Live Bird Markets Research Articles

Characterization of Avian Influenza Viruses Detected in Kenyan Live Bird Markets and Wild Bird Habitats Reveal Genetically Diverse Subtypes and High Proportion of A(H9N2), 2018-2020.

Following the detection of highly pathogenic avian influenza (HPAI) virus in countries bordering Kenya to the west, we conducted surveillance among domestic and wild birds along the shores of Lake Victoria. In addition, between 2018 and 2020, we conducted surveillance among poultry and poultry workers in live bird markets and among wild migratory birds in various lakes that are resting sites during migration to assess introduction and circulation of avian influenza viruses in these populations. We tested 7464 specimens (oropharyngeal (OP) and cloacal specimens) from poultry and 6531 fresh fecal specimens from wild birds for influenza A viruses by real-time RT-PCR. Influenza was detected in 3.9% (n = 292) of specimens collected from poultry and 0.2% (n = 10) of fecal specimens from wild birds. On hemagglutinin subtyping, most of the influenza A positives from poultry (274/292, 93.8%) were H9. Of 34 H9 specimens randomly selected for further subtyping, all were H9N2. On phylogenetic analysis, these viruses were genetically similar to other H9 viruses detected in East Africa. Only two of the ten influenza A-positive specimens from the wild bird fecal specimens were successfully subtyped; sequencing analysis of one specimen collected in 2018 was identified as a low-pathogenicity avian influenza H5N2 virus of the Eurasian lineage, and the second specimen, collected in 2020, was subtyped as H11. A total of 18 OP and nasal specimens from poultry workers with acute respiratory illness (12%) were collected; none were positive for influenza A virus. We observed significant circulation of H9N2 influenza viruses in poultry in live bird markets in Kenya. During the same period, low-pathogenic H5N2 virus was detected in a fecal specimen collected in a site hosting a variety of migratory and resident birds. Although HPAI H5N8 was not detected in this survey, these results highlight the potential for the introduction and establishment of highly pathogenic avian influenza viruses in poultry populations and the associated risk of spillover to human populations.

Amplification of avian influenza virus circulation along poultry marketing chains in Bangladesh: A controlled field experiment

The prevalence of avian influenza viruses is commonly found to increase dramatically as birds are transported from farms to live bird markets. Viral transmission dynamics along marketing chains are, however, poorly understood. To address this gap, we implemented a controlled field experiment altering chicken supply to a live bird market in Chattogram, Bangladesh. Broilers and backyard chickens traded along altered (intervention) and conventional (control) marketing chains were tested for avian influenza viruses at different time points. Upon arrival at the live bird market, the odds of detecting avian influenza viruses did not differ between control and intervention groups. However, 12 h later, intervention group odds were lower, particularly for broilers, indicating that viral shedding in live bird markets resulted partly from infections occurring during transport and trade. Curtailing avian influenza virus prevalence in live bird markets requires mitigating risk in marketing chain nodes preceding chickens’ delivery at live bird markets.

Transmission dynamics of avian influenza viruses in Egyptian poultry markets

Live bird markets (LBMs) are considered hotspots for Avian Influenza Viruses (AIVs). In such markets, AIVs pose threats to both poultry and public health. Within LBMs, AIVs spread through various routes, including direct contact, environmental contamination, and aerosol transmission. Unique factors in Egyptian LBMs, such as the coexistence of wild and domestic birds, increase transmission risks between birds as well as spill-overs into exposed humans. Understanding the transmission dynamics of AIVs is vital for implementing effective control measures. We conducted a study in four Egyptian LBMs located in Mediterranean coast cities from November 2021 to March 2023. In this study we tested 3,971 samples from poultry, wild birds, and the environment, out of which 692 (17.4%) were positive for AIV. Poultry exhibited a higher prevalence (42.2%) than wild birds (34.4%). Environmental samples, including water (30.8%), surfaces (17.2%), and air (18.2%), also tested positive for AIV. Diverse AIV subtypes, including H5N1, H9N2, H5/H9 co-infection, and H5N8, were detected among avian species and the environment. Temporal analysis revealed fluctuating IAV positivity rates from November 2021 to March 2023. These results emphasize the importance of continuous surveillance, resource allocation, and multisectoral collaboration to protect poultry and human health, and prevent novel influenza strains’ emergence in Egyptian LBMs.

