To understand the importance of those three ducks and the virus they carry, we need a quick tour of the School of Flu. Lesson One: The tree of the influenza virus family is immense, shining brightly; it contains types — A, B, C, D — and subtypes, specified with Hs and Ns. (It stands for proteins that allow viruses to infect cells.) Within As alone, there are nearly 200 subtypes; A few affect humans, but almost all of them can infect birds.
Lesson two: For a long time, scientists thought humans were in less danger from all other strains of flu. That assumption was broken in 1997, when an avian flu, H5N1, struck multiple species in Hong Kong and infected 18 people, killing six of them. To shut it down, the local government slaughtered every chicken in the territory, denying the virus was the host. That worked for a few years, but in 2003 the H5N1 started moving around the world again, and it’s been moving ever since.
Lesson three: Bird flu can be dangerous to people, but it also threatens some birds. Waterfowl, mainly ducks, carry it without illness, but it does make the chickens sick. Here are the subcategories again: Avian influenza is low-grade, which means it causes mild illness in birds and slows egg production. Either it can be highly pathogenic, or highly contagious: a fast-moving infection so deadly that it can kill an entire flock in two days. (A famous avian researcher once called it “Ebola in chickens.”)
All that in a nutshell (there won’t be a riddle): The flu found in the Carolinas is H5N1, which means it’s in a subtype that typically infects birds but has made people sick in the past. It is a high sugar breed that can wipe out domesticated flocks. It belongs to a strain that was implicated in the first species jump in 1997. And, to make matters worse, it represents just one notable case of highly virulent H5N1 emerging across the globe. world right now.
Last year, the World Organization for Animal Health (known by its French abbreviation OIE) estimates that between May 1 and November 1, 41 countries had outbreaks of highly pathogenic avian influenza, with 16,000 virus isolates reported in October alone. Fifteen countries also reported outbreaks of avian influenza. outbreaks from October to December.
It is not unusual for avian influenza to be isolated from wild birds at times, but last fall, high-altitude H5N1 outbreaks began in the UK with unusual intensity. Since October and in this year, the virus has been found in wild species, including swans, geese, seabirds, and birds of prey. But it has also made its way onto poultry farms, mainly in Lincolnshire and Yorkshire. By January, more than 1 million chickens and other birds were exterminated to prevent it from spreading. In December, the UK’s chief veterinary officer called the arrival of avian flu there “extraordinary“Say the tension has spread to the largest number of farm properties ever seen.
At about the same time, the Dutch authorities were order to slaughter of hundreds of thousands of poultry on farms throughout the country. In the Czech Republic, more than 100,000 hens die outbreak of avian flu at an egg farm, and another 100,000 birds and about 1 million eggs were culled to prevent further spread of the virus. In France, farmers fear the virus will invade the southwestern region of duck farming, home of foie gras. Last week, the Department of Agriculture ordered the killing of 2.5 million birds. In Italy, more than 4 million poultry are killed or slaughtered between October and December. And the Friedrich Loeffler Institute, the German government’s animal disease research unit, said in late December that Europe experienced “Strongest bird flu outbreak ever”, with cases spreading as far north as the Faroe Islands and as far south as Portugal.
