Ireland has avoided recent outbreaks of bird flu but the global threat remains and is growing
Elsewhere Months Still In Ireland Cases Avoided Are Outbreaks In Has Widespread Recent Europe, But
Concern notched up in global medical circles after the highly pathogenic bird flu virus was detected in a person in Texas who probably contracted it from infected cows.
Ireland has been one of the countries least affected by bird flu. There were no outbreaks in poultry on the island of Ireland in 2023 or 2024. Elsewhere in Europe, cases are still widespread, but the overall number of detections has fallen.
Since about 2005, governments have monitored the risks of a covid-like pandemic of bird flu affecting humans. But the risk for the general population in Europe remains low, according to the EU's European Food Safety Authority, which continues to monitor the reassortment, mutation, and adaptation of bird flu viruses to mammals, including humans.
Thankfully, the infected Texan's only symptom was conjunctivitis, (also known as red or pink eye, usually caused by infection or allergies, a condition which usually does not need treatment, at least in an adult). The patient was told to isolate and was treated with an antiviral drug for flu.
However, the spread of bird flu to cattle, first seen in Texas, brings to more than 40 the number of different species of mammals infected.
Texas agriculture commissioner Sid Miller said infection was reported in several dairy herds in the state, which has the biggest cattle population in the USA.
The outbreak may have started about a month ago, when a mysterious illness affected about 40% of the state's dairy herds, Miller said. He said he now suspects it was bird flu, though officials did not know it at the time and cannot confirm it, because the animals recovered since then.
Bird flu primarily affected older cows, and only a small portion of each herd had clinical signs. Surprisingly, the US Department of Agriculture did not receive any reports of sickness in the state's huge beef herds.
Some dairy farmers in the US have banned visitors, cut down trees, and disinfected visiting vehicles, to keep bird flu at bay.
They fear a drop in demand for milk and cheese, despite safety assurances to consumers. Futures prices for milk dropped temporarily as infections increased. Beef cattle futures also plunged.
States have tightened up cattle movement regulations.
Meanwhile, almost two million hens had to be recently euthanised at a Texas poultry farm infected with bird flu.
Highly pathogenic bird flu first emerged in 1997 in Hong Kong and then China in 2003, spreading through wild bird migration and poultry trading.
The unique variant causing the current epidemic emerged in late 2020 and is now widespread globally, especially in the Americas. The USA and Canada currently account for almost 80% of reported outbreaks in domestic birds worldwide.
There is concern now for the virus spreading from infected wild birds in Antarctica to Australia and New Zealand.
In the past, outbreaks could be controlled by culling infected birds. But this became increasingly difficult due to escalating outbreaks since 2021.
Infection spread to more and more mammals, including sea lions, goats, foxes, martens, skunks, minks, coyotes, domestic dogs and cats, and more recently, dairy cows and goats.
In Europe, the European Food Safety Authority says bird flu viruses continue to evolve globally, and with the migration of wild birds, new strains could mutate for mammalian adaptation.
If strains evolve which could spread efficiently among humans, large‐scale transmission could occur, due to the lack of immune defences. Measures to mitigate this pandemic risk focus on limiting exposure and preventing spread.
Vaccination of poultry may be considered, but has been largely avoided so far, because it’s only partially effective and can mask outbreaks.
France began vaccinating poultry in October, 2023. This compulsory vaccination was targeted at duck production, and 80% of subsequent French outbreaks reported were in unvaccinated poultry farms.
Worldwide, 889 human cases since 2003 ranged from mild to severe illness, that resulted in deaths in some countries. To date, there has been no sustained human-to-human transmission. And there have been no symptomatic human cases detected in Europe.
Health agencies worldwide say the risk to humans remains low, but they point to the ever-changing and unpredictable way the viruses are changing.
Infected wild birds are the suspected source of the infection found in cows in Texas, North Carolina, Kansas, Ohio, Michigan, Idaho. and New Mexico.
Genetic analysis detected a virus variant that is widespread among birds globally, but not very similar to the one found in Europe. However, no changes were found that would make the virus resistant to flu antiviral medications.
The cows in Texas showed milk yield decrease (20-30%), decreased appetite, and fever. Farmers were forbidden to sell milk from infected cows. But bird flu is not expected to undermine US milk production, which is generally trending higher seasonally.
The USA's Centers for Disease Control and Prevention did not change its bird flu human health risk assessment, It remains at "low". The CDC worked with state health departments to monitor workers in contact with infected or potentially infected birds or animals.
Milk samples in infected herds showed relatively high virus concentrations. But the commercial milk supply remains safe, because products are pasteurised before entering the market.
The general public in the US was reminded not to prepare or eat uncooked or undercooked food or related products, such as unpasteurised (raw) milk, or products made from raw milk. Also advised against was unprotected exposure to sick or dead animals including wild birds, poultry, cattle.
Similar precautions were recommended around animal carcasses, raw milk, faeces, litter, or materials contaminated by birds or other animals with confirmed or suspected infection.
Some bird flu experts say massive outbreaks in wild birds, but reduced cases in humans, may point to bird flu viruses becoming better adapted to wild birds, but less adapted to humans (and to domestic poultry).
The risk of infection “is currently low for the general population and low-to-moderate for those people exposed to infected animals due to their occupation”, said Angeliki Melidou, principal expert on respiratory viruses at the European Centre for Disease Prevention and Control, when interviewed by Euractiv.
