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.
Human-to-human transmission of avian influenza A/H7N7, The Netherlands, 2003
M Du Ry van Beest Holle, A Meijer, M Koopmans3 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 .
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 NetherlandsA 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.
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.
