Germany: H7 Outbreak On A Poultry Farm in Bad Bentheim - Identified as HPAI H7N5

[Michael Coston]

Germany: H7 Outbreak On A Poultry Farm in Bad Bentheim

Bad Bentheim, Germany

#18,162

After several years of relative quiescence, H7 avian influenza is suddenly back in the headlines, with Australia suffering their largest avian epizootic (H7N3, H7N8 & H7N9) on record, numerous reports of H7N6 in South Africa since last summer, and now Germany reporting an outbreak of H7 at a poultry farm on their border with the Netherlands.

Unlike our current H5 epizootic, which is driven by the ongoing global spread of clade 2.3.4.4b H5 viruses, these scattered H7 outbreaks appear to be the result of unrelated spillovers of LPAI H7 viruses from wild birds into poultry operations where they mutate into HPAI viruses.​

Until the outbreak of H7N9 in China (2013-2018), H7 viruses were considered less of a threat to human health than H5, mainly causing mild symptoms like conjunctivitis. While H7N9 - with a 30%-40% CFR (among hospitalized patients) - was an outlier, it reminds us that H7 viruses can surprise us.

First, my thanks to Professor Thijs Kuiken for posting the following (translated) notice on Twitter/X overnight from the Netherland's Rijksoverheid.​

I'll have a bit more after the break.

Bird flu detected in German border area

News item | 02-07-2024 | 22:48

In Bad Bentheim, just across the border in Germany, bird flu has been detected on a laying farm. Germany has established a restricted area that partly falls within the Netherlands. For this reason, the Ministry of Agriculture, Fisheries, Food Security and Nature (LVVN) has established a restricted zone around the municipality of Losser.

The infection in Germany is with a different serotype, namely H7. This is a new development. Since 2003, there has been no outbreak with a highly pathogenic variant of this serotype so close to the Netherlands. There are no indications in the Netherlands yet that H7 is circulating in wild birds.

Transport ban

Due to the outbreak close to the Dutch border, a restricted zone with a radius of 10 km must be established. Six poultry farms are located within the 3 and 10 kilometre zones. A transport ban applies immediately within the 10 kilometre zone. This means that no poultry, hatching and consumption eggs may be transported from locations with birds in this zone. There is also a ban on the removal of bird manure and used litter, and on other animals and animal products from farms with birds. These measures are necessary to prevent the spread to other parts of the country. Where exactly this is can be seen on the animal disease viewer of the Netherlands Enterprise Agency (RVO).​

Tracing research

Following this contamination, a tracing investigation will be carried out by Germany. The two companies in the Dutch part of the 3 km zone will be screened by the Dutch Food and Consumer Product Safety Authority. measures are necessary to prevent the spread to other parts of the country. Where exactly this is can be seen on the animal disease viewer of the Netherlands Enterprise Agency (RVO).​

Tracing research

Following this contamination, a tracing investigation will be carried out by Germany. The two companies in the Dutch part of the 3 km zone will be screened by the Dutch Food and Consumer Product Safety Authority.​

While the Netherlands is understandably concerned due to the close proximity of this outbreak to their border, they also remember that 21 years ago they suffered a record setting H7 outbreak which resulted in the loss of 30 million birds across 1,000 farms, and saw scores of mild human infections and the death of a veterinarian.

While we've seen other notable H7 outbreaks, including the 2004 H7N3 outbreak in British Columbia, and a small number of human infections in Wales in 2007, the 2003 outbreak in the Netherlands really put public health agencies on notice.​

Details of the outbreak were reported in the December 2005 issue of the Eurosurveillance Journal.

Human-to-human transmission of avian influenza A/H7N7, The Netherlands, 2003

M Du Ry van Beest Holle, A Meijer, M Koopmans[SUP]3[/SUP] CM de Jager, EEHM van de Kamp, B Wilbrink, MAE. Conyn-van Spaendonck, A Bosman


An outbreak of highly pathogenic avian influenza A virus subtype H7N7 began in poultry farms in the Netherlands in 2003. Virus infection was detected by RT-PCR in 86 poultry workers and three household contacts of PCR-positive poultry workers, mainly associated with conjunctivitis.​

(SNIP)​

In conclusion, our study suggests that human-to-human transmission of HPAI A/H7N7 can occur within household contacts in the absence of contact with infected poultry.​

Monitoring of clinical symptoms alone in household contacts of confirmed A/H7N7 cases underestimates the extent of human-to-human spread. In addition, our results suggest that cloth handkerchiefs, having indoor pet birds at home or having at least two toilets at home could be risk factors for household transmission A/H7N7 .​

(Continue . . . )



A separate analysis, performed by the RIVM (Ministry of Health) found the spread of the virus to be much greater than originally reported.

