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Emerging and endemic zoonotic diseases continue to threaten human and animal health, our social fabric, and the global economy. Zoonoses frequently emerge from congregate interfaces where multiple animal species and humans coexist, including farms and markets. Traditional food markets are widespread across the globe and create an interface where domestic and wild animals interact among themselves and with humans, increasing the risk of pathogen spillover. Despite decades of evidence linking markets to disease outbreaks across the world, there remains a striking lack of pathogen surveillance programs that can relay timely, cost-effective, and actionable information to decision-makers to protect human and animal health. However, the strategic incorporation of environmental surveillance systems in markets coupled with novel pathogen detection strategies can create an early warning system capable of alerting us to the risk of outbreaks before they happen. Here, we explore the concept of “smart” markets that utilize continuous surveillance systems to monitor the emergence of zoonotic pathogens with spillover potential. IMPORTANCE Fast detection and rapid intervention are crucial to mitigate risks of pathogen emergence, spillover and spread-every second counts. However, comprehensive, active, longitudinal surveillance systems at high-risk interfaces that provide real-time data for action remain lacking. This paper proposes "smart market" systems harnessing cutting-edge tools and a range of sampling techniques, including wastewater and air collection, multiplex assays, and metagenomic sequencing. Coupled with robust response pathways, these systems could better enable Early Warning and bolster prevention efforts. [ABSTRACT FROM AUTHOR]

Background: 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. Methods: 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. Results: 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. Conclusions: 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. [ABSTRACT FROM AUTHOR]

Chicken infectious anemia virus (CIAV) is an economically important immunosuppressive pathogen of poultry. At present, very minimal information is available regarding CIAV in the Philippines. In this study, a total of fortynine Philippine native chickens from selected live bird markets from the municipalities of Rosario, Padre Garcia, and Lemery in Batangas were randomly collected and analyzed for the presence of CIAVs. All birds showed varying signs of non-specific disease ranging from respiratory signs, traumatic wounds and integumentary disorders. Five out of ten pooled tissue samples (10.20-51.02%) from the native chickens were confirmed to be positive for CIAV using polymerase chain reaction. Nucleotide sequencing and phylogenetic analyses showed that the field CIAV strains were genetically diverse and belong to genotypes A2, D1, and D2. Comparison of the nucleotide sequences of the VP1 gene showed that the Philippine CIAV strains had sequence similarity of 98-99% to field strains from South Korea, Taiwan, and China. Data obtained in this study are useful references in the development of molecular diagnostic tools and vaccine design to prevent CIAV in Philippine native chickens. [ABSTRACT FROM AUTHOR]

In 2013 to 2017, avian influenza A(H7N9) virus has caused five severe epidemic waves of human infections in China. The role of live bird markets (LBMs) in the transmission dynamics of H7N9 remains unclear. Using a Bayesian phylodynamic approach, we shed light on past H7N9 transmission events at the human-LBM interface that were not directly observed using case surveillance data-based approaches. Our results reveal concurrent circulation of H7N9 lineages in Yangtze and Pearl River Delta regions, with evidence of local transmission during each wave. Our results indicate that H7N9 circulated in humans and LBMs for weeks to months before being first detected. Our findings support the seasonality of H7N9 transmission and suggest a high number of underreported infections, particularly in LBMs. We provide evidence for differences in virus transmissibility between low and highly pathogenic H7N9. We demonstrate a regional spatial structure for the spread of H7N9 among LBMs, highlighting the importance of further investigating the role of local live poultry trade in virus transmission. Our results provide estimates of avian influenza virus (AIV) transmission at the LBM level, providing a unique opportunity to better prepare surveillance plans at LBMs for response to future AIV epidemics. [ABSTRACT FROM AUTHOR]

The influenza A virus of the H7N9 subtype (FLUAV H7N9) emerged in Eastern China provinces in 2013 causing illness in both poultry and humans. Most reported FLUAV H7N9 human cases were related to those associated with the live poultry market chain. From 2013 to 2017, there were five epidemic waves of human infections, and from the end of 2016, the number of human cases increased sharply. To control FLUAV H7N9 in the market chain, the so‐called '1110' policy at live poultry markets and a national vaccination programme were implemented. The relative efficacy of these two measures on the number of poultry and human infections has not been quantified and compared. To explore their efficacy, a cross‐sectional study was conducted in six provinces of China, and the vaccination and surveillance data of H7N9 were analysed. Our survey data showed that poultry vendors were not widely aware of and did not accept the '1110' policy. For subjective and objective factors, some measures of the '1110' policy were not implemented in live bird markets (LBMs). However, the national vaccination programme achieved good immune effects and sharply decreased poultry FLUAV H7N9 infections. The detection rates of FLUAV H7N9 in LBMs and farms gradually decreased since the vaccination programme was implemented. Our analysis also indicated that human infections were closely related to poultry virus carriage rates; therefore, controlling FLUAV H7N9 circulation in poultry was an effective measure to control FLUAV H7N9 infections in humans. Although LBMs play a significant role in human infections, the management measures may not be implemented efficiently; hence, we need to conduct more investigations before developing related policies. [ABSTRACT FROM AUTHOR]

