Explainer: How serious is Europe's latest bird flu outbreak?

BRUSSELS, Oct 23 (Xinhua) -- Europe has seen a sharp rise in cases of highly pathogenic avian influenza (HPAI), also known as the bird flu, since September, forcing governments to raise alert levels and order mass culling.

France, Germany, the Netherlands, and others are racing to contain the virus as it spreads rapidly among poultry and wild birds. Here's what you need to know:

HOW BAD IS THE OUTBREAK?

According to the World Organization for Animal Health (WOAH), Europe saw a steep increase in bird flu cases in September. Bird infections jumped from 759 to more than 61,000, while poultry losses (from deaths and culling) surged from 291 to around 334,000. Germany, Spain and France are among the worst affected.

Belgium reported an outbreak on Wednesday, with 319 birds dead and over 60,000 culled. The federal food safety agency ordered all poultry to be kept indoors nationwide.

France raised its national alert level from "moderate" to "high" on October 21 after reporting four outbreaks at poultry farms since early October. Meanwhile, Germany has logged infections at more than 15 farms this month, up from just four in September, and upgraded its risk level for poultry holdings to "high."

In Spain's Castilla y Leon region, the province of Valladolid has been the hardest hit, with six outbreaks affecting more than 2 million birds. Portugal has reported seven cases since September, including one at a duck farm that impacted 250,000 birds.

HOW DO COUNTRIES RESPOND?

The main response across Europe has been mass culling and movement restrictions on poultry. France, Germany, the Netherlands, Spain, Portugal and Poland have all adopted such measures to slow the spread.

In the Netherlands, for instance, authorities culled 161,000 birds at a layer farm in Gelderland province on Oct. 22 and 71,000 more earlier this month at another site. The country has also imposed nationwide indoor housing rules and 10-km transport bans around affected farms, covering birds, eggs, manure and related materials.

According to Euronews, European governments are also expanding monitoring and vaccination programs to help the poultry sector prevent and recover from the HPAI outbreaks.

WHERE DID THE VIRUS COME FROM?

According to the WOAH, wild birds, especially waterfowl, are the natural hosts of avian influenza viruses and are often responsible for transmitting the virus to domestic flocks.

France's Agriculture Ministry said detections among migratory birds have risen significantly in recent weeks. Many outbreaks were located along the Atlantic migratory flyway, suggesting that wild birds traveling south between September and December are a key source of infection.

Environmental authorities in Germany's Brandenburg state said that they are dealing with the largest-ever wild bird outbreak, mainly among migrating cranes. More than 1,000 crane deaths have been confirmed. The virus has also been detected in dead swans and ducks in the Netherlands, Portugal, and Latvia.

The Friedrich-Loeffler-Institut, Germany's federal animal health agency, said infected birds can still fly in the early stages of the disease, potentially spreading the virus along migration routes.

HOW BIG COULD THE IMPACT BE?

WOAH said September's bird flu outbreaks in poultry hit the highest level compared to the same month in the previous two seasonal waves, and are expected to rise further in the coming months.

As migratory birds move southwest, environmental authorities of Germany's Brandenburg state expect the virus to spread deeper into France and Spain, causing more bird deaths. Dutch officials warned that the spread of HPAI remains highly unpredictable and requires close monitoring.

The outbreak could also threaten endangered species such as the great bustard, of which only about 100 remain in Germany.

According to Euronews, the outbreaks pose a threat to Europe's poultry industry and trade. For instance, Morocco suspended imports of poultry, eggs and related products from Portugal in September.

CAN HUMANS CATCH IT?

It is extremely rare for humans to become infected with bird flu, and no sustained human-to-human transmission has been observed, the European Center for Disease Prevention and Control said on Oct. 17 in a statement. The risk to the general population in the EU and European Economic Area is considered low.

Spain's health authorities said there is no evidence that bird flu can spread through properly cooked poultry or eggs.

Germany's Robert Koch Institute said transmission to humans has only occurred in isolated cases, mainly among people having close contact with infected birds, such as farm workers or veterinarians. Officials advise avoiding any direct contact with sick or dead wild birds. ■