Saturday, June 24, 2017

WHO Avian Flu Risk Assessment - June 2017

WHO H7N9 Epi Curve - June 12th

















#12,572


Just 12 months ago H7N9 was closing out its 4th, and least impressive, epidemic wave in its short tenure in China.  After making a big splash over 2013-2014, the virus appeared on the decline (see epi curve above), despite dozens of genotypes in circulation.
But the only real constant with influenza is that it is constantly changing.
And so we find ourselves a year later watching the biggest bird flu human epidemic on record winding down, two distinct new H7N9 variants (1 LPAI, 1 HPAI) taking hold, and the virus edging closer to escaping the confines of Mainland China.

The recent surge, and continuing evolution H7N9 in China, has scientists increasingly  concerned.  A few recent blogs include:
PLoS Pathogens: Three Mutations Switch H7N9 To Human-type Receptor Specificity

EID Journal: 2 Expedited HPAI H7N9 Studies

Eurosurveillance: Preliminary Epidemiology & Analysis Of Jiangsu's 5th H7N9 Wave

The saving grace to all of this, so far at least, is that the H7N9 virus still doesn't transmit efficiently between humans. Clusters remain rare, and very few human-to-human transmissions have been observed.

Roughly once a month the World Health Organization releases an updated Influenza at the human-animal interface report that details novel human flu infections reported since the last update and provides a risk assessment.
Today's report - covering the 30 days between May 17th and June 15th - adds 47 H7N9 cases. No other avian or novel flu infections were reported during this time period.
Some excerpts from the 5-page PDF report follow, after which I'll return with a bit more.
Influenza at the human-animal interface
 

Summary and assessment, 17 May 2017 to 15 June 2017
  • New infections1: Since the previous update, new human infections with influenza A(H7N9) viruses were reported.
  •  Risk assessment: The overall public health risk from currently known influenza viruses at the human-animal interface has not changed, and the likelihood of sustained human-to-human transmission of these viruses remains low. Further human infections with viruses of animal origin are expected.
  • IHR compliance: All human infections caused by a new influenza subtype are required to be reported under the International Health Regulations (IHR, 2005).2 This includes any animal and non-circulating seasonal influenza viruses. Information from these notifications is critical to inform risk assessments for influenza at the human-animal interface.
(SNIP)

Avian influenza A(H7N9) viruses

 
Current situation: During this reporting period, 47 laboratory-confirmed human cases of influenza A(H7N9) virus infection were reported to WHO from China. Among these cases, one cluster of cases were reported; both cases in the cluster had exposure to live poultry. Cases were reported from Shaanxi province for the first time and cases had likely exposure in Inner Mongolia for the first time as well.
1 For epidemiological and virological features of human infections with animal influenza viruses not reported in this assessment, see the yearly report on human cases of influenza at the human-animal interface published in the Weekly Epidemiological Record. Available at: www.who.int/wer/en/
2 World Health Organization. Case definitions for the four diseases requiring notification in all
circumstances under the International Health Regulations (2005). Available at: www.who.int/ihr/Case_Definitions.pdf 3 WHO Cumulative number of confirmed human cases of avian influenza A(H5N1) reported to WHO tables. Available at: www.who.int/influenza/human_animal_interface/H5N1_cumulative_table_archives/en/


Case and cluster details are presented in the table in the Annex of this document. For additional details on these cases, public health interventions, and the highly pathogenic avian influenza (HPAI) A(H7N9) viruses, see the Disease Outbreak News.


As of 15 June 2017, a total of 1533 laboratory-confirmed cases of human infection with avian influenza A(H7N9) viruses, including at least 592 deaths4, have been reported to WHO (Figure 1). The number of human infections with avian influenza A(H7N9) viruses and the geographical distribution of human cases in the fifth epidemic wave (i.e. onset since 1 October 2016) is greater than in any earlier wave.
This suggests that the virus is spreading, and emphasizes that further intensive surveillance and control measures in both the human and animal health sectors are crucial. However, the number of reported confirmed cases has continued to decline over the past few weeks indicating that the peak of cases this wave was reached in mid-February 2017.

According to reports received by the Food and Agriculture Organization (FAO) on surveillance activities for avian influenza A(H7N9) viruses in China, positives among virological samples continue to be detected in poultry from live bird markets, commercial and backyard farms. The agricultural authorities in China have also announced plans to commence vaccination of domestic poultry in certain areas against infection with avian influenza A(H7) viruses beginning in July.5


(Continue . . . .)
 
Although eerily quiet now, just a year or two ago the  WHO considered H5 viruses the most obvious pandemic threat, particularly after Egypt's record setting H5N1 outbreak in the spring of 2015 and the emergence and global spread of H5N8, the reports of a new virus - H5N6 - infecting people and poultry in China. 
Like H7N9, those viruses continue to spread and evolve, and while reported human infections have been few and far between over the past year, they could easily stage a comeback just as H7N9 has over the past 8 months. 
H7N9 is viewed, rightfully so, as having the greatest pandemic potential right now (see Updated CDC Assessment On Avian H7N9 and NPR: A Pessimistic Guan Yi On H7N9's Evolution).
But influenza posesses remarkable evolutionary speed - where generations are measured in minutes or hours, not years or decades - and abrupt changes can occur literally overnight via viral reassortment.
Which means that we could just as easily be blindsided by a different mutated bird flu subtype, one of the many H1, H2, or H3 swine flu viruses in ciruculation around the globe, or something else that isn't even on our radar right now.