Gross and microscopic changes associated with intestinal parasitism of local scavenging chickens in Maiduguri, Borno State, Nigeria

A survey of intestinal parasitism and gross and microscopic lesions in local scavenging chickens (Gallus gallus domesticus) was carried out at the Maiduguri live bird market. A total of 100 intestinal samples were collected from the slaughter slab immediately after slaughter for gross, microscopic and parasitological examinations using standard procedures. Out of the 100 intestinal samples collected 56% were found to be harbouring helminthes ranging from Ascaridia spp (18%), Heterakis spp (8%), Rallietina spp (13%), Choanotaenia spp (3%) and Hymenolepis spp (3%). Others showed mixed infections of two or more parasites at 11%. The prevalence was higher in adult chickens (46%) than in young chickens (10%) and also higher in males (34%) than in females (22%). Gross lesions observed included nodule formation, haemorrhages and nodular/haemorrhagic lesions; while microscopic lesions seen included matting and stunting of intestinal villi, loss of crypts and goblet cell hyperplasia. Others were epithelial desquamation and necrosis with leucocytic aggregation and circumscribed eosinophilic aggregation in the submucosa. Conclusively, the overall prevalence of 56% of intestinal parasitism observed among local scavenging chickens in the study suggests endemicity of the disease condition in the study area. Also, age and sex appear to be risk factors associated with the incidence of intestinal parasitism in local scavenging chickens. Therefore, there is a need to apply strict biosecurity and good sanitary measures coupled with regular deworming of birds to serve as control and preventive measures. This will help to boost production, improve the economy and provide more protein to the populace.

High Prevalence of Highly Pathogenic Avian Influenza: A Virus in Vietnam's Live Bird Markets.

In recent years, Vietnam has suffered multiple epizootics of influenza in poultry. From 10 January 2019 to 26 April 2021, we employed a One Health influenza surveillance approach at live bird markets (LBMs) and swine farms in Northern Vietnam. When the COVID-19 pandemic permitted, each month, field teams collected oral secretion samples from poultry and pigs, animal facility bioaerosol and fecal samples, and animal worker nasal washes at 4 LBMs and 5 swine farms across 5 sites. Initially samples were screened with molecular assays followed by culture in embryonated eggs (poultry swabs) or Madin-Darby canine kidney cells (human or swine swabs). Many of the 3493 samples collected had either molecular or culture evidence for influenza A virus, including 314 (37.5%) of the 837 poultry oropharyngeal swabs, 144 (25.1%) of the 574 bioaerosol samples, 438 (34.9%) of the 1257 poultry fecal swab samples, and 16 (1.9%) of the 828 human nasal washes. Culturing poultry samples yielded 454 influenza A isolates, 83 of which were H5, and 70 (84.3%) of these were highly pathogenic. Additionally, a positive human sample had a H9N2 avian-like PB1 gene. In contrast, the prevalence of influenza A in the swine farms was much lower with only 6 (0.4%) of the 1700 total swine farm samples studied, having molecular evidence for influenza A virus. This study suggests that Vietnam's LBMs continue to harbor high prevalences of avian influenza A viruses, including many highly pathogenic H5N6 strains, which will continue to threaten poultry and humans.

Modelling the transmission dynamics of H9N2 avian influenza viruses in a live bird market

H9N2 avian influenza viruses (AIVs) are a major concern for the poultry sector and human health in countries where this subtype is endemic. By fitting a model simulating H9N2 AIV transmission to data from a field experiment, we characterise the epidemiology of the virus in a live bird market in Bangladesh. Many supplied birds arrive already exposed to H9N2 AIVs, resulting in many broiler chickens entering the market as infected, and many indigenous backyard chickens entering with pre-existing immunity. Most susceptible chickens become infected within one day spent at the market, owing to high levels of viral transmission within market and short latent periods, as brief as 5.3 hours. Although H9N2 AIV transmission can be substantially reduced under moderate levels of cleaning and disinfection, effective risk mitigation also requires a range of additional interventions targeting markets and other nodes along the poultry production and distribution network.

