National Institute for Agricultural and Food Research and Technology (INIA-CSIC)

Viruses that cause avian influenza are capable of replicating at temperatures higher than a typical fever, according to a study in in vitro models and mice. ‘Fever-resistant replication could help explain why avian viruses and pandemic influenza viruses with avian PB1 cause more severe disease in humans,’ the authors write in the journal Science.

Some ecosystems are able to adapt to moderate droughts, even if they last for several years. However, in scrublands and grasslands, when the phenomenon is extreme and prolonged, their capacity to store carbon plummets. This is the main conclusion of an international study that has assessed the effects of the duration and severity of droughts on the productivity of 74 grassland and pasture ecosystems on six continents. According to the authors, the most vulnerable areas are arid and semi-arid regions, such as those in the Mediterranean region and the southwestern United States. The study, published in Science, involves CREAF, CSIC and IICG-URJC, among other centres.

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.

Avian influenza has returned to Spain this summer. In addition to a few cases in wild birds, since 18 July there have been several outbreaks in poultry in different autonomous communities, causing the country to lose its disease-free status. To answer questions about the situation, its possible causes, evolution and consequences, SMC Spain organised an information session with researchers Inmaculada Casas, Ursula Höfle and Elisa Pérez Ramírez.

Climate change has made the hot, dry and windy weather conditions that spread fires across the Iberian Peninsula 40 times more frequent and 30% more intense than in the pre-industrial climate, according to a rapid study by World Weather Attribution. The ten-day heatwave was also 200 times more likely and 3°C hotter due to climate change. The study, which analysed weather observations rather than climate models, warns that fires in Europe are overwhelming firefighting resources and highlights the importance of controlling vegetation in affected areas.

US Department of Health Secretary Robert Kennedy Jr's proposal to let bird flu spread in turkeys and chickens to identify surviving animals would be "dangerous and unethical", a group of scientists warns in a policy forum article published by Science. In addition to the suffering of infected animals, allowing a highly lethal, rapidly evolving and contagious virus to follow a natural course of infection "would prolong exposure for farmworkers, which could increase viral adaptation and transmission risks for poultry, other peridomestic animals, and humans," they warn.

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’.

A team of researchers from the USA has analyzed the B lymphocytes of seven healthy people in whom no exposure to H5 influenza viruses, such as the avian flu virus, had been documented. The results show that they present antibodies capable of recognizing this type of virus, which, according to the authors, could represent “a first line of defense” in the event of a pandemic. The results are published in the journal Science Immunology.

A study carried out in China has analyzed tissues from 461 fur animals, mostly farm-raised. They found 125 virus species, 39 of which presented a high risk of interspecies transmission. According to the authors, who publish the results in the journal Nature, “there is a need for more extensive and regular surveillance to assess the public health risks that could result from fur animal farming”.

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.