Executive summaryAvian Flu Epidemic 2003 : Public health consequences ​

Investigation of risk factors, health, well-being, health-care needs, and preventive measures with regard to poultry farmers and persons involved in controlling the AI H7N7 epidemic in the Netherlands

A Bosman, YM Mulder, JRJ de Leeuw1 , A Meijer, M Du Ry van Beest Holle, RA Kamst, PG van der Velden1 , MAE Conyn-van Spaendonck, MPG Koopmans, MWMM Ruijten​

It is estimated that at least one thousand persons were infected with avian flu during the outbreak in the Netherlands in 2003. One-third of the poultry farmers whose holdings were cleared reported stress reactions, fatigue, and depression.​

The extensive spread of the virus to humans underscores the importance of measures to prevent poultry-to-human transmission among people handling infected poultry. The possible uncertainty, stress, and anxiety associated with avian flu control demand specific health care attention. A total of 453 people reported symptoms, predominantly conjunctivitis.​

Antibodies were found in 59% of family members of infected poultry workers. Of the 500 tested persons who had handled infected poultry, about 50% showed an antibody response.​

The poultry farmers and workers did not comply adequately with preventive measures. The antiviral drug oseltamivir protected against infection, whereas a protective effect of mouth-nose masks could not be found. The attention that was given to counseling of poultry farmers and other workers, and the attention given to the provision of information and communication during the clearing out of poultry worked well. Approximately 25% of the poultry farmers worried about the survival of their holding and the sector as a whole, while 16% felt a need for additional support, help, or health care because of the avian flu. They usually consulted agricultural care providers and family doctors, less often mental health-care providers.​

(Continue . . . )



While we've seen far more virulent H7 viruses emerge (i.e. H7N9 in China), this remains the largest documented example of human-to-human spread of a novel zoonotic avian flu virus.

A proof-of-concept, if you will.​

Which is why, even though HPAI H5 may seem a more immediate concern, we can't afford to ignore the `lesser' threats that continue to simmer in the wild.


https://afludiary.blogspot.com/2024/07/germany-h7-outbreak-on-poultry-farm-in.html
​

 

[Michael Coston]

Germany: Avian Influenza Outbreak Identified As HPAI H7N5

Bad Bentheim, Germany

#18,164

Following yesterday's announcement of an H7 outbreak on a German poultry farm on the border with the Netherlands we learned overnight that the virus has been sub-typed as HPAI H7N5. While we've seen reports of LPAI H7N5 in wild birds in the past, this is - as far as I can tell - the first detection of an HPAI version.

So far, much of the information we are seeing is coming from the Netherlands, which suffered a historic outbreak of H7N7 in 2003, which resulted in at least 1,000 (mostly mild) human infections, and the loss of 30 million birds.​

The following is the translated text of a letter sent from the Dutch Minister of Agriculture to their House of Representatives.

Date 4 July 2024

Subject Information about the bird flu outbreak in Germany on July 2, 2024

Dear Chairman,

With this letter I inform the House of Representatives about the outbreak of highly pathogenic bird flu at a laying farm in Bad Bentheim, Germany, just across the border with the Netherlands.

It was quiet for a long time regarding the number of bird flu outbreaks in Europe. In the Netherlands, the last outbreak was on December 2, 2023. Unfortunately, on July 2, the Chief Veterinary Officer of Germany reported that a bird flu infection had been detected at a laying hen farm in Bad Bentheim, Germany.​

The location is close to the Dutch border. This time it concerns a different serotype than the H5N1 variant that has led to many outbreaks in recent years. This company in Germany concerns a highly pathogenic serotype H7N5, which has not previously led to outbreaks in Europe.

