scholarly journals Mortality and Pathology Associated with Highly Pathogenic Avian Influenza H5N1 Outbreaks in Commercial Poultry Production Systems in Nigeria

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Olatunde Babatunde Akanbi ◽  
Victor Olusegun Taiwo
Keyword(s):  
Avian Influenza ◽  
Production Systems ◽  
Highly Pathogenic Avian Influenza ◽  
Poultry Production ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Hpai H5n1 ◽  
Commercial Poultry ◽  
The One ◽  
Influenza H5n1

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.

The space–time clustering of highly pathogenic avian influenza (HPAI) H5N1 outbreaks in Bangladesh

2010 ◽  
Vol 138 (6) ◽  
pp. 843-852 ◽  
Author(s):  
S. S. U. AHMED ◽  
A. K. ERSBØLL ◽  
P. K. BISWAS ◽  
J. P. CHRISTENSEN
Keyword(s):  
Avian Influenza ◽  
Production Systems ◽  
Highly Pathogenic Avian Influenza ◽  
Space Time ◽  
Scan Statistics ◽  
Northwestern Part ◽  
Spatial And Temporal Patterns ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Hpai H5n1

SUMMARYBangladesh faced two epidemic waves of highly pathogenic avian influenza (HPAI) H5N1 in two consecutive years. The peaks of the waves were observed in February–July 2007 and January–April 2008, respectively. We examined the spatial and temporal patterns of the 293 outbreaks in 143 subdistricts in 2007 and 2008. Global clustering assessed by K-function was seen at distances 150–300 km between subdistricts. Significant local clusters were detected by space–time scan statistics. In both waves, significant primary clusters of HPAI outbreaks were identified in the central part of the country dominated by commercial production systems and in the northwestern part primarily in backyard production systems. Secondary clusters varied from the northwestern part in 2007 and the southern part in 2008. The findings are highly relevant for the successful planning and implementation of control, prevention and surveillance strategies by highlighting areas where detailed investigations should be initiated.

scholarly journals Regional Transmission and Reassortment of 2.3.4.4b Highly Pathogenic Avian Influenza (HPAI) Viruses in Bulgarian Poultry 2017/18

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 605 ◽  
Author(s):  
Divya Venkatesh ◽  
Adam Brouwer ◽  
Gabriela Goujgoulova ◽  
Richard Ellis ◽  
James Seekings ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Matrix Protein ◽  
Production Systems ◽  
Highly Pathogenic Avian Influenza ◽  
Wild Birds ◽  
Poultry Production ◽  
Ancestral Reconstruction ◽  
Domestic Ducks ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza

Between 2017 and 2018, several farms across Bulgaria reported outbreaks of H5 highly-pathogenic avian influenza (HPAI) viruses. In this study we used genomic and traditional epidemiological analyses to trace the origin and subsequent spread of these outbreaks within Bulgaria. Both methods indicate two separate incursions, one restricted to the northeastern region of Dobrich, and another largely restricted to Central and Eastern Bulgaria including places such as Plovdiv, Sliven and Stara Zagora, as well as one virus from the Western region of Vidin. Both outbreaks likely originate from different European 2.3.4.4b virus ancestors circulating in 2017. The viruses were likely introduced by wild birds or poultry trade links in 2017 and have continued to circulate, but due to lack of contemporaneous sampling and sequences from wild bird viruses in Bulgaria, the precise route and timing of introduction cannot be determined. Analysis of whole genomes indicates a complete lack of reassortment in all segments but the matrix protein gene (MP), which presents as multiple smaller clusters associated with different European 2.3.4.4b viruses. Ancestral reconstruction of host states of the hemagglutinin (HA) gene of viruses involved in the outbreaks suggests that transmission is driven by domestic ducks into galliform poultry. Thus, according to present evidence, we suggest the surveillance of domestic ducks as they are an epidemiologically relevant species for subclinical infection. Monitoring the spread due to movement between farms within regions and links to poultry production systems in European countries can help to predict and prevent future outbreaks. The 2.3.4.4b lineage which caused the largest recorded poultry epidemic in Europe continues to circulate, and the risk of further transmission by wild birds during migration remains.

scholarly journals Molecular characterization and epidemiology of the highly pathogenic avian influenza H5N1 in Nigeria

2008 ◽  
Vol 137 (4) ◽  
pp. 456-463 ◽  
Author(s):  
F. O. FASINA ◽  
S. P. R. BISSCHOP ◽  
T. M. JOANNIS ◽  
L. H. LOMBIN ◽  
C. ABOLNIK
Keyword(s):  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
Influenza Viruses ◽  
Control Measures ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Hpai H5n1 ◽  
Monospecific Antisera ◽  
Influenza H5n1 ◽  
Live Bird

SUMMARYAvian influenza caused infection and spread throughout Nigeria in 2006. Carcass samples (lung, liver, spleen, heart, trachea and intestine) from the different regions of Nigeria were processed for virus isolation. Infective allantoic fluids were tested for avian influenza viruses (AIV) and Newcastle disease virus using monospecific antisera. Thirty-five isolates were generated and characterized molecularly using the haemagglutinin gene. The molecular analysis indicated that different sublineages of the highly pathogenic avian influenza (HPAI) H5N1 viruses spread throughout Nigeria. We compared the Nigerian isolates with others from Africa and results indicated close similarities between isolates from West Africa and Sudan. Some of the analysed viruses showed genetic drift, and the implications of these for future epidemiology and ecology of avian influenza in Africa require further evaluation. The spread of primary outbreaks was strongly linked to trade (legal and illegal), live bird markets, inappropriate disposal, and poorly implemented control measures. No strong correlation existed between wild birds and HPAI H5N1 in Nigeria.

scholarly journals Highly Pathogenic Avian Influenza Viruses at the Wild–Domestic Bird Interface in Europe: Future Directions for Research and Surveillance

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 212
Author(s):  
Josanne H. Verhagen ◽  
Ron A. M. Fouchier ◽  
Nicola Lewis
Keyword(s):  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Highly Pathogenic ◽  
Future Directions ◽  
Pathogenic Avian Influenza ◽  
Domestic Bird ◽  
Hpai H5n1 ◽  
Host Identification

Highly pathogenic avian influenza (HPAI) outbreaks in wild birds and poultry are no longer a rare phenomenon in Europe. In the past 15 years, HPAI outbreaks—in particular those caused by H5 viruses derived from the A/Goose/Guangdong/1/1996 lineage that emerged in southeast Asia in 1996—have been occuring with increasing frequency in Europe. Between 2005 and 2020, at least ten HPAI H5 incursions were identified in Europe resulting in mass mortalities among poultry and wild birds. Until 2009, the HPAI H5 virus outbreaks in Europe were caused by HPAI H5N1 clade 2.2 viruses, while from 2014 onwards HPAI H5 clade 2.3.4.4 viruses dominated outbreaks, with abundant genetic reassortments yielding subtypes H5N1, H5N2, H5N3, H5N4, H5N5, H5N6 and H5N8. The majority of HPAI H5 virus detections in wild and domestic birds within Europe coincide with southwest/westward fall migration and large local waterbird aggregations during wintering. In this review we provide an overview of HPAI H5 virus epidemiology, ecology and evolution at the interface between poultry and wild birds based on 15 years of avian influenza virus surveillance in Europe, and assess future directions for HPAI virus research and surveillance, including the integration of whole genome sequencing, host identification and avian ecology into risk-based surveillance and analyses.

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