Molecular And Serological Detection Of Newcastle Disease Virus In Live-Bird Markets, Jos, Plateau State In Nigeria

Newcastle disease (ND) is a highly infectious viral disease of birds caused by the Newcastle disease virus (NDV) and it has been reported in domestic birds in Nigeria. Waterfowls and village poultry in live bird markets (LBM) acts as reservoirs, potentially reintroducing the virus to commercial poultry. This study aims at molecular and serological detection of NDV at live bird markets in Plateau State, Nigeria. A cross sectional analysis involved 309 pooled cloacal and tracheal swabs over three months were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR), RT-qPCR, virus isolation and haemagglutination and haemagglutinationinhibition test (HA &HI). Virus isolation was attempted in 9 to 11 days old specific antibody negative (SAN) embryonated chicken eggs and fifteen samples showed haemagglutination. Subsequent tests confimed nine of these as NDV positive through haemagglutination and haemagglutination inhibition (HI) tests. Conventional RT-PCR and RT-qPCR further validated five of the nine NDV positive isolates. The phylogenetic analysis of partial F gene nucleotide sequences revealed that all three isolates belonged to class II genotype XIV.2_XIVb. This finding underscores the persistent threat of NDV to local poultry, necessitating comprehensive virological surveillance to understand, isolate and characterize the virus in Nigeria. Therefore, monitoring for emerging lineages and sub-lineages in Nigeria birds is crucial for safeguarding commercial poultry production.

Genetic and virological characteristics of a reassortant avian influenza A H6N1 virus isolated from wild birds at a live-bird market in Egypt.

The first detection of a human infection with avian influenza A/H6N1 virus in Taiwan in 2013 has raised concerns about this virus. During our routine surveillance of avian influenza viruses (AIVs) in live-bird markets in Egypt, an H6N1 virus was isolated from a garganey duck and was characterized. Phylogenetic analysis indicated that the Egyptian H6N1 strain A/Garganey/Egypt/20869C/2022(H6N1) has a unique genomic constellation, with gene segments inherited from different subtypes (H5N1, H3N8, H7N3, H6N1, and H10N1) that have been detected previously in AIVs from Egypt and some Eurasian countries. We examined the replication of kinetics of this virus in different mammalian cell lines (A549, MDCK, and Vero cells) and compared its pathogenicity to that of the ancestral H6N1 virus A/Quail/HK/421/2002(H6N1). The Egyptian H6N1 virus replicated efficiently in C57BL/6 mice without prior adaptation and grew faster and reached higher titers than in A549 cells than the ancestral strain. These results show that reassortant H6 AIVs might pose a potential threat to human health and highlight the need to continue surveillance of H6 AIVs circulating in nature.

Spatiotemporal Patterns and Risk Factors for Newcastle Disease Virus among Chickens in a Tanzania Live Bird Market

Village poultry plays a vital role in providing essential nutrition and income for rural communities in Africa. In this context, poultry are often traded through live bird markets (LBMs), which serve as central trading hubs where producers connect with traders and consumers, facilitating the flow of poultry products along the value chain. While they serve as important trading hubs, these markets create an environment where avian pathogens, like Newcastle disease virus (NDV) and avian influenza virus, can easily emerge and spread. Improving our understanding of the epidemiology of NDV in LBMs is important for assessing disease risks and identifying factors that contribute to its persistence. Local chickens at the Mawenzi LBM in Morogoro municipality were surveyed for NDV presence, its temporal and spatial distribution, and risk factors for NDV infection. Twenty-three percent of 659 local chickens sampled over a 1-year period were positive for NDV based on PCR. Increased odds of NDV infection were identified in chickens that had been in the market for 2 or more days prior to sampling and during the period extending from August through October. Four significant spatiotemporal clusters of NDV-positive chickens encompassing 13 villages were detected between August and October 2020, illustrating geographic hotspots of infection when NDV was most prevalent. Similar to the other LBMs, this market had enclosures with high densities of birds of mixed species, limited biosecurity, and the presence of birds with observable illness. Bird traders who source the chickens from the villages, described long transit times in mixed enclosures with limited sanitation practices and without consideration of sick birds or vaccination status prior to arriving at the LBM. This study highlights the need to invest in improvements to infrastructure and biosecurity for LBMs as well as training opportunities for increasing traders’ knowledge on hygiene and sanitation practices, animal welfare, and poultry biosecurity measures.

