China: Guangdong CDC Reporting 1 H3N8 Infection (Zhongshan City) - Added Macao Statement

[Michael Coston]

China: Guangdong CDC Reporting 1 H3N8 Infection (Zhongshan City)

First two H3N8 cases in Humans April-May 2022,
Henan Province roughly 400 miles apart


#17,372

We've a curious report this morning from the Guangdong Provincial CDC announcing a single avian H3N8 infection has been detected in Zhongshan City (pop 4.4 million), which sits across the Pearl River Delta about 60 miles from Hong Kong.

Assuming this case is confirmed, it would become China's 3rd reported case in less than a year (see the 1st and 2nd case reports).​

Notably in the first (severe) case, the family dog and cat both tested positive for H3N8, and a full-length HA sequencing revealed the HA to be identical to the boy's.

Last summer we followed a number of reports on these two cases in China, and somewhat ominously, the detection of H3N8 in Hong Kong's poultry roughly 1000 km away from the first human case.

IJID: A Review Of The Pandemic Potential Of Avian H3N8​

EID Journal: Novel Zoonotic Avian Influenza Virus A(H3N8) Virus in Chicken, Hong Kong, China​

Preprint: Human infection With a Novel Reassortment Avian Influenza A H3N8 Virus: An Epidemiological Investigation Study​

FAO/OIE/WHO Joint Rapid Risk Assessment Human infection with Influenza A(H3N8)​

The following brief announcement (below) provides remarkably little information, other than the age, gender, and location of the case. No onset date is provided, although it is worded as if the investigation is ongoing, and the woman's condition is not disclosed.

I'll have a bit more after the break.

(translated)

One H3N8 case reported in Zhongshan City

Source of information: This website Release date: 2023-03-26


One case of H3N8 was reported in Zhongshan City. The case was a 56-year-old female with multiple myeloma and other basic medical history. She had a history of exposure to live poultry before the onset of the disease, and a history of wild bird activities around her home. The Chinese Center for Disease Control and Prevention checked and tested the case specimens, and the result was positive for H3N8 avian influenza virus nucleic acid.

Our center has guided Zhongshan City to carry out epidemiological investigations, close contact tracking management, investigation of epidemic-related places, on-site elimination and other epidemic disposal work in accordance with relevant plans. No abnormalities have been found in close contacts so far. Experts believe that this case is a sporadic case, and the risk of virus transmission is low at this stage.​

Experts suggest that the public should try to avoid direct contact with live poultry and dead poultry in daily life; take personal protection, pay attention to food hygiene, separate raw and cooked meat, and cook meat thoroughly before eating; once you find fever, cough, throat People with respiratory symptoms such as pain should wear a mask and seek medical treatment as soon as possible. If they have been in contact with birds before the illness, they should take the initiative to tell the doctor. Farmer's markets at all levels and types should abide by the "Guangdong Provincial Poultry Management Measures" and implement measures such as market poultry management and sanitation.​

Since H3N8 doesn't tend to seriously impact poultry, and until 10 months ago was not considered much of a zoonotic threat, it has received relatively little attention. However:

• H3N8 remains a plausible cause of a global influenza pandemic that spread out of Russia in 1889-1900 (some researchers now suspect a coronavirus instead).
• about 60 years ago H3N8 jumped unexpectedly to horses, supplanting the old equine H7N7 and is now the only equine-specific influenza circulating the globe
• in 2004 the equine H3N8 virus mutated enough to jump to canines, and began to spread among greyhounds in Florida (see EID Journal article Influenza A Virus (H3N8) in Dogs with Respiratory Disease, Florida).
• in 2011 avian H3N8 was found in marine mammals (harbor seals), and 2012’s mBio: A Mammalian Adapted H3N8 In Seals, provided evidence that this virus had recently adapted to bind to alpha 2,6 receptor cells, the type found in the human upper respiratory tract.
• And lastly, in 2015's J.Virol.: Experimental Infectivity Of H3N8 In Swine, we saw a study that found that avian (but not canine or equine) H3N8 could easily infect pigs.

So far China's state media has remained unusually silent on this case, and Hong Kong's CHP has yet to make an announcement.