We evaluated the presence of influenza A(H5) virus environmental contamination in live bird markets (LBMs) in Dhaka, Bangladesh. By using Bernoulli generalized linear models and multinomial logistic regression models, we quantified LBM-level factors associated with market work zone-specific influenza A(H5) virus contamination patterns. Results showed higher environmental contamination in LBMs that have wholesale and retail operations compared with retail-only markets (relative risk 0.69, 95% 0.51-0.93; p = 0.012) and in March compared with January (relative risk 2.07, 95% CI 1.44-2.96; p<0.001). Influenza A(H5) environmental contamination remains a public health problem in most LBMs in Dhaka, which underscores the need to implement enhanced biosecurity interventions in LBMs in Bangladesh. [ABSTRACT FROM AUTHOR]

The development of an antimicrobial stewardship plan (AMSP) for live bird sellers (LBS) requires an understanding of the current biosecurity status, antimicrobial use (AMU) and the practices involved in live bird selling (e.g., drivers, sellers, etc.) which is a direct source of poultry meat for human consumption. Seven Live Bird Markets (LBMs) within Abeokuta, Ogun State were surveyed using a semi-structured questionnaire. Data on LBMs characteristics, LBS demographics, biosecurity, and AMU practices, awareness on Antimicrobial Resistance (AMR), as well as preferred channels of information on antimicrobial stewardship were gathered. A total of 40 consenting LBS with 82.5% female and 17.5% male participants were included in the study. The participants' mean age was 45.3 years (SD±11.9, range: 23-70 years). Laying hens, broilers, and cockerels were the main poultry types sold by LBS. Antimicrobials (AMs) were used for growth promotion (57.5%), therapeutic (40.0%), and prophylactic (2.5%) purposes. Tetracycline, metronidazole, and chloramphenicol were the most frequently used AMs. The majority of the participants (90.0%) have treated birds based on their empirical experience, with little or no inputs from veterinarians. Biosecurity and AMU practices were generally low (54.0% and 34.0%, respectively). The contact with veterinarians was associated with satisfactory biosecurity practices (p=0.049). No significant factors were found to be linked with AMU. This study has provided recent evidence-based data on practices in poultry management among LBS in Abeokuta, Ogun state. The findings would be useful for policy decisions and the development of AMSP on prudent AMU among LBS. [ABSTRACT FROM AUTHOR]

In Bangladesh, live bird market environments are frequently contaminated with avian influenza viruses. Shop-level biosecurity practices might increase risk for environmental contamination. We sought to determine which shop-level biosecurity practices were associated with environmental contamination. We surveyed 800 poultry shops to describe biosecurity practices and collect environmental samples. Samples from 205 (26%) shops were positive for influenza A viral RNA, 108 (14%) for H9, and 60 (8%) for H5. Shops that slaughtered poultry, kept poultry overnight, remained open without rest days, had uneven muddy floors, held poultry on the floor, and housed sick and healthy poultry together were more frequently positive for influenza A viruses. Reported monthly cleaning seemed protective, but disinfection practices were not otherwise associated with influenza A virus detection. Slaughtering, keeping poultry overnight, weekly rest days, infrastructure, and disinfection practices could be targets for interventions to reduce environmental contamination. [ABSTRACT FROM AUTHOR]

Vietnamese poultry are host to co‐circulating subtypes of avian influenza viruses, including H5N1 and H9N2, which pose a great risk to poultry productivity and to human health. AIVs circulate throughout the poultry trade network in Vietnam, with live bird markets being an integral component to this network. Traders at LBMs exhibit a variety of trading practices, which may influence the transmission of AIVs. We identified trading practices that impacted on AIV prevalence in chickens marketed in northern Vietnamese LBMs. We generated sequencing data for 31 H9N2 and two H5N6 viruses. Viruses isolated in the same LBM or from chickens sourced from the same province were genetically closer than viruses isolated in different LBMs or from chickens sourced in different provinces. The position of a vendor in the trading network impacted on their odds of having AIV‐infected chickens. Being a retailer and purchasing chickens from middlemen was associated with increased odds of infection, whereas odds decreased if vendors purchased chickens directly from large farms. Odds of infection were also higher for vendors having a greater volume of ducks unsold per day. These results indicate how the spread of AIVs is influenced by the structure of the live poultry trading network. [ABSTRACT FROM AUTHOR]

The local chicken constitutes a major part of our poultry population providing eggs and meat for domestic and commercial purposes. They however get very little or no medical attention making them vulnerable to parasitic infection. This study was conducted to determine the prevalence of gastrointestinal (GI) helminths of local chickens slaughtered in four Live Bird Markets (LBMs) in Makurdi between September and December, 2016. A total of 200 gastrointestinal samples were collected from male and female chickens and were examined for GI helminths using the flotation method. A total of 110 chickens were infected with an overall prevalence of 55.0% with 69(34.5%) having single infection, 32(16.0%) double infection, 8(4.0%) triple infection and 1(0.50%) had quadruple infection. Ten species of GI helminths were encountered, three cestodes and seven nematodes. Rallietina species with 73(36.5%) was the most prevalent followed by Ascaridia galli 36(18.0%), Amidostomum anseris 1(0.5%) and Davainea proglottina 1(0.5%) as the least prevalent. There was no statistical significant difference between the four different LBMs (p = 0.058) but there was statistical significant difference in the infection rate based on sex (P= 0.041) and site of preference by the parasite (p = 0.00). Based on location of parasites in the GIT 60.5% of the species were restricted to the small intestine, with the large intestine having 19.5%. This study confirms the presence of GI parasites in the local chickens slaughtered in Makurdi. There is need to institute proper measures in the control of GI helminthes which will further improve the productivity of our local chicken. [ABSTRACT FROM AUTHOR]

