Isolation, identification, and phylogenetic analysis of reassortant low-pathogenic avian influenza virus H3N1 from Pakistan

Circulation of low pathogenic avian influenza (LPAI) viruses in wild birds and poultry in the Netherlands, 2006-2016

In this study, we explore the circulation of low pathogenic avian influenza (LPAI) viruses in wild birds and poultry in the Netherlands. Surveillance data collected between 2006 and 2016 was used to evaluate subtype diversity, spatiotemporal distribution and genetic relationships between wild bird and poultry viruses. We observed close species-dependent associations among hemagglutinin and neuraminidase subtypes. Not all subtypes detected in wild birds were found in poultry, suggesting transmission to poultry is selective and likely depends on viral factors that determine host range restriction. Subtypes commonly detected in poultry were in wild birds most frequently detected in mallards and geese. Different temporal patterns in virus prevalence were observed between wild bird species. Virus detections in domestic ducks coincided with the prevalence peak in wild ducks, whereas virus detections in other poultry types were made throughout the year. Genetic analysis of the surface genes demonstrated that most poultry viruses were related to locally circulating wild bird viruses, but no direct spatiotemporal link was observed. Results indicate prolonged undetected virus circulation and frequent reassortment events with local and newly introduced viruses within the wild bird population. Increased knowledge on LPAI virus circulation can be used to improve surveillance strategies.

Investigation of equine influenza virus in two geographical regions of Pakistan

PURPOSE

The present study was an attempt to elucidate the seroprevalence of equine influenza virus (H3N8) in two geographically distinct regions of Pakistan where vaccination is not routinely practiced.

METHODS

A total number of 315 animals of family Equidae were included in the survey. Blood samples and nasal swabs were collected from the same animal and analyzed through ELISA and Hemagglutination Inhibition.

RESULTS

The seroprevalence for EIV was 10 and 8.39 in districts under study. Out of 29 ELISA positive sera, 7 (24.1 %) showed antibodies against H1 and 22 (75.9 %) showed against H3 of influenza strains. Specie-wise antibody titer against H1 was 7.5 and 9.0 for horses and donkeys, respectively, while mules were negative. Similarly, antibody titer against H3 was 7.12, 6.9, and 6.0 for horses, donkeys, and mules, respectively. No strain was isolated from the nasal swabs despite very high antibody titers of H1 and H3 in the sera of the same animals.

CONCLUSIONS

Influenza viruses are circulating in equine species and continuous surveillance is needed to keep check on any future outbreak.