Experts say that although contamination in humans is rare, the risk may increase as the number of sick animals and the possibility of the virus mutating increases.
cause of bird flu (bird flu), the H5N1 viruses it was first identified in Brazil in May of this year. Until this Friday, 2, 19 cases of birds infected with the disease have been confirmed since Ministry of Agriculture and Livestock (Mapa). The file even declared an animal health emergency in the country for 180 days and limited poultry farming events to prevent the disease from spreading into commercial production and affecting people’s health.
There are currently no reports of human contamination in the national territory. But, although the transmission of H5N1 to people is difficult, the specialists consulted by the Stadium explain that this risk may increase with the increase of the number of sick animals and, consequently, of the possibility of mutation of the virus.
Infectologist Nancy Bellei, professor and head of the respiratory virus research laboratory at the Federal University of São Paulo (Unifesp), explains that birds are naturally reservoirs of the flu virus, but that some types, such as H5N , are more prone to become highly pathogenic to these animals, which then carry highly pathogenic avian influenza (HPAI).
Why is Brazil experiencing a bird flu outbreak?
According to the specialist, who is also scientific adviser on influenza for the Ministry of Health and the World Health Organization (WHO), the current outbreak affecting Brazil and South America – places where bird flu had not been detected earlier – it is precisely related to the development of a more pathogenic version of the flu in migratory birds, which move from one country to another in search of better living conditions.
“This highly pathogenic virus has already been detected for several decades in other continents, such as Africa and Asia, and is now making its way to South America,” he says.
“The H5N1 virus is most common in domesticated birds, such as ducks and geese, but some migratory birds that travel around the world in search of a better climate have also started to become infected. And when they are contaminated, they survive, at most, up to 48 hours,” says Nancy.
He explains that transmission to people is rarer because humans, unlike birds, do not carry receptors for the virus that transmits bird flu. This does not mean, however, that the human population is not free from contracting the disease. According to Nancy Bellei, people’s risks of being contaminated by H5N1 will depend on the ability of the virus to undergo mutations that make it suitable for the human species.
How is the disease transmitted?
Transmission occurs through contact with secretions, blood, feces, and even tissue from the infected bird. The Unifesp professor explains that, due to the history of human contamination, people tend to become infected when they directly manipulate the animal with the virus to prepare it for their own consumption. However, Nancy points out that transmission can also occur through aerosol particles, which leach from the faeces of sick birds and contaminate the air.
symptoms in humans
Symptoms of bird flu in humans begin much like a classic flu, with high fever, body aches, back pain, headaches, nausea and fatigue, as well as respiratory symptoms such as cough and sputum.
However, according to the doctor, this condition can develop very seriously and the patient has breathing difficulties and even pulmonary hemorrhages. There are also cases where the person may be asymptomatic and show no signs of the disease.
50% mortality rate.
According to an infectious disease specialist, around 900 people worldwide have been diagnosed with avian flu since 2003 – the number could be higher due to asymptomatic cases – and the case fatality has reached 50%. “There is no other virus with such a high fatality rate,” she said.
What to do in case of suspicion?
If a person is exposed to birds suspected or known to have H5N1, they should be monitored by the local health service and isolated for 10 days, the incubation time of the virus (the time when symptoms appear).
If the patient has symptoms, it is necessary to collect secretions from the nasopharynx region – as done in covid-19 with the swab – and remain isolated until the symptoms disappear.
Nancy Bellei explains that, although to date there is no trace of human-to-human contamination, the isolation is carried out to avoid the risk of mutation of the virus.
disease treatment
Treatment of a patient suffering from bird flu is carried out with antiviral drugs, which have already proven themselves well. If the clinical condition worsens, the person should go to the hospital and receive other treatment in addition to the antiviral drug, according to the infection specialist. Also according to the Unifesp professor, several countries, such as the United States, the United Kingdom, India, Japan and China, are working to develop a vaccine capable of protecting people from the H5N1 virus.
Is eating poultry safe?
YES. According to WHO, Brazil maintains highly pathogenic avian influenza (IAAP) free status because there is no record of contamination in commercial production. And the Brazilian Animal Protein Association (ABPA) says the registration of new cases should not generate impacts on Brazilian exports.
Despite this, on 22 May the Ministry of Agriculture and Livestock (Mapa) declared a state of animal health emergency throughout Brazil for 180 days. At the time, Brazil recorded only eight cases. The measure was taken after the Federal Agricultural Defense Laboratory of São Paulo (LFDA-SP) confirmed that three other wild birds had tested positive for highly pathogenic avian influenza (H5N1) (IAAP) in the state of Espírito Santo .
According to Mapa, the declaration of animal health emergency was made to prevent the disease from reaching livelihoods and commercial poultry production and also to preserve fauna and people’s health. Furthermore, the text also extended, indefinitely, the suspension of events promoting agglomerations and bird breeding, such as exhibitions, tournaments and fairs.
Fernanda Maris, professor of Veterinary Medicine at the Centro Universitário Braz Cubas, explains that the confirmed cases have occurred in wild birds and not in farms where chickens intended for consumption are treated. “Even so, it’s important to handle and cook this meat well to eliminate any kind of risk,” says the professor.
Source: Terra
Ben Stock is a lifestyle journalist and author at Gossipify. He writes about topics such as health, wellness, travel, food and home decor. He provides practical advice and inspiration to improve well-being, keeps readers up to date with latest lifestyle news and trends, known for his engaging writing style, in-depth analysis and unique perspectives.