Avian influenza in domestic poultry can have varied impacts on the health and welfare of birds and an economic burden on producers, consumers, and animal health agencies including the cost to control and eradicate avian influenza. Low pathogenic avian influenza has historically been a recurring issue in U.S. live bird markets, but rarely studied. Live bird markets source various species of birds and mammals from a variety of wholesalers and sell either live animals or freshly harvested animals. Using cost estimates from the 2016 outbreak of low pathogenic avian influenza in northeastern U.S. live bird markets, estimates of the mean per market costs were calculated for responding government agencies ($804) and the market itself ($3,997), including traceback investigation, testing costs, and cleaning and disinfection. The economic impact also included market impacts which the majority are affected by income that the live bird markets forego during cleaning and disinfection ($3,998 per market) with an expected shutdown of 3–5d. Animal health agencies' responses to a disease depend on the established disease response and resources, such as labor and funding. Understanding the economic costs of disease management improves the decision-making process for these agencies and markets as a whole to limit disease introduction, spread, longevity, and market impacts through business disruptions and foregone income. [ABSTRACT FROM AUTHOR]

Background: In this study, we aimed to identify the effect of market-level risk factors on avian influenza (AI) infection in poultry and humans and generate evidence that will inform AI prevention and control programs at live bird markets (LBMs).Methods: We performed a systematic literature review in both English and Chinese search engines. We estimated the pooled odds ratios of biosecurity indicators relating to AI infections at market level using a quality effects (QE) meta-analysis model.Results: Biosecurity measures effective at reducing AI market contamination and poultry infection at LBMs include smaller market size, selling single poultry species and separating different species, performing cleaning and disinfection and market closures, ban on overnight storage, and sourcing poultry from local areas. Our meta-analysis indicates that higher risk of exposure to AI infection occurs in workers at retail LBMs, female workers, and those who contact ducks, conduct cleaning, slaughtering, defeathering, or evisceration.Conclusions: The most effective strategies to reduce AI market contamination identified in this study should target larger LBMs that are located at noncentral city areas and sell and slaughter multispecies of live poultry. Live bird market workers directly involved in cleaning and poultry processing tasks should participate in occupational health and safety programs. [ABSTRACT FROM AUTHOR]

Abstract Live bird market surveillance for avian influenza viruses in Cambodia in 2015 has led to the detection of two 7:1 reassortant influenza A(H5N1) clade 2.3.2.1c viruses. These reassortant strains, designated A/duck/Cambodia/Z564W35M1/2015 and A/chicken/Cambodia/Z850W49M1/2015, both contained a single gene (PB1 and matrix gene, respectively) from concurrently circulating A(H9N2) influenza viruses. All other viral genes from both isolates clustered with A(H5N1) clade 2.3.2.1 viruses. Continued and prolonged co-circulation of influenza A(H5N1) and A(H9N2) viruses in Cambodian live bird markets may present a risk for the emergence of novel influenza reassortant viruses with negative agricultural and/or public health implications. Highlights • Two 7:1A(H5N1) reassortant viruses were isolated from Cambodian live bird markets. • Viruses contained single genes (PB1 and matrix gene) from A(H9N2) influenza viruses. • Emergence of novel avian influenza reassortants presents a public health risk. [ABSTRACT FROM AUTHOR]

Live bird markets (LBM) are important for trading poultry in many developing countries where they are being considered hotspots of Avian Influenza Virus (AIV) prevalence and contamination. An active surveillance for Avian Influenza Virus (AIV) was conducted on four species of LBM birds (chickens, ducks, quails and pigeons) from 10 of the largest LBM in Chittagong, Bangladesh, and two species of peri-domestic wild birds (house crow and Asian pied starling) in their direct vicinity from November 2012 until September 2016. Our aim was to identify the scale and annual pattern of AIV circulation in both the LBM birds and the two per-domestic wild bird species living in close proximity of the LBM. In the latter two species, the annual pattern in AIV antibody prevalence was additionally investigated. A total of 4770 LBM birds and 1119 peri-domestic wild birds were sampled. We used rt-PCR for detection of the AIV M-gene and AIV subtypes H5, H7 and H9 from swab samples. We used c-ELISA for AIV antibody detection from serum samples of peri-domestic wild birds. Average AIV prevalence among the four LBM species varied between 16 and 28%, whereas no AIV was detected in peri-domestic wild birds by rt-PCR. In all LBM species we found significantly higher AIV prevalence in winter compared to summer. A similar pattern was found in AIV antibody prevalence in peri-domestic wild birds feeding in the direct vicinity of LBM. For the subtypes of AIV investigated, we found a significantly higher proportion of AIV H5 in LBM chickens and H9 in LBM ducks. No H7 was detected in any of the investigated samples. We conclude that AIV and notably AIV H5 and H9 were circulating in the investigated LBM of Bangladesh with clear seasonality that matched the prevalence of AIV antibodies of peri-domestic wild birds. These patterns show great resemblance to the annual outbreak patterns in Bangladeshi poultry industry. Our data suggest considerable exchange of AIV within and among the four LBM bird species and peri-domestic wild birds, which likely contributes to the maintenance of the AIV problems in Bangladesh. Increasing biosecurity and notably reducing the direct and indirect mixing of various domestic bird species and peri-domestic wild birds and developing all-in-all-out selling systems with regular use of disinfectant are likely to reduce the risk of transmission and spread of AIV, including HPAI. [ABSTRACT FROM AUTHOR]

