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.

Spatial distribution and hydrogeochemical evaluations of groundwater and its suitability for drinking and irrigation purposes in kaligonj upazila of satkhira district of Bangladesh.

Groundwater is a significant water resource for drinking and irrigation in Satkhira district, Bangladesh. The depletion of groundwater resources and deterioration in its quality are the results of the confluence of factors such as industrialization, intensive irrigation, and rapid population growth. For this reason, this study focused on the evaluation of tubewell water of six unions of Kaligonj upazila in Satkhira district, which is situated in the coastal southwest part of Bangladesh. Major and trace elemental concentrations were assimilated into positive matrix factorization (PMF) to identify potential sources and their respective contributions. Principal component analysis (PCA) revealed that groundwater salinization and manmade activities were the primary causes of heavy metals in the coastal groundwater. Its average pH value was found to be 7.5, while Dissolved oxygen, Total dissolved solids, salinity, and conductivity, with values ranging from 1.18 to 7.38 mg/L, 0.5-4.88 g/L, 0.4-5%, and 0.95 to 8.56 mS/cm, respectively. The total hardness average value was 561.7 mg/L, classified into the very hard water categories, which is why 90% of the tubewell water samples were unfit for household purposes. All samples had an excessive level of arsenic present. The iron concentration of fifteen (15) samples crossed the standard limit according to WHO 2011 value. Around 63% of the samples were of the Na+-K+-Cl--SO42- type, and about 72% were sodium-potassium and alkali types. 98% of samples were covered in chloride and bicarbonate. The findings showed that 45.83% of the groundwater samples had negative Chloroalkaline index (CAIs), while 54.16% had positive. The permeability index (PI) was an average of 73%, and residual sodium carbonate (RSC) averaged 260.2 mg/L, and the findings clearly showed that 80% of the samples weren't appropriate for irrigation. According to the sodium adsorption ratio (SAR) value, 65% of the samples fell into the unsuitable category. These calculations indicated a high overall salinity hazard in the study area, which may be caused by the intrusion of sea water given that the study area is close to the coastal region. Findings compared to standards revealed that the majority of the samples were deemed unfit for drinking and irrigation purposes. Hence, additional attention must be paid to this area to ensure the availability of drinkable water and to preserve sustainable farming practices.

Mapping of dressed and processed poultry products in Bangladesh: Identifying the food safety risks for policy intervention.

Bangladesh's commercial poultry production is growing rapidly, including the commercial processing of poultry. This expansion of poultry processing plants is fueled by the belief that this sub-sector provides safer food and has less food-borne disease risks compared to traditional live bird markets (LBMs). The purpose of this study is to describe Bangladesh's dressed and processed poultry production and distribution network (PDN), identify what and where quality control occurs, and suggest where improvements could be made. Engaging with PDN for dressed and processed poultry, we used in-depth interviews with key informants to identify the stakeholders involved and their connections with other poultry PDNs. In addition, we mapped out the supply and distribution of dressed and processed poultry and quality control processes occurring throughout the network. We argue that dressed and processed poultry PDNs are closely connected with traditional PDNs such as LBMs, with multiple crossover points between them. Also, there is a lack of consistency in quality control testing and a lack of meat traceability. Consequently, perceptions of dressed and processed poultry being safer than birds from LBMs needs to be treated with caution. Otherwise, unsubstantiated consumer confidence in dressed poultry may inadvertently increase the risk of food-borne diseases from these products.

Measures, Gaps, and Mitigation Strategies in Bangladesh's COVID-19 Response.

The Coronavirus Disease 2019 (COVID-19) spread rapidly from China to most other countries around the world in early 2020 killing millions of people. To prevent virus spread, world governments implemented a variety of response measures. This paper's objectives were to discuss the country's adopted measures to combat the virus through June 2020, identify gaps in the measures' effectiveness, and offer possible mitigations to those gaps. The measures taken included screening device deployment across international air and land ports, flight suspensions and closures from COVID-19 affected countries, and declaration and extension of a national public holiday (equivalent to lockdowns in other countries). Identified gaps were test kit, PPE, ICU beds, and ventilator shortages, limited public awareness, and insufficient coordination and collaboration among national and international partners. Proper and timely risk mapping, preparedness, communication, coordination, and collaboration among governments and organizations, and public awareness and engagement would have provided sufficient COVID-19 mitigation in Bangladesh.

