission route formation. Additionally, the contribution of PPVM among phylogenetically clustered IPs was estimated to have 28.25% of HPAI infections in IPs on average. Conclusions HPAI control strategies including targeted movement restriction and standstill should be established against the HPAI transmission via PPVM. Key messages This is a solid and novel study depicting the need for combining epidemiological analysis with data regarding molecular epidemiology of pathogens.


Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1389 ◽  
Author(s):  
Sol Jeong ◽  
Dong-Hun Lee ◽  
Jung-Hoon Kwon ◽  
Yu-Jin Kim ◽  
Sun-Hak Lee ◽  
...  

In October 2020, a highly pathogenic avian influenza (HPAI) subtype H5N8 virus was identified from a fecal sample of a wild mandarin duck (Aix galericulata) in South Korea. We sequenced all eight genome segments of the virus, designated as A/Mandarin duck/Korea/K20-551-4/2020(H5N8), and conducted genetic characterization and comparative phylogenetic analysis to track its origin. Genome sequencing and phylogenetic analysis show that the hemagglutinin gene belongs to H5 clade 2.3.4.4 subgroup B. All genes share high levels of nucleotide identity with H5N8 HPAI viruses identified from Europe during early 2020. Enhanced active surveillance in wild and domestic birds is needed to monitor the introduction and spread of HPAI via wild birds and to inform the design of improved prevention and control strategies.


2021 ◽  
Author(s):  
Pierre Bessière ◽  
Thomas Figueroa ◽  
Amelia Coggon ◽  
Charlotte Foret-Lucas ◽  
Alexandre Houffschmitt ◽  
...  

Highly pathogenic avian influenza viruses (HPAIV) emerge from low pathogenic avian influenza viruses (LPAIV) through the introduction of basic amino acids at the hemagglutinin (HA) cleavage site. Following viral evolution, the newly formed HPAIV likely represents a minority variant within the index host, predominantly infected with the LPAIV precursor. Using reverse-genetics engineered H5N8 viruses differing solely at the HA cleavage, we tested the hypothesis that the interaction between the minority HPAIV and the majority LPAIV could modulate the risk of HPAIV emergence and that the nature of the interaction could depend on the host species. In chickens, we observed that the H5N8 LP increased H5N8 HP replication and pathogenesis. By contrast, the H5N8 LP antagonized H5N8 HP replication and pathogenesis in ducks. Ducks mounted a more potent antiviral innate immune response than chickens against the H5N8 LP , which correlated with H5N8 HP inhibition. These data provide experimental evidence that HPAIV may be more likely to emerge in chickens than in ducks and underscore the importance of within-host viral variants interactions in viral evolution. IMPORTANCE Highly pathogenic avian influenza viruses represent a threat to poultry production systems and to human health because of their impact on food security and because of their zoonotic potential. It is therefore crucial to better understand how these viruses emerge. Using a within-host competition model between highly and low pathogenic avian influenza viruses, we provide evidence that highly pathogenic avian influenza viruses could be more likely to emerge in chickens than in ducks. These results have important implications for highly pathogenic avian influenza virus emergence prevention and they underscore the importance of within-host viral variants interactions in virus evolution.


2008 ◽  
Vol 137 (2) ◽  
pp. 219-226 ◽  
Author(s):  
M. P. WARD ◽  
D. MAFTEI ◽  
C. APOSTU ◽  
A. SURU

SUMMARYThree different methods were used for estimating the basic reproductive number (R0) from data on 110 outbreaks of highly pathogenic avian influenza (HPAI) subtype H5N1 that occurred in village poultry in Romania, 12 May to 6 June 2006. We assumed a village-level infectious period of 7 days. The methods applied were GIS-based identification of nearest infectious neighbour (based on either Euclidean or road distance), the method of epidemic doubling time, and a susceptible–infectious (SI) modelling approach. In general, the estimated basic reproductive numbers were consistent: 2·14, 1·95, 2·68 and 2·21, respectively. Although the true basic reproductive number in this epidemic is unknown, results suggest that the use of a range of methods might be useful for characterizing epidemics of infectious diseases. Once the basic reproductive number has been estimated, better control strategies and targeted surveillance programmes can be designed.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Olatunde Babatunde Akanbi ◽  
Victor Olusegun Taiwo

Commercial layer-type, pullet, cockerel, and broiler chicken flocks infected with highly pathogenic avian influenza (HPAI) H5N1 in Nigeria between 2006 and 2008 were investigated for morbidity, mortality, and pathology. Of the one hundred and fifty-three (153) farms confirmed with HPAI infection, one hundred and twenty-seven (127) were layer-type farms, nine (9) were pullet and broiler farms each, and eight (8) were cockerel rearing farms. This study revealed the morbidity and mortality of a total of 939,620 commercial layer chickens, 16,421 pullets, 3,109 cockerels, and 6,433 broilers. Mortality rates were 11.11% in commercial layers, 26.84% in pullets, 45.51% in cockerels, and 73.92% in broilers in a total of eighteen (18) states and the Federal Capital Territory, Abuja. A total of 316 carcasses were examined of which 248 were commercial layer, 25 were pullet, 14 were cockerel, and 29 were broiler. Main clinical and pathologic findings were observed in the nervous, circulatory, respiratory, integumentary, musculoskeletal, hemopoietic, gastrointestinal, and reproductive systems and, occasionally, lesions were generally nonspecific and multisystemic. Lesions occurred more frequently, severely, and in most of the carcasses examined, irrespective of chicken type.