In Vietnam, live bird markets are found in most populated centres, providing the means by which fresh poultry can be purchased by consumers for immediate consumption. Live bird markets are aggregation points for large numbers of poultry, and therefore, it is common for a range of avian influenza viruses to be mixed within live bird markets as a result of different poultry types and species being brought together from different geographical locations. We conducted a cross-sectional study in seven live bird markets in four districts of Thua Thien Hue Province in August and December, 2014. The aims of this study were to (i) document the prevalence of avian influenza in live bird markets (as measured by virus isolation); and (ii) quantify individual bird-, seller- and market-level characteristics that rendered poultry more likely to be positive for avian influenza virus at the time of sale. A questionnaire soliciting details of knowledge, attitude and avian influenza practices was administered to poultry sellers in study markets. At the same time, swabs and faecal samples were collected from individual poultry and submitted for isolation of avian influenza virus. The final data set comprised samples from 1,629 birds from 83 sellers in the seven live bird markets. A total of 113 birds were positive for virus isolation; a prevalence of 6.9 (95% CI 5.8-8.3) avian influenza virus-positive birds per 100 birds submitted for sale. After adjusting for clustering at the market and individual seller levels, none of the explanatory variables solicited in the questionnaire were significantly associated with avian influenza virus isolation positivity. The proportions of variance at the individual market, seller and individual bird levels were 6%, 48% and 46%, respectively. We conclude that the emphasis of avian influenza control efforts in Vietnam should be at the individual seller level as opposed to the market level. [ABSTRACT FROM AUTHOR]

Highly pathogenic avian influenza H5N1 has resulted in large losses to the Indonesian poultry sector. Evidence suggests that live bird markets ( LBMs) play an important role in the epidemiology of the disease. Knowledge of the frequency and type of contact between the various poultry market players should allow animal health authorities to develop a better understanding of factors influencing virus transmission between Indonesian villages. A questionnaire-based cross-sectional survey was conducted in 17 LBMs on the neighbouring Indonesian islands of Bali and Lombok to investigate the movement patterns of poultry to and from markets. Using social network analyses, a network of contacts was created for each island from a total of 413 live poultry traders and 134 customers. Individual nodes with high degree and/or betweenness were identified in each network. The Lombok network was more dense and connected than the Bali network indicating that disease transmission would be more efficient in the Lombok network. Our findings indicate that whilst live poultry are typically transported over relatively short distances of approximately 10 km, it is not uncommon for traders and customers to travel in excess of 100 km to buy or sell poultry, which may facilitate the spread of disease over a large geographical area. This study highlights the different roles markets play in poultry movement networks and their potential for disease dissemination. The identification of highly influential market nodes allows authorities to target HPAI surveillance activities to locations where disease is more likely to be present, which is crucial in low-resource settings. [ABSTRACT FROM AUTHOR]

H5N1, a highly pathogenic avian influenza (H5N1 HPAI), is an endemic disease that is significant for public health in Egypt. Live bird markets ( LBMs) are widespread in Egypt and play an important role in HPAI disease dynamics. The aim of the study was to evaluate the H5N1 HPAI prevalence in representative LBMs from 2009 to 2014, assess the effects of other variables and evaluate past outbreaks and human cases. It was found that ducks and geese are high-risk species and that the prevalence of H5N1 HPAI was higher immediately after the political crises of 2011. The end of a calendar year (June to December) was a high-risk period for positive samples, and the risk in urban LBMs was twice the risk in rural LBMs. Winter and political unrest was associated with higher H5N1 HPAI prevalence. Both human and poultry populations will continue to rise in Egypt, so continued poultry outbreaks are likely to be linked to more human cases. LBMs will continue to play a role in the dynamics of poultry disease in Egypt, and there is a need to reorganize markets in terms of biosecurity and traceability. It may also be beneficial to reduce inter-governorate inter-regional movements associated with poultry trade through promotion of regional trade or in the alternative provide sanitary features along the poultry market chain to reduce the speed of H5N1 HPAI infections. Policy formulation, design and enforcement must be pro-poor, and consideration of the sociocultural and economic realities in Egypt is important. The LBMs provide ideal platforms to carry out sound surveillance plans and mitigate zoonotic risks of H5N1 HPAI to humans. [ABSTRACT FROM AUTHOR]

In Pakistan, avian influenza surveillance has been both active and passive. Here, we present the results of a survey effort focusing solely on the live bird markets and wild bird species from different zoos and national parks to understand the impact of live bird markets on the spread of highly pathogenic avian influenza viruses. A cross sectional survey was conducted from Jan-Dec 2011 to identify and isolate the circulating avian influenza virus subtypes in live bird markets and wild birds from different localities in and around Islamabad Capital Territory. Swabs, tracheal tissues and sera samples were collected, screened and diagnosed by hemagglutination inhibition assay and RT-PCR. The highest seropositivity was recorded for H9 (100 %) followed by H5 (89.4%) and H7 (72.3%). All 27 isolates were of the low pathogenic H9N2 subtypes and no viruses could be successfully isolated of subtype H5N1 or H7N7. The higher prevalence of H5N1 (89.4%) observed in the present study was an alarming threat; therefore, we suggested immediate control strategies against this emerging risk of H5N1 for human in live bird markets in Pakistan. The factors unveiled in this study will help in understanding the lapses in controlling persistent outbreaks of avian influenza in country. [ABSTRACT FROM AUTHOR]