Avian Influenza Risk Environment: Live Bird Commodity Chains in Chattogram, Bangladesh.

In this paper, we identify behaviours in live bird commodity chains in Chattogram, Bangladesh, which may influence the risk of pathogen emergence and transmission: the nature of poultry trade, value appropriation and selling sick or infected birds. Examining the reasons why actors engage in these behaviours, we emphasise the politics of constraints within a context of real-world decisions, governed by existential and pragmatic agency. Focusing on contact zones and entanglement, analysing patron-client relationships and precarious circumstances, we argue that agency and structure specific to the Bangladeshi context produce a risk environment. Structural constraints may reinforce risky occupational practises and limit individual agency. Structural constraints need to be addressed in order to tackle animal and zoonotic disease risk along live animal commodity chains.

Avian influenza transmission risk along live poultry trading networks in Bangladesh.

Live animal markets are known hotspots of zoonotic disease emergence. To mitigate those risks, we need to understand how networks shaped by trading practices influence disease spread. Yet, those practices are rarely recorded in high-risk settings. Through a large cross-sectional study, we assessed the potential impact of live poultry trading networks' structures on avian influenza transmission dynamics in Bangladesh. Networks promoted mixing between chickens sourced from different farming systems and geographical locations, fostering co-circulation of viral strains of diverse origins in markets. Viral transmission models suggested that the observed rise in viral prevalence from farms to markets was unlikely explained by intra-market transmission alone, but substantially influenced by transmission occurring in upstream network nodes. Disease control interventions should therefore alter the entire network structures. However, as networks differed between chicken types and city supplied, standardised interventions are unlikely to be effective, and should be tailored to local structural characteristics.

Intensification of fragility: Poultry production and distribution in Bangladesh and its implications for disease risk.

Poultry production is a valuable source of nutritious food and income and is considered a crucial part of global development. This is especially important for countries such as Bangladesh where levels of hunger and childhood stunting remain high. However, in many low- and middle-income countries poultry production remains dominated by small to medium scale enterprises operating with poor farm biosecurity associated with poultry and zoonotic disease risks. We aimed to characterize the structure of poultry production in Bangladesh in order to identify the underlying structural factors and resulting practices which create risk environments for emergence, persistence and transmission of infectious diseases. Using the concept of a production and distribution network (PDN), we conducted a review of the literature, 27 in-depth interviews with key-informants and stakeholders, and 20 structured interviews with poultry distributors to map the ways which poultry are raised, distributed and marketed in Bangladesh. Findings indicate that the PDN can be considered in the context of four major sub-networks, based on the types of chickens; broadly indigenous, cross-bred, exotic broiler, and layer chickens. These sub-networks do not exist in isolation; their transactional nodes - actors and sites - are dynamic and numerous interactions occur within and between the PDN. Our findings suggest that the growth in small and medium scale poultry enterprises is conducted within 'fragile' enterprises by inexperienced and poorly supported producers, many of whom lack capacity for the level of system upgrading needed to mitigate disease risk. Efforts could be taken to address the structural underlying factors identified, such as the poor bargaining power of producers and lack of access to independent credit and indemnity schemes, as a way to reduce the fragility of the PDN and increase its resilience to disease threats. This knowledge on the PDN structure and function provide the essential basis to better study the generation, mitigation and consequences of disease risks associated to livestock, including the analysis of potential hotspots for disease emergence and transmission.

Live bird market in Bangladesh: Regulatory systems and operations.

