Dr. Mackay On H7N9 Market Closures & Case Reporting Out Of China

 

# 8301

 

Over night Dr. Ian Mackay on his VDU blog has been busy, posting a pair of blogs on the (apparent) effects of market closures in China on the spread of H7N9, and other possible reasons behind the recent drop in case reports. 

 

In the second blog listed, he articulates some of the concerns that many flu watchers have over the recent decline in reporting out of China.

Follow the links to read:

 

Zhejiang province leads the way in H7N9 cases and their decline 3-weeks after market closures...

Click on image to enlarge.

It's the Province in China that has seen more H7N9 cases confirmed in human than any other Province (39% of all cases have originated here).

It reached 50 cases faster in 2014 than 2013.

It closed its markets back in 24-Jan. And for a little while it kept finding new cases.

But the past 2-days have see no new cases announced from Zhejiang province. Eerily reminiscent of 2013 sudden disappearance of cases announcements.

(Continue . . .)

 

 

H7N9 case announcements dropping: is Wave 2 under control? [UPDATED]

Its a very tough question to answer. There has been public pressure by China's poultry-farming groups on China to take measures to stem the industry's financial losses. These have been driven by the public concern that H7N9 can seriously afflict people and in about a fifth of recorded instances, kill them.

(Continue . . .)

HK: Notification Of Positive H7N9 Test Results From Shenzhen Bird Markets

Photo Credit – FAO

 

# 8061

 

 

While Hong Kong has recently detected two human infections from the H7N9 virus – both with recent travel history to Shenzhen in neighboring Guangdong Province – up until now Mainland officials have denied finding the virus in Shenzhen’s live bird markets. Complicating matters, birds infected with H7N9 usually appear perfectly healthy.

 

As such, these lucrative markets have remained open, despite the suspicions that they may have been the source of one, or both, of these infections. 

 

Today Hong Kong’s government was informed by Guangdong’s Health and Family Planning Commission (HFPC) that recent testing has finally revealed three H7N9 positive test results from two different markets in Shenzhen.   This from info.gov.hk.

CHP's response to media enquiries on notification from Guangdong HFPC

In response to media enquiries on the notification from the Health and Family Planning Commission (HFPC) of Guangdong Province, a spokesman for the Centre for Health Protection (CHP) of the Department of Health today (December 11) gave the following reply:

The CHP received notification this evening from the Guangdong HFPC that among the 70 environmental samples collected from 13 live poultry markets in Shenzhen, three samples collected from two live poultry markets in Longgang tested positive for the avian influenza A(H7N9) virus.

The CHP will continue to maintain liaison with the Mainland health authorities to monitor the latest developments.

Ends/Wednesday, December 11, 2013
Issued at HKT 19:45

 

 

At this point, I’ve seen no announcements on the fate of live markets in Shenzhen.

 

While contact with poultry is currently considered to be the most likely route of human infection, we’ve seen a good deal of resistance to the closing of live markets in China.  Poultry is one of the few relatively inexpensive, and readily available, sources of protein for his country of 1.3 billion people.   

 

Massive culling to rid themselves of the infection would be a drastic, and very unpopular, course of action. It could even be politically destabilizing.

 

For the Ministry of Agriculture, which is responsible for the largest poultry production on earth (estimated at 15 billion birds), having a silent but (potentially) deadly virus circulating among the nation’s poultry industry has to be nothing short of a political and economic nightmare.

 

So we tend to see compromises – like the temporary shutdowns of live markets last April in affected provinces, and the proposal from Shanghai To Close Poultry Markets Over Lunar New Years To Curtail H7N9.

 

As if the risk of bird flu infection were not enough, this morning there are reports of a deadly fire sweeping through a Shenzhen farmer’s market, killing at least 15 people.

 

16 killed, 5 others injured in China market blaze

At least 16 people were killed and 5 others injured in a major fire at a market in south China's Shenzhen city on Wednesday, state media said.

The fire engulfed the Rongjiyan Agricultural Wholesale Market in Gongming New District of Shenzhen bordering Hong Kong at about 1 am local time, state broadcaster CCTV reported.

It took nearly two hours for 145 fire fighters and 29 fire engines to put out the fire. It damaged an area of 1,000 square meters, the report said.

(Continue . . . )

 

The cause of the fire is at this point undisclosed.  China has a history of lax safety precautions, and some tragic fires, including a mall fire in 2000 that claimed nearly 400 lives.

