Occurrence Of Avian Influenza Research Articles

Risk factors for avian influenza in Danish poultry and wild birds during the epidemic from June 2020 to May 2021.

Exploring the risk factors of avian influenza (AI) occurrence helps us to monitor and control the disease. Since late 2020, the number of avian influenza outbreaks in domestic and wild birds has increased in most European countries, including Denmark. This study was conducted to identify potential risk factors for wild birds and poultry during the epidemic in 2020/2021 in Denmark. Using Danish AI surveillance data of actively surveyed poultry and passively surveyed wild birds from June 2020 to May 2021, we calculated geographical attributes for bird locations and assessed the potential risk factors of AI detections using logistic regression analyses. 4% of actively surveyed poultry and 39% of passively surveyed wild birds were detected with AI circulating or ongoing at the time. Of these, 10 and 99% tested positive for the H5/H7 AI subtypes, respectively. Our analyses did not find any statistically significant risk factors for actively surveyed poultry within the dataset. For passively surveyed wild birds, bird species belonging to the Anseriformes order had a higher risk of being AI virus positive than five other taxonomic bird orders, and Galliformes were of higher risk than two other taxonomic bird orders. Besides, every 1 km increase in the distance to wetlands was associated with a 5.18% decrease in the risk of being AI positive (OR (odds ratio) 0.95, 95% CI 0.91, 0.99), when all other variables were kept constant. Overall, bird orders and distance to wetlands were associated with the occurrence of AI. The findings may provide targets for surveillance strategies using limited resources and assist in risk-based surveillance during epidemics.

THE IMPACT OF AVIAN INFLUENZA ON THE POULTRY MARKET

The main goal of the study is an attempt to indicate the effects of the occurrence of avian influenza on the poultry market (production, gate price, export to third countries) in Poland in three seasons of this disease (2016/2017, 2019/2020, 2020/2021). In Poland, in the last few years there has been a fairly frequent occurrence of avian influenza in poultry flocks. The eradication of this disease is associated with huge costs to the state budget. Compensation is payable for the birds killed if biosecurity requirements were respected on the farm. Farms, although probably not all, whose operations are in a protection or surveillance zone also suffer losses. These losses are related to many veterinary constraints on kept stocks. Poultry farms must bear the costs associated with undertaking and searching for innovative activities aimed at preventing the penetration of this disease into the herd. Another consequence of the occurrence of this disease in poultry is the introduction of restrictions on imports from Poland by some non-EU countries

Insidensi dan Risiko Penularan Avian Influenza pada Peternakan Ayam Petelur di Kabupaten Pinrang

Avian Influenza (AI) is an infectious disease on poultry with a high mortality rate, caused by Avian Influenza type A viruses from the family Orthomyxoviridae. For the layer chicken, the negative impacts of AI are the decrease of egg production until the death. The aims of the study were to analyze disease’s case data, measure the spread of disease, describe the distribution of disease, and mapping the risk of AI occurrence. The data were collected from the records of Dinas Peternakan dan Perkebunan by conducting interviews using the structured questionnaires. The data were analysed by calculating the incidence rate and performing a geographic information system (GIS) for mapping. The results showed that the highest incidence rate among sub-districts for 3 years was in Mattiro Sompe sub-district of 2.015 cases per 10.000 animals-year, while the lowest incidence rate among 3 sub-districts for 3 years was in Duampanua, Lanrisang, and Mattiro Bulu sub-districts of 0 case per 10.000 animals-year. The highrisk district was Mattiro Sompe Subdistrict, so that the control measures need to be emphasized in this area by increasing the biosecurity practices, depopulation and stamping out in new infected area, vaccination, surveillance, routine socialization, monitoring, and provide additional animal health facilities and human resources, especially the veterinarians, to optimize the disease control measures. Keywords: Avian Influenza (AI), incidence rate, layer chicken, Pinrang district

A framework for the risk prediction of avian influenza occurrence: An Indonesian case study.