Avian H6 Influenza Viruses in Vietnamese Live Bird Markets during 2018-2021.

Avian influenza viruses of the H6 subtype are prevalent in wild ducks and likely play an important role in the ecology of influenza viruses through reassortment with other avian influenza viruses. Yet, only 152 Vietnamese H6 virus sequences were available in GISAID (Global Initiative on Sharing All Influenza Data) prior to this study with the most recent sequences being from 2018. Through surveillance in Vietnamese live bird markets from 2018 to 2021, we identified 287 samples containing one or several H6 viruses and other influenza A virus subtypes, demonstrating a high rate of co-infections among birds in Vietnamese live bird markets. For the 132 H6 samples with unique influenza virus sequences, we conducted phylogenetic and genetic analyses. Most of the H6 viruses were similar to each other and closely related to other H6 viruses; however, signs of reassortment with other avian influenza viruses were evident. At the genetic level, the Vietnamese H6 viruses characterized in our study encode a single basic amino acid at the HA cleavage site, consistent with low pathogenicity in poultry. The Vietnamese H6 viruses analyzed here possess an amino acid motif in HA that confers binding to both avian- and human-type receptors on host cells, consistent with their ability to infect mammals. The frequent detection of H6 viruses in Vietnamese live bird markets, the high rate of co-infections of birds with different influenza viruses, and the dual receptor-binding specificity of these viruses warrant their close monitoring for potential infection and spread among mammals.

Phylogenetic Analysis of Newcastle Disease Virus Isolated from Poultry in Live Bird Markets and Wild Waterfowl in Zambia.

Poultry production is essential to the economy and livelihood of many rural Zambian households. However, the industry is threatened by infectious diseases, particularly Newcastle disease virus (NDV) infection. Therefore, this study employed next-generation sequencing to characterise six NDV isolates from poultry in Zambia's live bird markets (LBMs) and wild waterfowl. Four NDV isolates were detected from 410 faecal samples collected from chickens in LBMs in Lusaka and two from 2851 wild birds from Lochinvar National Park. Phylogenetic analysis revealed that the four NDVs from LBM clustered in genotype VII and sub-genotype VII.2 were closely related to viruses previously isolated in Zambia and other Southern African countries, suggesting possible local and regional transboundary circulation of the virus. In contrast, the two isolates from wild birds belonged to class I viruses, genotype 1, and were closely related to isolates from Europe and Asia, suggesting the possible introduction of these viruses from Eurasia, likely through wild bird migration. The fusion gene cleavage site motif for all LBM-associated isolates was 112RRQKR|F117, indicating that the viruses are virulent, while the isolates from wild waterfowl had the typical 112ERQER|L117 avirulent motif. This study demonstrates the circulation of virulent NDV strains in LBMs and has, for the first time, characterised NDV from wild birds in Zambia. The study further provides the first whole genomes of NDV sub-genotype VII.2 and genotype 1 from Zambia and stresses the importance of surveillance and molecular analysis for monitoring the circulation of NDV genotypes and viral evolution.

Prevalence of Antimicrobial Resistance in Escherichia coli and Salmonella Species Isolates from Chickens in Live Bird Markets and Boot Swabs from Layer Farms in Timor-Leste.

The rapid emergence of antimicrobial resistance is a global concern, and high levels of resistance have been detected in chicken populations worldwide. The purpose of this study was to determine the prevalence of antimicrobial resistance in Escherichia coli and Salmonella spp. isolated from healthy chickens in Timor-Leste. Through a cross-sectional study, cloacal swabs and boot swabs were collected from 25 live bird markets and two layer farms respectively. E. coli and Salmonella spp. from these samples were tested for susceptibility to six antimicrobials using a disk diffusion test, and a subset was tested for susceptibility to 27 antimicrobials using broth-based microdilution. E. coli and Salmonella spp. isolates showed the highest resistance towards either tetracycline or ampicillin on the disk diffusion test. E. coli from layer farms (odds ratio:5.2; 95%CI 2.0-13.1) and broilers (odds ratio:18.1; 95%CI 5.3-61.2) were more likely to be multi-drug resistant than those from local chickens. Based on the broth-based microdilution test, resistance to antimicrobials in the Timor-Leste Antimicrobial Guidelines for humans were low, except for resistance to ciprofloxacin in Salmonella spp. (47.1%). Colistin resistance in E. coli was 6.6%. Although this study shows that antimicrobial resistance in chickens was generally low in Timor-Leste, there should be ongoing monitoring in commercial chickens as industry growth might be accompanied with increased antimicrobial use.

