Virus World

The government is investigating the source of contagion as well as others who were in contact with the patient. Chile has reported cases of the H5N1 bird flu since late last year. Chile detected the first case of bird flu in a human, the country’s health ministry reported on Wednesday. The case was detected in a 53-year-old man who presented severe influenza symptoms, according to a statement issued by the ministry, but they noted the patient was in stable condition. The government is also investigating the source of contagion as well as others who were in contact with the patient. Chile has reported cases of the H5N1 bird flu since late last year in wild animals. Recent cases in industrial farms caused the government to halt poultry exports. Industrial cases have also been detected in Argentina, but Brazil, the world’s largest exporter of poultry, remains free of the contagion. Chilean health authorities noted the virus can be transmitted from birds or marine mammals to humans, but there is no known human-to-human transmission. Earlier this year, Ecuador confirmed its first case of human transmission of bird flu in a nine-year-old girl. Global health officials have said risk of transmission between humans is low, but vaccine makers have been preparing bird flu shots for humans “just in case.”

Bird flu is infecting the brains of wild mammals such as foxes and raccoons and may be making them behave in unusual ways, according to a study in the US. Out of 57 live mammals found to be infected, 53 had neurological symptoms, such as seizures, problems with balance, tremors and a lack of fear of people. The risk to people appears to be low. “There isn’t yet any evidence that red foxes or other wild mammals …

As a new version of bird flu spread through North America this spring, scientists began finding the virus in red foxes, bobcats and other mammals.  Something was wrong with the foxes. That was what callers to the Dane County Humane Society in Wisconsin kept saying in April, as they reported fox kits, or young foxes, behaving in strange ways: shaking, seizing or struggling to stand. The kits, which were often lethargic and wandering by themselves, also seemed unusually easy to approach, showing little fear of humans. “We just kept getting calls,” said Erin Lemley, a wildlife veterinary technician at the humane society’s wildlife center. “And the foxes started coming in.” Some of the kits that were admitted for treatment were quiet and withdrawn, she said. Others stumbled around or had seizures, their heads ticcing, their eyes flicking rhythmically. After the staff ruled out rabies, low blood sugar and other potential causes, laboratory testing revealed a surprising culprit: a highly virulent strain of avian influenza. “It was not a fun surprise,” said Dr. Shawna Hawkins, a zoo and wildlife veterinarian at the University of Wisconsin-Madison.

A woman in southern China has tested positive for H3N8 bird flu, local officials say, making it only the third time that the virus has been found in humans, although a previous strain may have caused the 1889 pandemic. The Guangdong Provincial Center for Disease Control and Prevention, in a brief statement released on Monday, said a 56-year-old woman from Zhongshan City had been infected with H3N8. The woman, who has multiple myeloma and other underlying health conditions, had exposure to live poultry before falling ill, the statement said. Wild birds are also frequently found near her home. Details about her condition have not been released. “No abnormalities have been found in close contacts so far,” the Guangdong CDC said. “Experts believe that this is a sporadic case and the risk of virus transmission is low at this stage.”

The news comes nearly a year after the H3N8 virus was confirmed in humans for the first time, when a 4-year-old boy in central China became seriously ill. The family’s pets – a dog and a cat – were also infected. A second person, a 5-year-old boy from Hunan province, was infected about a month later, in May 2022. He recovered quickly after only mild symptoms, according to the Chinese government. H3N8 is found in birds but also in horses and is one of the two viruses which cause dog flu. The new case in China is only the third confirmed case in humans, and the first in an adult. But while it was never found in humans until 2022, researchers have long believed that a previous strain of the virus may have caused the 1889 pandemic, which was known as “Asiatic flu” or “Russian flu.” More recent research suggests a strain of coronavirus may have caused the pandemic.

The Centers for Disease Control and Prevention and National Center for Immunization and Respiratory Diseases have provided updated results of a preliminary assessment of the H5N1 viruses identified in two human infections detected in Cambodia in 2023 based on their genetic sequences and gives an update on the epidemiological investigation. On February 26, 2023, the Institut Pasteur du Cambodge, in collaboration with the Cambodian Ministry of Health, shared the full genetic sequence of the H5N1 virus recovered from the patient who died in that country on February 22, 2023 The genetic sequence of the second case was later also shared by the Institut Pasteur du Cambodge. CDC has conducted a preliminary analysis of the genetic sequences of these H5N1 bird flu viruses. They are H5N1 viruses from clade 2.3.2.1c, which are different from the H5N1 viruses now spreading in U.S. wild birds and poultry, which are from clade 2.3.4.4b. These viruses are similar to past 2.3.2.1c viruses detected in that geographic area over recent years. The genetic sequences suggest that an existing clade 2.3.2.1c candidate vaccine virus (CVV), called NIBRG-301 (A/duck/Vietnam/NCVD-1584/2012-like) would offer protection against the viruses identified in Cambodia.

Additionally, there were no genetic changes identified that are known to be associated with increased ability to spread to people or reduce susceptibility to influenza antiviral drugs. CDC had requested virus samples from both cases in Cambodia in order to conduct additional laboratory testing/analysis to confirm these and other characteristics of the viruses and to provide a more detailed risk assessment. CDC continues to support the Ministry of Health, Ministry of Agriculture, Animal, Forestry and Fisheries, and Ministry of Environment, in its ongoing One Health investigation. Evidence to date continues to support the conclusion that these two human infections are the result of two instances of bird-to-human spread. There is still no indication of person-to-person spread associated with these two cases. The investigation has revealed that both patients became sick at about the same time and were likely exposed to sick or dead poultry prior to becoming ill, including being near sick/dead poultry kept in a coop under the house or through butchering, cleaning, and cooking chicken that died. Investigation and containment efforts continue, including monitoring and/or testing of contacts of the two cases for 10 days after their last exposure, along with active surveillance for influenza-like-illness in the village. CDC will provide additional updates as needed.

Russia has registered the first case of a strain of bird flu virus named A(H5N8) being passed to humans from birds and has reported the matter to the World Health Organization (WHO), Anna Popova, head of consumer health watchdog Rospotrebnadzor, said on Saturday.  Outbreaks of the H5N8 strain have been reported in Russia, Europe, China, the Middle East and North Africa in recent months but so far only in poultry. Other strains - H5N1, H7N9 and H9N2 - have been known here) to spread to humans. Russia reported the case of human infection to the WHO “several days ago, just as we became absolutely certain of our results,” Popova said on Rossiya 24 state TV. There was no sign yet of transmission between humans, she added. Seven workers at a poultry plant in Russia’s south had been infected with the H5N8 strain in an outbreak at the plant in December, Popova said, adding that the individuals involved felt fine now. “This situation did not develop further,” she said.

In an email WHO’s European arm said it had been notified by Russia about a case of human infection with H5N8 and acknowledged this would if confirmed be the first time the strain had infected people. “Preliminary information indicates that the reported cases were workers exposed to bird flocks,” the email said. “They were asymptomatic and no onward human to human transmission was reported. “We are in discussion with national authorities to gather more information and assess the public health impact of this event,” the email added.  The majority of human bird flu infections have been associated with direct contact with infected live or dead poultry, though properly cooked food is considered to be safe. Bird flu outbreaks often prompt poultry plants to kill their birds to prevent the virus from spreading, and avoid importing countries having to impose trade restrictions. The vast majority of cases are spread by migrating wild birds, so producing countries tend to keep their poultry indoors or protected from contact with wildlife. Siberia’s Vector Institute said on Saturday it would start developing human tests and a vaccine against H5N8, RIA news agency reported.