2010 ◽  
Vol 8 (61) ◽  
pp. 1079-1089 ◽  
Author(s):  
G. Fournié ◽  
F. J. Guitian ◽  
P. Mangtani ◽  
A. C. Ghani

Live bird markets (LBMs) act as a network ‘hub’ and potential reservoir of infection for domestic poultry. They may therefore be responsible for sustaining H5N1 highly pathogenic avian influenza (HPAI) virus circulation within the poultry sector, and thus a suitable target for implementing control strategies. We developed a stochastic transmission model to understand how market functioning impacts on the transmission dynamics. We then investigated the potential for rest days—periods during which markets are emptied and disinfected—to modulate the dynamics of H5N1 HPAI within the poultry sector using a stochastic meta-population model. Our results suggest that under plausible parameter scenarios, HPAI H5N1 could be sustained silently within LBMs with the time spent by poultry in markets and the frequency of introduction of new susceptible birds' dominant factors determining sustained silent spread. Compared with interventions applied in farms (i.e. stamping out, vaccination), our model shows that frequent rest days are an effective means to reduce HPAI transmission. Furthermore, our model predicts that full market closure would be only slightly more effective than rest days to reduce transmission. Strategies applied within markets could thus help to control transmission of the disease.


2016 ◽  
Vol 19 (1-2) ◽  
pp. 44-49 ◽  
Author(s):  
M Giasuddin ◽  
ME Haque ◽  
AHM Kamal ◽  
MR Islam ◽  
A Jahangir ◽  
...  

Bangladesh first experienced outbreaks of highly pathogenic avian influenza (HPAI) subtype H5N1 in poultry 2007 and by December 2012 a total of five hundred fifty six (556) outbreaks have been reported of which four hundred ninety nine (499) outbreaks occur in commercial poultry farm as against only fifty seven (57) in backyard poultry chicken. The virus appeared to be a deadly pathogen causing a total of six hundred eight (608) human cases with three hundred fifty nine (359) deaths in the world. In Bangladesh seven (7) human cases have been reported with a singular mortality of a child acquiring the infection from household poultry. There had been six epidemic waves of AI outbreaks in Bangladesh since March 2007 and other new waves seem to have started. From the six year’s incidence analysis it was found that higher number of outbreaks occurred in the month of February followed by March. The outbreak started from the middle to late winter and continued up to summer. The phylogenetic analysis of viruses isolated till 2010 revealed only one clade 2.2 virus circulating in Bangladesh. But from 2011 two new clades 2.3.2 and 2.3.4 viruses have been introduced. In 2012, it was observed that Clade 2.2 viruses that was in circulation since 2007 were replaced by 2.3.2.1 viruses. Extensive backyard poultry including a large number of ducks, dense human population, and economic dependence of poor people on poultry with low awareness about risk of infection, live bird trading and poor bio-security were critical factors in the spread of avian influenza infection that posses key challenge in rapid containment. Because of the complex situation in poultry production and marketing system, attempts to control this disease through stamping out and bio-security measures have apparently failed in Bangladesh.Bangladesh J. of Livestock Res. 19(1-2): 44-49, Jan-Dec 2012


2019 ◽  
Vol 15 (2) ◽  
pp. 9-22
Author(s):  
Wioleta Drobik-Czwarno ◽  
Anna Wolc ◽  
Kornelia Kucharska ◽  
Elżbieta Martyniuk

Highly pathogenic avian influenza (HPAI) poses a huge threat to poultry production and also introduces an epidemiological risk in the human population. Thus far, HPAI has been controlled mainly through widespread implementation of biosecurity, and in the case of an outbreak, liquidation of flocks and establishment of protection zones. Alternative strategies for combating HPAI include the use of vaccines, genetic modification, and genetic selection for increased general and specific immunity in birds. These kinds of strategies often require identification of the genes involved in the immune response to the pathogen. Many genes have been identified as potentially associated with differences in the response to HPAI between poultry species and between individuals. Thus far, the most attention has been focused on genes taking part in regulating the innate immune response, which is responsible for preventing infection and limiting the replication and spread of the virus. The most commonly mentioned candidates for layer chickens include interferon-stimulated genes (ISGs) and RIG-I-like receptors. Proteins encoded by genes of the BTLN family, defensins, and proteins involved in apoptosis have also been associated with differences in the response to HPAI. Recent years have seen an increasing number of studies on the genetic determinants of individual differences in the response to HPAI in chickens. Data from HPAI outbreaks in the US in the spring of 2015 and Mexico in the years 2012-2016 have enabled a more precise analysis of this problem. A number of genes have been identified as associated with the immune response, but their specific role in determining the survival of birds requires further study. Preliminary results indicate that genetic determinants of resistance to HPAI are highly complex and can vary depending on the virus strain and the genetic line of birds.


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