Farm biosecurity practices affecting avian influenza virus circulation in commercial chicken farms in Bangladesh.

Avian influenza virus (AIV) is of major concern to livestock, wildlife, and human health. In many countries in the world, including Bangladesh, AIV is endemic in poultry, requiring improving biosecurity. In Bangladesh, we investigated how variation in biosecurity practices in commercial chicken farms affected their AIV infection status to help guide AIV mitigation strategies. We collected pooled fecal swabs from 225 farms and tested the samples for the AIV matrix gene followed by H5, H7, and H9 subtyping using rRT-PCR. We found that 39.6% of chicken farms were AIV positive, with 13% and 14% being positive for subtypes H5 and H9, respectively. Using a generalized linear mixed effects model, we identified as many as 12 significant AIV risk factors. Two major factors promoting AIV risk that cannot be easily addressed in the short term were farm size and the proximity of the farm to a live bird market. However, the other ten significant determinants of AIV risk can be more readily addressed, of which the most important ones were limiting access by visitors (reducing predicted AIV risk from 42 to 6%), isolation and treatment of sick birds (42 to 7%), prohibiting access of vehicles to poultry sheds (38 to 8%), improving hand hygiene (from 42 to 9%), not sharing farm workers across farms (37 to 8%), and limiting access by wild birds to poultry sheds (37 to 8%). Our findings can be applied to developing practical and cost-effective measures that significantly decrease the prevalence of AIV in chicken farms. Notably, in settings with limited resources, such as Bangladesh, these measures can help governments strengthen biosecurity practices in their poultry industry to limit and possibly prevent the spread of AIV.

Molecular and serological detection of Newcastle disease virus in live-bird markets, Jos, Plateau State Nigeria.

Newcastle disease (ND) is a highly infectious viral disease of birds caused by the Newcastle disease virus (NDV) and it has been reported in domestic birds in Nigeria. Waterfowls and village poultry in live bird markets (LBM) acts as reservoirs, potentially reintroducing the virus to commercial poultry. This study aims at molecular and serological detection of NDV at live bird markets in Plateau State, Nigeria. A cross sectional analysis involved 309 pooled cloacal and tracheal swabs over three months were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR), RT-qPCR, virus isolation and haemagglutination and haemagglutination-inhibition test (HA &HI). Virus isolation was attempted in 9 to 11 days old specific antibody negative (SAN) embryonated chicken eggs and fifteen samples showed haemagglutination. Subsequent tests confimed nine of these as NDV positive through haemagglutination and haemagglutination inhibition (HI) tests. ConventionalRT-PCR and RT-qPCR further validated five of the nine NDV positive isolates. The phylogenetic analysis of partial F gene nucleotide sequences revealed that all three isolates belonged to class II genotype XIV.2_XIVb. This finding underscores the persistent threat of NDV to local poultry, necessitating comprehensive virological surveillance to understand, isolate and characterize the virus in Nigeria. Therefore, monitoring for emerging lineages and sub-lineages in Nigeria birds is crucial for safeguarding commercial poultry production.

Assessment Of Biosecurity Limitation In Live Poultry Markets Inyaounde, Center Region Of Cameroon

