Hong Kong CHP Acknowledges The Jiangsu H5N1 Case Reported Last Week

#17,333

Nine days ago reports of another H5N1 case - this time in Jiangsu, China - began to emerge in the Chinese media (see Flutracker's Thread), which were confirmed on March 2nd to Lisa Schnirring at CIDRAP by the WHO (see China reports new H5N1 avian flu case). 

Details were scant, and limited to the age (53), gender (F), location, and recent `poultry exposure' of the patient, along with the onset dates (late January), and the clade (2.3.4.4b). 

There was no mention of the severity of the patient's illness, other than the fact that the patient had been hospitalized.  Conspicuously absent has been any official mention of this case by Chinese officials, or by Hong Kong's CHP.   

Delayed reporting of avian flu cases from China is nothing new, although the reasons behind when they decide to release the information remains murky.  The H5N6 case they announced on March 1st was hospitalized in December, and only announced after delay of more than 2 months. 

The H5N1 case before that was hospitalized on September 25, died on October 18th, and was reported on November 30th; a delay of 66 days.

This morning Hong Kong's CHP has published their first mention of this latest case, which provides very little additional information, other than the woman's illness was `severe'. 

First the HK CHP announcement, including safety advice for the public, after which I'll have a bit more.

CHP closely monitors human case of avian influenza A(H5N1) in Mainland
 
The Centre for Health Protection (CHP) of the Department of Health is today (March 8) closely monitoring a human case of avian influenza A(H5N1) in the Mainland, and again urged the public to maintain strict personal, food and environmental hygiene both locally and during travel.

The case involves a 53-year-old woman from Jiangsu, who had exposure to live domestic poultry before the onset of her symptoms. She developed symptoms on January 31, was admitted for treatment on February 4 and was in serious condition.

From 2005 to date, 55 human cases of avian influenza A(H5N1) have been reported by Mainland health authorities.

"All novel influenza A infections, including H5N1, are notifiable infectious diseases in Hong Kong," a spokesman for the CHP said.

Travellers to the Mainland or other affected areas must avoid visiting wet markets, live poultry markets or farms. They should be alert to the presence of backyard poultry when visiting relatives and friends. They should also avoid purchasing live or freshly slaughtered poultry, and avoid touching poultry/birds or their droppings. They should strictly observe personal and hand hygiene when visiting any place with live poultry.

Travellers returning from affected areas should consult a doctor promptly if symptoms develop, and inform the doctor of their travel history for prompt diagnosis and treatment of potential diseases. It is essential to tell the doctor if they have seen any live poultry during travel, which may imply possible exposure to contaminated environments. This will enable the doctor to assess the possibility of avian influenza and arrange necessary investigations and appropriate treatment in a timely manner.

While local surveillance, prevention and control measures are in place, the CHP will remain vigilant and work closely with the World Health Organization and relevant health authorities to monitor the latest developments.

The public should maintain strict personal, hand, food and environmental hygiene and take heed of the advice below when handling poultry:

• Avoid touching poultry, birds, animals or their droppings;
• When buying live chickens, do not touch them and their droppings. Do not blow at their bottoms. Wash eggs with detergent if soiled with faecal matter and cook and consume the eggs immediately. Always wash hands thoroughly with soap and water after handling chickens and eggs;
• Eggs should be cooked well until the white and yolk become firm. Do not eat raw eggs or dip cooked food into any sauce with raw eggs. Poultry should be cooked thoroughly. If there is pinkish juice running from the cooked poultry or the middle part of its bone is still red, the poultry should be cooked again until fully done;
• Wash hands frequently, especially before touching the mouth, nose or eyes, before handling food or eating, and after going to the toilet, touching public installations or equipment such as escalator handrails, elevator control panels or door knobs, or when hands are dirtied by respiratory secretions after coughing or sneezing; and
• Wear a mask if fever or respiratory symptoms develop, when going to a hospital or clinic, or while taking care of patients with fever or respiratory symptoms.

The public may visit the CHP's pages for more information: the avian influenza page, the weekly Avian Influenza Report, global statistics and affected areas of avian influenza, the Facebook Page and the YouTube Channel.

Ends/Wednesday, March 8, 2023
Issued at HKT 17:30

It is worth noting that the safety advice offered is pretty much boiler plate, has been included in HK updates on avian flu in China for years, and has not just been added due to the recent upsurge in H5N1. 

Although this is only the 2nd H5N1 clade 2.3.4.4b human infection reported by China, they have reported 53 other H5N1 infections since 2005 (and 83 H5N6 cases).  

But to have any chance of being reported (in China, or elsewhere), an H5 patient must first be sick enough to be hospitalized, and then be lucky enough to have the proper testing done. 

Seroprevalence studies have suggested that some subclinical or mild infections (see 2012's H5N1 Seroprevalence Among Jiangsu Province Poultry Workers) likely go unreported.  And severe, or even fatal, cases may occur - particularly in rural settings - and go unrecognized. 

The good news in all of this is that the incessant reports of H5N1 having a 50% fatality rate are probably overblown.  For now, it appears to be fatal in 50% of those cases sick enough to be hospitalized, but we don't know what percentage of those infected will go on to develop severe illness (see Revisiting the H5N1 CFR Debate). 

That said, a CFR (Case Fatality Rate) of 1% or 2% would be more than sufficient to surpass COVID's impact, particularly given H5N1's history of impacting younger people harder.  And H5N1 could easily go higher. 

Thus far, we've not seen any evidence to suggest that H5N1 has gained the ability to transmit in a sustained of efficient manner in humans. The caveat being, that even the best surveillance system might not pick up those kinds of signals until several weeks after-the-fact. 

Which is why the recent decline in the timely sharing of disease outbreak information (see Flying Blind In The Viral Storm) is so dangerous right now.