This study evaluated the virucidal efficacy of a chlorine dioxide (ClO2) gas-generating fumigation disinfectant consisting of sodium chlorate solution (25% sodium chlorate) and reaction solution against avian influenza virus (AIV). After AIV suspensions had been deposited on stainless steel carriers, the 9 dried carriers were exposed to the fumigant (sodium chlorate solution: 8.5, 17, 34, 50, and 100 mL) in a 25-m³ test room for 2, 3, and 4 h, respectively. Thereafter, all carriers were submerged in a neutralizing solution (20% fetal bovine serum) to scrape off the surviving viruses, and the respective suspensions were diluted. Each diluent was inoculated into the allantoic membrane of five 10-day-old embryos. After incubation for 5 days at 37℃, AIV viability in the collected allantoic fluids was examined, and the egg infectious dose 50 (EID50) was calculated. When the carrier was exposed to ClO2 gas generated from reacting 34 mL of the fumigant for 3 h, the AIV titer reduced by more than 104.0 EID50/carrier compared to the control, which was exposed to the fumigant without inoculation of AIV suspension. In addition, the control was non-toxic to the embryos.

Wild birds, especially aquatic birds, are the natural reservoir of avian influenza virus (AIV), and many kinds of water body can be contaminated with feces of these birds. Seasonally, AIVs can be dissolved in the environmental water from the feces of the infected birds, and this water can be a target for viral detection and identification. In this study, we employed and tested three different filters for concentrating AIV, and it was shown that high concentration factor in terms of viral density could be achieved with viral samples diluted with natural water. Wild bird fecal samples containing low pathogenicity H5 AIVs were successfully concentrated with the adsorption and elution method using mixed cellulose esters membrane; the recovery rate of virus was 35.5 % and the concentration factor was about 50 on average. For the larger volume of water sample, we proved that an inline disposable filter with high surface area, 300 cm2, has a comparable concentration factor to the adsorption and elution method and the filter could be used in the field conveniently by being plugged into peristaltic pump. These validated methods for water sampling may be used as a supplementary for virological surveillance on wild migratory birds or during the epidemiological investigation on the environment near affected premises by AIV.

To attenuate and control the spread of infectious disease, a body of research has been conducted to generate safe vaccines and to continue national-level surveillance. However, understanding on viability and persistence of avian influenza virus (AIV) in infected carcasses, and effective disposal approaches are still limited up to date. Here, using HA test and RT-PCR, we assessed active status of AIV and degradation of viral RNA in collected specimens at different sites and time points. First, AIV infectivity was recovered until day 2, and viral nucleic acids persisted to day 14 and 21 in inorganic and organic samples, respectively, in sealed vials incubated at room temperature. Second, AIV was totally inactivated in all examined specimens, and viral RNA was not detectable at all time points tested at least one month post-infection in AIV-inoculated carcasses buried directly in soil or fiber reinforced plastic (FRP) bin. Lastly, among different burial sites in South Korea, 6 out of 17 sampling sites in Jeonbuk province showed the presence of viral genetic materials, while the rest of the field samples displayed neither the presence of infective AIV nor detectable viral RNA. This study showed a linear relation between time and degradation degree of viral RNA in buried samples suggesting that burial disposal method is effective for the control or at least attenuation of spread of AI infection in infected animals although consistent monitoring is required to verify safety of disposal.

Highly pathogenic avian influenza virus (HPAIV) damages vital organs and tissues, frequently leading to death in birds, and causes serious economic losses in the poultry industry. In addition, HPAIV can infect humans and other mammals, often with fatal outcomes. In this study, the virucidal efficacy of Clean-Zone®, which contains citric acid, malic acid and phosphoric acid, against avian influenza virus (AIV, H9N2) was investigated. Virucidal efficacy was determined by examining the viability of AIV after contact with the disinfectant in the allantoic membrane of chicken embryos. The disinfectant and AIV were reacted under hard water (HW) and organic matter suspension (OM) condition. AIV was inactivated with 200- and 50-fold dilutions of the disinfectant under HW and OM conditions, respectively. As the disinfectant, Clean-Zone®, has a virucidal efficacy against AIV, it can be used to prevent the spread of animal viral diseases.

In this study, the virucidal efficacy of a fumigant (35% paraformaldehyde) against avian influenza virus (AIV) was examined. After AIV suspensions had been deposited on stainless steel carriers, the dried carriers were exposed to the fumigant in a 300-m3 test room for 3 h. Thereafter, all carriers were submerged in a neutralizing solution to scrape off the surviving viruses, and the respective suspensions were diluted. Each dilution factor was respectively inoculated into the allantoic membrane of five 10-day-old embryos. After incubation, AIV viability in the collected allantoic fluids was examined and the EID50 was calculated. The fumigant inactivated ≥5.7log10EID50 of AIV and was nontoxic to the embryos.

