Highly Pathogenic Avian Influenza Virus (HPAIV) (AH5N8) detected in migratory and domestic birds in Uganda, 2017

Outbreaks caused by highly pathogenic avian influenza A(H5N8) viruses have been reported from south-east Asia since 2010. The viruses have been detected in captured and apparently healthy wild migratory birds and dead wild... [ view full abstract ]

Outbreaks caused by highly pathogenic avian influenza A(H5N8) viruses have been reported from south-east Asia since 2010. The viruses have been detected in captured and apparently healthy wild migratory birds and dead wild birds, as well as in domestic chickens, geese and ducks.

In Uganda, highly pathogenic avian influenza A(H5N8) viruses where detected in migratory birds a week after reports came out in local newspapers of die-offs of migratory white-winged black terns allegedly due to poisoning because of waste disposal from a nearby flower green house. Initially, seven RNA samples isolated from dead migratory birds at the shores of Lake Victoria at Lutembe Bay, and tested at Uganda Virus Research Institute (UVRI) by the National Influenza Center (NIC) were shipped from the National Animal Disease Diagnostics and Epidemiology Centre (NADDEC) after the first detection of influenza A by polymerase chain reaction (PCR). Because NADDEC did not have hemagglutinin (H) sub-typing primers at the time of the outbreak, the samples were referred to UVRI-NIC and tested for influenza A, H1pdm09, H3, H5 and H7. All seven RNA samples tested positive for influenza AH5. A week later, the initial seven samples and five new RNA samples collected in Bukakata, Masaka district from domestic birds mainly ducks were tested for neuraminidase (N) N1 and N8 subtype. All twelve samples tested positive for viral RNA A(H5N8). These results confirmed the introduction and detection for the first time of highly pathogenic avian influenza A(H5N8) in migratory birds and domestic ducks. The spread of the virus may have occurred via migratory bird flyways. No human cases of avian influenza A(H5N8) have been reported related to the current circulating virus. Future tests using Next-Generation Sequencing (NGS) on the MiSeq platform will characterize the avian influenza A(H5N8) virus to see how it relates to the strains detected and circulating in Europe and South-east Asia.