Thursday, December 16, 2021

Migrating Birds Signal the Next Influenza Pandemics


This article discussed the patterns of influenza and how it mutates among generations and how these strains reach different parts of the globe. The avian flu seasons run parallel with the migratory patterns of certain trans-oceanic birds that end up mingling with local species of birds, especially along shorelines where certain food resources are abundant during times of the year. In the Delaware Bay and surrounding areas, the common birds that bring the strains of influenza each year are the Red Knots and Ruddy Turnstones. These birds migrate from the southern tip of South America to the Delaware Bay to feed on the food resources along the shorelines, especially horseshoe crab eggs. Along the shorelines these influenza strains carrying birds share disease with local birds like dunlins, sandpipers, sanderlings, herring gulls, and laughing gulls. Ruddy Turnstones have a low antibody count to influenza and by the time they reach their breeding grounds about 60% of the populations is exposed to the virus. This common food source creates a pool of disease transfer between different bird species, which allows to the virus to be transferred to other animals and thus humans. Birds can die from the strains of influenza and die offs of bird species can allow scientists to pinpoint where certain strains of influenza are currenting being exchanged in the world. 119 countries sample dead wild bird populations for new avian flu strains, but for decades scientists in the Delaware Bay have been swabbing live birds for diseases. Influenza in the Americas follows the winter bird migration mainly and spikes the avian flu only occur after generations cycle the strains and new strains arise in populations that have lower antibodies for that particular strain. The influenza virus is made up of 8 pieces of RNA that can mix in a pool of different RNA strands creating new strains. The most common seasonal flu virus is H3N2 and H1N2. These are genes for tracking the flu where “H” is hemagglutinin and “N” is neuraminidase, which help the virus bind to cells in the respiratory track. There are 16 different “H” gene variants and 9 different “N” gene variants creating 150 possible strains. Each of these strains has the potential to mutate across generations and in the pools of birds that transfer the disease. The most common points of transfer between birds and humans occurs in Asia at wet bird markets and poultry farms where birds are kept in crowded and stressful environments creating a perfect situation of the flu to spike in reproduction and transfer rates. These birds that are then infected mingle with birds that have intersecting flyway migratory paths that expose themselves to species of birds that make trans-oceanic migrations.

No comments:

Post a Comment