One Health - a strategy for resilience in a changing arctic.

The circumpolar north is uniquely vulnerable to the health impacts of climate change. While international Arctic collaboration on health has enhanced partnerships and advanced the health of inhabitants, significant challenges lie ahead. One Health is an approach that considers the connections between the environment, plant, animal and human health. Understanding this is increasingly critical in assessing the impact of global climate change on the health of Arctic inhabitants. The effects of climate change are complex and difficult to predict with certainty. Health risks include changes in the distribution of infectious disease, expansion of zoonotic diseases and vectors, changing migration patterns, impacts on food security and changes in water availability and quality, among others. A regional network of diverse stakeholder and transdisciplinary specialists from circumpolar nations and Indigenous groups can advance the understanding of complex climate-driven health risks and provide community-based strategies for early identification, prevention and adaption of health risks in human, animals and environment. We propose a regional One Health approach for assessing interactions at the Arctic human-animal-environment interface to enhance the understanding of, and response to, the complexities of climate change on the health of the Arctic inhabitants.

Impact of virus strain characteristics on early detection of highly pathogenic avian influenza infection in commercial table-egg layer flocks and implications for outbreak control.

Early detection of highly pathogenic avian influenza (HPAI) infection in commercial poultry flocks is a critical component of outbreak control. Reducing the time to detect HPAI infection can reduce the risk of disease transmission to other flocks. The timeliness of different types of detection triggers could be dependent on clinical signs that are first observed in a flock, signs that might vary due to HPAI virus strain characteristics. We developed a stochastic disease transmission model to evaluate how transmission characteristics of various HPAI strains might effect the relative importance of increased mortality, drop in egg production, or daily real-time reverse transcriptase (RRT)-PCR testing, toward detecting HPAI infection in a commercial table-egg layer flock. On average, daily RRT-PCR testing resulted in the shortest time to detection (from 3.5 to 6.1 days) depending on the HPAI virus strain and was less variable over a range of transmission parameters compared with other triggers evaluated. Our results indicate that a trigger to detect a drop in egg production would be useful for HPAI virus strains with long infectious periods (6-8 days) and including an egg-drop detection trigger in emergency response plans would lead to earlier and consistent reporting in some cases. We discuss implications for outbreak control and risk of HPAI spread attributed to different HPAI strain characteristics where an increase in mortality or a drop in egg production or both would be among the first clinical signs observed in an infected flock.