Avian influenza viruses (AIVs) continue to pose a global threat. Waterfowl are the main reservoir and are responsible for the spillover of AIVs to other hosts. This study was conducted as part of routine surveillance activities in Bangladesh and it reports on the serological and molecular detection of H5N1 AIV subtype. A total of 2169 cloacal and 2191 oropharyngeal swabs as well as 1725 sera samples were collected from live birds including duck and chicken in different locations in Bangladesh between the years of 2013 and 2014. Samples were tested using virus isolation, serological tests and molecular methods of RT-PCR. Influenza A viruses were detected using reverse transcription PCR targeting the virus matrix (M) gene in 41/4360 (0.94%) samples including both cloacal and oropharyngeal swab samples, 31 of which were subtyped as H5N1 using subtype-specific primers. Twenty-one live H5N1 virus isolates were recovered from those 31 samples. Screening of 1,868 blood samples collected from the same birds using H5-specific ELISA identified 545/1603 (34%) positive samples. Disconcertingly, an analysis of 221 serum samples collected from vaccinated layer chicken in four districts revealed that only 18 samples (8.1%) were seropositive for anti H5 antibodies, compared to unvaccinated birds (n = 105), where 8 samples (7.6%) were seropositive. Our result indicates that the vaccination program as currently implemented should be reviewed and updated. In addition, surveillance programs are crucial for monitoring the efficacy of the current poultry vaccinations programs, and to monitor the circulating AIV strains and emergence of AIV subtypes in Bangladesh. [ABSTRACT FROM AUTHOR]

Summary Background Previous research has suggested that avian influenza A H7N9 has a greater potential pandemic risk than influenza A H5N1. This research investigated the difference in human clustered and sporadic cases of H7N9 virus and estimated the relative risk of clustered infections. Methods Comparative epidemiology and virology studies were performed among 72 sporadic confirmed cases, 17 family clusters (FCs) caused by human-to-human transmission, and eight live bird market clusters (LCs) caused by co-exposure to the poultry environment. Results The case fatality of FCs, LCs and sporadic cases (36%, 26%, and 29%, respectively) did not differ among the three groups ( p > 0.05). The average age (36 years, 60 years, and 58 years), co-morbidities (31%, 60%, and 54%), exposure to birds (72%, 100%, and 83%), and H7N9-positive rate (20%, 64%, and 35%) in FCs, LCs, and sporadic cases, respectively, differed significantly ( p < 0.05). These higher risks were associated with increased mortality. There was no difference between primary and secondary cases in LCs ( p > 0.05). However, exposure to a person with confirmed avian influenza A H7N9 (primary 12% vs. secondary 95%), history of visiting a live bird market (100% vs. 59%), multiple exposures (live bird exposure and human-to-human transmission history) (12% vs. 55%), and median days from onset to antiviral treatment (6 days vs. 3 days) differed significantly between primary and secondary cases in FCs ( p < 0.05). Mild cases were found in 6% of primary cases vs. 32% of secondary cases in FCs ( p < 0.05). Twenty-five isolates from the three groups showed 99.1–99.9% homology and increased human adaptation. Conclusions There was no statistical difference in the case fatality rate and limited transmission between FCs and LCs. However, the severity of the primary cases in FCs was much higher than that of the secondary cases due to the older age and greater underlying disease of the latter patients. [ABSTRACT FROM AUTHOR]

Live bird markets (LBMs) are essential for marketing poultry, but have been linked to many outbreaks of avian influenza (AI) and its spread. In Uganda, it has been observed that demographic characteristics of poultry traders/handlers influence activities and decision-making in LBMs. The study investigated the influence of socio-demographic characteristics of poultry handlers: age, sex, religion, educational background, level of income, location of residence and region of operation on 20 potential risk factors for introduction and spread of AI in LBMs. Study sites included 39 LBMs in the four regions of Uganda. Data was collected using a semi-structured questionnaire administered to 424 poultry handlers. We observed that background of education was a predictor for slaughter and processing of poultry in open sites. Location of residence was associated with slaughter of poultry from open sites and selling of other livestock species. Region influenced stacking of cages, inadequate cleaning of cages, feeders and drinkers, and provision of dirty feed and water. Specifically, bird handlers with secondary level of education (OR = 12.9, 95% CI: 2.88-57.4, P < 0.01) were more likely to be involved in open site slaughter of poultry than their counterparts without formal education. Comparatively, urbanite bird handlers were less likely to share poultry equipment (OR = 0.4, 95% CI: 0.22-0.63, P < 0.01) than rural resident handlers. Poultry handlers in Northern were 3.5 times more likely to practise insufficient cleaning of cages (OR = 3.5, 95% CI: 1.52-8.09) compared to those in Central region. We demonstrated that some socio-demographic characteristics of poultry handlers were predictors to risky practices for introduction and spread of AI viruses in LBMs in Uganda. [ABSTRACT FROM AUTHOR]

