Wednesday, June 22, 2022

Southern China: Several Provinces Issue H3N2 Influenza Alerts

WHO Global Influenza Update N° 421

Most non-tropical countries experience a distinct winter respiratory season, which is punctuated by a yearly return of influenza A or B (or both). In tropical climes, influenza spreads at low levels more or less year-round.    
There are a few notable exceptions, such as Hong Kong, which often sees a biphasic flu season (see Seasonality of Influenza A(H3N2) Virus: A Hong Kong Perspective (1997–2006)
While it doesn't happen nearly as often, during the summer of 2017 parts of Southern China saw an unusually severe, summer H3N2 summer flu season (see Hong Kong's Summer Flu Appears To Have Peaked).  

One which was followed by an unprecedented and intense out-of-season summer flu epidemic in Australia, as described below in a 2019 Eurosurveillance report:
There was a record number of laboratory-confirmed influenza cases during the interseasonal period November 2018 to May 2019 (n= 85,286; 5 times the previous 3-year average) and also more institutional outbreaks, hospitalisations and deaths, than what is normally seen.
After two years of interrupted flu seasons due to the COVID pandemic, we are seeing unusual patterns of influenza, RSV, and other infectious disease outbreaks around the world. 

Over the past couple of months Australia and (more recently) New Zealand have reported an early arrival of influenza, (see chart below) while flu continues to hang on well into summer in parts of North America.

In recent days Chinese media has been filled with reports of rising H3N2 flu cases in Southern China, with several local health ministries issuing alerts.  Given the recent spread of COVID in China, the arrival of a summer wave of influenza has the potential to severely complicate their Zero-COVID response. 

First this translated report from the People's Daily.
H3N2 flu is coming! Many southern provinces enter the summer high incidence period
2022-06-21 15:45:40 [Source: People's Daily Health Client] [Editor: Pan Hua]
"Influenza still needs attention under the new crown epidemic". Influenza surveillance data released by both the World Health Organization and the Chinese Center for Disease Control and Prevention show that this year's influenza activity has increased compared with the previous year. According to the latest influenza surveillance report, the positive rate of influenza in southern provinces of my country continued to rise, with A(H3N2) subtype influenza virus being the main one. At the 2022 Academic Exchange Meeting on Seasonal Influenza Prevention and Control Strategies, Director Wang Dayan of the National Influenza Center of the Chinese Center for Disease Control and Prevention reminded.

According to the latest weekly influenza report of the National Influenza Center on June 17 (6.6-6.12), the proportion of influenza-like cases (ILI%) among outpatient cases reported by sentinel hospitals in southern provinces was 5.8%, higher than the previous week's level (5.1%). , higher than the levels in the same period of 2019-2021 (4.4%, 3.0% and 4.3%), and significantly higher than the proportion of influenza-like cases (ILI%) in outpatient cases during the same period of the influenza pandemic season in 2019.

In addition, according to the latest data from the World Health Organization's Global Influenza Surveillance and Response System, the incidence of influenza in the northern and southern hemispheres has rebounded significantly since 2022.

Since June, Fujian, Guangdong, Shenzhen, Hainan, Jiangxi and other places have issued emergency warnings one after another, and the number of fever clinic admissions in some medical institutions has increased, and many places in the south have entered the peak of influenza in summer.

Since it is impossible to tell whether you have the flu or COVID without a PCR test, it isn't surprising that one of the notices posted today by the Fuzhou government in Fujian Province stresses the importance of mask wearing (including N95s) and enhanced infection control by caregivers and family members even when influenza is suspected. 

How to prevent H3N2 flu from respiratory disease experts
2022-06-22 09:45 Source: [Fuzhou Daily] Font size: large, medium and small   

Recently, our province has entered a high season of influenza. Due to climate change and other reasons, the number of fever outpatients, especially children, in major hospitals in our city has increased significantly. It is understood that the current epidemic is the A (H3N2) subtype of the influenza A virus. How to deal with the ferocious H3N2 flu? What should I pay attention to when visiting a doctor? On the 21st, the reporter interviewed Professor Chen Xiaohong, chief physician of the Tuberculosis Department of Fuzhou Pulmonary Hospital.

Chen Xiaohong introduced that when there is a suspected flu patient at home, the first thing to do is to wear a mask. Patients are recommended to wear surgical masks to avoid infecting their family members, while family members should wear medical protective masks. It is best for family members who are in close contact with the patient and take care of the patient to be fixed as one person, and need to wear N95 masks. Other family members should minimize Contact with patients to prevent infection.
Secondly, both patients and their family members should wash their hands frequently, especially after direct contact with patients, or after handling items used by patients and contact with respiratory secretions, they should use disinfectant to disinfect their hands.
Patients should maintain cough etiquette, avoid others when coughing or sneezing, cover their mouth and nose with a tissue, or cover their mouth and nose with the inside of their elbow.
Third, it is necessary to do a good job of cleaning and disinfection. When opening the window for ventilation, it is best to put a fan at the door to blow air outside the window to reduce the indoor virus density.
Finally, be sure to observe the patient's condition. When symptoms worsen, such as shortness of breath, pale face, and cold limbs, you should seek medical attention as soon as possible, especially children. If you have a high fever, seek medical attention as soon as possible.

Chen Xiaohong introduced that influenza is mainly transmitted through droplets of respiratory secretions, and can also be transmitted through direct or indirect contact with mucous membranes such as the mouth, nose, and eyes. The common incubation period is 1 day to 4 days (average 2 days), and it is infectious from the end of the incubation period to the acute phase of the onset. Therefore, in order to avoid cross-infection, patients and their families should take precautions when visiting a doctor.

"Personal protection measures for the new crown, such as wearing masks, one-meter noodles, frequent ventilation, hand hygiene, etc., are also applicable to influenza prevention." Chen Xiaohong reminded that public transportation should be avoided when going to a fever clinic, and protection should be taken during the whole process of treatment: recommended norms Wear medical surgical masks or protective masks; keep a social distance of more than 1 meter from others, do not touch, especially hands, do not touch your mouth and nose, wash your hands frequently or use hand sanitizer; after returning home from the fever clinic, take off your masks, Wash your hands, take off your coat, wash and sanitize well.

Between potentially masking of COVID infections, and the possibility of seeing more severe illness from COVID-Influenza confections, the return of H3N2 only adds to the difficulties that China faces with the coronavirus.  

Unfortunately, Australia and New Zealand face similar scenarios in the months ahead, and the start of the Northern Hemisphere's flu season is not all that far away. 

No one quite knows what a full-fledged flu season alongside COVID will look like, but it appears we may be about to find out. 

Stay tuned.