Avian influenza overview March-June 2024.

Between 16 March and 14 June 2024, 42 highly pathogenic avian influenza (HPAI) A(H5) virus detections were reported in domestic (15) and wild (27) birds across 13 countries in Europe. Although the overall number of detections in Europe has not been this low since the 2019-2020 epidemiological year, HPAI viruses continue to circulate at a very low level. Most detections in poultry were due to indirect contact with wild birds, but there was also secondary spread. Outside Europe, the HPAI situation intensified particularly in the USA, where a new A(H5N1) virus genotype (B3.13) has been identified in >130 dairy herds in 12 states. Infection in cattle appears to be centred on the udder, with milk from infected animals showing high viral loads and representing a new vehicle of transmission. Apart from cattle, HPAI viruses were identified in two other mammal species (alpaca and walrus) for the first time. Between 13 March and 20 June 2024, 14 new human cases with avian influenza virus infection were reported from Vietnam (one A(H5N1), one A(H9N2)), Australia (with travel history to India, one A(H5N1)), USA (three A(H5N1)), China (two A(H5N6), three A(H9N2), one A(H10N3)), India (one A(H9N2)), and Mexico (one fatal A(H5N2) case). The latter case was the first laboratory-confirmed human infection with avian influenza virus subtype A(H5N2). Most of the human cases had reported exposure to poultry, live poultry markets, or dairy cattle prior to avian influenza virus detection or onset of illness. Human infections with avian influenza viruses remain rare and no human-to-human transmission has been observed. The risk of infection with currently circulating avian A(H5) influenza viruses of clade 2.3.4.4b in Europe remains low for the general public in the EU/EEA. The risk of infection remains low-to-moderate for those occupationally or otherwise exposed to infected animals or contaminated environments.

Evaluating hunting and capture methods for urban wild boar population management.

Wild ungulates are expanding in range and number worldwide leading to an urgent need to manage their populations to minimize conflicts and promote coexistence with humans. In the metropolitan area of Barcelona (MAB), wild boar is the main wildlife species causing a nuisance, from traffic accidents to health risks. Selective harvesting of specific sex and age classes and reducing anthropogenic food resources would be the most efficient approach to dealing with overpopulation. Nonetheless, there is a gap in knowledge regarding the age and sex selectivity of the capture methods currently applied in the MAB for wild boar population control. Thus, this study aimed to evaluate the performance and age and sex bias of different hunting and capture methods and the seasonal patterns in their performance (number of captured individuals per event). From February 2014 to August 2022, 1454 wild boars were captured in the MAB using drop net, teleanaesthesia, cage traps, night stalks, and drive hunting. We applied generalized linear models (GLM) to compare the performance of these methods for the total number of wild boars, the wild boars belonging to each age category (i.e., adult, yearling, and juvenile), and for each season. The studied capture methods showed age-class bias and sex bias in adults (>2 years). Drive hunting and drop net removed mainly adult females and yearlings (1-2 years), with drive hunting having the highest performance for adult males. Instead, cage traps and drop net were the best methods to capture juveniles (<1 year). Overall, global performance was higher in summer, decreasingly followed by autumn and spring, winter being the worst performing season. Wildlife managers and researchers should consider the different performance and sex and age bias of each hunting and capture method, as well as the associated public cost, to improve efficiency and achieve the best results in wild boar population management.

The local skin cellular immune response determines the clinical outcome of sarcoptic mange in Iberian ibex (Capra pyrenaica).

