Gustavo del Real

According to a statement issued Monday by the World Health Organisation (WHO), Poland has reported that "unusual" cat deaths have been found in several areas of the country. Of the 47 samples tested (46 from cats and one from a caracal, another type of feline), 29 were positive for the avian influenza A(H5N1) virus. The surveillance period for all contacts has now ended and no contacts have shown symptoms. According to WHO, "sporadic A(H5N1) infections of cats have been reported previously, but this is the first report of a large number of infected cats in a large geographical area within a country".

Although outbreaks of H5N1 avian influenza have reached record numbers in recent years, human infections remain anecdotal. A study published today in Nature identifies a protein responsible for inhibiting the replication of this virus in humans, while 'human' flus are able to evade it. The authors propose that this protein with antiviral activity evolved in primates and consider that resistance or sensitivity to it should be taken into account when assessing the zoonotic potential of avian influenza viruses.

Analysis of the two asymptomatic cases of H5N1 avian influenza detected in Spain in autumn 2022 in workers at a poultry farm in Guadalajara has confirmed the theory that no actual infections occurred, but that both were in contact with genetic material of the virus found in the environment. Spain has recently modified its protocols, according to the analysis published in Eurosurveillance.

On 27 September, the National Microbiology Centre detected a positive H5N1 avian influenza in a worker at a poultry farm in Guadalajara (Castilla-La Mancha). The sample was taken on the 23rd and the affected person remained asymptomatic until he tested negative, according to Animal's Health.