Background: Newcastle disease is still a serious disease of poultry especially in backyard free-range production systems despite the availability of cross protective vaccines. Healthy-looking poultry from live bird markets have been suspected as a major source of disease spread although limited studies have been conducted to ascertain the presence of the virulent strains in the markets and to understand how they are related to outbreak strains. Methods: This study evaluated the occurrence of Newcastle disease virus in samples collected from poultry in live bird markets across Uganda. The isolates were pathoyped using standard methods (mean death time (MDT), intracelebral pathogenicity index (ICPI), and sequencing of the fusion protein cleavage site motif) and also phylogenetically analysed after sequencing of the full fusion and hemagglutin-neuraminidase genes. The isolates were classified into genotypes and subgenotypes based on the full fusion protein gene classification system and compared with other strains in the region and world-wide. Results: Virulent avian paramyxovirus type I (APMV-1) (Newcastle disease virus) was isolated in healthy-looking poultry in live bird markets. The viruses belonged to a new subgenotype, Vd, in genotype V, and clustered together with Tanzania and Kenya strains. They harbored low genetic diversity. Conclusion: The occurrence of virulent AMPV-1 strains in live bird markets may serve as sources of Newcastle disease outbreaks in non-commercial farms. [ABSTRACT FROM AUTHOR]

Abstract: Indonesia continues to report the highest number of human and poultry cases of highly pathogenic avian influenza H5N1. The disease is considered to be endemic on the island of Bali. Live bird markets are integral in the poultry supply chain on Bali and are important, nutritionally and culturally, for the rural and urban human populations. Due to the lack of biosecurity practiced along the supply chain from producer to live bird markets, there is a need to understand the risks associated with the spread of H5N1 through live bird movements for effective control. Resources to control H5N1 in Indonesia are very limited and cost effective strategies are needed. We assessed the probability a live bird market is infected through live poultry movements and assessed the effects of implementing two simple and low cost control measures on this risk. Results suggest there is a high risk a live bird market is infected (0.78), and risk mitigation strategies such as detecting and removing infected poultry from markets reduce this risk somewhat (range 0.67–0.76). The study demonstrates the key role live poultry movements play in transmitting H5N1 and the need to implement a variety of control measures to reduce disease spread. [Copyright &y& Elsevier]

Background: The endemic H5N1 high pathogenicity avian influenza virus (A/H5N1) in poultry in Egypt continues to cause heavy losses in poultry and poses a significant threat to human health. Methods: Here we describe results of A/H5N1 surveillance in domestic poultry in 2009 and wild birds in 2009-2010. Tracheal and cloacal swabs were collected from domestic poultry from 22024 commercial farms, 1435 backyards and 944 live bird markets (LBMs) as well as from 1297 wild birds representing 28 different types of migratory birds. Viral RNA was extracted from a mix of tracheal and cloacal swabs media. Matrix gene of avian influenza type A virus was detected using specific real-time reverse-transcription polymerase chain reaction (RT-qPCR) and positive samples were tested by RT-qPCR for simultaneous detection of the H5 and N1 genes. Results: In this surveillance, A/H5N1 was detected from 0.1% (n = 23/) of examined commercial poultry farms, 10.5% (n = 151) of backyard birds and 11.4% (n = 108) of LBMs but no wild bird tested positive for A/H5N1. The virus was detected from domestic poultry year-round with higher incidence in the warmer months of summer and spring particularly in backyard birds. Outbreaks were recorded mostly in Lower Egypt where 95.7% (n = 22), 68.9% (n = 104) and 52.8% (n = 57) of positive commercial farms, backyards and LBMs were detected, respectively. Higher prevalence (56%, n = 85) was reported in backyards that had mixed chickens and waterfowl together in the same vicinity and LBMs that had waterfowl (76%, n = 82). Conclusion: Our findings indicated broad circulation of the endemic A/H5N1 among poultry in 2009 in Egypt. In addition, the epidemiology of A/H5N1 has changed over time with outbreaks occurring in the warmer months of the year. Backyard waterfowl may play a role as a reservoir and/or source of A/H5N1 particularly in LBMs. The virus has been established in poultry in the Nile Delta where major metropolitan areas, dense human population and poultry stocks are concentrated. Continuous surveillance, tracing the source of live birds in the markets and integration of multifaceted strategies and global collaboration are needed to control the spread of the virus in Egypt. [ABSTRACT FROM AUTHOR]

Please cite this paper as: Chander et al. (2012) Molecular and phylogenetic analysis of matrix gene of avian influenza viruses isolated from wild birds and live bird markets in the USA. Influenza and Other Respiratory Viruses 7(4), 513-520. Background Wild birds are the natural hosts for influenza A viruses (IAVs) and provide a niche for the maintenance of this virus. Objectives This study was undertaken to analyze nucleotide sequences of the matrix (M) gene of AIVs isolated from wild birds and live bird markets (LBMs) to index the changes occurring in this gene. Methods M-gene of 229 avian influenza virus (AIV) isolates obtained from wild birds and LBMs was amplified and sequenced. Full-length sequences (∼900 nt.) thus obtained were analyzed to identify changes that may be associated with resistance to adamantanes. Phylogenetic analysis of all sequences was performed using clustalw, and evolutionary distances were calculated by maximum composite likelihood method using mega ( ver. 5.0) software. Results Twenty-seven different viral subtypes were represented with H3N8 being the most dominant subtype in wild birds and H7N2 being the predominant subtype among isolates from LBMs. Phylogenetic analysis of the M-gene showed a high degree of nucleotide sequence identity with US isolates of AIVs but not with those of Asian or European lineages. While none of the isolates from wild birds had any antiviral resistance-associated mutations, 17 LBM isolates carried polymorphisms known to cause reduced susceptibility to antiviral drugs (adamantanes). Of these 17 isolates, 16 had S31N change and one isolate had V27A mutation. Conclusions These results indicate independent evolution of M-gene in the absence of any antiviral drugs leading to mutations causing resistance indicating the need for continued active surveillance of AIVs. [ABSTRACT FROM AUTHOR]

