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.
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.
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.
Many ribonucleases (RNases) are able to inhibit the reproduction of viruses in infected cell cul tures and laboratory animals, but the molecular mechanisms of their antiviral activity remain unclear. The review discusses the well known RNases that possess established antiviral effects, including both intracellular RNases (RNase L, MCPIP1 protein, and eosinophil associated RNases) and exogenous RNases (RNase A, BS RNase, onconase, binase, and synthetic RNases). Attention is paid to two important, but not always obligatory, aspects of molecules of RNases that have antiviral properties, i.e., catalytic activity and ability to dimerize. The hypothetic scheme of virus elimination by exogenous RNases that reflects possible types of interaction of viruses and RNases with a cell is proposed. The evidence for RNases as classical components of immune defense and thus perspective agents for the development of new antiviral therapeutics is proposed.
The lack of effective antiviral drugs restricts the control of the dangerous
RNA-containing influenza A (H1N1) virus. Extracellular ribonuclease of Bacilli
(binase) was shown to manifest antiviral activity during single- and
multi-cycle viral replication in the range of concentrations non-toxic to
epithelial cells and 0.01-0.1 multiplicity of infection. During antiviral
treatment for 15-30 min, the concentration of 1 μg/ml binase reduced the
amount of focus-forming units of viruses by a factor of 3-10 and suppressed the
virus-induced cytopathic effect in A549 human lung cells. The possible
mechanisms of interaction between the virus and enzyme are discussed. Positive
charges in both binase and viral hemagglutinin cause electrostatic interaction
with negatively charged sialic acid on the host cell’s surface followed
by its penetration into the cell. Capsid elimination and release of viral RNA
from endosome to the cytoplasm allows catalytic RNA cleavage by internalized
binase. The data obtained confirm that binase is an effective antiviral agent
against the pandemic influenza A (H1N1) virus. Certain progress in this field
is associated with clarifying the detailed mechanism underlying the antiviral
action of binase and development of the most effective way for its practical
use.
This paper anthropologically explores how key actors in the Chittagong live bird trading network perceive biosecurity and risk in relation to avian influenza between production sites, market maker scenes and outlets. They pay attention to the past and the present, rather than the future, downplaying the need for strict risk management, as outbreaks have not been reported frequently for a number of years. This is analysed as 'temporalities of risk perception regarding biosecurity', through Black Swan theory, the idea that unexpected events with major effects are often inappropriately rationalized (Taleb in The Black Swan. The impact of the highly & Erling Høg
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