Introduction: Sarcoptic mange, caused by Sarcoptes scabiei, is a disease with implications for wildlife conservation and management. Its severity depends on the host's local skin immune response, which is largely unknown in Iberian ibex (Capra pyrenaica), a mountain ungulate dramatically affected by mange. In this species, the clinical outcome of sarcoptic mange varies among individuals, and the local immune response could be key to controlling the infestation. This study aims to characterize the local cellular immune response and its relationship with the clinical outcome. Methods: Fourteen Iberian ibexes were experimentally infested with S. scabiei and six more served as controls. Clinical signs were monitored, and skin biopsies were collected from the withers at 26, 46, and 103 days post-infection (dpi). The presence and distribution of macrophages (including M1 and M2 phenotypes), T lymphocytes, B lymphocytes, plasma cells, and interleukine 10 were quantitatively evaluated using immunohistochemical techniques. Results: An inflammatory infiltrate that decreased significantly from 26 to 103 dpi was observed in all the infested ibexes. The predominant inflammatory cell population in the skin of the mangy ibexes was formed by macrophages (mainly the M2 phenotype) followed by T lymphocytes, with lower numbers of B lymphocytes and plasma cells. Three clinical courses were identified: total recovery, partial recovery, and terminal stage. The inflammatory infiltrates were less pronounced in the fully recovered ibexes than in those that progressed to the terminal stage throughout the study. Discussion: The results suggest an exacerbated but effective Th1-type cellular immune response controlling mange in Iberian ibex. Furthermore, the local immune response appears to determine the variability of the clinical responses to S. scabiei infestation in this species. This first report on the progression of local skin immune cells is relevant not only for individuals but also for population management and conservation.

Diseases of Iberian ibex (Capra pyrenaica).

Iberian ibex (Capra pyrenaica) is an ecologically and economically relevant medium-sized emblematic mountain ungulate. Diseases participate in the population dynamics of the species as a regulating agent, but can also threaten the conservation and viability of vulnerable population units. Moreover, Iberian ibex can also be a carrier or even a reservoir of pathogens shared with domestic animals and/or humans, being therefore a concern for livestock and public health. The objective of this review is to compile the currently available knowledge on (1) diseases of Iberian ibex, presented according to their relevance on the health and demography of free-ranging populations; (2) diseases subjected to heath surveillance plans; (3) other diseases reported in the species; and (4) diseases with particular relevance in captive Iberian ibex populations. The systematic review of all the information on diseases affecting the species unveils unpublished reports, scientific communications in meetings, and scientific articles, allowing the first comprehensive compilation of Iberian ibex diseases. This review identifies the gaps in knowledge regarding pathogenesis, immune response, diagnostic methods, treatment, and management of diseases in Iberian ibex, providing a base for future research. Moreover, this challenges wildlife and livestock disease and wildlife population managers to assess the priorities and policies currently implemented in Iberian ibex health surveillance and monitoring and disease management.

Assessing mammal trapping standards in wild boar drop-net capture.

Applying contemporary trapping standards when managing wildlife should no longer be an option, but a duty. Increasing wild boar populations originate a growing number of conflicts and hunting is the only cost-effective management option in most cases. However, new scenarios where hunting is unfeasible emerge and trapping necessities cope with lacking regulatory frameworks and technical guidelines. In this research, we evaluated drop nets, a capture method not considered by the international trapping standards, to capture Eurasian wild boar (Sus scrofa), a wildlife species not included in the list of mammal species under the scope of the Agreement on International Humane Trapping Standards (AIHTS). Less than 20% of the captured wild boars presented moderate or severe injuries attributable to the capture method, hence fulfilling the acceptance thresholds of the outdated AIHTS. Based on the new standards thresholds of acceptance, the humaneness of drop-nets in our study ranged 66-78%, under the 85% required. The capture success and selectivity were 100%, as ensured by operator-driven triggering, which should be considered the main strengths of this method, together with the minimization of animal suffering owing the short duration of the stressful situation. Additionally, in spite of the socially adverse environment, with people contrary to wild boar removal, no disturbances against the capture system or operations occurred. This is the first assessment of a drop-net capture method according to internationally accepted mammal trapping standards, with unconclusive results. However, there is a need for adapted procedures and thresholds of acceptance aimed at not-mechanical traps in general, and specifically at drop-nets. Compared to other live-capture methods, drop-nets minimize the duration of the stressful situation -at the expense of a strong adrenergic acute response-, maximize the probabilities of capturing entire sounders of prosocial species, which may be also considered as more humane, and has the ability to coordinate higher values of capture success, absolute selectivity and adaptability to difficult environments.