In the poultry value chain, live animal markets are common hotspots for dispersing multiple infectious diseases. This work was initiated to assess biosecurity practices in the poultry market. For this purpose, a survey was conducted in 8 live poultry markets in Yaoundé, in combination with a questionnaire-based survey with the stakeholders of the livestock markets. The data collected were analyzed using descriptive statistics. The results revealed that all the markets (100%) were not only used for selling live poultry, and the birds were not confined. In all the markets (100%), poultry was sold without any disinfection observed, and no program was implemented to fight against rodents. The introduction of birds into the market without quarantine was observed at 33.9%; 46.9% of traders and slaughtering persons were working together in closed proximity, birds were kept in wooden cages on the ground in all the market (85.8%) and, when transported inter-urbanely the birds were kept in plastic cages (100%). Cages were piled on top of one another (61.4%) had poultry of different breeds (30.3%) and of different ages (100%). All traders do not put on clean uniforms reserved for their poultry selling activities only, and they do not carry out any medical check-ups. Most customers (72.8%) slaughtered their birds in the market, and the unsold birds (100%) were not returned. Stray dogs, rodents, and cats were found in the market (100%). It was concluded that there is a limited application of biosecurity measures in the live poultry markets in Yaoundé, which, therefore, represents a risk of the dissemination of high pathogenic avian/zoonosis diseases. Live bird market stakeholders should be educated on adhering to biosecurity measures and practices.

Avian Salmonellosis and Evaluation of Haematological Changes in Indigenous Birds at Bukuru Live Bird Market

Avian Salmonellosis and Evaluation of Haematological Changes in Indigenous Birds at Bukuru Live Bird Market

Occurrence of Salmonella Species in Local and Commercial Chickens Slaughtered at Samaru and Sabongari Live Bird Markets, Kaduna State

Salmonellosis is a bacterial infection caused by members of the genus Salmonella. It is one of the most common and important zoonotic diseases. The route of infection from animals to humans is usually through contaminated food, water and environment. Bacteriological investigation on 303 cloacal swab samples collected from local (139) and commercial (164) chickens slaughtered at Samaru and Sabon-gari live bird markets, Kaduna State was carried out to determine the occurrence of Salmonella species. Cultural isolation and identification using conventional biochemical tests, microgen test kit™ and Polymerase Chain Reaction (PCR) amplification of invA gene of the Salmonella isolates was carried out. Isolates were subjected to antimicrobial susceptibility tests, phenotypic detection of Extended Spectrum Beta Lactamases (ESBLs) producing Salmonella isolates using the modified Clinical and Laboratory Standards Institute (CLSI) ESBL confirmatory test. The occurrence of Salmonella species based on cultural and biochemical tests was found to be 13 (4.29%), microgen kit identified 7 (53.8%) of the 13 Salmonella species while PCR based on invA gene confirmed 9 (69.2%) as the overall occurrence rate of Salmonella species. Meanwhile, the study also revealed rate of occurrence of Salmonella species in local chickens 8 (61.5%) which was higher compared to commercial chickens 1 (7.69%) with a statistical significant association (χ2 = 8.775, P = 0.003) between the occurrence of Salmonella species in local and commercial chickens. Antimicrobial susceptibility testing was carried out using panel of 12 antibiotics from 8 different antibiotic classes. Highest rate of sensitivity of the isolates to antibiotics was observed for Ofloxacin with 90%, while all the isolates (100%) were resistant to Nalidixic Acid, Cefazolin, Amoxicillin + Clavulanic Acid, Oxacillin and Penicillin. This study revealed multidrug-resistance (MDR) profile of Salmonella with a total of (25%) of Salmonella isolates being resistant to 5 antibiotics belonging to 4 different classes of antimicrobials with the highest multiple antibiotic-resistant (MAR) indices ranging from 0.58 to 0.91. All the nine (9) isolates of Salmonella tested were found to be negative for ESBLs production. Therefore, it is concluded that Salmonella species are present in local and commercial chickens slaughtered at Samaru and Sabon-gari live bird markets, Kaduna State and could pose serious public health risks to handlers and to consumers of poultry meat and its products.

Avian influenza A(H5) virus circulation in live bird markets in Vietnam, 2017-2022.

