While official updates on H5N1 infected cats in Poland have been few and far-between over the past week, yesterday the Italian MOH announced that several dogs (and 1 cat) on a farm in Brescia recently hit by avian flu have apparently seroconverted, indicating previous (possibly mild) infection.
The Italian website https://sivemp.it/ (Sindacato Italiano Veterinari Medicina Pubblica) has a brief news story (link), which describes the virus as HPAI H5N1 clade 22.214.171.124b of a genotype recently found in northern Italian gulls, and that carries a mammalian adaption (T271A in the PB2 protein) that may increase its zoonotic potential.
This is the same mutation that sparked considerable concern earlier this year when it was detected in infected mink in the fall of 2002 (see Eurosurveillance: HPAI A(H5N1) Virus Infection in Farmed Minks, Spain, October 2022) as it `enhances the polymerase activity of influenza A viruses in mammalian host cells and mice'.
Below I've posted some (Google) translated excerpts from the original MOH document. I'll have a postscript after the break.
SUBJECT: HPAI outbreak in rural herd with detection of serological positivity in domestic mammals. New cases of HPAI in seagulls in the province of Ravenna.
In relation to the object it is represented that the seroconversion of five has recently been ascertained dogs and a cat present in a rural poultry farm in the province of Brescia, site of an outbreak of HPAI H5N1.
The genetic analyzes of the virus found in the birds that died in the outbreak carried out by the Center of National and European Reference (CRN) for Avian Influenza and Newcastle Disease Institute Zooprofilattico Sperimentale delle Venezie (IZSVe) have shown to be a HPAI H5N1 belonging to the clade 126.96.36.199b, And in particular to the H5N1- genotype A/Herring_gull/France/22P015977/2022-like, responsible for the cases reported in northern Italy in the seagulls.This virus also has a mutation considered a marker of adaptation of ai viruses mammals (T271A in PB2 protein) with a possible increase in its zoonotic potential.
In relation to the reported event, as envisaged by the 'national strategic-operational plan of pandemic influenza preparedness and response (PanFlu 2021 – 2023)', dated 14 June 2023, the 'group of experts' was brought together to define the functioning of the national network of public human and veterinary laboratories for the early detection of circulating virus strains influenza with zoonotic potential in order to activate an early warning system for epidemics pandemic influenza.Although the group has not changed the risk assessment produced on February 27, 2023 and disseminated with the Circular prot. no. 0007782-07/03/2023-DGPRE-DGPRE-P 'Avian Influenza from subtype H5N1: information and indications' the importance of recalling the Regions/PPAA emerged the application of the measures envisaged by the aforementioned Circular and by the DGSAF “Influenza highly pathogenic avian flu H5N1 –Device containing control and surveillance measures for prevent the introduction and spread of avian flu" prot. no. 14856 of 6 June 2023.In consideration of new cases of HPAI H5N1 in rosy gulls (Chroicocephalus genei) and gulls common (Chroicocephalus ridibundus) in the province of Ravenna confirmed by the CRN on 06.16.2023, it is also deemed necessary to intensify with the utmost promptness and effectiveness the application of biosecurity measures in poultry farms present in particular in the Zones A and B of the State Regions agreement rep 125 and surveillance in farms located in the area national towards suspected cases of HPAI on the basis of the provisions of article 2 of the device 14856 of 6 June 2023.In particular, it is recommended to apply the general indications for the prevention of infection in humans included, inform the population to avoid contact with domestic and wild animals deceased or with signs of illness. The importance of applying the indications for the seasonal flu vaccination that is recommended and offered actively and free of charge to personnel who, for work reasons, are in contact with animals that could be a source of infection with non-human influenza viruses and to all subjects who for reasons other than those professionals are potentially exposed to epidemiological risk.
The Circular also recalls the importance of applying the measures for the protection of workers exposed and the monitoring of the state of health of exposed people and expressly requests the Regions/PP.AA. performing diagnostic tests for influenza viruses in people exposed to 5-7 days from exposure or at the onset of any symptoms and to provide this Ministry1 weekly in the form of aggregated data the number of tests carried out on exposed persons.It is also proposed to carry out serum-prevalence surveys among workers exposed to viruses of bird flu. With regard to the aspects of animal health, particular reference is made to compliance with the provided for in article 4 of the prot. no. 14856 of 6 June 2023 and specifically:a) the continuation by the regions of surveillance plans in wild birds in order to monitor the avian influenza viruses currently circulating in particular following phenomena of death;
b) considering the recent cases of H5N1 detected in two foxes and the seroconversion of some dogs and a cat present in a rural poultry farm outbreak of bird flu, the intensification of passive surveillance in wild mammals (subjects that have died) especially in areas where there have been cases of avian flu in wild birds; in this sense it is considered appropriate that samples (brains) taken from wild carnivores sent to the II.ZZ.SS are also used for the surveillance of wild rabies and coming from areas where the circulation of avian viruses;
c) the maintenance of the sampling of domestic animals (birds, carnivores, pigs) present in the poultry farms where HPAI outbreaks have been confirmed and prevent them from having access to establishments where poultry is reared;
d) evaluation in the CRAS with the veterinarian in charge of the structure of the use of euthanasia birds and carnivores with symptoms attributable to a possible avian flu infection (in particularly nervous symptoms) in structures where it is not possible to isolate the animals. The carcasses of deceased or euthanized subjects with suspected HPAI must be promptly sent to the competent IZS for virus research.In consideration of new cases of HPAI H5N1 in rosy gulls (Chroicocephalus genei) and gulls common (Chroicocephalus ridibundus) in the province of Ravenna confirmed by the CRN on 06.16.2023, it is also deemed necessary to intensify with the utmost promptness and effectiveness the application of biosecurity measures in poultry farms present in particular in the Zones A and B of the State Regions agreement rep 125 and surveillance in farms located in the area national towards suspected cases of HPAI on the basis of the provisions of article 2 of the device 14856 of 6 June 2023.We remain at your disposal for any clarification
While susceptible to avian flu, dogs have been less often reported to be infected by HPAI H5 than cats, and a study from 2015 may hold some clues as to why. Dogs, according to this report, are less likely to be sickened by H5N1 than felines.
Highly pathogenic H5N1 influenza virus continues to infect animals and humans. We compared the infectivity and pathogenesis of H5N1 virus in domestic cats and dogs to find out which animal is more susceptible to H5N1 influenza virus. When cats and dogs were infected with the H5N1 virus, cats suffered from severe outcomes including death, whereas dogs did not show any mortality.
While it is not surprising that evidence of past 2009 H1N1 infection was found in both dogs and cats, researchers also found evidence of avian H5, H7, and H9 virus exposure in cats and dogs (see chart below).
Fortunately, the Italian government appears to be aggressively investigating spillovers of H5N1 to mammals.
Unfortunately, on far too many farms in far too many countries around the globe, very little attention is being paid at all.