Avian influenza viruses can cause economically devastating diseases in poultry and have the potential for zoonotic transmission. To mitigate the consequences of avian influenza, disease prediction systems have become increasingly important. In this study, we have proposed a framework for the prediction of the occurrence and spread of avian influenza events in a geographical area. The application of the proposed framework was examined in an Indonesian case study. An extensive list of historical data sources containing disease predictors and target variables was used to build spatiotemporal and transactional datasets. To combine disparate sources, data rows were scaled to a temporal scale of 1-week and a spatial scale of 1-degree × 1-degree cells. Given the constructed datasets, underlying patterns in the form of rules explaining the risk of occurrence and spread of avian influenza were discovered. The created rules were combined and ordered based on their importance and then stored in a knowledge base. The results suggested that the proposed framework could act as a tool to gain a broad understanding of the drivers of avian influenza epidemics and may facilitate the prediction of future disease events.

Waterfowl occurrence and residence time as indicators of H5 and H7 avian influenza in North American Poultry

Avian influenza (AI) affects wild aquatic birds and poses hazards to human health, food security, and wildlife conservation globally. Accordingly, there is a recognized need for new methods and tools to help quantify the dynamic interaction between wild bird hosts and commercial poultry. Using satellite-marked waterfowl, we applied Bayesian joint hierarchical modeling to concurrently model species distributions, residency times, migration timing, and disease occurrence probability under an integrated animal movement and disease distribution modeling framework. Our results indicate that migratory waterfowl are positively related to AI occurrence over North America such that as waterfowl occurrence probability or residence time increase at a given location, so too does the chance of a commercial poultry AI outbreak. Analyses also suggest that AI occurrence probability is greatest during our observed waterfowl northward migration, and less during the southward migration. Methodologically, we found that when modeling disparate facets of disease systems at the wildlife-agriculture interface, it is essential that multiscale spatial patterns be addressed to avoid mistakenly inferring a disease process or disease-environment relationship from a pattern evaluated at the improper spatial scale. The study offers important insights into migratory waterfowl ecology and AI disease dynamics that aid in better preparing for future outbreaks.

A novel I117T substitution in neuraminidase of highly pathogenic avian influenza H5N1 virus conferring reduced susceptibility to oseltamivir and zanamivir

Occurrence of avian influenza (AI) with Neuraminidase (NA) mutations which confer reduced neuraminidase inhibitor (NAI) susceptibility has remained a cause of concern. The susceptibility to NAIs of 67 highly pathogenic avian influenza H5N1 viruses isolated during 2006–2012 in India was tested in phenotypic fluorescence-based NA inhibition assay, sequence analysis and in ovo. One isolate showed a novel NA I117T amino acid substitution (N2 numbering) and eight isolates showed previously known NAI-resistance marker mutations (I117V, E119D, N294S, total 9/67). The overall incidence of resistant variants was 13.4%. The novel I117T substitution reduced oseltamivir susceptibility by 18.6-fold and zanamivir susceptibility by 11.8-fold, compared to the wild type AI H5N1virus, thus showed cross-resistance to both oseltamivir and zanamivir in NA inhibition assays. However, the other two isolates with I117V substitution were sensitive to both the NAIs. In addition, the comparison of growth of the I117T and I117V variants in presence of NAI’s in the in ovo assays exhibited difference in growth levels. The present study reports the natural occurrence of a novel I117T mutation in AI H5N1 virus conferring cross-resistance to oseltamivir and zanamivir highlighting the urgent need of antiviral surveillance of AI viruses.

Identification of Areas at Increased Risk of Highly Pathogenic Avian Influenza Occurrence in Commercial Poultry in Poland.

