Everything you need to know about bird flu in Peru

It is important to know that the flu or influenza viruses constitute a large family of seven genera, of which four (A, B, C and D) infect various species of birds and mammals (seals, dogs, horses, pigs, cattle , among others). Humans are infected with genera A, B, and C.

Influenza viruses are classified according to the characteristics and combination of two glycoproteins located on their surface: hemagglutinin (H) and neuraminidase (N). Hence the name of these viruses: H5N1, which concerns us today, or others such as H1N1, H2N3, etc.

Hemagglutinin allows the virus to enter the cell it infects, while neuraminidase causes viruses that have replicated within the infected cell to be released to infect new cells. H and N are key targets against which antibodies and antiviral drugs are directed.

Influenza viruses are considered pandemic-causing because they when two or more infect an animal (including humans) at the same timeit is possible that they combine their genetic material and – in a phenomenon called rearrangement – ​​generate mutant viruses with different behavior and capable of causing a new type of disease.

This is thought to have happened in 1918, when an avian virus rearranged itself with a pig virus, forming a new H1N1 virus that caused the great pandemic with 50 million to 90 million victims.

High pathogenicity

Of the seven genera of influenza viruses, only type A infects birds, which – depending on the type of disease it causes – can be of low or high pathogenicity. The virus found in dead pelicans from Paita, Pimentel, Puerto Viejo and Cañete is H5N1, group A, and highly pathogenic. These viruses are extraordinarily contagious among birds, causing severe illness and a fatality close to 100%.

“Knowing that the current variant affects more egg-laying birds […]it is expected that the price of eggs can rise, but not that of chicken meat”.

Due to the high contagiousness and lethality of the virus, the poultry industry has resorted to culling millions of poultry to prevent the infection from spreading and decimating that population. This year, the US record for culled chickens and turkeys has been broken, with 52.7 million birds culled. In 2015, the number was more than 50 million. More birds are killed by their owners than by bird flu.

Recently, the inhumane disposal practices of the birds have been exposed, one of which consists of raising the temperature of the houses, which causes their death by heat stroke after a terrible agony that can last from one to three hours. Another is to spray houses with a foam that suffocates birds in 7 to 15 minutes. The technique that uses CO2 in small spaces and that fades them in 30 seconds is not widely used because it is very expensive.

Risk to humans

While it is true that the virus is highly lethal in infected poultry, it is believed to pose very little threat to humans, except for people who come into very close contact with infected birds. It is also accepted that, when a human infection occurs, the virus is not transmitted efficiently between people.

However, some infected people may die. In an outbreak caused by an old strain of H5N1 between 2003 and 2021, just over half of the 863 sick people died.

The currently spreading H5N1 strain (which is in Peru) appears to be less transmissible and severe to humans, with only two mild cases diagnosed: a UK man in December 2021 and another in the US. , which was exposed to dead birds in a cleanup program last April.

Corollary

The viruses that cause bird flu are unlikely to cause disease in humans, except in people handling sick or dead birds. So far, only two cases caused by the current variant have been found. It is important to know that eating well-cooked eggs or poultry does not have the ability to cause infection.

The main threat of bird flu is its impact on the poultry meat and egg industry. Knowing that the current variant [2.3.4.4b] it affects egg-laying birds much more than birds that are slaughtered for their meat, it is expected that the price of eggs may rise, but not the price of chicken meat.

Since it is not possible to distinguish a vaccinated bird from an asymptomatic infected bird, which creates trade conflicts in the poultry export industry, the existing vaccine is not used.

At this time, the main recommendation is that people, both in the community and in the poultry industry, avoid direct contact with sick and dead birds.