Tuesday, December 26, 2017

Seasonal Flu Reports Increasing Across China, Asia



Last summer Southern China, Hong Kong, and Taiwan reported an unusually severe out-of-season spike in (mostly) H3N2 flu cases (see HK Flu Express Wk 29: Influenza Activity Remains At A Very High Level). 
Now that the traditional season for flu has arrived, we are seeing another rise in  flu cases again after only a 5 month respite.
Today Taiwan's CDC issued the following statement:
Domestic influenza epidemic will enter the epidemic period, people participate in New Year's Eve weekends and personal protective measures

Domestic influenza epidemic continues to heat up, is about to enter the epidemic period, this weekend coincides with the New Year's Day holiday, public places, a large number of people in and out of public places such as arranging travel or participate in New Year's activities, hand hygiene and cough etiquette should be done, if any respiratory symptoms Wear masks, and implement the rest at home to rest in order to prevent the spread of the virus to speed up the spread of people and improve the risk of outbreaks.

According to statistics from the Department, there were 77,444 outpatient visits last week ( December 17 to December 23 ) , an increase of 16% over the previous week . The percentage of other emergency flu cases also showed an upward trend, approaching The prevalence threshold into the epidemic. In the past four weeks, a total of 17 cases of flu aggression were found, of which 13 ( 76% ) occurred on campus.

Last week, an additional 14 cases of severe flu confirmed cases of influenza, of which 12 cases were not vaccinated this season's flu; the other 5 cases of newly diagnosed cases of severe flu-related deaths, have a history of chronic disease and did not inoculate the seasonal flu vaccine; since From October 1 , 2017 onwards, a total of 76 confirmed severe cases of influenza were confirmed. Among them, 8 were examined for influenza-related deaths ( 2 cases of type H3N2 and 6 cases of type B ); the type of case infection was identified as type B More ( 62% ). 
(Continue . .. )

Meanwhile, the headline from the South China Morning Post today reads:

Eight-hour waits in emergency rooms as Hong Kong hospitals feel flu season surge over Christmas holidays

Public hospital wards saw overall occupancy rate of 108 per cent on Christmas Day

From China, Sharon Sanders and the newshounds at FluTrackers are seeing a number of media reports describing an early, and potentially severe flu season.  These recent reports are translated and posted in their China Seasonal Flu Tracking thread.

China - "This year's flu is the fiercest in recent years, with a long duration and a wide area of ​​infection.." - Yangzhou, Jiangsu province - December 26, 2017

China - Many children hospitalized because of flu in Ningbo, Zhejiang province - December 20, 2017

China - Expert: Pediatric respiratory infections and fever at this time are about 2% more than usual - Beijing - December 19, 2017

China - Tianjin: due to the recent high incidence of influenza, police in charge of traffic control at City Children's Hospital December 19th, 2017

All of which is accented by this (translated) statement today from China's CDC, which acknowledges significantly higher numbers of flu cases than in recent years.  It appears from today's report that much of this activity is being attributed to Influenza B.

China has entered the peak season of influenza pandemic this winter
Time: 2017-12-26 font: Tai Zhong Small
Influenza, referred to as the flu, is an acute respiratory infection caused by seasonal influenza viruses. Flu spread around the world each year, usually in northern China were popular in winter and spring, winter and spring and the South there are two popular summer peak. Different years will show varying degrees of prevalence levels fluctuate.

A current flu epidemic

China's mainland influenza surveillance results show that the recent South flu in northern China have entered the winter epidemic peak season, sentinel hospital door emergency reporting flu -like illness proportion is higher than the past 3 years earlier levels, influenza virus detection positive rate has reached peak levels in previous years, and it is still increasing .
National reports of flu outbreaks several cases significantly higher than in previous years, the same period, most of which influenza B cause. Our monitoring system found no effects of influenza virus transmissibility, disease severity and variability of drug resistance , the national influenza epidemic levels overall are still expected in the range. 
         (Continue . . . .)

Missing in China this fall, so far anyway, has been any significant H7N9 or H5N6 activity.

That could be due to reporting issues, or reduced viral shedding from recently vaccinated birds, but it could also be due to seasonal influenza either masking cases - or, at least in theory - due to the high prevalence of seasonal flu itself.
Last October, In PLoS Comp. Bio.: Spring & Early Summer Most Likely Time For A Pandemic, we looked at the potential dampening effects of any influenza virus's circulation on the ability of a novel flu to take hold.
It's called the Temporary Immunity Hypothesis, and while not entirely proven, it would explain why the last 6 pandemics have all emerged in the Northern Hemisphere in late spring or early summer. 

As this drought in human novel flu infections - whatever the cause - is unlikely to last for very long, we should enjoy the break while we can.

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