The objective of the study was to identify the areas at increased risk of highly pathogenic avian influenza (HPAI) occurrence in commercial poultry in Poland. To identify the risk factors related to the occurrence of HPAI outbreaks, the opinions of Polish experts were combined with literature-driven knowledge. The relative impact of each risk factor was determined using a multicriteria decision analysis approach. The applied model suggests that the greatest risk of HPAI occurrence is concentrated in several counties in the eastern, western, and central parts of the country. The most influential risk actors responsible for HPAI occurrence in Poland included waterfowl density and proximity to waterbodies. The model had a high predictive value (area under the curve = 0.78). The developed spatial risk assessment of HPAI occurrence provides a valuable source of information for risk managers and can contribute to early detection of potential outbreaks of HPAI in poultry.

Identification of Areas at Increased Risk of Highly Pathogenic Avian Influenza Occurrence in Commercial Poultry in Poland

Identification of Areas at Increased Risk of Highly Pathogenic Avian Influenza Occurrence in Commercial Poultry in Poland

Avian Influenza in California: Does El Niño Southern Oscillation affect disease presence?

Event Abstract Back to Event Avian Influenza in California: Does El Niño Southern Oscillation affect disease presence? Narjara V. Grossmann1*, Kathryn Conlon2 and Beatriz Martínez-López1 1 Center for Animal Disease Modeling and Surveillance, School of Veterinary Medicine, University of California, Davis, United States 2 Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, United States High risk areas and important environmental factors contributing to avian influenza in multiple regions1,2,3 as well as in California4 have been detected using Ecological niche models. The surge of highly pathogenic avian influenza in domestic poultry has been also proved to be related to the presence and contact with migratory birds4. However, few studies have evaluated the effect of other seasonal and climatic changes, such as those that accompany the El Niño phenomenon. El Niño Southern Oscillation (ENSO) is a climatic phenomenon characterized by two phases: an increase in ocean temperatures (El Niño) and a decrease (La Niña). The NOAA (National Oceanic and Atmospheric Administration) monitors this phenomenon by reporting the average three-month sea surface temperature (https://www.climate.gov/enso). This event is accompanied by global changes in precipitation and wind patterns, which indirectly may affect distribution patterns and behavior of migratory birds. For the state of California, there are many evidences that El Niño promotes an increase in precipitation, in terms of quantity and spatial distribution6,7. During the 1992-93 cycle, rainfall increased over 5 times the historical mean for arid islands in the Gulf of California and the biological consequences included a 160-fold increase in plant cover and a doubling of insect abundance8. Coastal productivity follows a similar pattern as those observed for the Peruvian/Equatorial coast9. Migratory birds can be affected by these events especially when migrating from areas that have reduced precipitation caused by El Niño. During La Niña, the inverse relationship is expected, that is, a decrease in precipitation affecting the vegetation cover, insect and rodent population and subsequently their avian consumers10,11. We believe that avian influenza cases among wild bird populations are influenced by seasonal changes in climate such as ENSO phenomenon. To evaluate this we extracted raw information from the Influenza Research Database (https://www.fludb.org). Month of the year and season were extracted from this dataset and added as new columns, as well as the tri-monthly sea surface temperature (https://www.climate.gov/enso). Temperature, snow cover and precipitation were extracted from the NOAA database usng the rnoaa package though the R interface. So far, preliminary analyses indicated that during El Niño years there are overall fewer cases of avian influenza compared to La Niña. This detection is apparently not associated with differences in sampling efforts. Normal years do not seem to follow a pattern, therefore other factors can be associated to predicting the high-risk season for occurrence of avian influenza. To further evaluate this relationship we looked at the years, 2006 (a normal year in terms of ENSO), 2009 (El Niño year) and 2010 (strong La Nina). A geographic weighted regression was done to all three datasets that consisted of: case ratio (dependent variable), temperature, precipitation and snowfall. For 2006 precipitation did not seem to be strongly associated to positive cases, whereas temperature was more important. For both 2010 and 2009 temperature was no longer important, and precipitation was the best predicting variable. However, these preliminary results should be evaluated with caution since they only represent one year for each type of ENSO variation. Also, these models explained around 20 - 24% of the observed variation, therefore, other variables might be more important in predicting cases than those that were included in the model. These values indicate that we are in the right direction and should gather more data to create more robust models. Considering that this year is an El Nino year, and that 2020 is predicted to be a strong La Niña year, if our predictions are correct, we might see a surge of cases in the coming year. A model that can account for that may better prepare us for these events. Acknowledgements This project was conducted in part thanks to the UC Davis Wildlife Health Center fellowship.

