Avian Influenza: A growing threat to Africa

Authors: Suarez, David

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The H9N2 low pathogenic avian influenza (LPAI) is probably the most widespread avian influenza subtype in poultry around the world being endemic in a large part of Asia, the Middle East, Northern Africa, and in Germany. Currently, there is no standardized clade system to describe the antigenic variation like we have for H5N1 highly pathogenic avian influenza, but the H9N2 lineages are more diverse than the H5N1 lineages. For example, Israel has two sublineages that differ by over 6 percent different at the amino acid level and differ by over 15% to H9N2 viruses from other countries. The H9N2 viruses in SPF chickens generally cause no or only minor disease, but in the field in combination with other respiratory pathogens and poor environmental conditions, severe disease with high mortality is commonly reported. Vaccines are commonly used to control the disease, but if the vaccines are not well matched to the field strain you may have poor protection. The other growing threat to Africa is the spread of highly pathogenic avian influenza in West Africa and most recently in South Africa. Likely originally introduced by wild birds, once introduced the virus is typically spread directly farm to farm. The presence and spread of both H9N2 and H5 viruses provided a continued threat to food security in the region. Different control strategies will be discussed.