Highly pathogenic avian influenza A(H5) human infections are a global concern, with many A(H5) human cases detected in Vietnam, including a case in October 2022. Using avian influenza virus surveillance from March 2017-September 2022, we described the percent of pooled samples that were positive for avian influenza A, A(H5), A(H5N1), A(H5N6), and A(H5N8) viruses in live bird markets (LBMs) in Vietnam. Monthly at each LBM, 30 poultry oropharyngeal swab specimens and five environmental samples were collected. Samples were pooled in groups of five and tested for influenza A, A(H5), A(H5N1), A(H5N6), and A(H5N8) viruses by real-time reverse-transcription polymerase chain reaction. Trends in the percent of pooled samples that were positive for avian influenza were summarized by LBM characteristics and time and compared with the number of passively detected avian influenza outbreaks using Spearman's rank correlation. A total of 25,774 pooled samples were collected through active surveillance at 167 LBMs in 24 provinces; 36.9% of pooled samples were positive for influenza A, 3.6% A(H5), 1.9% A(H5N1), 1.1% A(H5N6), and 0.2% A(H5N8). Influenza A(H5) viruses were identified January-December and at least once in 91.7% of sampled provinces. In 246 A(H5) outbreaks in poultry; 20.3% were influenza A(H5N1), 60.2% A(H5N6), and 19.5% A(H5N8); outbreaks did not correlate with active surveillance. In Vietnam, influenza A(H5) viruses were detected by active surveillance in LBMs year-round and in most provinces sampled. In addition to outbreak reporting, active surveillance for A(H5) viruses in settings with high potential for animal-to-human spillover can provide situational awareness.

The One Health Epidemiology of Avian Influenza Infection in Bangladesh: Lessons Learned from the Past 15 Years

Avian influenza viruses (AIVs) are significant transboundary zoonotic pathogens that concern both animal and human. Since the first report of H5N1 AIV in Bangladesh in early 2007, it resulted in numerous outbreaks across the country, hindering the sustainable growth of the poultry industry through economic losses in different production systems (commercial and backyard). Highly pathogenic avian influenza (HPAI) virus and low pathogenic avian influenza (LPAI) virus are currently cocirculating and causing infection in poultry sectors in an endemic manner in Bangladesh as well as in wild bird species. The introduction of multiple clades of H5N1 in different poultry species and the reassortment of AIVs with different patterns of infections have complicated the epidemiological situation for control and created conditions to increase the virulence of the virus, host range, and potential zoonotic transmission. The risk of viral transmission at the human–poultry interface is increasing over time due to inadequate surveillance and early detection strategies and practices, ineffective biosecurity practices among poultry raisers, and the complex supply chains of backyard and commercial poultry and live bird market (LBM) systems. Improving AIV surveillance in poultry flocks and LBMs, vaccination, biosecurity, and awareness among poultry professionals is beneficial to controlling the disease burden in the poultry sector. However, human cases of AIV related to poultry production and marketing chain in Bangladesh suggest a One Health approach engaging various stakeholders from the public and private would be a better option for successfully controlling avian influenza outbreaks in Bangladesh. This review of literature presents the comprehensive overview of AIV infection status in Bangladesh, including a description of pathways for zoonotic transmission at different epidemiological interfaces, the genetic evolution of the virus, and the need for improvement of disease control strategies incorporated with early detection, application of effective vaccines, increases the proper biosecurity practices and improvement of awareness among the poultry raisers, traders and consumers using a One Health approach.

Serosurvey for H5, H7 and H9 avian influenza viruses in local chickens in live bird markets within Kaduna metropolis, Nigeria

Since the first 2006 Avian Influenza (AI) outbreak in Nigeria, it has continued to circulate and ravage the poultry industry with huge economic losses above 130 billion naira. Local poultry are important sources of AI transmission and maintenance of the highly pathogenic avian influenza H5N1. Live bird markets (LBMs) are “breeding grounds” and major risk factors for human infection of AI. The seroprevalence of AI in local chickens in LBMs in Kaduna Metropolis, Nigeria was determined. Sera were obtained from the local chickens (n=300) in 5 daily LBMs and subjected to competitive enzyme-linked immunosorbent assay (c-ELISA) to detect the nucleoprotein antibodies. The c-ELISA positive samples were further screened by haemagglutination inhibition (HI) test for AI using H5, H7 and H9 antigens. The overall AI seroprevalence was 1.7 % with the highest individual seroprevalence of 3.3% in Kawo and Railway LBMs. There was no statistically significant association between the location of LBMs and AI presence, and between the sex and presence of AI antibodies (p = 0.427). One sample was HI positive for antibodies against H5, H7 and H9 with mean titers of 4, 2.5 and 3.5 log2, respectively. This implies the potential danger of the spread of AI among humans and animals. There should be sustained surveillance and biosecurity in the live bird market.