Avian Influenza in the U.S. Commercial Upland Game Bird Industry: An Analysis of Selected Practices as Potential Exposure Pathways and Surveillance System Data Reporting.

Producing a smaller yield of higher-value birds compared to conventional poultry production, the U.S. commercial upland game bird industry deals primarily in the sale of live birds for recreational hunting. In this study, our aims were to gain insights into the occurrence of avian influenza (AI) in the U.S. commercial upland game bird industry in comparison to other poultry sectors, to identify the presence of the specific AI risk factors in the practices of raising ducks on site and having connections to live bird markets (LBMs), and to assess how AI surveillance systems may have played a role in the reporting of the presence of exposure pathway-related information. We found that 23 AI epizootics involving upland game bird premises were reported, compared to 485 epizootics in the other poultry industries, and 86% of epizootics involving upland game birds were limited to only one premises. Regarding specific AI risk factors, 70% of upland game bird epizootics involved one of the two examined practices. In assessing the impact of surveillance systems, data framed around the implementation of surveillance systems revealed that the introduction of active surveillance coincided with the more thorough reporting of both the raising of ducks on site and premises having connections to LBMs. Our results suggest the need for more thorough data collection during epizootics and the need to assess additional exposure pathways specific to the commercial raise-for-release upland game bird industry.

QUALITATIVE RISK ASSESSMENT OF AVIAN INFLUENZA VIRUS TRANSMISSION THROUGH INCUBATION EGGS

Analysis of literature on avian influenza (AI) virus transmission through incubation eggs and qualitative assessment of risk of incubation egg import to the Russian Federation in the contest of veterinary and sanitary measures against avian influenza currently in place for imported products are presented. Probability of low-pathogenic AI virus transmission through poultry incubation eggs due to possible contamination of the egg and package surfaces with the said agents is indicated. Probability of AI virus transmission through commercial eggs derived from quails, turkeys, geese, chickens is shown to be high. Evidence of actual vertical transmission of highly pathogenic avian influenza virus is limited, however, it is recognized that the infection manifests by systemic lesions in the organs (bursa, thymus, spleen, heart, pancreas, kidneys, brain, trachea, lungs, adrenals and skeletal muscles). It is noted that the virus can persist on bird feathers and in bird meat for a long period. In addition, high humidity, neutral pH level and low temperature are shown to be favourable conditions for the virus survival in the ambient environment. Incubation egg movement restrictive measures are considered the most adequate for prevention of the disease spread between holdings. It is underlined that no country can guarantee the absence of the risk of avian influenza occurrence in avifauna. Anti-AI measures for incubation egg importation recommended by the World Organization for Animal Health are considered adequate for prevention of international disease spread regardless of the virus pathogenicity.

Seroepidemiology and assessment of risk factors for the spread of avian influenza in birds in two Nigerian states.

