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Highly Pathogenic Avian Influenza (HPAI) H5N1 is a major problem in poultry industry in many countries. It became endemic disease in Indonesia since 2003. Recently, research revealed that current circulate HPAI in Indonesia has switched from clades 2.1 to 2.3.2.1. To eradicate this disease, methods such as stamping out and quarantine seem not suitable applied since poultry industry is one of main sector in agricultural commodity in some areas such as Central Java, Yogyakarta, and East Java. It provides large of job opportunity for native people from rural to city areas. To prevent the morbidity of this disease, vaccination use local seed is primarily needed. This research was conducted to explore local isolate of HPAI clade 2.3.2.1 as vaccine candidate. Samples were obtained from some areas in East Java where outbreak occurred. Molecular characteristic according to Neuraminidase (N) gene was conducted. Samples has close relativity to circulating virus was used as seed vaccine then processed into killed vaccine production. It was challenged to observe the protectivity on poultry. The effectivity of the vaccine was measured through Haemagglutination Inhibition (HI) assay. The result of study showed that isolate DOD_3_2013 has close relativity to circulating virus thus it used as vaccine candidate. Challenged test showed that this vaccine candidate induced higher antibody titer compared to control. The average of antibody titer was 8.2 (log2) with the protection level 100%. It is concluded that this isolate could be used as vaccine candidate to eradicate HPAI clade 2.3.2.1 around East Java.

In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt.

The risk for influenza A(H5N1) virus infection is unclear among poultry workers in countries where the virus is endemic. To assess H5N1 seroprevalence and seroconversion among workers at live bird markets (LBMs) in Bangladesh, we followed a cohort of workers from 12 LBMs with existing avian influenza surveillance. Serum samples from workers were tested for H5N1 antibodies at the end of the study or when LBM samples first had H5N1 virus–positive test results. Of 404 workers, 9 (2%) were seropositive at baseline. Of 284 workers who completed the study and were seronegative at baseline, 6 (2%) seroconverted (7 cases/100 poultry worker–years). Workers who frequently fed poultry, cleaned feces from pens, cleaned food/water containers, and did not wash hands after touching sick poultry had a 7.6 times higher risk for infection compared with workers who infrequently performed these behaviors. Despite frequent exposure to H5N1 virus, LBM workers showed evidence of only sporadic infection.

In Cambodia, influenza A(H5N1) virus surveillance at live poultry markets (LPMs) relies on virus isolation from poultry specimens; however, virus is rarely detected by this method. We tested 502 environmental LPM samples: 90 were positive by PCR, 10 by virus isolation. Virus circulation could be better monitored by environmental sampling of LPMs.

Since the outbreaks of highly pathogenic avian influenza (HPAI) subtype H5N1 virus, wild birds have been suspected of transmitting this virus to poultry. On January 23, 2004, the Ministry of Public Health in Thailand informed the World Health Organization of an avian influenza A (H5N1) outbreak. To determine the epidemiology of this viral infection and its relation to poultry outbreaks in Thailand from 2004 through 2007, we investigated how wild birds play a role in transmission. A total of 24,712 serum samples were collected from migratory and resident wild birds. Reverse transcription PCR showed a 0.7% HPAI (H5N1) prevalence. The highest prevalence was observed during January–February 2004 and March–June 2004, predominantly in central Thailand, which harbors most of the country’s poultry flocks. Analysis of the relationship between poultry and wild bird outbreaks was done by using a nonhomogeneous birth and death statistical model. Transmission efficiency among poultry flocks was 1.7× higher in regions with infected wild birds in the given or preceding month. The joint presence of wild birds and poultry is associated with increased spread among poultry flocks.

Eight new full-length sequences from highly pathogenic avian influenza viruses (H5N1) from 4 states in southwest Nigeria were analyzed. All gene sequences were more closely related to the first strains found in Nigeria in 2006 than to any strain found outside the country. Six viruses had evolved by at least 3 reassortment events (ACHA/NS, ACNS) from previously identified sublineages A (EMA 2) and C (EMA 1). Our results suggest that highly pathogenic avian influenza viruses (H5N1) initially imported into Nigeria in 2006 have been gradually replaced by various reassortments. In all reassortants, nonstructural genes were derived from sublineage C with 2 characteristic amino acids (compared with sublineage A). If the high prevalence of reassortants was typical for West Africa in 2007, the absence of such reassortants anywhere else suggests that reintroductions of influenza A (H5N1) from Africa into Eurasia must be rare.

Adult, healthy mute swans were experimentally infected with highly pathogenic avian influenza virus A/Cygnus cygnus/Germany/R65/2006 subtype H5N1. Immunologically naive birds died, whereas animals with preexisting, naturally acquired avian influenza virus–specific antibodies became infected asymptomatically and shed virus. Adult mute swans are highly susceptible, excrete virus, and can be clinically protected by preexposure immunity.

