Composting for avian influenza virus elimination.

Effective sanitization is important in viral epizootic outbreaks to avoid further spread of the pathogen. This study examined thermal inactivation as a sanitizing treatment for manure inoculated with highly pathogenic avian influenza virus H7N1 and bacteriophages MS2 and 6. Rapid inactivation of highly pathogenic avian influenza virus H7N1 was achieved at both mesophilic (35°C) and thermophilic (45 and 55°C) temperatures. Similar inactivation rates were observed for bacteriophage 6, while bacteriophage MS2 proved too thermoresistant to be considered a valuable indicator organism for avian influenza virus during thermal treatments. Guidelines for treatment of litter in the event of emergency composting can be formulated based on the inactivation rates obtained in the study.

Biosecurity aspects and pathogen inactivation in acidified high risk animal by-products.

The aim of the study was to investigate the effects of formic acid addition to ground high risk animal by-products (ABP 1) in terms of stabilization and pathogen inactivation and to evaluate the biosecurity risk connected with the ABP 1 based combustion fuel Biomal. Laboratory studies were performed on the persistence of Salmonella Typhimurium, Bacillus cereus spores, porcine herpes virus, avian influenza virus, bovine viral diarrhea virus, equine rhinitis A virus and porcine parvovirus in Biomal at different storage times. It was shown that Salmonella and enveloped viruses were inactivated within 1 day (24 h). Bacillus cereus spores were not reduced during 147 days and the non-enveloped virus porcine parvovirus was still detected after 168 days of storage. The conclusion that can be drawn from the study is that transmission of some highly contagious diseases such as foot-and-mouth-disease, swine vesicular disease and egg drop syndrome, caused by non-enveloped viruses, may follow accidental leakages of Biomal. In addition, there is a risk of transmission of the diseases anthrax and black leg, caused by sporulating bacteria.

Ammonia disinfection of hatchery waste for elimination of single-stranded RNA viruses.

Hatchery waste, an animal by-product of the poultry industry, needs sanitation treatment before further use as fertilizer or as a substrate in biogas or composting plants, owing to the potential presence of opportunistic pathogens, including zoonotic viruses. Effective sanitation is also important in viral epizootic outbreaks and as a routine, ensuring high hygiene standards on farms. This study examined the use of ammonia at different concentrations and temperatures to disinfect hatchery waste. Inactivation kinetics of high-pathogenic avian influenza virus H7N1 and low-pathogenic avian influenza virus H5N3, as representatives of notifiable avian viral diseases, were determined in spiked hatchery waste. Bovine parainfluenza virus type 3, feline coronavirus, and feline calicivirus were used as models for other important avian pathogens, such as Newcastle disease virus, infectious bronchitis virus, and avian hepatitis E virus. Bacteriophage MS2 was also monitored as a stable indicator. Coronavirus was the most sensitive virus, with decimal reduction (D) values of 1.2 and 0.63 h after addition of 0.5% (wt/wt) ammonia at 14 and 25°C, respectively. Under similar conditions, high-pathogenic avian influenza H7N1 was the most resistant, with D values of 3.0 and 1.4 h. MS2 was more resistant than the viruses to all treatments and proved to be a suitable indicator of viral inactivation. The results indicate that ammonia treatment of hatchery waste is efficient in inactivating enveloped and naked single-stranded RNA viruses. Based on the D values and confidence intervals obtained, guidelines for treatment were proposed, and one was successfully validated at full scale at a hatchery, with MS2 added to hatchery waste.

Comparison of two H1N2 swine influenza A viruses from disease outbreaks in pigs in Sweden during 2009 and 2010.

The influenza A virus subtypes H1N1, H1N2 and H3N2 are prevalent in pig populations worldwide. In the present study, two relatively uncommon swine influenza virus (SIV) H1N2 subtypes, isolated in Sweden in 2009 and 2010, were compared regarding their molecular composition and biological characteristics. The differences regarding markers purportedly related to pathogenicity, host adaptation or replication efficiency. They included a truncated PB1-F2 protein in the earlier isolate but a full length version in the more recent one; differences in the number of haemagglutinin glycosylation sites, including a characteristic human one; and a nuclear export protein with altered export signal. Of particular interest, the NS1 amino acid sequence of swine H1N2-2009 and 2010 has a 'unique or very unusual' PDZ binding domain (RPKV) at the C-terminal of the protein, a motif that has been implicated as a virulence marker. Concerning biological properties, these viruses reached lower titre and showed reduced cytopathogenicity in MDCK cells compared with an avian-like H1N1 isolate A/swine/Lidkoping/1193/2002 belonging to the same lineage as the 2009 and 2010 isolates. The findings should contribute to better understanding of factors related to the survival/extinction of this uncommon reassortant variant.

A laboratory study of survival of selected microorganisms after heat treatment of biowaste used in biogas plants.