The efficacy of chemical disinfectants is reduced owing to the inactivation of active ingredients after dilution. This study investigated the effect of time on the efficacy of six different disinfectants, after dilution, against avian influenza virus. When used at the recommended concentration, most disinfectants showed efficacy at a high concentrations in the presence of organic materials immediately after dilution, while sodium dichloroisocyanurate-based products, after dilution, showed reduced efficacy over time at low concentrations in the absence of organic materials. Most disinfectants were neutralized by organic materials; however, this could be compensated for by increasing the product dosage. For successful decontamination in farms, disinfectants should be used at high concentrations in accordance with the manufacturers’ recommendations. Furthermore, the presence of organic materials must be taken into consideration, and diluted disinfectant solution should be prepared no more than a day before use.

Highly pathogenic avian influenza virus (HPAIV) is already panzootic in poultry and caused a considerable economic loss in poultry industry. In addition, HPAIV continues to cross species barriers to infect humans and other mammals, often with fatal outcomes. In this study, the virucidal efficacy of Citra-Kill® composed to quaternary ammonium chloride and citric acid was investigated against avian influenza H9N2 virus (AIV). A virucidal efficacy was determined with the viability of AIV contacted with the disinfectant in the allantoic membrane of chicken embryos. Citra-Kill® and AIV was reacted on the distilled water (DW), hard water (HW) or organic matter suspension (OM) condition. On DW condition, AIV was inactivated with 2,000 fold dilutions of Citra-Kill®. When the antiviral effect on HW condition was evaluated, the antiviral activity of the disinfectant showed on 1,500 fold dilutions against AIV. With the investigation of the antiviral effect of the disinfectant on OM condition, AIV was inactivated on 500 fold dilutions of Citra-Kill®. As Citra-Kill® possesses virucidal efficacy against AIV, the disinfectant solution can be used to limit the spread of animal viral diseases.

Avian influenza (AI) and Newcastle disease (ND) distress a variety of avian species, especially domestic poultry. Severe syndromes are caused by highly virulent specific virus strains termed highly pathogenic AI and velogenic ND viruses, which are potential agrobioterrorism agents. This outbreak emphasizes the need for continuing cooperation between public health and veterinary medical communities in controlling AI and ND when it has a zoonotic potential. Up to date, the stamping out and burying system were applied for controlling methods against these highly infectious diseases in the ordinary way, however these methods had many environmental problems, including leachat and effluvium. Thus, we assessed that sterilization effect of AI and ND virus dependent on several treatment conditions, such as autoclaving time and cutting types of chicken. As a result, we found that the cutting type of chicken meat revealed a reduced HA titer (20) against both of AI and ND virus after 10 min of autoclaving, while whole chicken showed same titer after 30 and 60 min. Therefore, we propose that the conditions of treatment on infected chicken should be developed for convenient, affordable, and effective prevention methods against for AI and ND.

Korea had experienced second epidemic highly pathogenic avian influenza (HPAI), and there were the seven affected farms, including two breeder duck farms, from 22nd November 2006 to 6th March 2007. Here, we reported the clinico-pathological characteristics of domestic breeder ducks farms naturally infected with HPAI virus (H5N1). Clinically, the most ducks showed various signs from depression, decreased egg production and feed consumption to even, death. The most commonly gross changes were hepatomegaly, splenomegaly, petechial and ecchymotic hemorrhage on the liver surface, a white stripe on the cardiac muscle, and severely hemorrhagic and deformed eggs. The most significant histopathological changes were necrosis of various cells such as neuron, lymphocytes, cardiac myocytes, hepatocytes, blood vessels and pancreatic acinar epithelium. The viral antigen was mainly detected in the endothelium of blood vessels of various organs and tissues, peripheral nerves and neuronal cells. Based on the above results, we identified that HPAI H5N1 induced systemic infection in the adult breeder ducks.

Avian Influenza (AI) is an avian disease that break out by AI virus (AIV). As Hemagglutinin (HA) that is a main antigen surface protein of influenza virus that causes these influenza infection changes continuously, HA escapes bond of guided antibody by host"s immunity system. Specification region (HA91-261) of HA molecule that reconize receptor (sialic acid) of host cell is well-preserved without changing relatively, but is gotten buried on inside of trimer structure in natural conditions, is reported that development of effective vaccine or cure for HA protein is difficult because is not exposed to immunity system. Aptamer is relatively small strand DNA or RNA, and has high affinity to specific proteins. In this study, new aptamer DNAs were screened which can specifically bind to the receptor binding region of HA H9 protein.

농가를 방문하는 가금관련업체의 관계자 및 차량은 HPAI 질병 확산의 매개체가 된다. 농가들의 가금관련업체 이용 정보를 이용하면 농가간의 연결을 확인할 수 있고 HPAI 확산 가중 네트워크를 구성할 수 있다. 네트워크 분석중 중심성 측정은 질병에 취약하거나 타 농가에 영향력이 큰 역할을 하는 농가를 분석하는 방법으로 HPAI 초기 확산을 통제하는 방법으로 이용된다. 단, HPAI 바이러스는 네트워크의 연결선 가중치에 따라서 확산 경로가 달라질 수 있다.