Please cite this paper as: Munyua et al. (2013) Detection of influenza A virus in live bird markets in Kenya, 2009-2011. Influenza and Other Respiratory Viruses 7(2), 113-119. Background Surveillance for influenza viruses within live bird markets (LBMs) has been recognized as an effective tool for detecting circulating avian influenza viruses (AIVs). In Sub-Saharan Africa, limited data exist on AIVs in animal hosts, and in Kenya the presence of influenza virus in animal hosts has not been described. Objectives This surveillance project aimed to detect influenza A virus in poultry traded in five LBMs in Kenya. Methods We visited each market monthly and collected oropharyngeal and cloacal specimens from poultry and environmental specimens for virological testing for influenza A by real time RT-PCR. On each visit, we collected information on the number and types of birds in each market, health status of the birds, and market practices. Results During March 24, 2009-February 28, 2011, we collected 5221 cloacal and oropharyngeal swabs. Of the 5199 (99·6%) specimens tested, influenza A virus was detected in 42 (0·8%), including 35/4166 (0·8%) specimens from chickens, 3/381 (0·8%) from turkeys, and 4/335 (1·2%) from geese. None of the 317 duck specimens were positive. Influenza was more commonly detected in oropharyngeal [33 (1·3%)] than in cloacal [9 (0·4%)] specimens. None of the 485 environmental specimens were positive. Virus was detected in all five markets during most (14/22) of the months. Ducks and geese were kept longer at the market (median 30 days) than chickens (median 2 days). Conclusions Influenza A was detected in a small percentage of poultry traded in LBMs in Kenya. Efforts should be made to promote practices that could limit the maintenance and transmission of AIVs in LBMs. [ABSTRACT FROM AUTHOR]

Live bird markets and contacts between them through poultry traders are known risk factors in the spread of diseases such as Newcastle disease. A traders' questionnaire survey was used to build networks of chicken movements among 29 shared markets during and outside festive seasons in the Oromia region of Ethiopia. A comparison was made between typologies built using centrality indexes (in-degree, out-degree, in-closeness, out-closeness and random-walk betweenness) and descriptive characteristics of the markets (number of chickens, number and type of sellers and the frequency with which they use different markets). The festive seasons did not appear to have an impact on the network structure, implying that it was not necessary to make structural changes to surveillance targets during these periods. Based on centrality indices, three markets (Meki, Debre Zeit and Adulala) emerged from the typology as being central to the network, which would not have been deduced from their descriptive characteristics alone. These three poultry markets ideally would be chosen in a risk-based type of surveillance system and in targeted control policies. [ABSTRACT FROM AUTHOR]

Abstract: Live bird markets (LBMs) are at risk of contamination with the avian influenza H5N1 virus. There are a number of methods for prioritizing LBMs for intervention to curb the risk of contamination. Selecting a method depends on diagnostic objective and disease prevalence. In a low resource setting, options for prioritization are constricted by the cost of and resources available for tool development and administration, as well as the resources available for intervention. In this setting, tools can be developed using previously collected data on risk factors for contamination, and translated into prediction equations, including decision trees (DTs). DTs are a graphical type of classifier that combine simple questions about the data in an intuitive way. DTs can be used to develop tools tailored to different diagnostic objectives. To demonstrate the utility of this method, risk factor data arising from a previous cross-sectional study in 83 LBMs in Indonesia were used to construct DTs. A DT with high specificity was selected for the initial stage of an LBM intervention campaign in which authorities aim to focus intervention resources on a small set of LBMs that are at near-certain risk of contamination. Another DT with high sensitivity was selected for later stages in an intervention campaign in which authorities aim to detect and prioritize all LBMs with the risk factors for virus contamination. The best specific DT achieved specificity of 77% and the best sensitive DT achieved sensitivity of 90%. The specific DT had two variables: the size of the duck population in the LBM and the human population density in the LBM''s district. The sensitive DT had three variables: LBM location, whether solid waste was removed from the LBM daily and whether the LBM was zoned to separate the bird holding, slaughtering and sale areas. High specificity or sensitivity will be preferred by authorities depending on the stage of the intervention campaign. The study demonstrates that simple tools utilizing DTs can be developed to prioritize LBMs for intervention to control H5N1-virus. DT tools are simple to apply, suitable for low-resource settings and can be tailored to the particular needs and stage of the disease control program. [Copyright &y& Elsevier]

