Pathogen obtained from a dead bird in Espírito Santo, genetically similar to pathogens circulating in two of our South American vizinhos
The various avian influenza viruses we see circulating in Brazil likely originated in coastal areas of Chile or Peru. Brazilian researchers have sequenced the genome of the pathogen that infected the first Brazilian bird identified as the cause, a banded bird (Thalasseus acuflavidus) that was found in Mara, on the southern coast of Espírito Santo state, in May. Taizes was found dead, and it was concluded that his genes were similar to several viruses circulating in South America since 2022. The results of the analysis were published in an article in the Social Science Research Network (SSRN) preprint repository on August 21 and contain documents that have not yet been reviewed by independent researchers.
“We looked at the brief description of the first case detected in Brazil,” says microbiologist Aristóteles Góes-Neto of the Federal University of Minas Gerais (UFMG). Researchers associated with the Israelita Albert Einstein Hospital in São Paulo and the Ministry of Agriculture, Livestock and Supply were involved in the sequencing and analysis of the viral genome (map). “An infected species, or trita-reis-de-bando, is common in the country and has been found in Amapá, Rio Grande do Sul, including on oceanic islands.”
The highly pathogenic influenza A (H5N1) virus currently circulating here emerged in Europe in 2020 and has spread to other continents from there. It entered the United States in 2021 and has reached the Pacific coast of South America next year. In May of this year, or even earlier, it entered Brazil, possibly tracked by migratory birds.
This strain of the virus, spread through contact with respiratory secretions or infected feces, causes severe influenza in some bird groups and is fatal to all infected animals. In general, resistant migratory waterfowl are natural hosts and reservoirs of viruses and play an important role in their evolution, maintenance, and spread. “H5N1 causes clinical signs in the respiratory and digestive systems, as well as in the nervous system of species susceptible to this infection,” said veterinarian Helena Lage Ferreira, professor and rector of the University of São Paulo (USP). , and there are also cases in asymptomatic animals.” Member of the Brazilian Society of Virology.
From May to September 21, the Map team documented 106 production outbreaks in Brazil, 103 of which were in wild birds and three in birds raised for survival—there are currently no outbreaks on commercial farms. Other potential sources of research are still under investigation.
“Continuous surveillance and surveillance are necessary in order to quickly control and reduce damage, cases or spread of the virus to commercial breeders and thus avoid epidemics,” Góes-Neto said. If the virus is commercially produced in the country, it could have a significant impact on the economy. Brazil is the world’s second largest producer and largest exporter of fruit pulp. To reduce the risk of this happening, experts recommend that poultry production facilities implement biosecurity measures, such as housing poultry in screened environments to reduce contact with wild birds; disinfecting equipment and vehicles; and limiting visitor access to the farm. ; e Use personal protective equipment while working.
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Ryschak, D. et al. The highly pathogenic avian influenza A (H5N1) virus and its genetic characteristics were reported for the first time in the Brazilian Cabot tern (Thalasseus acuflavidus). SSRN. August 21, 2023.