Rokshana Parvin

New Introduction of Clade 2.3.2.1 Avian Influenza Virus (H5N1) into Bangladesh

Since the first outbreak of highly pathogenic H5N1 avian inafluenza (HPAI) in Bangladesh in February 2007, a total of 519 disease events have been reported till 22 October 2011. Partial HA gene sequences of 11 selected H5N1 HPAI isolates of 2007 to 2011 were determined and subjected to phylogenetic analysis. The study revealed a recent introduction of clade 2.3.2 and 2.3.4 viruses into Bangladesh in 2011 in addition to clade 2.2 viruses that had been in circulation since 2007. Clade 2.3.2 virus isolates from Bangladesh are phylogenetically related to the newly designated clade 2.3.2.1 viruses, reported recently from Asia and Eastern Europe.

Full-genome analysis of avian influenza virus H9N2 from Bangladesh reveals internal gene reassortments with two distinct highly pathogenic avian influenza viruses

Low-pathogenic avian influenza viruses (LPAIVs) of subtype H9N2 have become widespread in poultry in many Asian countries with relevance to respiratory diseases of multifactorial origin. In Bangladesh, LPAIVs of subtype H9N2 co-circulate simultaneously with highly pathogenic avian influenza viruses (HPAIVs) of subtype H5N1 in commercial and backyard poultry. The aim of this study was to characterize LPAIVs of subtype H9N2 currently circulating in Bangladesh. The selected isolate A/Chicken/Bangladesh/VP01/2006 (H9N2) was propagated in chicken embryos. All eight gene segments were amplified by RT-PCR, cloned, and subjected to full-length sequencing. The sequence data obtained were compared with reference strains available in GenBank. Phylogenetic analysis of LPAIV H9N2 from Bangladesh revealed a close relationship to Indian, Pakistani and Middle Eastern isolates and identified an ancestor relationship to LPAIV H9N2 Quail/HK/G1/1997. The internal genes M and NP belong to lineage G1, whereas NS, PA, PB1 and PB2 belong to the prototype virus A/Chicken/Korea/38349-p96323/96. The internal genes showed high sequence homology to an HPAIV of subtype H7N3 from Pakistan, whereas the PB1 gene showed similarly high nucleotide homologies to recently circulating HPAIV H5N1 from Bangladesh, revealing two independent reassortment events. Examination of the hemagglutinin cleavage site of LPAIV H9N2 confirmed its low pathogenicity. The receptor-binding sites indicated a binding preference for human-type receptors. Several mutations in internal proteins are associated with increased virulence and altered host range, while other amino acids were found to be highly conserved among LPAIV H9N2 isolates.

Genetic characterization of highly pathogenic H5N1 avian influenza virus from live migratory birds in Bangladesh

Since the first outbreak of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 in Bangladesh in 2007, the virus has been circulating among domestic poultry causing severe economic losses. To investigate the presence of HPAIV H5N1 in migratory birds and their potential role in virus spread, 205 pools of fecal samples from live migratory birds were analyzed. Here, the first virus isolation and genome characterization of two HPAIV H5N1 isolates from migratory birds (A/migratory bird/Bangladesh/P18/2010 and A/migratory bird/Bangladesh/P29/2010)are described. Full-length amplification, sequencing, and a comprehensive phylogenetic analysis were performed for HA, NA, M, NS, NP, PA, PB1, and PB2 gene segments. The selected migratory bird isolates belong to clade 2.3.2.1 along with recent Bangladeshi isolates from chickens, ducks, and crows which grouped in the same cluster with contemporary South and South-East Asian isolates. The studied isolates were genetically similar to other H5N1 isolates from different species within the respective clade although some unique amino acid substitutions were observed among them. Migratory birds remain a real threat for spreading pathogenic avian influenza viruses across the continent and introduction of new strains into Bangladesh.