Despite the strides that have been made in the identification and understanding of novel flu viruses, less than a month ago in World Bank: World Ill-Prepared For A Pandemic, that organization warned that far too many nations have let pandemic preparedness slide, and that the world remains ill-prepared to face even a moderately severe pandemic.

Friday, June 23, 2017

A Dearth Of Recent Reports From The Saudi MOH

Screen Shot of MOH Today - 9:45 am EST


 
 #12571


The screenshot above - taken at 0945 EST today - shows that after reporting 50+ cases in the 1st 18 days of June - the Saudi MOH hasn't updated their MERS surveillance page in several days.  

For some reason, they posted 2 updates for the 19th - and while the links state no new cases, the first report for that date lists 1 asymptomatic case in Riyadh.  The last report, dated the 19th, appears to be from the 20th, and lists 2 recoveries.

Since then, we've seen no new updates.  
With this being the last week of Ramadan, it is possible the MOH is working short staffed.  Hopefully after tomorrow (the end of Ramadan), the MOH will catch us up, and resume regular daily reporting.

Belgium Reports Two More Outbreaks Of HPAI H5N8













#12,570

Belgium, which was one of the least affected countries in Western Europe during this past winter's HPAI epizootic, reports their 10th and 11th outbreak of the month of June today.
Once again, the virus has turned up in hobby farms, this time in Tournai (very near the French Border) and Courcelles.
This (translated) press release from Belgium's AFSCA (Federal Agency For Food Safety).

Avian influenza: situation
 
two additional infections in Courcelles and Tournai
temporary buffer lifted in Wellin
(06/23/2017)

Two additional cases were again with the highly pathogenic avian influenza virus Influenza A virus subtype H5N8 fixed hobby holders in Tournai and Courcelles. Since June 1, the virus that total found in 11 locations in Belgium. The AFSCA requires all poultry to poultry bought at a market recently to be vigilant.


The temporary buffer in Wellin is released today. Which was established three weeks ago when the Influenza A virus subtype H5N8 virus was identified. The specific measures for this zone are no longer in effect.

The Minister of Agriculture Willy Borsus explains: "The situation is still alarming and biosecurity remain of paramount importance in order to avoid an impact on professional holders. I repeat that, in the current health context, must continue to appeal to a vet if the poultry is sick or dies suddenly. "

Around two new cases in Tournai and Courcelles delineated a temporary buffer zone with a radius of 3 kilometers. Within that area, each movement of poultry, other birds and eggs prohibited. The animals must be fed and watered in. Residents, which have within these zones to poultry and other birds, will be prompted so as to inform about an inventory to the mayor within 48 hours, which will indicate how many and which animals are kept. This zone will be maintained for at least 3 weeks.

The AFSCA requires all poultry farmers also to be vigilant and immediately go to the vet if their animals fall ill.

Abnormal mortality of wild birds can still be reported to the toll free number 0800/99777 .
For the consumer there is no danger at all poultry meat and eggs is safe and can be eaten without problems.
 
 Belgium joins FinlandLuxembourg, and the UK in reporting HPAI during the month of June.

OIE Confirms HPAI H7N9 In Heilongjiang Province

















#12,569



On Monday I reported (see MOA: Large Poultry Die Off In Heilongjiang - H7N9 Confirmed (HPAI Suspected) on what appeared - based on reported avian mortality - to be the farthest north outbreak of HPAI H7N9 to date, on a breeder farm only a few miles from the Russian border.

Today the OIE has confirmed HPAI H7N9, in the following announcement:


http://www.oie.int/wahis_2/public/wahid.php/Reviewreport/Review?page_refer=MapFullEventReport&reportid=24088


Since it emerged in 2013, we've seen a good deal of speculation as to when H7N9 would finally follow its HPAI H5 cousins and break out of Mainland China and begin to spread internationally (see FAO Warns On H7N9 In China).
For most of that time, the assumption was that Southeast Asia - most likely Vietnam, which shares a porous border with China - would be the first to encounter the virus (see Vietnam Wary Of H7N9).
But with the emergence of HPAI H7N9 in January, and its steady northward push over the past 5 months, Russia now finds the virus confirmed within 100 miles of its territory, and that increases its chances of spreading even further via the Asian migratory bird flyways. 




While these flyways are predominately north-south corridors, their overlapping allows for a degree of lateral (east-west) movement of avian viruses as well – often via shared nesting areas and ponds. 
Which explains how HPAI H5N1, HPAI H5N8, and H5N6 have all managed to expand their geographic range both east (to Korea, Japan, and North America) and west (to Europe, the Middle East, and Africa) in recent years.
It remains to be seen whether H7N9 has adapted well enough to migratory birds to follow suit, but this abrupt geographic expansion warrants close attention.