Following this outbreak, Germany must establish a 10 km restriction zone set, as prescribed by European Regulation (EU) 2020/687. Because part of that zone falls on Dutch territory, I established a restriction zone in the Netherlands on July 2. The regulations for this and the press release were published on that day (Bird flu detected in border area Germany | News item | Rijksoverheid.nl).

The two poultry farms located in the 3 km zone were, in accordance with current policy, examined for bird flu by the NVWA on July 3. The regular measures apply in the 10 km restriction zone, including transport restrictions for poultry and poultry products.

Commercially kept poultry in the 10 km zone must be caged. The area will remain intact for at least 30 days. The German authorities will conduct a tracing investigation. The source of the infection and the route of infection are now unknown, but I consider wild birds the most likely source of infection. It is known that many serotypes, mostly of a low pathogenic variety, circulate in wild birds. A low pathogenic variant of the H7 type may have led to infection of poultry on the farm, where it subsequently mutated into a highly pathogenic variant.

Such a scenario occurred in the Netherlands in 2003 with another H7 variant (H7N7), which led to a large number of outbreaks. The German tracing research into the infection may provide more information about the situation, the source of the infection and the virus characteristics.

No dead wild birds with HPAI have recently been found in the Netherlands, and monitoring of living wild birds in June showed no evidence of virus circulation of an H7 serotype. I have decided to ask the animal diseases expert group to conduct a risk assessment of the situation in the Netherlands.

I will use their assessment to determine whether additional measures are necessary in the Netherlands to reduce the risk of an outbreak. I will inform the House of Representatives about this.

In January this year, my predecessor informed the House of Representatives about the progress regarding the Intensification Plan for Bird Flu Prevention (Parliamentary Paper 28807, no. 296). In May this year, the House of Representatives was informed about the progress of the vaccination process (Parliamentary Paper 28807, no. 300).

This step-by-step plan and the actions in it are about vaccination against the H5N1 serotype. No vaccine is authorized against an H7 serotype in the European Union. I will bring the outbreak in Germany to the attention of the vaccine manufacturers.

I will inform the House of Representatives about new developments.

Yours faithfully,

Femke Marije Wiersma

Minister of Agriculture, Fisheries, Food Security and Nature​

The presumed origins of this outbreak was the introduction of an LPAI H7N5 virus - which can spread benignly through wild birds - into a poultry flock, where it mutated into an HPAI virus. While the exact process isn't fully understood, this in a known phenomenon (see graphic below), and is the reason why LPAI H5 and H7 viruses are treated as such a serious threat by WOAH/OIE.

While China's H7N9 virus proved exceptionally deadly for humans (killing roughly 40% of those hospitalized between 2013-2018), H7 outbreaks elsewhere in the world have tended to produce relatively mild symptoms in humans.

A few examples include:

• NYC's 016 dramatic H7N2 outbreak in cats, and spillover into animal shelter workers (see J Infect Dis: Serological Evidence Of H7N2 Infection Among Animal Shelter Workers, NYC 2016)
• 3 mild cases of LPAI H7N7 in Italy in 2013 (see ECDC Update & Assessment: Human Infection By Avian H7N7 In Italy).
• In 2006 1 person in the UK was confirmed to have contracted H7N3, and the following year, 4 people tested positive for H7N2 – both following local outbreaks in poultry.
• The Fraser Valley H7N3 outbreak of 2004 resulted in at least two human infections, as reported in this EID Journal report: Human Illness from Avian Influenza H7N3, British Columbia.

So far, we haven't seen anything to suggest that this H7N5 virus will be especially problematic, but with H7 viruses you never quite know what you are going to get.

In 2018 a woman in Jiangsu Province, China was seriously infected by an H7N4 virus (see WHO Update & Risk Assessment On Avian H7N4), spending 21 days in the hospital.​

While it is true there is no currently approved H7 vaccine (for humans) in the EU, the WHO has pre-selected a number of H7 CVVs (Candidate Vaccine Viruses) which could speed up the manufacturing process should they ever be needed.



A 7th CVV - for the H7N4 virus - is currently in development.

For now, the big concern with this outbreak is the close proximity of a large number of poultry farms, and the next few days should tell us whether this is a one-off outbreak, or the start of something bigger.​

Stay tuned.


https://afludiary.blogspot.com/2024/07/germany-avian-influenza-outbreak.html​