OBJECTIVE: In developing countries, such as Bangladesh, the live bird market (LBM) is a vital location for the trading of live poultry. The study was carried out in nine LBMs located around Bangladesh to ascertain the present regulations and procedures governing their operation. Additionally, the responsibilities and levels of engagement of the stakeholders were determined. MATERIALS AND METHODS: The data were gathered through the use of a semi-structured interview guide. Thematic analysis was used to code the interview transcripts iteratively. RESULTS: The findings indicated that the government was directly and indirectly involved in the leasing process of the markets. A market in this country is divided into numerous sectors, including LBM, fish market, vegetable market, and grocery stores. A market's hygienic condition is highly dependent on market authority's decisions. In some markets, market officials conducted routine sanitary inspections. Veterinarians played a little role in the inspection procedure. CONCLUSION: There is no adequate, functional monitoring system to ensure that LBMs adhere to cleanliness and adequate and functional biosecurity. Biosecurity enhancements, effective cleaning programs, and regular monitoring by relevant authorities are critical for LBMs in Bangladesh.

Epidemiological assessment of clinical poultry cases through the government veterinary hospital-based passive surveillance system in Bangladesh: a case study.

An epidemiological assessment of clinical poultry cases recorded through the existing passive surveillance at Kishoreganj District Veterinary Hospital during February-March 2016 was performed. A total of 200 cases (87 layers, 80 broilers, 21 ducks, and 12 pigeons) were included in this evaluation. The present study attempted to demonstrate the usefulness of passive surveillance data in quantifying the relative burden of poultry cases and their distribution along with drug prescription patterns. The cases were diagnosed based on clinical history, clinical signs, and observable post-mortem lesions by the registered veterinarian or intern veterinarian. The most prevalent diseases in chickens were infectious bursal disease (IBD) (31.7%; CI (confidence interval) 24.7-39.3%), coccidiosis (22.8%; CI 16.6-29.8%), Newcastle disease (ND) (21.6%; CI 15.5-28.5%), and coli-enteritis (8.4%; CI 4.6-13.6%). The most prevalent disease in ducks was duck plague (DP) (76.6%; CI 52.8-91.7%). Newcastle disease was most prevalent (66.7%; CI 34.8-90.0%) in pigeons. Infectious bursal disease, aspergillosis, and colibacillosis respectively were seen in a higher proportion of cases in broiler chickens than in layer chickens (58.7%, 12.5%, and 11.2% vs. 6.9%, 1.1%, and 3.4%; p ≤ 0.05). Contrarily, ND was seen in greater proportion of cases in layer chickens (32.1%) than in broiler chickens (10.0%) (p < 0.001). Infectious bursal disease, ND, coccidiosis, and aspergillosis were higher in older age broilers than in younger broilers (p ≤ 0.05). Antibiotics were often used to treat the poultry diseases such as trimethoprim with sulpha drugs (41%), ciprofloxacin (39%), sulphadiazine (27.5%), and erythromycin (26%). Through the present study, we can see how a passive surveillance system would be an effective tool for delineating disease distributions and common treatment regimens, thus helping to mitigate disease prevalence.

Prevalence of Avian Influenza A(H5) and A(H9) Viruses in Live Bird Markets, Bangladesh.

We conducted a cross-sectional study in live bird markets (LBMs) in Dhaka and Chittagong, Bangladesh, to estimate the prevalence of avian influenza A(H5) and A(H9) viruses in different types of poultry and environmental areas by using Bayesian hierarchical logistic regression models. We detected these viruses in nearly all LBMs. Prevalence of A(H5) virus was higher in waterfowl than in chickens, whereas prevalence of A(H9) virus was higher in chickens than in waterfowl and, among chicken types, in industrial broilers than in cross-breeds and indigenous breeds. LBMs with >1 wholesaler were more frequently contaminated by A(H5) virus than retail-only LBMs. Prevalence of A(H9) virus in poultry and level of environmental contamination were also higher in LBMs with >1 wholesaler. We found a high level of circulation of both avian influenza viruses in surveyed LBMs. Prevalence was influenced by type of poultry, environmental site, and trading.

