in the case of Swine flu For those who have recently registered in the UK, this is not the first, nor will it be the last. According to CuídatePlus, another virus was discovered in Spain last year, Gustavo del RealThe statement of the researcher of the National Institute of Agricultural and Food Research Technology (INIA) did not have much impact and “did not appear in the news”.its about A very common disease in pigs Almost all over the planet, but It is only occasionally transmitted to humans.. Neither condition is usually serious. Even so, swine flu experts still believe there is insufficient testing. In his view, “it would be convenient to have a system or a routine control system for what happens to pigs, especially for people who have some contact with these animals.” Certain measures have not been taken because it is not Notifiable diseases.
Why has this case caused so much controversy in the UK? The World Health Organization (WHO) issued a statement assuring that “the risk of swine flu spread through humans or communities is low.” However, he added, “As these viruses continue to be found in pig populations around the world, New human cases are likely to emerge Due to direct or indirect contact with infected pigs. ” And it cannot be ruled out that they evolved into more transmissible forms, which in fact has already happened.
The fact is that human, swine and avian influenza viruses are all related. They are influenza viruses and belong to the family Orthomyxoviridae. “The host of this virus is birds,” he stressed. Raul RivasProfessor of Microbiology at the University of Salamanca. “What happened was Some of them have the ability to infect mammals“. To differentiate, animal influenza viruses are named after the host species they infect: avian influenza viruses, swine influenza viruses, equine influenza viruses, canine influenza viruses, etc. These pathogens are not easily transmitted to humans or between humans.
swine flu virus
The major influenza virus subtypes circulating in pigs and occasionally infecting humans are A(H1N1), A(H1N2), and A(H3N2). What has just been recorded is the first reported case of H1N2 swine flu in the UK.
Del Real said that these viruses “originate in birds and because of their affinity they can be transmitted to pigs and then, once they adapt to the species, they can infect humans.” The expert clarified Transmission to humans “does not occur over long distances but requires more or less close contact.””. Therefore, the people most commonly affected are those who look after the farm, such as veterinarians, farmers and suppliers.
Generally, illness caused by swine flu viruses is mild in both pigs and people. INIA researchers commented: “Virtually all human cases, such as those in the UK or Spain last year, were discovered incidentally.” These people went to hospital with flu symptoms. Then, when the causative virus was studied, it was discovered that it actually originated from pigs. “that’s why, The situation may have been greatly underestimated“.
The real danger is what might happen in the future if these viruses evolve into more contagious and virulent forms. “In general, the pandemic potential of influenza viruses is very high,” Rivas said. “There is currently no evidence of ongoing human-to-human transmission of the H1N2 virus,” he noted.But it deserves attention because Pigs act as “shakers” There may be situations where multiple viruses converge and recombine, resulting in the emergence of pathogens important to humans.
That’s what happened with the 2009 influenza A pandemic., starting with pigs. Specifically, it originated from swine, avian, and human flu viruses that gave rise to H1N1 influenza, which, in Rivas’ words, “is currently circulating and causing seasonal flu spikes, but at the time it was devastating , causing many deaths.”
bird flu virus
Bird flu viruses are more worrisome than swine viruses. The most alarming ones are H5N3, H5N4, H5N8 and H5N5, especially H5N1. It has a very high lethality rate for animals. “In large chicken farmsthere may be tens of thousands of them, The mortality rate can reach almost 100%Real said.
Human cases of avian influenza are not as frequent as swine flu, and most occur in Asia, such as China, Vietnam or Cambodia. “These are places where people come into close contact with domestic birds and even wild birds,” INIA scientists emphasized. “If it is transmitted directly from birds to humans, the mortality rate is 60-70%.” However, the H5N1 virus has a high risk of transmission between humans and humans. Human-to-human transmission is “not easy.” The barriers that exist between species act as brakes, but “it’s not insurmountable.” Each virus “is adapted to grow in cells of a specific species, and in order to grow in cells of another species, it needs to undergo a series of adaptations.” These adaptations are achieved “Based on mutated genes that allow them to easily proliferate in cells of new species“. Is this process possible? Yes, it is only a matter of time before it reaches the necessary mutations so that “it can proliferate in the human species.”
Rivas confirmed concerns about the H5N1 avian influenza virus, which “is widely distributed around the world and is causing multiple outbreaks in wild and domestic poultry, More and more mammals are becoming infected with this virus and suffering massive deaths“. This huge expansion increases the chance that one of these infected species “could act as an intermediary, increasing its ability to infect mammalian cells and ultimately become a problem in humans.”
human influenza
There are three types of influenza viruses that infect humans: A, B, and C. Influenza A and B viruses cause seasonal epidemics of the disease almost every year.but A virus is the only virus that has been shown to cause epidemics. Influenza C virus infection usually causes mild illness and is not believed to cause an epidemic.
Influenza A viruses are divided into subtypes based on the combination of two proteins on their surface: hemagglutinin (HA) and neuraminidase (NA). The subtypes currently circulating in humans are A(H1N1) and A(H3N2). As mentioned previously, A(H1N1) was the cause of the 2009 pandemic and subsequently replaced the seasonal influenza virus A(H1N1) that was circulating at the time.
Type B viruses are not divided into subtypes, but currently circulating viruses are divided into two lineages: B/Yamagata and B/Victoria. Cs are also not subdivided, are tested less frequently, and are generally unimportant from a public health perspective.
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