 

Meanwhile, Hong Kong’s CHP continues to issue the following warnings:

 

"Travellers, especially those returning from avian influenza A(H7N9)-affected areas and provinces, with fever or respiratory symptoms are reminded to immediately wear facial masks, seek medical attention and reveal their travel history to doctors. Health-care professionals should also pay special attention to patients who might have had contact with birds, poultry or their droppings in affected areas and provinces," the spokesman advised.

The spokesman also urged travellers not to visit live poultry markets in the affected areas and provinces and avoid direct contact with poultry, birds and their droppings. If contact has been made, they should thoroughly wash their hands with soap and water.

Members of the public should remain vigilant and are reminded to take heed of the following preventive advice against avian influenza:

* Poultry and eggs should be thoroughly cooked before eating;
* Wash hands frequently with soap, especially before touching the mouth, nose or eyes, handling food or eating; after going to the toilet or 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;
* Cover the nose and mouth while sneezing or coughing, and hold the spit with a tissue and put it into a covered dustbin;
* Avoid crowded places and contact with fever patients; and
* Wear a mask when respiratory symptoms develop or when taking care of fever patients.

The Lancet: Poultry Market Closure Effect On H7N9 Transmission

Credit FAO 

 

# 7922

 

We’ve a report in The Lancet this morning that quantifies the benefits of closing live poultry markets in order to curb the spread of the H7N9 virus.  This infection control practice  – while costly, and not particularly popular among many in China – was credited with dramatically reduced the number of human infections with the virus in a very short period of time last spring.

 

Since that time, caveats about visiting live poultry markets have been included in nearly every public health statement issued by Hong Kong (and others) to travelers headed to mainland China. Last month Zeng Guang, chief epidemiologist at the China’s CDC, urged:

 

. . . .  the public to take precautions such as to avoid staying in public places for long and to be aware of good personal hygiene, including frequent hand-washing. In addition, to prevent H7N9 infection, "people shouldn't go to live poultry markets", he said. - Chinese CDC: Be Alert For H7N9

 

While poultry markets were closed in April and May in H7N9 affected regions, most have since re-opened, sparking fears that another round of human H7N9 cases may emerge this winter.

 

 

Effect of closure of live poultry markets on poultry-to-person transmission of avian influenza A H7N9 virus: an ecological study

Hongjie Yu MD a †, Joseph T Wu PhD e †, Dr Benjamin J Cowling PhD e , Qiaohong Liao MD a, Vicky J Fang MPhil e, Sheng Zhou MD a, Peng Wu PhD e, Hang Zhou MD a, Eric H Y Lau PhD e, Danhuai Guo PhD f, Michael Y Ni MPH e, Zhibin Peng MD a, Luzhao Feng MD a, Hui Jiang MD a, Huiming Luo MD b, Qun Li MD c, Zijian Feng MD c, Yu Wang PhD d, Dr Weizhong Yang MD d , Prof Gabriel M Leung MD e

Findings

85 human cases of avian influenza A H7N9 virus infection were reported in Shanghai, Hangzhou, Huzhou, and Nanjing by June 7, 2013, of which 60 were included in our main analysis. Closure of LPMs reduced the mean daily number of infections by 99% (95% credibility interval 93—100%) in Shanghai, by 99% (92—100%) in Hangzhou, by 97% (68—100%) in Huzhou, and by 97% (81—100%) in Nanjing. Because LPMs were the predominant source of exposure to avian influenza A H7N9 virus for confirmed cases in these cities, we estimated that the mean incubation period was 3·3 days (1·4—5·7).

Interpretation

LPM closures were effective in the control of human risk of avian influenza A H7N9 virus infection in the spring of 2013. In the short term, LPM closure should be rapidly implemented in areas where the virus is identified in live poultry or people. In the long term, evidence-based discussions and deliberations about the role of market rest days and central slaughtering of all live poultry should be renewed.

 

 

We’ve seen in China, Indonesia, and in other countries attempts to close or strictly regulate live bird markets in the past – only to be met with tremendous public resistance (see 2009 blog China Announces Plan To Shut Down Live Poultry Markets In Many Cities).  Their ambitious plan, announced 4 years ago to `shut live poultry markets in all large and medium-sized cities throughout China’, obviously never happened.

 

Purchasing live market birds is deeply ingrained in the culture, as it reassures the buyer that the bird is both fresh and healthy.   

 

When dealing with a highly pathogenic (in poultry) virus like H5N1 - where birds often sicken and die - vendors and the public can usually see the effect of the virus.  Not so with H7N9, as birds can carry it and remain healthy, while in humans it can produce severe illness.

 

Convincing vendors, and the public, that their perfectly healthy looking duck or chicken is a threat to human health can be a tough sell. 