Assessment of hygienic conditions of live bird markets on avian influenza in Chittagong metro, Bangladesh.

Live Bird Markets (LBMs) in Asian countries are considered as hubs for the spread and maintenance of different infectious diseases. In Bangladesh, LBMs are the major source of live and dressed poultry to consumers and until now only a few studies have been conducted targeting infectious agent status such as avian influenza virus (AIV) prevalence of LBMs in Bangladesh. Therefore, a cross sectional study was conducted using all 40 LBMs within the Chittagong Metropolitan Area (CMA) of Bangladesh targeting demographic information and hygienic status of LBMs in concurrence with AIV prevalence and its subtype distribution, as well as the associated risk factors for AIV. Pooled environmental swab samples were collected from 2 to 9 different sites per stall, with epidemiological data being obtained from a total of 290 stalls across 40 LBMs. The samples were evaluated by Real Time Reverse Transcriptase Polymerase Chain Reaction. The prevalence of AIV was 40% (95% CI: 20-60%; N=40) at a LBM level followed by 20.3% (CI: 10-30%, N=290) at a stall level. Specifically, the prevalence of H5, H7 and H9 subtypes at stall level were 2.8% (95% CI: 1-5%), 0% (CI: 0-1.3%) and 3.1% (CI: 1-6%), respectively. Generalized Estimating Equation model identified that the type of species sold (OR=2.5: Chicken and non-duck species versus Duck with other species), bird holding areas (OR=1.9: Cage versus Floor) and Hygienic score (OR=3.1: Score 3 or more versus score less than 3) as potential risk factors for the detection of AIV at stall level. These results suggest that housing chickens and ducks together in the stalls, birds kept on floors, and lack of adequate hygienic measures of the stall were the crucial factors for spreading AIV. This research outcome could be used to develop a proof-based program concerning environmental sanitation along with development of an effective surveillance system to reduce the AIV transmission through LBMs in Bangladesh.

Clinical and antiviral efficacy of an ophthalmic formulation of dexamethasone povidone-iodine in a rabbit model of adenoviral keratoconjunctivitis.

PURPOSE: To determine the efficacy of a new formulation of topical dexamethasone 0.1%/povidone-iodine 0.4% (FST-100) in reducing clinical symptoms and infectious viral titers in a rabbit model of adenoviral keratoconjunctivitis. METHODS: Rabbit corneas were inoculated bilaterally with 2×10(6) plaque-forming-units (PFU) of adenovirus type 5 (Ad5) after corneal scarification. Animals were randomized 1:1:1:1 (five rabbits per group) to FST-100, 0.5% cidofovir, tobramycin/dexamethasone (Tobradex; Alcon Laboratories, Fort Worth, TX) ophthalmic suspension, and balanced salt solution (BSS; Alcon Laboratories). Treatment began 12 hours after viral inoculation and continued for 7 consecutive days. The eyes were clinically scored daily for scleral inflammation (injection), ocular neovascularization, eyelid inflammation (redness), friability of vasculature, inflammatory discharge (pus), and epiphora (excessive tearing). Eye swabs were collected daily before treatment for the duration of the study. Virus was eluted from the swabs and PFU determined by titration on human A549 cells, according to standard procedures. RESULTS: The FST-100 treatment resulted in significantly lower clinical scores (P<0.05) than did the other treatments. The 0.5% cidofovir exhibited the most ocular toxicity compared with FST-100, tobramycin/dexamethasone, and balanced salt solution treatments. FST-100 and 0.5% cidofovir significantly (P<0.05) reduced viral titers compared with tobramycin/dexamethasone or balanced salt solution. CONCLUSIONS: FST-100 was the most efficacious in minimizing the clinical symptoms of adenovirus infection in rabbit eyes. FST-100 and 0.5% cidofovir were both equally effective in reducing viral titers and decreasing the duration of viral shedding. By providing symptomatic relief in addition to reducing infectious virus titers, FST-100 should be a valuable addition to treatment of epidemic adenoviral keratoconjunctivitis.