The aim of the study was to assess the effect of pasteurisation, as set by the European regulation EC 1774/2002, on selected pathogens and indicator organisms. Unpasteurised substrate (biowaste), including animal by-products from a full-scale biogas plant was heat treated under laboratory conditions at 70 degrees C and 55 degrees C for 30 min and 60 min. Heat treatment at 55 degrees C for 60 min was not sufficient to achieve a hygienically acceptable product. Heat treatment at 70 degrees C for 30 min and 60 min was effective in reducing pathogenic bacteria, Ascaris suum eggs, Swine vesicular disease virus and indicator organisms. However, this level of pasteurisation will still not reduce the quantity of Clostridia spores, or completely inactivate heat-resistant viruses such as Porcine parvovirus or Salmonella phage 28B. The results still give cause for some concern regarding the use of digested residue from biogasplants in agriculture.

Inactivation of Viruses and Bacteriophages as Models for Swine Hepatitis E Virus in Food Matrices.

Hepatitis E virus has been recognised as a food-borne virus hazard in pork products, due to its zoonotic properties. This risk can be reduced by adequate treatment of the food to inactivate food-borne viruses. We used a spectrum of viruses and bacteriophages to evaluate the effect of three food treatments: high pressure processing (HPP), lactic acid (LA) and intense light pulse (ILP) treatments. On swine liver at 400 MPa for 10 min, HPP gave log10 reductions of ≥4.2, ≥5.0 and 3.4 for feline calicivirus (FCV) 2280, FCV wildtype (wt) and murine norovirus 1 (MNV 1), respectively. Escherichia coli coliphage ϕX174 displayed a lower reduction of 1.1, while Escherichia coli coliphage MS2 was unaffected. For ham at 600 MPa, the corresponding reductions were 4.1, 4.4, 2.9, 1.7 and 1.3 log10. LA treatment at 2.2 M gave log10 reductions in the viral spectrum of 0.29-2.1 for swine liver and 0.87-3.1 for ham, with ϕX174 and MNV 1, respectively, as the most stable microorganisms. The ILP treatment gave log10 reductions of 1.6-2.8 for swine liver, 0.97-2.2 for ham and 1.3-2.3 for sausage, at 15-60 J cm-2, with MS2 as the most stable microorganism. The HPP treatment gave significantly (p < 0.05) greater virus reduction on swine liver than ham for the viruses at equivalent pressure/time combinations. For ILP treatment, reductions on swine liver were significantly (p < 0.05) greater than on ham for all microorganisms. The results presented here could be used in assessments of different strategies to protect consumers against virus contamination and in advice to food producers. Conservative model indicators for the pathogenic viruses could be suggested.

A size-exclusion nanocellulose filter paper for virus removal.

This is the first time a 100% natural, unmodified nanofibrous polymer-based membrane is demonstrated capable of removing viruses solely based on the size-exclusion principle, with a log10 reduction value (LRV) ≥ 6.3 as limited by the assay lower detection limit and the feed virus titre, thereby matching the performance of industrial synthetic polymer virus removal filters.

Cross-protection of chicken immunoglobulin Y antibodies against H5N1 and H1N1 viruses passively administered in mice.

Influenza viruses remain a major threat to global health due to their ability to undergo change through antigenic drift and antigenic shift. We postulated that avian IgY antibodies represent a low-cost, effective, and well-tolerated approach that can easily be scaled up to produce enormous quantities of protective antibodies. These IgY antibodies can be administered passively in humans (orally and intranasally) and can be used quickly and safely to help in the fight against an influenza pandemic. In this study, we raised IgY antibodies against H1N1, H3N2, and H5N1 influenza viruses. We demonstrated that, using whole inactivated viruses alone and in combination to immunize hens, we were able to induce a high level of anti-influenza virus IgY in the sera and eggs, which lasted for at least 2 months after two immunizations. Furthermore, we found that by use of in vitro assays to test for the ability of IgY to inhibit hemagglutination (HI test) and virus infectivity (serum neutralization test), IgYs inhibited the homologous as well as in some cases heterologous clades and strains of viruses. Using an in vivo mouse model system, we found that, when administered intranasally 1 h prior to infection, IgY to H5N1 protected 100% of the mice against lethal challenge with H5N1. Of particular interest was the finding that IgY to H5N1 cross-protected against A/Puerto Rico/8/34 (H1N1) both in vitro and in vivo. Based on our results, we conclude that anti-influenza virus IgY can be used to help prevent influenza virus infection.

Swine influenza viruses isolated in 1983, 2002 and 2009 in Sweden exemplify different lineages.

Swine influenza virus isolates originating from outbreaks in Sweden from 1983, 2002 and 2009 were subjected to nucleotide sequencing and phylogenetic analysis. The aim of the studies was to obtain an overview on their potential relatedness as well as to provide data for broader scale studies on swine influenza epidemiology. Nonetheless, analyzing archive isolates is justified by the efforts directed to the comprehension of the appearance of pandemic H1N1 influenza virus. Interestingly, this study illustrates the evolution of swine influenza viruses in Europe, because the earliest isolate belonged to 'classical' swine H1N1, the subsequent ones to Eurasian 'avian-like' swine H1N1 and reassortant 'avian-like' swine H1N2 lineages, respectively. The latter two showed close genetic relatedness regarding their PB2, HA, NP, and NS genes, suggesting common ancestry. The study substantiates the importance of molecular surveillance for swine influenza viruses.