Guangdong disease control: The human infection with H3N8 found so far is an episodic case The risk of transmission is low at this stage

Guangzhou, March 3 (Reporter Cai Minjie) Recently, Zhongshan City, Guangdong Province reported a case of H30N1 avian influenza, a 3-year-old woman. Li Yan, deputy director of the Guangdong Provincial Center for Disease Control and Prevention, said on the 8th that the human infection with H56N30 found so far is an occasional case, and there is a history of exposure to live poultry before the onset of the disease, and no new cases have been found in the health monitoring of close contacts and co-exposed persons, suggesting that the risk of transmission of the virus is low at this stage.

Li Yan introduced that H3N8 is a type of avian influenza, which is an infectious disease caused by a subtype of influenza A virus. The H3N8 virus has been detected globally in animals such as poultry, horses, dogs and seals, and human infections have rarely been detected.

Among them, H and N represent two proteins on the surface of avian influenza virus, and H is hemagglutinin, which can make the virus adhere and invade the host cell, like the key for the virus to invade the cell; N is neuraminidase that helps the virus be released from the host cell, allowing the virus to spread in the host body.

Due to frequent antigenic mutations of influenza viruses, new antigenic components appear, forming many new strains. Therefore, different number symbols indicate different types and subtypes of virus strains. Different virus strains also have different antigenicity and pathogenicity.

Specifically, according to the glycoprotein variation, H is divided into different types from H1 to H16, and N is divided into different types from N1 to N9. In addition to H3N8, avian influenza that has been infected by humans includes subtypes such as H5N6, H5N1, H9N2, H7N7, H7N9, H10N3, H10N8, H5N8 and so on.

After infection, patients typically present with influenza-like symptoms such as fever, cough, and sputum loss, which may be accompanied by headache, muscle aches, and general malaise. Severe patients have rapid development of disease, and most of them have severe pneumonia and other manifestations.

Among the many strains, H5 and H7 are highly pathogenic, and the H3 subtype causes milder symptoms of infection. In particular, after human infection with subtypes such as H5N1 and H5N6, the severe disease rate and case fatality rate are high, while the pathogenicity of human infection with H3N8 subtype needs to be further observed.

It is worth noting that the H3N8 virus infected by the Zhongshan avian influenza case has been mostly detected in poultry, horses, dogs and seals in the past, and human infection has rarely been detected worldwide.

After investigation and judgment, the Guangdong Provincial Center for Disease Control and Prevention believes that the human infection with H3N8 found so far are all sporadic cases, and all have a history of exposure to live poultry before the onset of illness. After health surveillance of close contacts and co-exposed persons of the case in Zhongshan City, no new cases were found, indicating that the risk of transmission of the virus is low at this stage.

Li Yan stressed that although the risk of transmission of the virus is low at this stage, and no human-to-human transmission has been found at present, it should not be taken lightly. The CDC found that the main source of infection for human cases of avian influenza was exposure to infected live poultry, sick and dead poultry or visits to contaminated live poultry sales markets.

Li Yan said that the public should not buy sick and dead poultry in daily life, and do not buy live poultry as much as possible, and it is recommended to directly purchase fresh or chilled poultry that have been slaughtered and processed in a centralized manner; Do not buy poultry and bird products of unknown origin, do not patronize mobile stalls that sell live poultry in violation of the law, and do not mix purchased live poultry with original poultry.

Guangdong CDC suggests that if you have respiratory symptoms such as fever and cough after contact with live or sick and dead poultry, you should wear a mask, seek medical attention as soon as possible, and tell the doctor about the history of poultry contact or whether you have been to a live poultry market. (End)