Despite modified stamping out eradication policy adopted in Nigeria, there was resurgence in 2015 of highly pathogenic avian influenza (HPAI) H5N1 with greater infectivity. A survey of the risk of spread of HPAI in two HPAI‐infected and ‐uninfected Nigerian states were studied. A cross‐sectional study to detect avian influenza (AI) H5 antibodies was conducted using haemagglutination inhibition (HI) test and enzyme‐linked immunosorbent assay (ELISA). A total of 950 birds’ sera were tested for AI H5 antibodies. Questionnaires were also administered to evaluate risks of AI spread in two states of Nigeria in 2013. AI H5 seroprevalence of 3% and 5% were obtained in Bauchi and Gombe states, respectively. Free flying and captive wild birds had 15% and 11% seroprevalence, respectively. Ninety‐two per cent AI awareness and 90% preparedness to report outbreaks of poultry diseases were recorded. Veterinary personnel, radio and television contributed 87% to HPAI awareness. Of the 10 risk categories evaluated, Gombe state had 3 moderate and 1 high risk of AI virus spread. Bauchi state recorded 5 moderate and 1 high risk of AI virus spread. Chi‐square analysis showed associations of altitude, temperature, rainfall and presence of live bird markets (LBMs) (P < 0.05) to AI seroprevalence. Odds ratio at 95% CI (1.313–6.333) indicated LBMs presence to be three times more likely to influence AI occurrence. HPAI H5N1 resurged in many states and occurred for the first time in Gombe state in 2015. Veterinary personnel, radio and television may be reliable in changing farmers’ attitudes to adopt good biosecurity practices.

Evidence that Life History Characteristics of Wild Birds Influence Infection and Exposure to Influenza A Viruses

We report on life history characteristics, temporal, and age-related effects influencing the frequency of occurrence of avian influenza (AI) viruses in four species of migratory geese breeding on the Yukon-Kuskokwim Delta, Alaska. Emperor geese (Chen canagica), cackling geese (Branta hutchinsii), greater white-fronted geese (Anser albifrons), and black brant (Branta bernicla), were all tested for active infection of AI viruses upon arrival in early May, during nesting in June, and while molting in July and August, 2006–2010 (n = 14,323). Additionally, prior exposure to AI viruses was assessed via prevalence of antibodies from sera samples collected during late summer in 2009 and 2010. Results suggest that geese are uncommonly infected by low pathogenic AI viruses while in Alaska. The percent of birds actively shedding AI viruses varied annually, and was highest in 2006 and 2010 (1–3%) and lowest in 2007, 2008, and 2009 (<0.70%). Contrary to findings in ducks, the highest incidence of infected birds was in late spring when birds first arrived from staging and wintering areas. Despite low prevalence, most geese were previously exposed to AI viruses, as indicated by high levels of seroprevalence during late summer (47%–96% across species; n = 541). Seroprevalence was >95% for emperor geese, a species that spends part of its life cycle in Asia and is endemic to Alaska and the Bering Sea region, compared to 40–60% for the other three species, whose entire life cycles are within the western hemisphere. Birds <45 days of age showed little past exposure to AI viruses, although antibodies were detected in samples from 5-week old birds in 2009. Seroprevalence of known age black brant revealed that no birds <4 years old had seroconverted, compared to 49% of birds ≥4 years of age.

Backtracking the movements of a migratory bird: a case study of a white‐fronted goose (Anser albifrons)

The occurrence of avian influenza has brought attention to migrating birds and their migratory routes as possible carriers and gates, respectively, of the pathogenic influenza virus. There is a need to verify migration routes and to back-track the migration routes of infected animals. Stable isotope analysis of bird feathers is a valuable tool for studying the migratory pattern of birds, by gaining information about the environmental conditions during the growth of the feathers. Ideally, if different feathers that have grown during different periods are investigated, not only can information about the molting region be extracted, but also some clues can be obtained about stop-overs during the migration of individual animals, enabling the reconstruction of the pathway. In the presented case study the hydrogen, carbon nitrogen and sulfur stable isotope ratios of different types of feathers (primaries, down feathers and blood pinfeathers) from one white-fronted goose specimen have been determined. These ratios differ significantly for some elements. By taking into account the different time of growth of the respective feathers, the isotope data can be interpreted with respect to the animal migration route from the summer (and molting) to the wintering region. This is the first paper to attempt to map the migration pathway using different types of feather from a single individual.