 

Add to that the economic impact of closing live markets – the often conflicting goals and mandate of  China’s Ministry of Agriculture - and prospects for a quick and permanent solution to the sale of live market birds appears low.

H7N9: Shanghai Reopens Live Poultry Markets

Photo Credit – FAO

 

 

# 7412

 

For reasons that are not entirely clear – but that many have attributed to warmer summer temperatures and the mass closure of live poultry markets – China’s spring H7N9 outbreak had lost steam and dissipated by the middle of May.

 

The source of this outbreak, which infected at least 132 individuals and produced 37 deaths (see WHO Human infection with avian influenza A(H7N9) virus – update) has never been determined, but a substantial portion of these infections appeared to be linked to live poultry markets.

 

While only a handful of market birds ever tested positive for the virus, one of the first steps taken in Shanghai - and across much of Eastern China  - was to shutter all of their live poultry markets.

 

Within weeks the number of new cases had dropped precipitously, seemingly confirming the wisdom of this decision. 

 

Today, roughly 10 weeks after they were first closed, Shanghai allowed the reopening of roughly 200 (of their 461) live markets. Chickens, pigeons, and quail may be sold (but not ducks & geese), and strict daily disinfections are required.

 

China’s health authorities (and indeed, the rest of the world) will be watching closely to see if this limited, highly regulated, re-opening of markets reintroduces the virus to the community.

 

Given that avian flu viruses historically spread best in cooler weather, the real test for these new poultry market regulations may not come until next winter and spring.

 

This from today’s Shanghai Daily.

 

Live poultry marts reopen as H7N9 bird flu ban lifted

By Ke Jiayun  |   2013-6-20  |LIVE poultry will be allowed for sale in local markets starting today, almost 10 weeks after the city imposed a ban to prevent the spread of H7N9 bird flu.

 

Live chickens, pigeons and quails will be for sale, while live ducks and geese still are prohibited, officials said yesterday. They did not say when other types of live poultry might be sold.

 

Retail outlets qualified to sell live poultry must follow regulations strictly and disinfect their spaces regularly. The stores will be separated from the other sections of markets and have their own entrances.

 

The number of live poultry retail stores in the city will shrink from 461 before the outbreak to 200. One of the three main wholesale poultry markets will remain closed while the two others, in the Pudong New Area and Songjiang District, will reopen after test results are accepted by authorities.

 

The city is considering cutting back on live poultry sales every year between Spring Festival and the end of April. A preliminary proposal would ask designated retail outlets to close one day per week, while wholesale markets would close one or two days a week.

(Continue . . .)

Shanghai: Testing Reveals No Widespread H7N9 In Market Poultry

Photo Credit – FAO

 

# 7099

 

 

A report this morning from Xinhua News reveals only a small percentage of Shanghai market birds tested this week showed signs of the newly emerging H7N9 virus.

 

Of 738 samples collected from  birds and surrounding environment, only 20 (less than 3%) proved positive for the H7N9 virus.

 

The type and sensitivity of these tests are not described in this report, nore are we provided with exactly how many birds were tested. We basically learn that only 10 chickens, and 3 pigeons tested positive.

 

 

No H7N9 epidemic among poultry: expert

 

English.news.cn   2013-04-09 15:32:06

BEIJING, April 9 (Xinhua) -- A preliminary analysis shows that H7N9 bird flu has not triggered an epidemic among poultry, according to a Tuesday report in the People's Daily that cited a veterinary expert.

 

Of the 738 samples collected from three live poultry markets in Shanghai, where the first known human deaths of the disease were reported, only 20 samples contained H7N9 virus, including 10 from chickens, three from pigeons and seven from environmental samples, the report said.

 

The government's chief veterinarian Yu Kangzhen was quoted as saying that it was the first time the Ministry of Agriculture had detected the virus in domestic animals.

 

The relationship between the virus detected in poultry and the virus that has infected humans has yet to be determined, Yu said.

 

The possibility of infection among animals in other regions has not been ruled out and the ministry has called for epidemic monitoring for animals across the nation, the report said.

 

It quoted Yu as saying that it's still safe to eat poultry meat purchased from regular channels, such as supermarkets, as long as they are thoroughly cooked.

 

"The virus could be killed under high temperature," said Yu.

 

While reassuring to poultry sellers in Shanghai, this report (if corroborated by additional testing in Shanghai and other provinces) leaves us without clear answers regarding the reservoir host (or hosts) for this virus, or the manner in which 24 people have recently been infected.

 

The epidemiological investigation continues.  Stay tuned.