Background: Uninterrupted transmission of highly pathogenic avian influenza virus (HPAIV) H5N1 of clade 2.2.1 in Egypt since 2006 resulted in establishment of two main genetic clusters. The 2.2.1/C group where all recent human and majority of backyard origin viruses clustered together, meanwhile the majority of viruses derived from vaccinated poultry in commercial farms grouped in 2.2.1.1 clade. Findings: In the present investigation, an HPAIV H5N1 was isolated from twenty weeks old layers chickens that were vaccinated with a homologous H5N1 vaccine at 1, 7 and 16 weeks old. At twenty weeks of age, birds showed cyanosis of comb and wattle, decrease in egg production and up to 27% mortality. Examined serum samples showed low antibody titer in HI test (Log2 3.2± 4.2). The hemagglutinin (HA) and neuraminidase (NA) genes of the isolated virus were closely related to viruses in 2.2.1/C group isolated from poultry in live bird market (LBM) and backyards or from infected people. Conspicuous mutations in the HA and NA genes including a deletion within the receptor binding domain in the HA globular head region were observed. Conclusions: Despite repeated vaccination of layer chickens using a homologous H5N1 vaccine, infection with HPAIV H5N1 resulted in significant morbidity and mortality. In endemic countries like Egypt, rigorous control measures including enforcement of biosecurity, culling of infected birds and constant update of vaccine virus strains are highly required to prevent circulation of HPAIV H5N1 between backyard birds, commercial poultry, LBM and humans. [ABSTRACT FROM AUTHOR]

Abstract: Live bird markets can become contaminated with and become a source of transmission for avian influenza viruses including the highly pathogenic H5N1 strain. Many countries affected by the H5N1-virus have limited resources for programs in environmental health, sanitation and disease control in live bird markets. This study proposes five critical control points (CCPs) to reduce the risk of H5N1-virus contamination in markets in low resource settings. The CCPs were developed based on three surveys conducted in Indonesia: a cross-sectional survey in 119 markets, a knowledge, attitudes and practice survey in 3 markets and a microbiological survey in 83 markets. These surveys assessed poultry workflow, market infrastructure, hygiene and regulatory practices and microbiological contamination with the H5N1-virus. The five CCPs identified were (1) reducing risk of receiving infected birds into the market, (2) reducing the risk of virus spread between different bird flocks in holding cages, (3) reducing surface contamination by isolating slaughter processes from other poultry-related processes, (4) minimizing the potential for contamination during evisceration of carcasses and (5) reducing the risk of surface contamination in the sale zone of the market. To be relevant for low resource settings, the CCPs do not necessitate large infrastructure changes. The CCPs are suited for markets that slaughter poultry and have capacity for daily disposal and removal of solid waste from the market. However, it is envisaged that the CCPs can be adapted for the development of risk-based programs in various settings. [Copyright &y& Elsevier]

Since 2006, multiple outbreaks of avian influenza (AI) have been reported in Nigeria involving different subtypes. Surveillance and molecular epidemiology have revealed the vital role of live bird markets (LBMs) in the dissemination of AI virus to commercial poultry farms. To better understand the ecology and epidemiology of AI in Nigeria, we performed whole-genome sequencing of nineteen H9N2 viruses recovered, from apparently healthy poultry species, during active surveillance conducted in nine LBMs across Nigeria in 2019. Analyses of the HA gene segment of these viruses showed that the H9N2 strains belong to the G1 lineage, which has zoonotic potential, and are clustered with contemporary H9N2 identified in Africa between 2016 and 2020. We observed two distinct clusters of H9N2 viruses in Nigeria, suggesting different introductions into the country. In view of the zoonotic potential of H9N2 and the co-circulation of multiple subtypes of AI virus in Nigeria, continuous monitoring of the LBMs across the country and molecular characterization of AIVs identified is advocated to mitigate economic losses and public health threats. [ABSTRACT FROM AUTHOR]

Yellow broilers are the primary source of poultry consumption in China and the predominant trade of live poultry. However, knowledge of the value chain is limited, which is vital evidence for the effective control of H7N9 and other zoonotic avian influenzas. The aim of the study was to map the yellow broiler value chain in Guangxi Zhuang Autonomous Region, China and investigate its governance structure and practices relevant to the risk of H7N9 transmission. A value chain analysis was conducted in five areas of Guangxi from May to August 2018. To map the value chain, three focus group discussions (FGDs) were conducted and stakeholders, products and premises involved and their interactions were identified. Then, 55 key informant interviews (KIIs) collected qualitative data on stakeholders' profile, practices and interactions with other stakeholders and rules/norms that exist along the value chain. On-site observations were also carried out at different types of premises along the value chain to complement and validate findings of KIIs and FGDs. Participants were also asked to provide proportional estimates of each component in the value chain where possible. The qualitative data from FGDs, KIIs and on-site observations were analysed to create stakeholder profiles and a diagram of product flows and stakeholders' interactions. Thematic analysis was used to identify the governance structure of the value chains and practices relevant to the risk of H7N9 transmission. The stakeholders and premises involved in Guangxi yellow broiler production, wholesale and retail were described, as well as their interactions. Contract farming is extensively adopted in Guangxi; consequently yellow broiler grower companies are the dominant stakeholders. The trading platform was identified as a key premise linking farms and live bird markets. The thematic analysis highlighted poor biosecurity practices in different premises along the value chain, which was supported by on-site observations. The operation of trading platforms reported in this study presents a disease risk but is not considered in the current H7N9 control programs. The study suggested that biosecurity management gaps need to be addressed through government-industry partnerships that require engagement with private stakeholders in the planning and implementation of H7N9 control strategies incentivising participation of grower companies, wholesalers and retailers. [ABSTRACT FROM AUTHOR]