In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt. [ABSTRACT FROM AUTHOR]

The 2006 outbreaks of H5N1 avian influenza in Egypt interrupted poultry production and caused staggering economic damage. In addition, H5N1 avian influenza viruses represent a significant threat to public health. Therefore, the rapid detection of H5 viruses is very important in order to control the disease. In this study, a qualitative reverse transcription recombinase polymerase amplification (RT-RPA) assay for the detection of hemagglutinin gene of H5 subtype influenza viruses was developed. The results were compared to the real-time reverse transcription polymerase chain reaction (RT-PCR). An in vitro transcribed RNA standard of 970 nucleotides of the hemagglutinin gene was developed and used to determine the assay sensitivity. The developed H5 RT-RPA assay was able to detect one RNA molecule within 7 min, while in real-time RT-PCR, at least 90 min was required. H5 RT-RPA assay did not detect nucleic acid extracted from H5 negative samples or from other pathogens producing respiratory manifestation in poultry. The clinical performance of the H5 RT-RPA assay was tested in 30 samples collected between 2014 and 2015; the sensitivity of H5 RT-RPA and real-time RT-PCR was 100%. In conclusion, H5 RT-RPA was faster than real-time RT-PCR and easily operable in a portable device. Moreover, it had an equivalent sensitivity and specificity. [ABSTRACT FROM AUTHOR]

Highly Pathogenic Avian Influenza (HPAI) H5N1 virus is a threat to animal and public health worldwide. Till date, the H5N1 virus has claimed 402 human lives, with a mortality rate of 58% and has caused the death or culling of millions of poultry since 2003. In this study, we have designed three siRNAs (PB2-2235, PB2-479 and NP-865) targeting PB2 and NP genes of avian influenza virus and evaluated their potential, measured by hemagglutination (HA), plaque reduction and Real time RT-PCR assay, in inhibiting H5N1 virus (A/chicken/Navapur/7972/2006) replication in MDCK cells. The siRNAs caused 8- to 16-fold reduction in virus HA titers at 24 h after challenged with 100TCID of virus. Among these siRNAs, PB2-2235 offered the highest inhibition of virus replication with 16-fold reduction in virus HA titer, 80% reduction in viral plaque counts and 94% inhibition in expression of specific RNA at 24 h. The other two siRNAs had 68-73% and 87-88% reduction in viral plaque counts and RNA copy number, respectively. The effect of siRNA on H5N1 virus replication continued till 48h (maximum observation period). These findings suggest that PB2-2235 could efficiently inhibit HPAI H5N1 virus replication. [ABSTRACT FROM AUTHOR]

Abstract: A systematic review was performed to assess the safety and immunogenicity of the prepandemic H5N1 influenza vaccines licensed so far. A bibliographic search according to the COSI protocol was carried out and 8 of 235 potentially relevant publications were selected. Quality assessment was defined with both CASP and Jadad checklists. Taken together, the results from the present systematic review suggest that the inactivated split-virion formulation that includes a low antigen dose (3.8μg) and an oil-in-water emulsion-based adjuvant, represents the best option in the case of a pandemic, due to its antigen-sparing capacity and its favorable safety profile. [Copyright &y& Elsevier]

Avian influenza virus (AIV) was recovered from the internal contents of eggs, including mixture of albumen and allantoic fluid, and from the oviduct of naturally infected Japanese quail ( Coturnix coturnix japonica) flocks in the southern part of Thailand. The virus titers of 104.6-106.2 ELD50/mL were directly measured from the internal content of infected eggs. The virus was isolated by chorioallantoic sac inoculation of embryonating chicken eggs. Infected allantoic fluid was identified as hemagglutinating virus and then was indicated the presence of H5 hemagglutinin. The virus was confirmed to be H5N1 subtype influenza A virus by reverse transcriptase-polymerase chain reaction. Additionally, real-time reverse transcriptase-polymerase chain reaction assay could specifically detect influenza virus subtype H5. Furthermore, indirect fluorescent antibody (IFA) test by using specific anti-influenza A monoclonal antibody indicated that virus antigens were detected in the parenchyma of multiple tissues. Systemic localization of viral antigen detected was certainly considered to be viremic stage. In addition, influenza virus antigen was also detected by IFA in allantoic fluid sediments isolated from internal content of egg or oviduct. The conclusion of isolated AIV type A subtype H5N1 from these two infected materials was correlated to the viremic stage of infection because the virus antigens could be observed in almost all tissues. Conclusively, the need for adequate safeguards to prevent contamination and spread of the virus to the environment during movement of eggs—including hatching eggs, cracked eggs, and other relevant infected materials— or egg consumption from area of outbreak is emphasized and must not be ignored for the reasons of animal, public, and environmental health. [ABSTRACT FROM AUTHOR]