HK CHP Notified Of 10 H7N9 Cases On The Mainland

FAO H7N9 Epidemic Waves - June 14th












#12,568



After falling to only 5 cases announced in last week's report, today China's NHFPC has notified Hong Kong of 10 H7N9 infections (2 fatal) during the past week.  Since June 1st, China has announced 35 cases, already making this the most active H7N9 summer by far.
The 10 patients, all male, range in age from 31 to 79, and all had onsets on or after June 5th.  They span 8 provinces/regions; Beijing (2), Sichaun (2), Anhui (1), Guizhou (1), Hebei (1), Inner Mongolia (1), Jiangsu (1), Tianjian (1).
The pronounced skewing towards older males is once again evident in this week's report, and 9 of the 12 reportedly had recent contact with live poultry.  We should get more details in next week's HK Avian Flu Report.

In past years, the heat of summer has forced a nearly complete shutdown of H7N9 activity in China, and seeing more than a dozen cases reported over the June-July-August period was a rarity. Last year, that pattern changed very slightly, prompting speculation that the virus was becoming more `heat tolerant'.
Those concerns were echoed again last March in Eurosurveillance: Preliminary Epidemiology & Analysis Of Jiangsu's 5th H7N9 Wave, when researchers reported ` . . . .  increased detection rate of H7N9 in environmental samples suggests that the virus might become more resistant to high ambient temperature'
While the expansion of H7N9 into more northern provinces might account for some of this year's late season persistence, we continue to see activity in some of China's southern provinces (Sichuan, Guizhou) as well, and temperatures reported this month in China's north have been running at or above average for much of June (see Chart below).    


Beijing Weather - Credit Accuweather

Between the rapid expansion of a new LPAI H7N9 lineage (Yangtze River Delta) over this  past winter, the emergence and spread of a new HPAI H7N9 strain, and the continual evolution of dozens of genotypes in the wild - some changes in the virus's behavior over time are to be expected. 
So far, no significant mutations have been reported that would account for increased `heat tolerance' in the virus, and so much of this speculation remains based on anecdotal evidence. 
The level of viral activity (both in birds, and in humans) over the summer should shed more light on the matter.  Some excerpts from today's HK CHP announcement follow:


     The Centre for Health Protection (CHP) of the Department of Health today (June 23) is monitoring a notification from the National Health and Family Planning Commission that 10 additional human cases of avian influenza A(H7N9), including two deaths, were recorded from June 16 to 22, and strongly urged the public to maintain strict personal, food and environmental hygiene both locally and during travel.

     The 10 male patients, aged from 31 to 79, had onset from June 5 to 19. Two each are from Beijing and Sichuan, and one each from Anhui, Guizhou, Hebei, Inner Mongolia Autonomous Region, Jiangsu and Tianjian. Among them, nine were known to have exposure to poultry or poultry markets.

     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 a 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 CHP's Port Health Office conducts health surveillance measures at all boundary control points. Thermal imaging systems are in place for body temperature checks on inbound travellers. Suspected cases will be immediately referred to public hospitals for follow-up.

     The display of posters and broadcasting of health messages in departure and arrival halls as health education for travellers is under way. The travel industry and other stakeholders are regularly updated on the latest information.

(Continue . . . )

Thursday, June 22, 2017

OIE: South Africa Reports Outbreak Of HPAI H5N8















#12,567


Just over 3 weeks ago HPAI H5N8 was confirmed in the DRC, and a week ago we learned it had spread to at least 14 locations.  A few days after the DRC's first report, the virus turned up at a large poultry facility in Zimbabwe - 1400 miles to the south - and only a few hundred miles from the South African border.
Since then, we've been waiting - along with officials in South Africa - to see whether virus would make it into poultry-rich South Africa.
Just shy of two weeks ago, in DAFF: South Africa On Alert For HPAI H5N8, we looked at the precautions the South African government ordered in an attempt to prevent the virus's entry.  Today, via the following OIE report, we now learn that a large poultry holding in Mpumalanga has tested positive for this well-traveled virus.



The concern, beyond the potential impact on a South Africa's poultry industry, is that this recently reassorted HPAI H5N8 virus continues to spread faster, and farther, than any HPAI virus we've seen to date.

Since it emerged as a threat in South Korea in 2014, it visited North America and Europe during the winter of 2014-15 - and after laying low for a year - this past winter it invaded Europe, the Middle East, West Africa, and now Southern Africa.
This recently emerged H5N8 virus seems particularly well adapted for carriage by wild and migratory birds, and has spawned a number of reassortants (H5N2, H5N5, H5N9) during its travels.
This is the first serious intrusion of HPAI H5 into the southern hemisphere, and given the migratory pathways between the Northern and Southern Hemisphere - particularly those linking Africa to Europe and Asia - could change the dynamic of HPAI H5's spread and future evolution. 


Last winter, the FLI: Updated Risk Assessment On HPAI H5 warned specifically that:

`Generation of reassortants always must be expected when different high and low pathogenic influenza viruses are circulating in one population.'

Relevant because, whatever happens with this promiscuous virus in the Southern Hemisphere, may not stay in the Southern Hemisphere.