Dried fluid spots for peste des petits ruminants virus load evaluation allowing for non-invasive diagnosis and genotyping

BackgroundActive surveillance of peste des petits ruminants (PPR) should ease prevention and control of this disease widely present across Africa, Middle East, central and southern Asia. PPR is now present in Turkey at the gateway to the European Union. In Bangladesh, the diagnosis and genotyping of PPR virus (PPRV) may be hampered by inadequate infrastructures and by lack of proper clinical material, which is often not preserved under cold chain up to laboratories. It has been shown previously that Whatman® 3MM filter paper (GE Healthcare, France) preserves the nucleic acid of PPRV for at least 3 months at 32°C.ResultsIn this study, we demonstrate the performances of filter papers for archiving RNA from local PPRV field isolates for further molecular detection and genotyping of PPRV, at -70°C combined with ambient temperature, for periods up to 16 months. PPR-suspected live animals were sampled and their blood and nasal swabs were applied on filter papers then air dried. Immediately after field sampling, RT-PCR amplifying a 448-bp fragment of the F gene appeared positive for both blood and nasal swabs when animals were in febrile stage and only nasal swabs were detected positive in non-febrile stage. Those tested positive were monitored by RT-PCR up to 10 months by storage at -70°C. At 16 months, using real time RT-PCR adapted to amplify the N gene from filter paper, high viral loads could still be detected (~2 x 107 copy numbers), essentially from nasal samples. The material was successfully sequenced and a Bayesian phylogenetic reconstruction achieved adequate resolution to establish temporal relationships within or between the geographical clusters of the PPRV strains.ConclusionsThis clearly reveals the excellent capacity of filter papers to store genetic material that can be sampled using a non-invasive approach.

Insights into genetic diversity and biological propensities of potentially zoonotic avian influenza H9N2 viruses circulating in Egypt

Low pathogenic avian influenza (LPAI) H9N2 viruses have established endemic status in Egyptian poultry populations since 2012. Recently, four cases of human H9N2 virus infections in Egypt demonstrated the zoonotic potential of these viruses. Egyptian H9N2 viruses obtained from 2011 to 2014 phylogenetically grouped into three clusters (1-3) within subclade B of the G1 lineage. Antigenically, a close clustering of the Egyptian H9N2 viruses with other recent G1-B like H9N2 strains and a significant antigenic distance from viruses outside the G1-B lineage was evident. Recent Egyptian LPAIV H9N2 showed a tendency to increased binding with erythrocytes expressing α 2,6-linked sialic acid which correlated with the Q226L amino acid substitution at the receptor binding unit of the hemagglutinin (Q234L, H9 numbering). Sequence analyses of the N2 neuraminidase (NA) revealed substitutions in the NA hemadsorption site similar to the N2 of prepandemic H3N2/1968, but no distinct antigenic or functional characteristics of the H9N2 NA associated with increased zoonotic potential could be identified.

Peste des petits ruminants virus infection of Black Bengal goats showed altered haematological and serum biochemical profiles

In Bangladesh, veterinarians often claim to reduce the mortality of natural peste des petits ruminants (PPR) outbreaks with the help of supportive fluid and electrolyte therapy. Information on haematological and biochemical parameters of PPR-infected goats, which is often altered because of associated tissue damages, is necessary to formulate the appropriate supportive therapy. This study determined the haematological and serum biochemical parameters of Black Bengal goats naturally infected with PPR virus. Blood and serum samples from 13 PPR-affected Black Bengal goats from 13 field outbreaks and 5 healthy goats were collected and analysed by routine haematological and biochemical examination. Haematological analysis of PRR-affected goats showed severe anaemia characterised by significant decrease in the values of haemoglobin, total erythrocyte counts (TECs) and packed cell volume (PCV). On the contrary, PPR-affected goats showed marked leucocytosis with absolute increase in lymphocytes and neutrophils counts compared to the healthy goats. Biochemical analysis revealed significant decrease in total protein and albumin level and increased creatine kinase, aspartate transaminase and alanine transaminase that mirrored the gross and histopathological changes in the PPR-affected goats. Significant increase in the values of sodium and chloride ions was found in the sera of PPR-infected goats. Peste des petits ruminants virus altered the haematological and serum biochemical parameters of the infected goats. Antidiarrheal agents with aqua solution together with other drugs to support liver and kidney function could help improve therapy of PPR-infected goats.