Hopefully we'll have more details soon.



https://afludiary.blogspot.com/2023/...ng-1-h3n8.html

 

[Michael Coston]

Macao Statement On Guangdong H3N8 Case

Credit Wikipedia

#17,373

While there is still remarkably little mention of the case in Chinese media, in the past hour Macao has issued a statement on the H3N8 case reported today from neighboring Zhongshan City.

1 case of human infection with H3N8 bird flu confirmed in Guangdong Province

source:Health Service (SS)

release date:March 27, 2023 at 19:27

The Health Bureau stated that according to the announcement of the health department in the Mainland, a case of human infection with the H3N8 avian influenza virus was confirmed in Guangdong Province. Residents are urged to avoid contact with poultry and birds, and pay attention to personal and food hygiene.

According to the notification information, the patient is a 56-year-old female who lives in Zhongshan City, Guangdong Province. She has a basic medical history, a history of exposure to live poultry before the onset of the disease, and a history of wild bird activities around her home.

The H3N8 avian influenza virus is an avian-origin virus, which cannot be directly transmitted between humans, and the risk of large-scale transmission is low. The H3N8 virus has been detected globally in horses, dogs, poultry and seals.

The Health Bureau will continue to maintain close contact with the health departments of the country and neighboring regions, and the World Health Organization, and closely monitor the epidemic situation in various places and Macao. To prevent human infection with avian influenza, the Health Bureau appeals to the public to pay attention to the following:

• Avoid contact with birds or their secretions and excreta; if in contact, wash your hands immediately;
• Do not buy or carry unquarantined poultry;
• Do not eat poultry meat, offal, blood products and eggs that have not been thoroughly cooked;
• Pay attention to personal hygiene and wash hands frequently;
• If symptoms such as fever, cough, and difficulty breathing occur, you should wear a mask, seek medical treatment as soon as possible, and describe your travel history and animal contact history to the doctor in detail.

For information on avian influenza, please visit the website of the Health Bureau (www.ssm.gov.mo) or call the infectious disease hotline of the Health Bureau at 28700800 during office hours.​

So far, Hong Kong's CHP has yet to make an announcement. Last May they were conspicuously late in announcing the second case (see Hong Kong CHP Finally Notified Of 2nd H3N8 Case On the Mainland), so it is not all that surprising.

While any spillover of a novel flu virus to humans is noteworthy, those belonging to the H1, H2, and H3 HA subtypes are of particular concern because all known human influenza pandemics going back 130 years have come from one of these 3 subtypes (see Are Influenza Pandemic Viruses Members Of An Exclusive Club?).​

Earlier this month we took a look at a study by Chinese researchers on the evolution and spread of H3N8 (and other) avian flu viruses in Eastern China (see Emerging Microbes & Inf.: Prevalence, Evolution, Replication and Transmission of H3N8 Avian Influenza Viruses).

The authors wrote:

Genetic and phylogenetic analyses showed that the H3N8 viruses circulating in migratory birds and ducks have evolved into different branches and have undergone complicated reassortment with viruses in waterfowl. The 21 viruses belonged to 12 genotypes, and some strains induced body weight loss and pneumonia in mice. All the tested H3N8 viruses preferentially bind to avian-type receptors, although they have acquired the ability to bind human-type receptors.​

Infection studies in ducks, chickens and pigeons demonstrated that the currently circulating H3N8 viruses in migratory birds have a high possibility of infecting domestic waterfowl and a low possibility of infecting chickens and pigeons.​

Our findings imply that circulating H3N8 viruses in migratory birds continue to evolve and pose a high infection risk in domestic ducks. These results further emphasize the importance of avian influenza surveillance at the wild bird and poultry interface.​

Although this is only the 3rd known human infection with H3N8, it requires a good deal of luck for a case to be picked up by surveillance, and then get reported.

First, the patient must be sick enough to be hospitalized, and then lucky enough to receive the proper tests. And often, that simply doesn't happen.​

So while rare, spillover of H3N8 (and other novel flu viruses) are probably more common than we know.

Stay tuned.

https://afludiary.blogspot.com/2023/03/macao-statement-on-guangdong-h3n8-case.html