Aitor Nogales González

The North American strain of the H5N1 avian influenza virus has been shown to be capable of causing outbreaks in mammals such as cows, something not seen elsewhere in the world, including Europe. An international team has identified and tested two mutations in ferrets that may explain improved adaptation and greater virulence. According to the authors, who published the results in the journal Science Advances, the finding "highlights the urgent need for strengthened surveillance and targeted interventions.

A team in the US has tested the efficacy of baloxavir, an antiviral already on the market for treating common flu, against avian influenza in mice. The results, published in the journal Nature Microbiology, show that it is more effective than the currently recommended oseltamivir (Tamiflu) except when the infection is via the mouth, in which case it is equally effective. According to the authors, baloxavir ‘could be considered for the potential treatment of serious H5N1 virus infections in humans’.

The H5N1 avian influenza virus can be transmitted between mammals, according to a study published in Nature. The research team isolated the virus from the milk of an infected cow in New Mexico (USA) and found that it spreads in mice and ferrets, reaching the mammary glands of both animals. In addition, the virus was also transmitted from infected lactating mice to their offspring. The European Centre for Disease Prevention and Control (ECDC) has issued a press release on Monday recommending increased surveillance for these viruses.

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".

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.