Avian Influenza Survey in Migrating Waterfowl in Sonora, Mexico

A two-year survey was carried out on the occurrence of avian influenza in migrating birds in two estuaries of the Mexican state of Sonora, which is located within the Pacific flyway. Cloacal and oropharyngeal swabs were collected from 1262 birds, including 20 aquatic bird species from the Moroncarit and Tobari estuaries in Sonora, Mexico. Samples were tested for type A influenza (M), H5 Eurasian and North American subtypes (H5EA and H5NA respectively) and the H7 North American subtype (H7NA). Gene detection was determined by one-step real-time reverse transcription polymerase chain reaction (RRT-PCR). The results revealed that neither the highly pathogenic avian influenza virus H5 of Eurasian lineage nor H7NA were detected. The overall prevalence of avian influenza type A (M-positive) in the sampled birds was 3.6% with the vast majority in dabbling ducks (Anas species). Samples from two birds, one from a Redhead (Aythya americana) and another from a Northern Shoveler (Anas clypeata), were positive for the low-pathogenic H5 avian influenza virus of North American lineage. These findings represented documented evidence of the occurrence of avian influenza in wintering birds in the Mexican wetlands. This type of study contributes to the understanding of how viruses spread to new regions of North America and highlights the importance of surveillance for the early detection and control of potentially pathogenic strains, which could affect animal and human health.

Investigation of the potential use of e-tracking and tracing of poultry using linear and 2D barcodes

Contemporary Precision Livestock Technology in poultry production is very limited and does not meet European standards for traceability and Best Available Technology (BAT), as laid down in EN ISO 2205:2007 standards (2007) and the European Directive 2008/1/EC (2008). A worldwide occurrence of Avian Influenza additionally calls for a fraud-proof tagging device and source verification system for poultry and poultry products in order to complete partially existing documentary trails. During a preliminary laboratory trial, a procedure for the application of miniature linear and two-dimensional Data Matrix (DM) barcodes onto poultry beaks and legs through inkjet printing was set up and assessed. Results regarding the proportion of readability ( p%), the standard error in readability (SE) and general statistics on the reading time were calculated. Tests for independence based on Chi-square and Pearson's were performed on the categorical data, to estimate the differences between proportions of readability of reading groups. The resulting data was used to define the optimal position of barcodes as well as the optimal reading mode of the barcode scanner to be used for further trials. As this experiment provided an estimate of readability of barcodes imprinted on chicken beaks and legs, it is intended to serve as a basis for sample size calculation for an ongoing live trial.

An analysis of the spatial and temporal patterns of highly pathogenic avian influenza occurrence in Vietnam using national surveillance data

The objectives of this study were to describe the spatio-temporal pattern of an epidemic of highly pathogenic avian influenza (HPAI) in Vietnam and to identify potential risk factors for the introduction and maintenance of infection within the poultry population. The results indicate that during the time period 2004–early 2006 a sequence of three epidemic waves occurred in Vietnam as distinct spatial and temporal clusters. The risk of outbreak occurrence increased with a greater percentage of rice paddy fields, increasing domestic water bird and chicken density. It increased with reducing distance to higher population density aggregations, and in the third epidemic wave with increasing percentage of aquaculture. The findings indicate that agri-livestock farming systems involving domestic water birds and rice production in river delta areas are important for the maintenance and spread of infection. While the government’s control measures appear to have been effective in the South and Central parts of Vietnam, it is likely that in the North of Vietnam the vaccination campaign led to transmission of infection which was subsequently brought under control.

International Attention for Zoonotic Infections

International Attention for Zoonotic Infections

The occurrence of avian influenza A subtype H6N2 in commercial layer flocks in Southern California (2000-02): clinicopathologic findings.

Between February 2000 and February 2002, the California Animal Health and Food Safety Laboratory System diagnosed 26 cases of low-pathogenic H6N2 avian influenza from 12 commercial egg-laying farms. The most common gross and histologic lesions observed in infected chickens were fibrinous yolk peritonitis, salpingitis, oophoritis, and nephritis. Edema of the mesentery of the oviduct and pale, swollen kidneys were also observed. Mortality in infected flocks ranged from 0.25% to 3%, and egg production dropped 7% to 40%.